1 //===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
11 // both before and after the DAG is legalized.
13 // This pass is not a substitute for the LLVM IR instcombine pass. This pass is
14 // primarily intended to handle simplification opportunities that are implicit
15 // in the LLVM IR and exposed by the various codegen lowering phases.
17 //===----------------------------------------------------------------------===//
19 #include "llvm/CodeGen/SelectionDAG.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallBitVector.h"
22 #include "llvm/ADT/SmallPtrSet.h"
23 #include "llvm/ADT/Statistic.h"
24 #include "llvm/Analysis/AliasAnalysis.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DerivedTypes.h"
29 #include "llvm/IR/Function.h"
30 #include "llvm/IR/LLVMContext.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/MathExtras.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetLowering.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/Target/TargetRegisterInfo.h"
39 #include "llvm/Target/TargetSubtargetInfo.h"
43 #define DEBUG_TYPE "dagcombine"
45 STATISTIC(NodesCombined , "Number of dag nodes combined");
46 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
47 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
48 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
49 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
50 STATISTIC(SlicedLoads, "Number of load sliced");
54 CombinerAA("combiner-alias-analysis", cl::Hidden,
55 cl::desc("Enable DAG combiner alias-analysis heuristics"));
58 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
59 cl::desc("Enable DAG combiner's use of IR alias analysis"));
62 UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(true),
63 cl::desc("Enable DAG combiner's use of TBAA"));
66 static cl::opt<std::string>
67 CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden,
68 cl::desc("Only use DAG-combiner alias analysis in this"
72 /// Hidden option to stress test load slicing, i.e., when this option
73 /// is enabled, load slicing bypasses most of its profitability guards.
75 StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden,
76 cl::desc("Bypass the profitability model of load "
81 MaySplitLoadIndex("combiner-split-load-index", cl::Hidden, cl::init(true),
82 cl::desc("DAG combiner may split indexing from loads"));
84 //------------------------------ DAGCombiner ---------------------------------//
88 const TargetLowering &TLI;
90 CodeGenOpt::Level OptLevel;
95 /// \brief Worklist of all of the nodes that need to be simplified.
97 /// This must behave as a stack -- new nodes to process are pushed onto the
98 /// back and when processing we pop off of the back.
100 /// The worklist will not contain duplicates but may contain null entries
101 /// due to nodes being deleted from the underlying DAG.
102 SmallVector<SDNode *, 64> Worklist;
104 /// \brief Mapping from an SDNode to its position on the worklist.
106 /// This is used to find and remove nodes from the worklist (by nulling
107 /// them) when they are deleted from the underlying DAG. It relies on
108 /// stable indices of nodes within the worklist.
109 DenseMap<SDNode *, unsigned> WorklistMap;
111 /// \brief Set of nodes which have been combined (at least once).
113 /// This is used to allow us to reliably add any operands of a DAG node
114 /// which have not yet been combined to the worklist.
115 SmallPtrSet<SDNode *, 64> CombinedNodes;
117 // AA - Used for DAG load/store alias analysis.
120 /// When an instruction is simplified, add all users of the instruction to
121 /// the work lists because they might get more simplified now.
122 void AddUsersToWorklist(SDNode *N) {
123 for (SDNode *Node : N->uses())
127 /// Call the node-specific routine that folds each particular type of node.
128 SDValue visit(SDNode *N);
131 /// Add to the worklist making sure its instance is at the back (next to be
133 void AddToWorklist(SDNode *N) {
134 // Skip handle nodes as they can't usefully be combined and confuse the
135 // zero-use deletion strategy.
136 if (N->getOpcode() == ISD::HANDLENODE)
139 if (WorklistMap.insert(std::make_pair(N, Worklist.size())).second)
140 Worklist.push_back(N);
143 /// Remove all instances of N from the worklist.
144 void removeFromWorklist(SDNode *N) {
145 CombinedNodes.erase(N);
147 auto It = WorklistMap.find(N);
148 if (It == WorklistMap.end())
149 return; // Not in the worklist.
151 // Null out the entry rather than erasing it to avoid a linear operation.
152 Worklist[It->second] = nullptr;
153 WorklistMap.erase(It);
156 void deleteAndRecombine(SDNode *N);
157 bool recursivelyDeleteUnusedNodes(SDNode *N);
159 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
162 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
163 return CombineTo(N, &Res, 1, AddTo);
166 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
168 SDValue To[] = { Res0, Res1 };
169 return CombineTo(N, To, 2, AddTo);
172 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
176 /// Check the specified integer node value to see if it can be simplified or
177 /// if things it uses can be simplified by bit propagation.
178 /// If so, return true.
179 bool SimplifyDemandedBits(SDValue Op) {
180 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
181 APInt Demanded = APInt::getAllOnesValue(BitWidth);
182 return SimplifyDemandedBits(Op, Demanded);
185 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
187 bool CombineToPreIndexedLoadStore(SDNode *N);
188 bool CombineToPostIndexedLoadStore(SDNode *N);
189 SDValue SplitIndexingFromLoad(LoadSDNode *LD);
190 bool SliceUpLoad(SDNode *N);
192 /// \brief Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed
195 /// \param EVE ISD::EXTRACT_VECTOR_ELT to be replaced.
196 /// \param InVecVT type of the input vector to EVE with bitcasts resolved.
197 /// \param EltNo index of the vector element to load.
198 /// \param OriginalLoad load that EVE came from to be replaced.
199 /// \returns EVE on success SDValue() on failure.
200 SDValue ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
201 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad);
202 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
203 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
204 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
205 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
206 SDValue PromoteIntBinOp(SDValue Op);
207 SDValue PromoteIntShiftOp(SDValue Op);
208 SDValue PromoteExtend(SDValue Op);
209 bool PromoteLoad(SDValue Op);
211 void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
212 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
213 ISD::NodeType ExtType);
215 /// Call the node-specific routine that knows how to fold each
216 /// particular type of node. If that doesn't do anything, try the
217 /// target-specific DAG combines.
218 SDValue combine(SDNode *N);
220 // Visitation implementation - Implement dag node combining for different
221 // node types. The semantics are as follows:
223 // SDValue.getNode() == 0 - No change was made
224 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
225 // otherwise - N should be replaced by the returned Operand.
227 SDValue visitTokenFactor(SDNode *N);
228 SDValue visitMERGE_VALUES(SDNode *N);
229 SDValue visitADD(SDNode *N);
230 SDValue visitSUB(SDNode *N);
231 SDValue visitADDC(SDNode *N);
232 SDValue visitSUBC(SDNode *N);
233 SDValue visitADDE(SDNode *N);
234 SDValue visitSUBE(SDNode *N);
235 SDValue visitMUL(SDNode *N);
236 SDValue visitSDIV(SDNode *N);
237 SDValue visitUDIV(SDNode *N);
238 SDValue visitSREM(SDNode *N);
239 SDValue visitUREM(SDNode *N);
240 SDValue visitMULHU(SDNode *N);
241 SDValue visitMULHS(SDNode *N);
242 SDValue visitSMUL_LOHI(SDNode *N);
243 SDValue visitUMUL_LOHI(SDNode *N);
244 SDValue visitSMULO(SDNode *N);
245 SDValue visitUMULO(SDNode *N);
246 SDValue visitSDIVREM(SDNode *N);
247 SDValue visitUDIVREM(SDNode *N);
248 SDValue visitAND(SDNode *N);
249 SDValue visitANDLike(SDValue N0, SDValue N1, SDNode *LocReference);
250 SDValue visitOR(SDNode *N);
251 SDValue visitORLike(SDValue N0, SDValue N1, SDNode *LocReference);
252 SDValue visitXOR(SDNode *N);
253 SDValue SimplifyVBinOp(SDNode *N);
254 SDValue visitSHL(SDNode *N);
255 SDValue visitSRA(SDNode *N);
256 SDValue visitSRL(SDNode *N);
257 SDValue visitRotate(SDNode *N);
258 SDValue visitCTLZ(SDNode *N);
259 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
260 SDValue visitCTTZ(SDNode *N);
261 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
262 SDValue visitCTPOP(SDNode *N);
263 SDValue visitSELECT(SDNode *N);
264 SDValue visitVSELECT(SDNode *N);
265 SDValue visitSELECT_CC(SDNode *N);
266 SDValue visitSETCC(SDNode *N);
267 SDValue visitSIGN_EXTEND(SDNode *N);
268 SDValue visitZERO_EXTEND(SDNode *N);
269 SDValue visitANY_EXTEND(SDNode *N);
270 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
271 SDValue visitSIGN_EXTEND_VECTOR_INREG(SDNode *N);
272 SDValue visitTRUNCATE(SDNode *N);
273 SDValue visitBITCAST(SDNode *N);
274 SDValue visitBUILD_PAIR(SDNode *N);
275 SDValue visitFADD(SDNode *N);
276 SDValue visitFSUB(SDNode *N);
277 SDValue visitFMUL(SDNode *N);
278 SDValue visitFMA(SDNode *N);
279 SDValue visitFDIV(SDNode *N);
280 SDValue visitFREM(SDNode *N);
281 SDValue visitFSQRT(SDNode *N);
282 SDValue visitFCOPYSIGN(SDNode *N);
283 SDValue visitSINT_TO_FP(SDNode *N);
284 SDValue visitUINT_TO_FP(SDNode *N);
285 SDValue visitFP_TO_SINT(SDNode *N);
286 SDValue visitFP_TO_UINT(SDNode *N);
287 SDValue visitFP_ROUND(SDNode *N);
288 SDValue visitFP_ROUND_INREG(SDNode *N);
289 SDValue visitFP_EXTEND(SDNode *N);
290 SDValue visitFNEG(SDNode *N);
291 SDValue visitFABS(SDNode *N);
292 SDValue visitFCEIL(SDNode *N);
293 SDValue visitFTRUNC(SDNode *N);
294 SDValue visitFFLOOR(SDNode *N);
295 SDValue visitFMINNUM(SDNode *N);
296 SDValue visitFMAXNUM(SDNode *N);
297 SDValue visitBRCOND(SDNode *N);
298 SDValue visitBR_CC(SDNode *N);
299 SDValue visitLOAD(SDNode *N);
300 SDValue visitSTORE(SDNode *N);
301 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
302 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
303 SDValue visitBUILD_VECTOR(SDNode *N);
304 SDValue visitCONCAT_VECTORS(SDNode *N);
305 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
306 SDValue visitVECTOR_SHUFFLE(SDNode *N);
307 SDValue visitSCALAR_TO_VECTOR(SDNode *N);
308 SDValue visitINSERT_SUBVECTOR(SDNode *N);
309 SDValue visitMLOAD(SDNode *N);
310 SDValue visitMSTORE(SDNode *N);
311 SDValue visitMGATHER(SDNode *N);
312 SDValue visitMSCATTER(SDNode *N);
313 SDValue visitFP_TO_FP16(SDNode *N);
315 SDValue visitFADDForFMACombine(SDNode *N);
316 SDValue visitFSUBForFMACombine(SDNode *N);
318 SDValue XformToShuffleWithZero(SDNode *N);
319 SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
321 SDValue visitShiftByConstant(SDNode *N, ConstantSDNode *Amt);
323 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
324 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
325 SDValue SimplifySelect(SDLoc DL, SDValue N0, SDValue N1, SDValue N2);
326 SDValue SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1, SDValue N2,
327 SDValue N3, ISD::CondCode CC,
328 bool NotExtCompare = false);
329 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
330 SDLoc DL, bool foldBooleans = true);
332 bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
334 bool isOneUseSetCC(SDValue N) const;
336 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
338 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
339 SDValue CombineExtLoad(SDNode *N);
340 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
341 SDValue BuildSDIV(SDNode *N);
342 SDValue BuildSDIVPow2(SDNode *N);
343 SDValue BuildUDIV(SDNode *N);
344 SDValue BuildReciprocalEstimate(SDValue Op);
345 SDValue BuildRsqrtEstimate(SDValue Op);
346 SDValue BuildRsqrtNROneConst(SDValue Op, SDValue Est, unsigned Iterations);
347 SDValue BuildRsqrtNRTwoConst(SDValue Op, SDValue Est, unsigned Iterations);
348 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
349 bool DemandHighBits = true);
350 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
351 SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
352 SDValue InnerPos, SDValue InnerNeg,
353 unsigned PosOpcode, unsigned NegOpcode,
355 SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
356 SDValue ReduceLoadWidth(SDNode *N);
357 SDValue ReduceLoadOpStoreWidth(SDNode *N);
358 SDValue TransformFPLoadStorePair(SDNode *N);
359 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
360 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
362 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
364 /// Walk up chain skipping non-aliasing memory nodes,
365 /// looking for aliasing nodes and adding them to the Aliases vector.
366 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
367 SmallVectorImpl<SDValue> &Aliases);
369 /// Return true if there is any possibility that the two addresses overlap.
370 bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const;
372 /// Walk up chain skipping non-aliasing memory nodes, looking for a better
373 /// chain (aliasing node.)
374 SDValue FindBetterChain(SDNode *N, SDValue Chain);
376 /// Holds a pointer to an LSBaseSDNode as well as information on where it
377 /// is located in a sequence of memory operations connected by a chain.
379 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
380 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
381 // Ptr to the mem node.
382 LSBaseSDNode *MemNode;
383 // Offset from the base ptr.
384 int64_t OffsetFromBase;
385 // What is the sequence number of this mem node.
386 // Lowest mem operand in the DAG starts at zero.
387 unsigned SequenceNum;
390 /// This is a helper function for MergeConsecutiveStores. When the source
391 /// elements of the consecutive stores are all constants or all extracted
392 /// vector elements, try to merge them into one larger store.
393 /// \return True if a merged store was created.
394 bool MergeStoresOfConstantsOrVecElts(SmallVectorImpl<MemOpLink> &StoreNodes,
395 EVT MemVT, unsigned NumElem,
396 bool IsConstantSrc, bool UseVector);
398 /// Merge consecutive store operations into a wide store.
399 /// This optimization uses wide integers or vectors when possible.
400 /// \return True if some memory operations were changed.
401 bool MergeConsecutiveStores(StoreSDNode *N);
403 /// \brief Try to transform a truncation where C is a constant:
404 /// (trunc (and X, C)) -> (and (trunc X), (trunc C))
406 /// \p N needs to be a truncation and its first operand an AND. Other
407 /// requirements are checked by the function (e.g. that trunc is
408 /// single-use) and if missed an empty SDValue is returned.
409 SDValue distributeTruncateThroughAnd(SDNode *N);
412 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
413 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
414 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {
415 auto *F = DAG.getMachineFunction().getFunction();
416 ForCodeSize = F->hasFnAttribute(Attribute::OptimizeForSize) ||
417 F->hasFnAttribute(Attribute::MinSize);
420 /// Runs the dag combiner on all nodes in the work list
421 void Run(CombineLevel AtLevel);
423 SelectionDAG &getDAG() const { return DAG; }
425 /// Returns a type large enough to hold any valid shift amount - before type
426 /// legalization these can be huge.
427 EVT getShiftAmountTy(EVT LHSTy) {
428 assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
429 if (LHSTy.isVector())
431 return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy)
432 : TLI.getPointerTy();
435 /// This method returns true if we are running before type legalization or
436 /// if the specified VT is legal.
437 bool isTypeLegal(const EVT &VT) {
438 if (!LegalTypes) return true;
439 return TLI.isTypeLegal(VT);
442 /// Convenience wrapper around TargetLowering::getSetCCResultType
443 EVT getSetCCResultType(EVT VT) const {
444 return TLI.getSetCCResultType(*DAG.getContext(), VT);
451 /// This class is a DAGUpdateListener that removes any deleted
452 /// nodes from the worklist.
453 class WorklistRemover : public SelectionDAG::DAGUpdateListener {
456 explicit WorklistRemover(DAGCombiner &dc)
457 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
459 void NodeDeleted(SDNode *N, SDNode *E) override {
460 DC.removeFromWorklist(N);
465 //===----------------------------------------------------------------------===//
466 // TargetLowering::DAGCombinerInfo implementation
467 //===----------------------------------------------------------------------===//
469 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
470 ((DAGCombiner*)DC)->AddToWorklist(N);
473 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
474 ((DAGCombiner*)DC)->removeFromWorklist(N);
477 SDValue TargetLowering::DAGCombinerInfo::
478 CombineTo(SDNode *N, ArrayRef<SDValue> To, bool AddTo) {
479 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
482 SDValue TargetLowering::DAGCombinerInfo::
483 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
484 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
488 SDValue TargetLowering::DAGCombinerInfo::
489 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
490 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
493 void TargetLowering::DAGCombinerInfo::
494 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
495 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
498 //===----------------------------------------------------------------------===//
500 //===----------------------------------------------------------------------===//
502 void DAGCombiner::deleteAndRecombine(SDNode *N) {
503 removeFromWorklist(N);
505 // If the operands of this node are only used by the node, they will now be
506 // dead. Make sure to re-visit them and recursively delete dead nodes.
507 for (const SDValue &Op : N->ops())
508 // For an operand generating multiple values, one of the values may
509 // become dead allowing further simplification (e.g. split index
510 // arithmetic from an indexed load).
511 if (Op->hasOneUse() || Op->getNumValues() > 1)
512 AddToWorklist(Op.getNode());
517 /// Return 1 if we can compute the negated form of the specified expression for
518 /// the same cost as the expression itself, or 2 if we can compute the negated
519 /// form more cheaply than the expression itself.
520 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
521 const TargetLowering &TLI,
522 const TargetOptions *Options,
523 unsigned Depth = 0) {
524 // fneg is removable even if it has multiple uses.
525 if (Op.getOpcode() == ISD::FNEG) return 2;
527 // Don't allow anything with multiple uses.
528 if (!Op.hasOneUse()) return 0;
530 // Don't recurse exponentially.
531 if (Depth > 6) return 0;
533 switch (Op.getOpcode()) {
534 default: return false;
535 case ISD::ConstantFP:
536 // Don't invert constant FP values after legalize. The negated constant
537 // isn't necessarily legal.
538 return LegalOperations ? 0 : 1;
540 // FIXME: determine better conditions for this xform.
541 if (!Options->UnsafeFPMath) return 0;
543 // After operation legalization, it might not be legal to create new FSUBs.
544 if (LegalOperations &&
545 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
548 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
549 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
552 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
553 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
556 // We can't turn -(A-B) into B-A when we honor signed zeros.
557 if (!Options->UnsafeFPMath) return 0;
559 // fold (fneg (fsub A, B)) -> (fsub B, A)
564 if (Options->HonorSignDependentRoundingFPMath()) return 0;
566 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
567 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
571 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
577 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
582 /// If isNegatibleForFree returns true, return the newly negated expression.
583 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
584 bool LegalOperations, unsigned Depth = 0) {
585 const TargetOptions &Options = DAG.getTarget().Options;
586 // fneg is removable even if it has multiple uses.
587 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
589 // Don't allow anything with multiple uses.
590 assert(Op.hasOneUse() && "Unknown reuse!");
592 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
593 switch (Op.getOpcode()) {
594 default: llvm_unreachable("Unknown code");
595 case ISD::ConstantFP: {
596 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
598 return DAG.getConstantFP(V, SDLoc(Op), Op.getValueType());
601 // FIXME: determine better conditions for this xform.
602 assert(Options.UnsafeFPMath);
604 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
605 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
606 DAG.getTargetLoweringInfo(), &Options, Depth+1))
607 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
608 GetNegatedExpression(Op.getOperand(0), DAG,
609 LegalOperations, Depth+1),
611 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
612 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
613 GetNegatedExpression(Op.getOperand(1), DAG,
614 LegalOperations, Depth+1),
617 // We can't turn -(A-B) into B-A when we honor signed zeros.
618 assert(Options.UnsafeFPMath);
620 // fold (fneg (fsub 0, B)) -> B
621 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
622 if (N0CFP->getValueAPF().isZero())
623 return Op.getOperand(1);
625 // fold (fneg (fsub A, B)) -> (fsub B, A)
626 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
627 Op.getOperand(1), Op.getOperand(0));
631 assert(!Options.HonorSignDependentRoundingFPMath());
633 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
634 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
635 DAG.getTargetLoweringInfo(), &Options, Depth+1))
636 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
637 GetNegatedExpression(Op.getOperand(0), DAG,
638 LegalOperations, Depth+1),
641 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
642 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
644 GetNegatedExpression(Op.getOperand(1), DAG,
645 LegalOperations, Depth+1));
649 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
650 GetNegatedExpression(Op.getOperand(0), DAG,
651 LegalOperations, Depth+1));
653 return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
654 GetNegatedExpression(Op.getOperand(0), DAG,
655 LegalOperations, Depth+1),
660 // Return true if this node is a setcc, or is a select_cc
661 // that selects between the target values used for true and false, making it
662 // equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to
663 // the appropriate nodes based on the type of node we are checking. This
664 // simplifies life a bit for the callers.
665 bool DAGCombiner::isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
667 if (N.getOpcode() == ISD::SETCC) {
668 LHS = N.getOperand(0);
669 RHS = N.getOperand(1);
670 CC = N.getOperand(2);
674 if (N.getOpcode() != ISD::SELECT_CC ||
675 !TLI.isConstTrueVal(N.getOperand(2).getNode()) ||
676 !TLI.isConstFalseVal(N.getOperand(3).getNode()))
679 if (TLI.getBooleanContents(N.getValueType()) ==
680 TargetLowering::UndefinedBooleanContent)
683 LHS = N.getOperand(0);
684 RHS = N.getOperand(1);
685 CC = N.getOperand(4);
689 /// Return true if this is a SetCC-equivalent operation with only one use.
690 /// If this is true, it allows the users to invert the operation for free when
691 /// it is profitable to do so.
692 bool DAGCombiner::isOneUseSetCC(SDValue N) const {
694 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
699 /// Returns true if N is a BUILD_VECTOR node whose
700 /// elements are all the same constant or undefined.
701 static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
702 BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
707 unsigned SplatBitSize;
709 EVT EltVT = N->getValueType(0).getVectorElementType();
710 return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
712 EltVT.getSizeInBits() >= SplatBitSize);
715 // \brief Returns the SDNode if it is a constant integer BuildVector
716 // or constant integer.
717 static SDNode *isConstantIntBuildVectorOrConstantInt(SDValue N) {
718 if (isa<ConstantSDNode>(N))
720 if (ISD::isBuildVectorOfConstantSDNodes(N.getNode()))
725 // \brief Returns the SDNode if it is a constant float BuildVector
726 // or constant float.
727 static SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) {
728 if (isa<ConstantFPSDNode>(N))
730 if (ISD::isBuildVectorOfConstantFPSDNodes(N.getNode()))
735 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
737 static ConstantSDNode *isConstOrConstSplat(SDValue N) {
738 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
741 if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
742 BitVector UndefElements;
743 ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
745 // BuildVectors can truncate their operands. Ignore that case here.
746 // FIXME: We blindly ignore splats which include undef which is overly
748 if (CN && UndefElements.none() &&
749 CN->getValueType(0) == N.getValueType().getScalarType())
756 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
758 static ConstantFPSDNode *isConstOrConstSplatFP(SDValue N) {
759 if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N))
762 if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
763 BitVector UndefElements;
764 ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements);
766 if (CN && UndefElements.none())
773 SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
774 SDValue N0, SDValue N1) {
775 EVT VT = N0.getValueType();
776 if (N0.getOpcode() == Opc) {
777 if (SDNode *L = isConstantIntBuildVectorOrConstantInt(N0.getOperand(1))) {
778 if (SDNode *R = isConstantIntBuildVectorOrConstantInt(N1)) {
779 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
780 if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, L, R))
781 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
784 if (N0.hasOneUse()) {
785 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one
787 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1);
788 if (!OpNode.getNode())
790 AddToWorklist(OpNode.getNode());
791 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
796 if (N1.getOpcode() == Opc) {
797 if (SDNode *R = isConstantIntBuildVectorOrConstantInt(N1.getOperand(1))) {
798 if (SDNode *L = isConstantIntBuildVectorOrConstantInt(N0)) {
799 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
800 if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, R, L))
801 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
804 if (N1.hasOneUse()) {
805 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one
807 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N1.getOperand(0), N0);
808 if (!OpNode.getNode())
810 AddToWorklist(OpNode.getNode());
811 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
819 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
821 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
823 DEBUG(dbgs() << "\nReplacing.1 ";
825 dbgs() << "\nWith: ";
826 To[0].getNode()->dump(&DAG);
827 dbgs() << " and " << NumTo-1 << " other values\n");
828 for (unsigned i = 0, e = NumTo; i != e; ++i)
829 assert((!To[i].getNode() ||
830 N->getValueType(i) == To[i].getValueType()) &&
831 "Cannot combine value to value of different type!");
833 WorklistRemover DeadNodes(*this);
834 DAG.ReplaceAllUsesWith(N, To);
836 // Push the new nodes and any users onto the worklist
837 for (unsigned i = 0, e = NumTo; i != e; ++i) {
838 if (To[i].getNode()) {
839 AddToWorklist(To[i].getNode());
840 AddUsersToWorklist(To[i].getNode());
845 // Finally, if the node is now dead, remove it from the graph. The node
846 // may not be dead if the replacement process recursively simplified to
847 // something else needing this node.
849 deleteAndRecombine(N);
850 return SDValue(N, 0);
854 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
855 // Replace all uses. If any nodes become isomorphic to other nodes and
856 // are deleted, make sure to remove them from our worklist.
857 WorklistRemover DeadNodes(*this);
858 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
860 // Push the new node and any (possibly new) users onto the worklist.
861 AddToWorklist(TLO.New.getNode());
862 AddUsersToWorklist(TLO.New.getNode());
864 // Finally, if the node is now dead, remove it from the graph. The node
865 // may not be dead if the replacement process recursively simplified to
866 // something else needing this node.
867 if (TLO.Old.getNode()->use_empty())
868 deleteAndRecombine(TLO.Old.getNode());
871 /// Check the specified integer node value to see if it can be simplified or if
872 /// things it uses can be simplified by bit propagation. If so, return true.
873 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
874 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
875 APInt KnownZero, KnownOne;
876 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
880 AddToWorklist(Op.getNode());
882 // Replace the old value with the new one.
884 DEBUG(dbgs() << "\nReplacing.2 ";
885 TLO.Old.getNode()->dump(&DAG);
886 dbgs() << "\nWith: ";
887 TLO.New.getNode()->dump(&DAG);
890 CommitTargetLoweringOpt(TLO);
894 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
896 EVT VT = Load->getValueType(0);
897 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
899 DEBUG(dbgs() << "\nReplacing.9 ";
901 dbgs() << "\nWith: ";
902 Trunc.getNode()->dump(&DAG);
904 WorklistRemover DeadNodes(*this);
905 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
906 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
907 deleteAndRecombine(Load);
908 AddToWorklist(Trunc.getNode());
911 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
914 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
915 EVT MemVT = LD->getMemoryVT();
916 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
917 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
919 : LD->getExtensionType();
921 return DAG.getExtLoad(ExtType, dl, PVT,
922 LD->getChain(), LD->getBasePtr(),
923 MemVT, LD->getMemOperand());
926 unsigned Opc = Op.getOpcode();
929 case ISD::AssertSext:
930 return DAG.getNode(ISD::AssertSext, dl, PVT,
931 SExtPromoteOperand(Op.getOperand(0), PVT),
933 case ISD::AssertZext:
934 return DAG.getNode(ISD::AssertZext, dl, PVT,
935 ZExtPromoteOperand(Op.getOperand(0), PVT),
937 case ISD::Constant: {
939 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
940 return DAG.getNode(ExtOpc, dl, PVT, Op);
944 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
946 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
949 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
950 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
952 EVT OldVT = Op.getValueType();
954 bool Replace = false;
955 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
956 if (!NewOp.getNode())
958 AddToWorklist(NewOp.getNode());
961 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
962 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
963 DAG.getValueType(OldVT));
966 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
967 EVT OldVT = Op.getValueType();
969 bool Replace = false;
970 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
971 if (!NewOp.getNode())
973 AddToWorklist(NewOp.getNode());
976 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
977 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
980 /// Promote the specified integer binary operation if the target indicates it is
981 /// beneficial. e.g. On x86, it's usually better to promote i16 operations to
982 /// i32 since i16 instructions are longer.
983 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
984 if (!LegalOperations)
987 EVT VT = Op.getValueType();
988 if (VT.isVector() || !VT.isInteger())
991 // If operation type is 'undesirable', e.g. i16 on x86, consider
993 unsigned Opc = Op.getOpcode();
994 if (TLI.isTypeDesirableForOp(Opc, VT))
998 // Consult target whether it is a good idea to promote this operation and
999 // what's the right type to promote it to.
1000 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1001 assert(PVT != VT && "Don't know what type to promote to!");
1003 bool Replace0 = false;
1004 SDValue N0 = Op.getOperand(0);
1005 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
1009 bool Replace1 = false;
1010 SDValue N1 = Op.getOperand(1);
1015 NN1 = PromoteOperand(N1, PVT, Replace1);
1020 AddToWorklist(NN0.getNode());
1022 AddToWorklist(NN1.getNode());
1025 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
1027 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
1029 DEBUG(dbgs() << "\nPromoting ";
1030 Op.getNode()->dump(&DAG));
1032 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1033 DAG.getNode(Opc, dl, PVT, NN0, NN1));
1038 /// Promote the specified integer shift operation if the target indicates it is
1039 /// beneficial. e.g. On x86, it's usually better to promote i16 operations to
1040 /// i32 since i16 instructions are longer.
1041 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
1042 if (!LegalOperations)
1045 EVT VT = Op.getValueType();
1046 if (VT.isVector() || !VT.isInteger())
1049 // If operation type is 'undesirable', e.g. i16 on x86, consider
1051 unsigned Opc = Op.getOpcode();
1052 if (TLI.isTypeDesirableForOp(Opc, VT))
1056 // Consult target whether it is a good idea to promote this operation and
1057 // what's the right type to promote it to.
1058 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1059 assert(PVT != VT && "Don't know what type to promote to!");
1061 bool Replace = false;
1062 SDValue N0 = Op.getOperand(0);
1063 if (Opc == ISD::SRA)
1064 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
1065 else if (Opc == ISD::SRL)
1066 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
1068 N0 = PromoteOperand(N0, PVT, Replace);
1072 AddToWorklist(N0.getNode());
1074 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
1076 DEBUG(dbgs() << "\nPromoting ";
1077 Op.getNode()->dump(&DAG));
1079 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1080 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
1085 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
1086 if (!LegalOperations)
1089 EVT VT = Op.getValueType();
1090 if (VT.isVector() || !VT.isInteger())
1093 // If operation type is 'undesirable', e.g. i16 on x86, consider
1095 unsigned Opc = Op.getOpcode();
1096 if (TLI.isTypeDesirableForOp(Opc, VT))
1100 // Consult target whether it is a good idea to promote this operation and
1101 // what's the right type to promote it to.
1102 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1103 assert(PVT != VT && "Don't know what type to promote to!");
1104 // fold (aext (aext x)) -> (aext x)
1105 // fold (aext (zext x)) -> (zext x)
1106 // fold (aext (sext x)) -> (sext x)
1107 DEBUG(dbgs() << "\nPromoting ";
1108 Op.getNode()->dump(&DAG));
1109 return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
1114 bool DAGCombiner::PromoteLoad(SDValue Op) {
1115 if (!LegalOperations)
1118 EVT VT = Op.getValueType();
1119 if (VT.isVector() || !VT.isInteger())
1122 // If operation type is 'undesirable', e.g. i16 on x86, consider
1124 unsigned Opc = Op.getOpcode();
1125 if (TLI.isTypeDesirableForOp(Opc, VT))
1129 // Consult target whether it is a good idea to promote this operation and
1130 // what's the right type to promote it to.
1131 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1132 assert(PVT != VT && "Don't know what type to promote to!");
1135 SDNode *N = Op.getNode();
1136 LoadSDNode *LD = cast<LoadSDNode>(N);
1137 EVT MemVT = LD->getMemoryVT();
1138 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
1139 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
1141 : LD->getExtensionType();
1142 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
1143 LD->getChain(), LD->getBasePtr(),
1144 MemVT, LD->getMemOperand());
1145 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
1147 DEBUG(dbgs() << "\nPromoting ";
1150 Result.getNode()->dump(&DAG);
1152 WorklistRemover DeadNodes(*this);
1153 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
1154 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
1155 deleteAndRecombine(N);
1156 AddToWorklist(Result.getNode());
1162 /// \brief Recursively delete a node which has no uses and any operands for
1163 /// which it is the only use.
1165 /// Note that this both deletes the nodes and removes them from the worklist.
1166 /// It also adds any nodes who have had a user deleted to the worklist as they
1167 /// may now have only one use and subject to other combines.
1168 bool DAGCombiner::recursivelyDeleteUnusedNodes(SDNode *N) {
1169 if (!N->use_empty())
1172 SmallSetVector<SDNode *, 16> Nodes;
1175 N = Nodes.pop_back_val();
1179 if (N->use_empty()) {
1180 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1181 Nodes.insert(N->getOperand(i).getNode());
1183 removeFromWorklist(N);
1188 } while (!Nodes.empty());
1192 //===----------------------------------------------------------------------===//
1193 // Main DAG Combiner implementation
1194 //===----------------------------------------------------------------------===//
1196 void DAGCombiner::Run(CombineLevel AtLevel) {
1197 // set the instance variables, so that the various visit routines may use it.
1199 LegalOperations = Level >= AfterLegalizeVectorOps;
1200 LegalTypes = Level >= AfterLegalizeTypes;
1202 // Add all the dag nodes to the worklist.
1203 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
1204 E = DAG.allnodes_end(); I != E; ++I)
1207 // Create a dummy node (which is not added to allnodes), that adds a reference
1208 // to the root node, preventing it from being deleted, and tracking any
1209 // changes of the root.
1210 HandleSDNode Dummy(DAG.getRoot());
1212 // while the worklist isn't empty, find a node and
1213 // try and combine it.
1214 while (!WorklistMap.empty()) {
1216 // The Worklist holds the SDNodes in order, but it may contain null entries.
1218 N = Worklist.pop_back_val();
1221 bool GoodWorklistEntry = WorklistMap.erase(N);
1222 (void)GoodWorklistEntry;
1223 assert(GoodWorklistEntry &&
1224 "Found a worklist entry without a corresponding map entry!");
1226 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1227 // N is deleted from the DAG, since they too may now be dead or may have a
1228 // reduced number of uses, allowing other xforms.
1229 if (recursivelyDeleteUnusedNodes(N))
1232 WorklistRemover DeadNodes(*this);
1234 // If this combine is running after legalizing the DAG, re-legalize any
1235 // nodes pulled off the worklist.
1236 if (Level == AfterLegalizeDAG) {
1237 SmallSetVector<SDNode *, 16> UpdatedNodes;
1238 bool NIsValid = DAG.LegalizeOp(N, UpdatedNodes);
1240 for (SDNode *LN : UpdatedNodes) {
1242 AddUsersToWorklist(LN);
1248 DEBUG(dbgs() << "\nCombining: "; N->dump(&DAG));
1250 // Add any operands of the new node which have not yet been combined to the
1251 // worklist as well. Because the worklist uniques things already, this
1252 // won't repeatedly process the same operand.
1253 CombinedNodes.insert(N);
1254 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1255 if (!CombinedNodes.count(N->getOperand(i).getNode()))
1256 AddToWorklist(N->getOperand(i).getNode());
1258 SDValue RV = combine(N);
1265 // If we get back the same node we passed in, rather than a new node or
1266 // zero, we know that the node must have defined multiple values and
1267 // CombineTo was used. Since CombineTo takes care of the worklist
1268 // mechanics for us, we have no work to do in this case.
1269 if (RV.getNode() == N)
1272 assert(N->getOpcode() != ISD::DELETED_NODE &&
1273 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1274 "Node was deleted but visit returned new node!");
1276 DEBUG(dbgs() << " ... into: ";
1277 RV.getNode()->dump(&DAG));
1279 // Transfer debug value.
1280 DAG.TransferDbgValues(SDValue(N, 0), RV);
1281 if (N->getNumValues() == RV.getNode()->getNumValues())
1282 DAG.ReplaceAllUsesWith(N, RV.getNode());
1284 assert(N->getValueType(0) == RV.getValueType() &&
1285 N->getNumValues() == 1 && "Type mismatch");
1287 DAG.ReplaceAllUsesWith(N, &OpV);
1290 // Push the new node and any users onto the worklist
1291 AddToWorklist(RV.getNode());
1292 AddUsersToWorklist(RV.getNode());
1294 // Finally, if the node is now dead, remove it from the graph. The node
1295 // may not be dead if the replacement process recursively simplified to
1296 // something else needing this node. This will also take care of adding any
1297 // operands which have lost a user to the worklist.
1298 recursivelyDeleteUnusedNodes(N);
1301 // If the root changed (e.g. it was a dead load, update the root).
1302 DAG.setRoot(Dummy.getValue());
1303 DAG.RemoveDeadNodes();
1306 SDValue DAGCombiner::visit(SDNode *N) {
1307 switch (N->getOpcode()) {
1309 case ISD::TokenFactor: return visitTokenFactor(N);
1310 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1311 case ISD::ADD: return visitADD(N);
1312 case ISD::SUB: return visitSUB(N);
1313 case ISD::ADDC: return visitADDC(N);
1314 case ISD::SUBC: return visitSUBC(N);
1315 case ISD::ADDE: return visitADDE(N);
1316 case ISD::SUBE: return visitSUBE(N);
1317 case ISD::MUL: return visitMUL(N);
1318 case ISD::SDIV: return visitSDIV(N);
1319 case ISD::UDIV: return visitUDIV(N);
1320 case ISD::SREM: return visitSREM(N);
1321 case ISD::UREM: return visitUREM(N);
1322 case ISD::MULHU: return visitMULHU(N);
1323 case ISD::MULHS: return visitMULHS(N);
1324 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1325 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1326 case ISD::SMULO: return visitSMULO(N);
1327 case ISD::UMULO: return visitUMULO(N);
1328 case ISD::SDIVREM: return visitSDIVREM(N);
1329 case ISD::UDIVREM: return visitUDIVREM(N);
1330 case ISD::AND: return visitAND(N);
1331 case ISD::OR: return visitOR(N);
1332 case ISD::XOR: return visitXOR(N);
1333 case ISD::SHL: return visitSHL(N);
1334 case ISD::SRA: return visitSRA(N);
1335 case ISD::SRL: return visitSRL(N);
1337 case ISD::ROTL: return visitRotate(N);
1338 case ISD::CTLZ: return visitCTLZ(N);
1339 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1340 case ISD::CTTZ: return visitCTTZ(N);
1341 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1342 case ISD::CTPOP: return visitCTPOP(N);
1343 case ISD::SELECT: return visitSELECT(N);
1344 case ISD::VSELECT: return visitVSELECT(N);
1345 case ISD::SELECT_CC: return visitSELECT_CC(N);
1346 case ISD::SETCC: return visitSETCC(N);
1347 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1348 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1349 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1350 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1351 case ISD::SIGN_EXTEND_VECTOR_INREG: return visitSIGN_EXTEND_VECTOR_INREG(N);
1352 case ISD::TRUNCATE: return visitTRUNCATE(N);
1353 case ISD::BITCAST: return visitBITCAST(N);
1354 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1355 case ISD::FADD: return visitFADD(N);
1356 case ISD::FSUB: return visitFSUB(N);
1357 case ISD::FMUL: return visitFMUL(N);
1358 case ISD::FMA: return visitFMA(N);
1359 case ISD::FDIV: return visitFDIV(N);
1360 case ISD::FREM: return visitFREM(N);
1361 case ISD::FSQRT: return visitFSQRT(N);
1362 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1363 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1364 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1365 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1366 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1367 case ISD::FP_ROUND: return visitFP_ROUND(N);
1368 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1369 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1370 case ISD::FNEG: return visitFNEG(N);
1371 case ISD::FABS: return visitFABS(N);
1372 case ISD::FFLOOR: return visitFFLOOR(N);
1373 case ISD::FMINNUM: return visitFMINNUM(N);
1374 case ISD::FMAXNUM: return visitFMAXNUM(N);
1375 case ISD::FCEIL: return visitFCEIL(N);
1376 case ISD::FTRUNC: return visitFTRUNC(N);
1377 case ISD::BRCOND: return visitBRCOND(N);
1378 case ISD::BR_CC: return visitBR_CC(N);
1379 case ISD::LOAD: return visitLOAD(N);
1380 case ISD::STORE: return visitSTORE(N);
1381 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1382 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1383 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1384 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1385 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1386 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1387 case ISD::SCALAR_TO_VECTOR: return visitSCALAR_TO_VECTOR(N);
1388 case ISD::INSERT_SUBVECTOR: return visitINSERT_SUBVECTOR(N);
1389 case ISD::MGATHER: return visitMGATHER(N);
1390 case ISD::MLOAD: return visitMLOAD(N);
1391 case ISD::MSCATTER: return visitMSCATTER(N);
1392 case ISD::MSTORE: return visitMSTORE(N);
1393 case ISD::FP_TO_FP16: return visitFP_TO_FP16(N);
1398 SDValue DAGCombiner::combine(SDNode *N) {
1399 SDValue RV = visit(N);
1401 // If nothing happened, try a target-specific DAG combine.
1402 if (!RV.getNode()) {
1403 assert(N->getOpcode() != ISD::DELETED_NODE &&
1404 "Node was deleted but visit returned NULL!");
1406 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1407 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1409 // Expose the DAG combiner to the target combiner impls.
1410 TargetLowering::DAGCombinerInfo
1411 DagCombineInfo(DAG, Level, false, this);
1413 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1417 // If nothing happened still, try promoting the operation.
1418 if (!RV.getNode()) {
1419 switch (N->getOpcode()) {
1427 RV = PromoteIntBinOp(SDValue(N, 0));
1432 RV = PromoteIntShiftOp(SDValue(N, 0));
1434 case ISD::SIGN_EXTEND:
1435 case ISD::ZERO_EXTEND:
1436 case ISD::ANY_EXTEND:
1437 RV = PromoteExtend(SDValue(N, 0));
1440 if (PromoteLoad(SDValue(N, 0)))
1446 // If N is a commutative binary node, try commuting it to enable more
1448 if (!RV.getNode() && SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1449 N->getNumValues() == 1) {
1450 SDValue N0 = N->getOperand(0);
1451 SDValue N1 = N->getOperand(1);
1453 // Constant operands are canonicalized to RHS.
1454 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1455 SDValue Ops[] = {N1, N0};
1457 if (const BinaryWithFlagsSDNode *BinNode =
1458 dyn_cast<BinaryWithFlagsSDNode>(N)) {
1459 CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops,
1460 BinNode->Flags.hasNoUnsignedWrap(),
1461 BinNode->Flags.hasNoSignedWrap(),
1462 BinNode->Flags.hasExact());
1464 CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops);
1467 return SDValue(CSENode, 0);
1474 /// Given a node, return its input chain if it has one, otherwise return a null
1476 static SDValue getInputChainForNode(SDNode *N) {
1477 if (unsigned NumOps = N->getNumOperands()) {
1478 if (N->getOperand(0).getValueType() == MVT::Other)
1479 return N->getOperand(0);
1480 if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1481 return N->getOperand(NumOps-1);
1482 for (unsigned i = 1; i < NumOps-1; ++i)
1483 if (N->getOperand(i).getValueType() == MVT::Other)
1484 return N->getOperand(i);
1489 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1490 // If N has two operands, where one has an input chain equal to the other,
1491 // the 'other' chain is redundant.
1492 if (N->getNumOperands() == 2) {
1493 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1494 return N->getOperand(0);
1495 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1496 return N->getOperand(1);
1499 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1500 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1501 SmallPtrSet<SDNode*, 16> SeenOps;
1502 bool Changed = false; // If we should replace this token factor.
1504 // Start out with this token factor.
1507 // Iterate through token factors. The TFs grows when new token factors are
1509 for (unsigned i = 0; i < TFs.size(); ++i) {
1510 SDNode *TF = TFs[i];
1512 // Check each of the operands.
1513 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1514 SDValue Op = TF->getOperand(i);
1516 switch (Op.getOpcode()) {
1517 case ISD::EntryToken:
1518 // Entry tokens don't need to be added to the list. They are
1523 case ISD::TokenFactor:
1524 if (Op.hasOneUse() &&
1525 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1526 // Queue up for processing.
1527 TFs.push_back(Op.getNode());
1528 // Clean up in case the token factor is removed.
1529 AddToWorklist(Op.getNode());
1536 // Only add if it isn't already in the list.
1537 if (SeenOps.insert(Op.getNode()).second)
1548 // If we've changed things around then replace token factor.
1551 // The entry token is the only possible outcome.
1552 Result = DAG.getEntryNode();
1554 // New and improved token factor.
1555 Result = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Ops);
1558 // Add users to worklist if AA is enabled, since it may introduce
1559 // a lot of new chained token factors while removing memory deps.
1560 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
1561 : DAG.getSubtarget().useAA();
1562 return CombineTo(N, Result, UseAA /*add to worklist*/);
1568 /// MERGE_VALUES can always be eliminated.
1569 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1570 WorklistRemover DeadNodes(*this);
1571 // Replacing results may cause a different MERGE_VALUES to suddenly
1572 // be CSE'd with N, and carry its uses with it. Iterate until no
1573 // uses remain, to ensure that the node can be safely deleted.
1574 // First add the users of this node to the work list so that they
1575 // can be tried again once they have new operands.
1576 AddUsersToWorklist(N);
1578 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1579 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1580 } while (!N->use_empty());
1581 deleteAndRecombine(N);
1582 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1585 static bool isNullConstant(SDValue V) {
1586 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1587 return Const != nullptr && Const->isNullValue();
1590 static bool isAllOnesConstant(SDValue V) {
1591 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1592 return Const != nullptr && Const->isAllOnesValue();
1595 static bool isOneConstant(SDValue V) {
1596 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V);
1597 return Const != nullptr && Const->isOne();
1600 /// If \p N is a ContantSDNode with isOpaque() == false return it casted to a
1601 /// ContantSDNode pointer else nullptr.
1602 static ConstantSDNode *getAsNonOpaqueConstant(SDValue N) {
1603 ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N);
1604 return Const != nullptr && !Const->isOpaque() ? Const : nullptr;
1607 SDValue DAGCombiner::visitADD(SDNode *N) {
1608 SDValue N0 = N->getOperand(0);
1609 SDValue N1 = N->getOperand(1);
1610 EVT VT = N0.getValueType();
1613 if (VT.isVector()) {
1614 if (SDValue FoldedVOp = SimplifyVBinOp(N))
1617 // fold (add x, 0) -> x, vector edition
1618 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1620 if (ISD::isBuildVectorAllZeros(N0.getNode()))
1624 // fold (add x, undef) -> undef
1625 if (N0.getOpcode() == ISD::UNDEF)
1627 if (N1.getOpcode() == ISD::UNDEF)
1629 // fold (add c1, c2) -> c1+c2
1630 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
1631 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
1633 return DAG.FoldConstantArithmetic(ISD::ADD, SDLoc(N), VT, N0C, N1C);
1634 // canonicalize constant to RHS
1635 if (isConstantIntBuildVectorOrConstantInt(N0) &&
1636 !isConstantIntBuildVectorOrConstantInt(N1))
1637 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N1, N0);
1638 // fold (add x, 0) -> x
1639 if (isNullConstant(N1))
1641 // fold (add Sym, c) -> Sym+c
1642 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1643 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1644 GA->getOpcode() == ISD::GlobalAddress)
1645 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1647 (uint64_t)N1C->getSExtValue());
1648 // fold ((c1-A)+c2) -> (c1+c2)-A
1649 if (N1C && N0.getOpcode() == ISD::SUB)
1650 if (ConstantSDNode *N0C = getAsNonOpaqueConstant(N0.getOperand(0))) {
1652 return DAG.getNode(ISD::SUB, DL, VT,
1653 DAG.getConstant(N1C->getAPIntValue()+
1654 N0C->getAPIntValue(), DL, VT),
1658 if (SDValue RADD = ReassociateOps(ISD::ADD, SDLoc(N), N0, N1))
1660 // fold ((0-A) + B) -> B-A
1661 if (N0.getOpcode() == ISD::SUB && isNullConstant(N0.getOperand(0)))
1662 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1, N0.getOperand(1));
1663 // fold (A + (0-B)) -> A-B
1664 if (N1.getOpcode() == ISD::SUB && isNullConstant(N1.getOperand(0)))
1665 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1.getOperand(1));
1666 // fold (A+(B-A)) -> B
1667 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1668 return N1.getOperand(0);
1669 // fold ((B-A)+A) -> B
1670 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1671 return N0.getOperand(0);
1672 // fold (A+(B-(A+C))) to (B-C)
1673 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1674 N0 == N1.getOperand(1).getOperand(0))
1675 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1676 N1.getOperand(1).getOperand(1));
1677 // fold (A+(B-(C+A))) to (B-C)
1678 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1679 N0 == N1.getOperand(1).getOperand(1))
1680 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1681 N1.getOperand(1).getOperand(0));
1682 // fold (A+((B-A)+or-C)) to (B+or-C)
1683 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1684 N1.getOperand(0).getOpcode() == ISD::SUB &&
1685 N0 == N1.getOperand(0).getOperand(1))
1686 return DAG.getNode(N1.getOpcode(), SDLoc(N), VT,
1687 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1689 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1690 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1691 SDValue N00 = N0.getOperand(0);
1692 SDValue N01 = N0.getOperand(1);
1693 SDValue N10 = N1.getOperand(0);
1694 SDValue N11 = N1.getOperand(1);
1696 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1697 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1698 DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
1699 DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
1702 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1703 return SDValue(N, 0);
1705 // fold (a+b) -> (a|b) iff a and b share no bits.
1706 if (VT.isInteger() && !VT.isVector()) {
1707 APInt LHSZero, LHSOne;
1708 APInt RHSZero, RHSOne;
1709 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1711 if (LHSZero.getBoolValue()) {
1712 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1714 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1715 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1716 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero){
1717 if (!LegalOperations || TLI.isOperationLegal(ISD::OR, VT))
1718 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
1723 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1724 if (N1.getOpcode() == ISD::SHL && N1.getOperand(0).getOpcode() == ISD::SUB &&
1725 isNullConstant(N1.getOperand(0).getOperand(0)))
1726 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
1727 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1728 N1.getOperand(0).getOperand(1),
1730 if (N0.getOpcode() == ISD::SHL && N0.getOperand(0).getOpcode() == ISD::SUB &&
1731 isNullConstant(N0.getOperand(0).getOperand(0)))
1732 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
1733 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1734 N0.getOperand(0).getOperand(1),
1737 if (N1.getOpcode() == ISD::AND) {
1738 SDValue AndOp0 = N1.getOperand(0);
1739 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1740 unsigned DestBits = VT.getScalarType().getSizeInBits();
1742 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1743 // and similar xforms where the inner op is either ~0 or 0.
1744 if (NumSignBits == DestBits && isOneConstant(N1->getOperand(1))) {
1746 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1750 // add (sext i1), X -> sub X, (zext i1)
1751 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1752 N0.getOperand(0).getValueType() == MVT::i1 &&
1753 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1755 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1756 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1759 // add X, (sextinreg Y i1) -> sub X, (and Y 1)
1760 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
1761 VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
1762 if (TN->getVT() == MVT::i1) {
1764 SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
1765 DAG.getConstant(1, DL, VT));
1766 return DAG.getNode(ISD::SUB, DL, VT, N0, ZExt);
1773 SDValue DAGCombiner::visitADDC(SDNode *N) {
1774 SDValue N0 = N->getOperand(0);
1775 SDValue N1 = N->getOperand(1);
1776 EVT VT = N0.getValueType();
1778 // If the flag result is dead, turn this into an ADD.
1779 if (!N->hasAnyUseOfValue(1))
1780 return CombineTo(N, DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N1),
1781 DAG.getNode(ISD::CARRY_FALSE,
1782 SDLoc(N), MVT::Glue));
1784 // canonicalize constant to RHS.
1785 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1786 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1788 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N1, N0);
1790 // fold (addc x, 0) -> x + no carry out
1791 if (isNullConstant(N1))
1792 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1793 SDLoc(N), MVT::Glue));
1795 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1796 APInt LHSZero, LHSOne;
1797 APInt RHSZero, RHSOne;
1798 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1800 if (LHSZero.getBoolValue()) {
1801 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1803 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1804 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1805 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1806 return CombineTo(N, DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1),
1807 DAG.getNode(ISD::CARRY_FALSE,
1808 SDLoc(N), MVT::Glue));
1814 SDValue DAGCombiner::visitADDE(SDNode *N) {
1815 SDValue N0 = N->getOperand(0);
1816 SDValue N1 = N->getOperand(1);
1817 SDValue CarryIn = N->getOperand(2);
1819 // canonicalize constant to RHS
1820 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1821 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1823 return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
1826 // fold (adde x, y, false) -> (addc x, y)
1827 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1828 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);
1833 // Since it may not be valid to emit a fold to zero for vector initializers
1834 // check if we can before folding.
1835 static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
1837 bool LegalOperations, bool LegalTypes) {
1839 return DAG.getConstant(0, DL, VT);
1840 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
1841 return DAG.getConstant(0, DL, VT);
1845 SDValue DAGCombiner::visitSUB(SDNode *N) {
1846 SDValue N0 = N->getOperand(0);
1847 SDValue N1 = N->getOperand(1);
1848 EVT VT = N0.getValueType();
1851 if (VT.isVector()) {
1852 if (SDValue FoldedVOp = SimplifyVBinOp(N))
1855 // fold (sub x, 0) -> x, vector edition
1856 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1860 // fold (sub x, x) -> 0
1861 // FIXME: Refactor this and xor and other similar operations together.
1863 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
1864 // fold (sub c1, c2) -> c1-c2
1865 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
1866 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
1868 return DAG.FoldConstantArithmetic(ISD::SUB, SDLoc(N), VT, N0C, N1C);
1869 // fold (sub x, c) -> (add x, -c)
1872 return DAG.getNode(ISD::ADD, DL, VT, N0,
1873 DAG.getConstant(-N1C->getAPIntValue(), DL, VT));
1875 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1876 if (isAllOnesConstant(N0))
1877 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
1878 // fold A-(A-B) -> B
1879 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1880 return N1.getOperand(1);
1881 // fold (A+B)-A -> B
1882 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1883 return N0.getOperand(1);
1884 // fold (A+B)-B -> A
1885 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1886 return N0.getOperand(0);
1887 // fold C2-(A+C1) -> (C2-C1)-A
1888 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? nullptr :
1889 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1890 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1892 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1894 return DAG.getNode(ISD::SUB, DL, VT, NewC,
1897 // fold ((A+(B+or-C))-B) -> A+or-C
1898 if (N0.getOpcode() == ISD::ADD &&
1899 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1900 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1901 N0.getOperand(1).getOperand(0) == N1)
1902 return DAG.getNode(N0.getOperand(1).getOpcode(), SDLoc(N), VT,
1903 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1904 // fold ((A+(C+B))-B) -> A+C
1905 if (N0.getOpcode() == ISD::ADD &&
1906 N0.getOperand(1).getOpcode() == ISD::ADD &&
1907 N0.getOperand(1).getOperand(1) == N1)
1908 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1909 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1910 // fold ((A-(B-C))-C) -> A-B
1911 if (N0.getOpcode() == ISD::SUB &&
1912 N0.getOperand(1).getOpcode() == ISD::SUB &&
1913 N0.getOperand(1).getOperand(1) == N1)
1914 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1915 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1917 // If either operand of a sub is undef, the result is undef
1918 if (N0.getOpcode() == ISD::UNDEF)
1920 if (N1.getOpcode() == ISD::UNDEF)
1923 // If the relocation model supports it, consider symbol offsets.
1924 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1925 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1926 // fold (sub Sym, c) -> Sym-c
1927 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1928 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1930 (uint64_t)N1C->getSExtValue());
1931 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1932 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1933 if (GA->getGlobal() == GB->getGlobal())
1934 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1938 // sub X, (sextinreg Y i1) -> add X, (and Y 1)
1939 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
1940 VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
1941 if (TN->getVT() == MVT::i1) {
1943 SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
1944 DAG.getConstant(1, DL, VT));
1945 return DAG.getNode(ISD::ADD, DL, VT, N0, ZExt);
1952 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1953 SDValue N0 = N->getOperand(0);
1954 SDValue N1 = N->getOperand(1);
1955 EVT VT = N0.getValueType();
1957 // If the flag result is dead, turn this into an SUB.
1958 if (!N->hasAnyUseOfValue(1))
1959 return CombineTo(N, DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1),
1960 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1963 // fold (subc x, x) -> 0 + no borrow
1966 return CombineTo(N, DAG.getConstant(0, DL, VT),
1967 DAG.getNode(ISD::CARRY_FALSE, DL,
1971 // fold (subc x, 0) -> x + no borrow
1972 if (isNullConstant(N1))
1973 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1976 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1977 if (isAllOnesConstant(N0))
1978 return CombineTo(N, DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0),
1979 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1985 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1986 SDValue N0 = N->getOperand(0);
1987 SDValue N1 = N->getOperand(1);
1988 SDValue CarryIn = N->getOperand(2);
1990 // fold (sube x, y, false) -> (subc x, y)
1991 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1992 return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);
1997 SDValue DAGCombiner::visitMUL(SDNode *N) {
1998 SDValue N0 = N->getOperand(0);
1999 SDValue N1 = N->getOperand(1);
2000 EVT VT = N0.getValueType();
2002 // fold (mul x, undef) -> 0
2003 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2004 return DAG.getConstant(0, SDLoc(N), VT);
2006 bool N0IsConst = false;
2007 bool N1IsConst = false;
2008 bool N1IsOpaqueConst = false;
2009 bool N0IsOpaqueConst = false;
2010 APInt ConstValue0, ConstValue1;
2012 if (VT.isVector()) {
2013 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2016 N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
2017 N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
2019 N0IsConst = isa<ConstantSDNode>(N0);
2021 ConstValue0 = cast<ConstantSDNode>(N0)->getAPIntValue();
2022 N0IsOpaqueConst = cast<ConstantSDNode>(N0)->isOpaque();
2024 N1IsConst = isa<ConstantSDNode>(N1);
2026 ConstValue1 = cast<ConstantSDNode>(N1)->getAPIntValue();
2027 N1IsOpaqueConst = cast<ConstantSDNode>(N1)->isOpaque();
2031 // fold (mul c1, c2) -> c1*c2
2032 if (N0IsConst && N1IsConst && !N0IsOpaqueConst && !N1IsOpaqueConst)
2033 return DAG.FoldConstantArithmetic(ISD::MUL, SDLoc(N), VT,
2034 N0.getNode(), N1.getNode());
2036 // canonicalize constant to RHS (vector doesn't have to splat)
2037 if (isConstantIntBuildVectorOrConstantInt(N0) &&
2038 !isConstantIntBuildVectorOrConstantInt(N1))
2039 return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
2040 // fold (mul x, 0) -> 0
2041 if (N1IsConst && ConstValue1 == 0)
2043 // We require a splat of the entire scalar bit width for non-contiguous
2046 ConstValue1.getBitWidth() == VT.getScalarType().getSizeInBits();
2047 // fold (mul x, 1) -> x
2048 if (N1IsConst && ConstValue1 == 1 && IsFullSplat)
2050 // fold (mul x, -1) -> 0-x
2051 if (N1IsConst && ConstValue1.isAllOnesValue()) {
2053 return DAG.getNode(ISD::SUB, DL, VT,
2054 DAG.getConstant(0, DL, VT), N0);
2056 // fold (mul x, (1 << c)) -> x << c
2057 if (N1IsConst && !N1IsOpaqueConst && ConstValue1.isPowerOf2() &&
2060 return DAG.getNode(ISD::SHL, DL, VT, N0,
2061 DAG.getConstant(ConstValue1.logBase2(), DL,
2062 getShiftAmountTy(N0.getValueType())));
2064 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
2065 if (N1IsConst && !N1IsOpaqueConst && (-ConstValue1).isPowerOf2() &&
2067 unsigned Log2Val = (-ConstValue1).logBase2();
2069 // FIXME: If the input is something that is easily negated (e.g. a
2070 // single-use add), we should put the negate there.
2071 return DAG.getNode(ISD::SUB, DL, VT,
2072 DAG.getConstant(0, DL, VT),
2073 DAG.getNode(ISD::SHL, DL, VT, N0,
2074 DAG.getConstant(Log2Val, DL,
2075 getShiftAmountTy(N0.getValueType()))));
2079 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
2080 if (N1IsConst && N0.getOpcode() == ISD::SHL &&
2081 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2082 isa<ConstantSDNode>(N0.getOperand(1)))) {
2083 SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
2084 N1, N0.getOperand(1));
2085 AddToWorklist(C3.getNode());
2086 return DAG.getNode(ISD::MUL, SDLoc(N), VT,
2087 N0.getOperand(0), C3);
2090 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
2093 SDValue Sh(nullptr,0), Y(nullptr,0);
2094 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
2095 if (N0.getOpcode() == ISD::SHL &&
2096 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2097 isa<ConstantSDNode>(N0.getOperand(1))) &&
2098 N0.getNode()->hasOneUse()) {
2100 } else if (N1.getOpcode() == ISD::SHL &&
2101 isa<ConstantSDNode>(N1.getOperand(1)) &&
2102 N1.getNode()->hasOneUse()) {
2107 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2108 Sh.getOperand(0), Y);
2109 return DAG.getNode(ISD::SHL, SDLoc(N), VT,
2110 Mul, Sh.getOperand(1));
2114 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
2115 if (N1IsConst && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
2116 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
2117 isa<ConstantSDNode>(N0.getOperand(1))))
2118 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
2119 DAG.getNode(ISD::MUL, SDLoc(N0), VT,
2120 N0.getOperand(0), N1),
2121 DAG.getNode(ISD::MUL, SDLoc(N1), VT,
2122 N0.getOperand(1), N1));
2125 if (SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1))
2131 SDValue DAGCombiner::visitSDIV(SDNode *N) {
2132 SDValue N0 = N->getOperand(0);
2133 SDValue N1 = N->getOperand(1);
2134 EVT VT = N->getValueType(0);
2138 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2141 // fold (sdiv c1, c2) -> c1/c2
2142 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2143 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2144 if (N0C && N1C && !N0C->isOpaque() && !N1C->isOpaque())
2145 return DAG.FoldConstantArithmetic(ISD::SDIV, SDLoc(N), VT, N0C, N1C);
2146 // fold (sdiv X, 1) -> X
2147 if (N1C && N1C->isOne())
2149 // fold (sdiv X, -1) -> 0-X
2150 if (N1C && N1C->isAllOnesValue()) {
2152 return DAG.getNode(ISD::SUB, DL, VT,
2153 DAG.getConstant(0, DL, VT), N0);
2155 // If we know the sign bits of both operands are zero, strength reduce to a
2156 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
2157 if (!VT.isVector()) {
2158 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2159 return DAG.getNode(ISD::UDIV, SDLoc(N), N1.getValueType(),
2163 // fold (sdiv X, pow2) -> simple ops after legalize
2164 if (N1C && !N1C->isNullValue() && !N1C->isOpaque() &&
2165 (N1C->getAPIntValue().isPowerOf2() ||
2166 (-N1C->getAPIntValue()).isPowerOf2())) {
2167 // If dividing by powers of two is cheap, then don't perform the following
2169 if (TLI.isPow2SDivCheap())
2172 // Target-specific implementation of sdiv x, pow2.
2173 SDValue Res = BuildSDIVPow2(N);
2177 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
2180 // Splat the sign bit into the register
2182 DAG.getNode(ISD::SRA, DL, VT, N0,
2183 DAG.getConstant(VT.getScalarSizeInBits() - 1, DL,
2184 getShiftAmountTy(N0.getValueType())));
2185 AddToWorklist(SGN.getNode());
2187 // Add (N0 < 0) ? abs2 - 1 : 0;
2189 DAG.getNode(ISD::SRL, DL, VT, SGN,
2190 DAG.getConstant(VT.getScalarSizeInBits() - lg2, DL,
2191 getShiftAmountTy(SGN.getValueType())));
2192 SDValue ADD = DAG.getNode(ISD::ADD, DL, VT, N0, SRL);
2193 AddToWorklist(SRL.getNode());
2194 AddToWorklist(ADD.getNode()); // Divide by pow2
2195 SDValue SRA = DAG.getNode(ISD::SRA, DL, VT, ADD,
2196 DAG.getConstant(lg2, DL,
2197 getShiftAmountTy(ADD.getValueType())));
2199 // If we're dividing by a positive value, we're done. Otherwise, we must
2200 // negate the result.
2201 if (N1C->getAPIntValue().isNonNegative())
2204 AddToWorklist(SRA.getNode());
2205 return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), SRA);
2208 // If integer divide is expensive and we satisfy the requirements, emit an
2209 // alternate sequence.
2210 if (N1C && !TLI.isIntDivCheap()) {
2211 SDValue Op = BuildSDIV(N);
2212 if (Op.getNode()) return Op;
2216 if (N0.getOpcode() == ISD::UNDEF)
2217 return DAG.getConstant(0, SDLoc(N), VT);
2218 // X / undef -> undef
2219 if (N1.getOpcode() == ISD::UNDEF)
2225 SDValue DAGCombiner::visitUDIV(SDNode *N) {
2226 SDValue N0 = N->getOperand(0);
2227 SDValue N1 = N->getOperand(1);
2228 EVT VT = N->getValueType(0);
2232 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2235 // fold (udiv c1, c2) -> c1/c2
2236 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2237 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2239 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UDIV, SDLoc(N), VT,
2242 // fold (udiv x, (1 << c)) -> x >>u c
2243 if (N1C && !N1C->isOpaque() && N1C->getAPIntValue().isPowerOf2()) {
2245 return DAG.getNode(ISD::SRL, DL, VT, N0,
2246 DAG.getConstant(N1C->getAPIntValue().logBase2(), DL,
2247 getShiftAmountTy(N0.getValueType())));
2249 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
2250 if (N1.getOpcode() == ISD::SHL) {
2251 if (ConstantSDNode *SHC = getAsNonOpaqueConstant(N1.getOperand(0))) {
2252 if (SHC->getAPIntValue().isPowerOf2()) {
2253 EVT ADDVT = N1.getOperand(1).getValueType();
2255 SDValue Add = DAG.getNode(ISD::ADD, DL, ADDVT,
2257 DAG.getConstant(SHC->getAPIntValue()
2260 AddToWorklist(Add.getNode());
2261 return DAG.getNode(ISD::SRL, DL, VT, N0, Add);
2265 // fold (udiv x, c) -> alternate
2266 if (N1C && !TLI.isIntDivCheap()) {
2267 SDValue Op = BuildUDIV(N);
2268 if (Op.getNode()) return Op;
2272 if (N0.getOpcode() == ISD::UNDEF)
2273 return DAG.getConstant(0, SDLoc(N), VT);
2274 // X / undef -> undef
2275 if (N1.getOpcode() == ISD::UNDEF)
2281 SDValue DAGCombiner::visitSREM(SDNode *N) {
2282 SDValue N0 = N->getOperand(0);
2283 SDValue N1 = N->getOperand(1);
2284 EVT VT = N->getValueType(0);
2286 // fold (srem c1, c2) -> c1%c2
2287 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2288 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2290 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::SREM, SDLoc(N), VT,
2293 // If we know the sign bits of both operands are zero, strength reduce to a
2294 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
2295 if (!VT.isVector()) {
2296 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2297 return DAG.getNode(ISD::UREM, SDLoc(N), VT, N0, N1);
2300 // If X/C can be simplified by the division-by-constant logic, lower
2301 // X%C to the equivalent of X-X/C*C.
2302 if (N1C && !N1C->isNullValue()) {
2303 SDValue Div = DAG.getNode(ISD::SDIV, SDLoc(N), VT, N0, N1);
2304 AddToWorklist(Div.getNode());
2305 SDValue OptimizedDiv = combine(Div.getNode());
2306 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2307 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2309 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2310 AddToWorklist(Mul.getNode());
2316 if (N0.getOpcode() == ISD::UNDEF)
2317 return DAG.getConstant(0, SDLoc(N), VT);
2318 // X % undef -> undef
2319 if (N1.getOpcode() == ISD::UNDEF)
2325 SDValue DAGCombiner::visitUREM(SDNode *N) {
2326 SDValue N0 = N->getOperand(0);
2327 SDValue N1 = N->getOperand(1);
2328 EVT VT = N->getValueType(0);
2330 // fold (urem c1, c2) -> c1%c2
2331 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2332 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2334 if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UREM, SDLoc(N), VT,
2337 // fold (urem x, pow2) -> (and x, pow2-1)
2338 if (N1C && !N1C->isNullValue() && !N1C->isOpaque() &&
2339 N1C->getAPIntValue().isPowerOf2()) {
2341 return DAG.getNode(ISD::AND, DL, VT, N0,
2342 DAG.getConstant(N1C->getAPIntValue() - 1, DL, VT));
2344 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2345 if (N1.getOpcode() == ISD::SHL) {
2346 if (ConstantSDNode *SHC = getAsNonOpaqueConstant(N1.getOperand(0))) {
2347 if (SHC->getAPIntValue().isPowerOf2()) {
2350 DAG.getNode(ISD::ADD, DL, VT, N1,
2351 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), DL,
2353 AddToWorklist(Add.getNode());
2354 return DAG.getNode(ISD::AND, DL, VT, N0, Add);
2359 // If X/C can be simplified by the division-by-constant logic, lower
2360 // X%C to the equivalent of X-X/C*C.
2361 if (N1C && !N1C->isNullValue()) {
2362 SDValue Div = DAG.getNode(ISD::UDIV, SDLoc(N), VT, N0, N1);
2363 AddToWorklist(Div.getNode());
2364 SDValue OptimizedDiv = combine(Div.getNode());
2365 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2366 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2368 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2369 AddToWorklist(Mul.getNode());
2375 if (N0.getOpcode() == ISD::UNDEF)
2376 return DAG.getConstant(0, SDLoc(N), VT);
2377 // X % undef -> undef
2378 if (N1.getOpcode() == ISD::UNDEF)
2384 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2385 SDValue N0 = N->getOperand(0);
2386 SDValue N1 = N->getOperand(1);
2387 EVT VT = N->getValueType(0);
2390 // fold (mulhs x, 0) -> 0
2391 if (isNullConstant(N1))
2393 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2394 if (isOneConstant(N1)) {
2396 return DAG.getNode(ISD::SRA, DL, N0.getValueType(), N0,
2397 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2399 getShiftAmountTy(N0.getValueType())));
2401 // fold (mulhs x, undef) -> 0
2402 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2403 return DAG.getConstant(0, SDLoc(N), VT);
2405 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2407 if (VT.isSimple() && !VT.isVector()) {
2408 MVT Simple = VT.getSimpleVT();
2409 unsigned SimpleSize = Simple.getSizeInBits();
2410 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2411 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2412 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2413 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2414 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2415 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2416 DAG.getConstant(SimpleSize, DL,
2417 getShiftAmountTy(N1.getValueType())));
2418 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2425 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2426 SDValue N0 = N->getOperand(0);
2427 SDValue N1 = N->getOperand(1);
2428 EVT VT = N->getValueType(0);
2431 // fold (mulhu x, 0) -> 0
2432 if (isNullConstant(N1))
2434 // fold (mulhu x, 1) -> 0
2435 if (isOneConstant(N1))
2436 return DAG.getConstant(0, DL, N0.getValueType());
2437 // fold (mulhu x, undef) -> 0
2438 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2439 return DAG.getConstant(0, DL, VT);
2441 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2443 if (VT.isSimple() && !VT.isVector()) {
2444 MVT Simple = VT.getSimpleVT();
2445 unsigned SimpleSize = Simple.getSizeInBits();
2446 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2447 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2448 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2449 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2450 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2451 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2452 DAG.getConstant(SimpleSize, DL,
2453 getShiftAmountTy(N1.getValueType())));
2454 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2461 /// Perform optimizations common to nodes that compute two values. LoOp and HiOp
2462 /// give the opcodes for the two computations that are being performed. Return
2463 /// true if a simplification was made.
2464 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2466 // If the high half is not needed, just compute the low half.
2467 bool HiExists = N->hasAnyUseOfValue(1);
2469 (!LegalOperations ||
2470 TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) {
2471 SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
2472 return CombineTo(N, Res, Res);
2475 // If the low half is not needed, just compute the high half.
2476 bool LoExists = N->hasAnyUseOfValue(0);
2478 (!LegalOperations ||
2479 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2480 SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
2481 return CombineTo(N, Res, Res);
2484 // If both halves are used, return as it is.
2485 if (LoExists && HiExists)
2488 // If the two computed results can be simplified separately, separate them.
2490 SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
2491 AddToWorklist(Lo.getNode());
2492 SDValue LoOpt = combine(Lo.getNode());
2493 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2494 (!LegalOperations ||
2495 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2496 return CombineTo(N, LoOpt, LoOpt);
2500 SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
2501 AddToWorklist(Hi.getNode());
2502 SDValue HiOpt = combine(Hi.getNode());
2503 if (HiOpt.getNode() && HiOpt != Hi &&
2504 (!LegalOperations ||
2505 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2506 return CombineTo(N, HiOpt, HiOpt);
2512 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2513 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2514 if (Res.getNode()) return Res;
2516 EVT VT = N->getValueType(0);
2519 // If the type is twice as wide is legal, transform the mulhu to a wider
2520 // multiply plus a shift.
2521 if (VT.isSimple() && !VT.isVector()) {
2522 MVT Simple = VT.getSimpleVT();
2523 unsigned SimpleSize = Simple.getSizeInBits();
2524 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2525 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2526 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2527 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2528 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2529 // Compute the high part as N1.
2530 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2531 DAG.getConstant(SimpleSize, DL,
2532 getShiftAmountTy(Lo.getValueType())));
2533 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2534 // Compute the low part as N0.
2535 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2536 return CombineTo(N, Lo, Hi);
2543 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2544 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2545 if (Res.getNode()) return Res;
2547 EVT VT = N->getValueType(0);
2550 // If the type is twice as wide is legal, transform the mulhu to a wider
2551 // multiply plus a shift.
2552 if (VT.isSimple() && !VT.isVector()) {
2553 MVT Simple = VT.getSimpleVT();
2554 unsigned SimpleSize = Simple.getSizeInBits();
2555 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2556 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2557 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2558 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2559 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2560 // Compute the high part as N1.
2561 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2562 DAG.getConstant(SimpleSize, DL,
2563 getShiftAmountTy(Lo.getValueType())));
2564 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2565 // Compute the low part as N0.
2566 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2567 return CombineTo(N, Lo, Hi);
2574 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2575 // (smulo x, 2) -> (saddo x, x)
2576 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2577 if (C2->getAPIntValue() == 2)
2578 return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
2579 N->getOperand(0), N->getOperand(0));
2584 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2585 // (umulo x, 2) -> (uaddo x, x)
2586 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2587 if (C2->getAPIntValue() == 2)
2588 return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
2589 N->getOperand(0), N->getOperand(0));
2594 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2595 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2596 if (Res.getNode()) return Res;
2601 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2602 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2603 if (Res.getNode()) return Res;
2608 /// If this is a binary operator with two operands of the same opcode, try to
2610 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2611 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2612 EVT VT = N0.getValueType();
2613 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2615 // Bail early if none of these transforms apply.
2616 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2618 // For each of OP in AND/OR/XOR:
2619 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2620 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2621 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2622 // fold (OP (bswap x), (bswap y)) -> (bswap (OP x, y))
2623 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2625 // do not sink logical op inside of a vector extend, since it may combine
2627 EVT Op0VT = N0.getOperand(0).getValueType();
2628 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2629 N0.getOpcode() == ISD::SIGN_EXTEND ||
2630 N0.getOpcode() == ISD::BSWAP ||
2631 // Avoid infinite looping with PromoteIntBinOp.
2632 (N0.getOpcode() == ISD::ANY_EXTEND &&
2633 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2634 (N0.getOpcode() == ISD::TRUNCATE &&
2635 (!TLI.isZExtFree(VT, Op0VT) ||
2636 !TLI.isTruncateFree(Op0VT, VT)) &&
2637 TLI.isTypeLegal(Op0VT))) &&
2639 Op0VT == N1.getOperand(0).getValueType() &&
2640 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2641 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2642 N0.getOperand(0).getValueType(),
2643 N0.getOperand(0), N1.getOperand(0));
2644 AddToWorklist(ORNode.getNode());
2645 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
2648 // For each of OP in SHL/SRL/SRA/AND...
2649 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2650 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2651 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2652 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2653 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2654 N0.getOperand(1) == N1.getOperand(1)) {
2655 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2656 N0.getOperand(0).getValueType(),
2657 N0.getOperand(0), N1.getOperand(0));
2658 AddToWorklist(ORNode.getNode());
2659 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
2660 ORNode, N0.getOperand(1));
2663 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2664 // Only perform this optimization after type legalization and before
2665 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2666 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2667 // we don't want to undo this promotion.
2668 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2670 if ((N0.getOpcode() == ISD::BITCAST ||
2671 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2672 Level == AfterLegalizeTypes) {
2673 SDValue In0 = N0.getOperand(0);
2674 SDValue In1 = N1.getOperand(0);
2675 EVT In0Ty = In0.getValueType();
2676 EVT In1Ty = In1.getValueType();
2678 // If both incoming values are integers, and the original types are the
2680 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2681 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2682 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2683 AddToWorklist(Op.getNode());
2688 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2689 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2690 // If both shuffles use the same mask, and both shuffle within a single
2691 // vector, then it is worthwhile to move the swizzle after the operation.
2692 // The type-legalizer generates this pattern when loading illegal
2693 // vector types from memory. In many cases this allows additional shuffle
2695 // There are other cases where moving the shuffle after the xor/and/or
2696 // is profitable even if shuffles don't perform a swizzle.
2697 // If both shuffles use the same mask, and both shuffles have the same first
2698 // or second operand, then it might still be profitable to move the shuffle
2699 // after the xor/and/or operation.
2700 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG) {
2701 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2702 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2704 assert(N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() &&
2705 "Inputs to shuffles are not the same type");
2707 // Check that both shuffles use the same mask. The masks are known to be of
2708 // the same length because the result vector type is the same.
2709 // Check also that shuffles have only one use to avoid introducing extra
2711 if (SVN0->hasOneUse() && SVN1->hasOneUse() &&
2712 SVN0->getMask().equals(SVN1->getMask())) {
2713 SDValue ShOp = N0->getOperand(1);
2715 // Don't try to fold this node if it requires introducing a
2716 // build vector of all zeros that might be illegal at this stage.
2717 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2719 ShOp = DAG.getConstant(0, SDLoc(N), VT);
2724 // (AND (shuf (A, C), shuf (B, C)) -> shuf (AND (A, B), C)
2725 // (OR (shuf (A, C), shuf (B, C)) -> shuf (OR (A, B), C)
2726 // (XOR (shuf (A, C), shuf (B, C)) -> shuf (XOR (A, B), V_0)
2727 if (N0.getOperand(1) == N1.getOperand(1) && ShOp.getNode()) {
2728 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2729 N0->getOperand(0), N1->getOperand(0));
2730 AddToWorklist(NewNode.getNode());
2731 return DAG.getVectorShuffle(VT, SDLoc(N), NewNode, ShOp,
2732 &SVN0->getMask()[0]);
2735 // Don't try to fold this node if it requires introducing a
2736 // build vector of all zeros that might be illegal at this stage.
2737 ShOp = N0->getOperand(0);
2738 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2740 ShOp = DAG.getConstant(0, SDLoc(N), VT);
2745 // (AND (shuf (C, A), shuf (C, B)) -> shuf (C, AND (A, B))
2746 // (OR (shuf (C, A), shuf (C, B)) -> shuf (C, OR (A, B))
2747 // (XOR (shuf (C, A), shuf (C, B)) -> shuf (V_0, XOR (A, B))
2748 if (N0->getOperand(0) == N1->getOperand(0) && ShOp.getNode()) {
2749 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2750 N0->getOperand(1), N1->getOperand(1));
2751 AddToWorklist(NewNode.getNode());
2752 return DAG.getVectorShuffle(VT, SDLoc(N), ShOp, NewNode,
2753 &SVN0->getMask()[0]);
2761 /// This contains all DAGCombine rules which reduce two values combined by
2762 /// an And operation to a single value. This makes them reusable in the context
2763 /// of visitSELECT(). Rules involving constants are not included as
2764 /// visitSELECT() already handles those cases.
2765 SDValue DAGCombiner::visitANDLike(SDValue N0, SDValue N1,
2766 SDNode *LocReference) {
2767 EVT VT = N1.getValueType();
2769 // fold (and x, undef) -> 0
2770 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2771 return DAG.getConstant(0, SDLoc(LocReference), VT);
2772 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2773 SDValue LL, LR, RL, RR, CC0, CC1;
2774 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2775 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2776 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2778 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2779 LL.getValueType().isInteger()) {
2780 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2781 if (isNullConstant(LR) && Op1 == ISD::SETEQ) {
2782 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2783 LR.getValueType(), LL, RL);
2784 AddToWorklist(ORNode.getNode());
2785 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
2787 if (isAllOnesConstant(LR)) {
2788 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2789 if (Op1 == ISD::SETEQ) {
2790 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(N0),
2791 LR.getValueType(), LL, RL);
2792 AddToWorklist(ANDNode.getNode());
2793 return DAG.getSetCC(SDLoc(LocReference), VT, ANDNode, LR, Op1);
2795 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2796 if (Op1 == ISD::SETGT) {
2797 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2798 LR.getValueType(), LL, RL);
2799 AddToWorklist(ORNode.getNode());
2800 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
2804 // Simplify (and (setne X, 0), (setne X, -1)) -> (setuge (add X, 1), 2)
2805 if (LL == RL && isa<ConstantSDNode>(LR) && isa<ConstantSDNode>(RR) &&
2806 Op0 == Op1 && LL.getValueType().isInteger() &&
2807 Op0 == ISD::SETNE && ((isNullConstant(LR) && isAllOnesConstant(RR)) ||
2808 (isAllOnesConstant(LR) && isNullConstant(RR)))) {
2810 SDValue ADDNode = DAG.getNode(ISD::ADD, DL, LL.getValueType(),
2811 LL, DAG.getConstant(1, DL,
2812 LL.getValueType()));
2813 AddToWorklist(ADDNode.getNode());
2814 return DAG.getSetCC(SDLoc(LocReference), VT, ADDNode,
2815 DAG.getConstant(2, DL, LL.getValueType()),
2818 // canonicalize equivalent to ll == rl
2819 if (LL == RR && LR == RL) {
2820 Op1 = ISD::getSetCCSwappedOperands(Op1);
2823 if (LL == RL && LR == RR) {
2824 bool isInteger = LL.getValueType().isInteger();
2825 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2826 if (Result != ISD::SETCC_INVALID &&
2827 (!LegalOperations ||
2828 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
2829 TLI.isOperationLegal(ISD::SETCC,
2830 getSetCCResultType(N0.getSimpleValueType())))))
2831 return DAG.getSetCC(SDLoc(LocReference), N0.getValueType(),
2836 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2837 VT.getSizeInBits() <= 64) {
2838 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2839 APInt ADDC = ADDI->getAPIntValue();
2840 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2841 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2842 // immediate for an add, but it is legal if its top c2 bits are set,
2843 // transform the ADD so the immediate doesn't need to be materialized
2845 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2846 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2847 SRLI->getZExtValue());
2848 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2850 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2853 DAG.getNode(ISD::ADD, DL, VT,
2854 N0.getOperand(0), DAG.getConstant(ADDC, DL, VT));
2855 CombineTo(N0.getNode(), NewAdd);
2856 // Return N so it doesn't get rechecked!
2857 return SDValue(LocReference, 0);
2868 SDValue DAGCombiner::visitAND(SDNode *N) {
2869 SDValue N0 = N->getOperand(0);
2870 SDValue N1 = N->getOperand(1);
2871 EVT VT = N1.getValueType();
2874 if (VT.isVector()) {
2875 if (SDValue FoldedVOp = SimplifyVBinOp(N))
2878 // fold (and x, 0) -> 0, vector edition
2879 if (ISD::isBuildVectorAllZeros(N0.getNode()))
2880 // do not return N0, because undef node may exist in N0
2881 return DAG.getConstant(
2882 APInt::getNullValue(
2883 N0.getValueType().getScalarType().getSizeInBits()),
2884 SDLoc(N), N0.getValueType());
2885 if (ISD::isBuildVectorAllZeros(N1.getNode()))
2886 // do not return N1, because undef node may exist in N1
2887 return DAG.getConstant(
2888 APInt::getNullValue(
2889 N1.getValueType().getScalarType().getSizeInBits()),
2890 SDLoc(N), N1.getValueType());
2892 // fold (and x, -1) -> x, vector edition
2893 if (ISD::isBuildVectorAllOnes(N0.getNode()))
2895 if (ISD::isBuildVectorAllOnes(N1.getNode()))
2899 // fold (and c1, c2) -> c1&c2
2900 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
2901 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2902 if (N0C && N1C && !N1C->isOpaque())
2903 return DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, N0C, N1C);
2904 // canonicalize constant to RHS
2905 if (isConstantIntBuildVectorOrConstantInt(N0) &&
2906 !isConstantIntBuildVectorOrConstantInt(N1))
2907 return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
2908 // fold (and x, -1) -> x
2909 if (isAllOnesConstant(N1))
2911 // if (and x, c) is known to be zero, return 0
2912 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2913 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2914 APInt::getAllOnesValue(BitWidth)))
2915 return DAG.getConstant(0, SDLoc(N), VT);
2917 if (SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1))
2919 // fold (and (or x, C), D) -> D if (C & D) == D
2920 if (N1C && N0.getOpcode() == ISD::OR)
2921 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2922 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2924 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2925 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2926 SDValue N0Op0 = N0.getOperand(0);
2927 APInt Mask = ~N1C->getAPIntValue();
2928 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2929 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2930 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
2931 N0.getValueType(), N0Op0);
2933 // Replace uses of the AND with uses of the Zero extend node.
2936 // We actually want to replace all uses of the any_extend with the
2937 // zero_extend, to avoid duplicating things. This will later cause this
2938 // AND to be folded.
2939 CombineTo(N0.getNode(), Zext);
2940 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2943 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2944 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2945 // already be zero by virtue of the width of the base type of the load.
2947 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2949 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2950 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2951 N0.getOpcode() == ISD::LOAD) {
2952 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2953 N0 : N0.getOperand(0) );
2955 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2956 // This can be a pure constant or a vector splat, in which case we treat the
2957 // vector as a scalar and use the splat value.
2958 APInt Constant = APInt::getNullValue(1);
2959 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2960 Constant = C->getAPIntValue();
2961 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2962 APInt SplatValue, SplatUndef;
2963 unsigned SplatBitSize;
2965 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2966 SplatBitSize, HasAnyUndefs);
2968 // Undef bits can contribute to a possible optimisation if set, so
2970 SplatValue |= SplatUndef;
2972 // The splat value may be something like "0x00FFFFFF", which means 0 for
2973 // the first vector value and FF for the rest, repeating. We need a mask
2974 // that will apply equally to all members of the vector, so AND all the
2975 // lanes of the constant together.
2976 EVT VT = Vector->getValueType(0);
2977 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2979 // If the splat value has been compressed to a bitlength lower
2980 // than the size of the vector lane, we need to re-expand it to
2982 if (BitWidth > SplatBitSize)
2983 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2984 SplatBitSize < BitWidth;
2985 SplatBitSize = SplatBitSize * 2)
2986 SplatValue |= SplatValue.shl(SplatBitSize);
2988 // Make sure that variable 'Constant' is only set if 'SplatBitSize' is a
2989 // multiple of 'BitWidth'. Otherwise, we could propagate a wrong value.
2990 if (SplatBitSize % BitWidth == 0) {
2991 Constant = APInt::getAllOnesValue(BitWidth);
2992 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2993 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2998 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2999 // actually legal and isn't going to get expanded, else this is a false
3001 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
3002 Load->getValueType(0),
3003 Load->getMemoryVT());
3005 // Resize the constant to the same size as the original memory access before
3006 // extension. If it is still the AllOnesValue then this AND is completely
3009 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
3012 switch (Load->getExtensionType()) {
3013 default: B = false; break;
3014 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
3016 case ISD::NON_EXTLOAD: B = true; break;
3019 if (B && Constant.isAllOnesValue()) {
3020 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
3021 // preserve semantics once we get rid of the AND.
3022 SDValue NewLoad(Load, 0);
3023 if (Load->getExtensionType() == ISD::EXTLOAD) {
3024 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
3025 Load->getValueType(0), SDLoc(Load),
3026 Load->getChain(), Load->getBasePtr(),
3027 Load->getOffset(), Load->getMemoryVT(),
3028 Load->getMemOperand());
3029 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
3030 if (Load->getNumValues() == 3) {
3031 // PRE/POST_INC loads have 3 values.
3032 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
3033 NewLoad.getValue(2) };
3034 CombineTo(Load, To, 3, true);
3036 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
3040 // Fold the AND away, taking care not to fold to the old load node if we
3042 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
3044 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3048 // fold (and (load x), 255) -> (zextload x, i8)
3049 // fold (and (extload x, i16), 255) -> (zextload x, i8)
3050 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
3051 if (N1C && (N0.getOpcode() == ISD::LOAD ||
3052 (N0.getOpcode() == ISD::ANY_EXTEND &&
3053 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
3054 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
3055 LoadSDNode *LN0 = HasAnyExt
3056 ? cast<LoadSDNode>(N0.getOperand(0))
3057 : cast<LoadSDNode>(N0);
3058 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
3059 LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
3060 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
3061 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
3062 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
3063 EVT LoadedVT = LN0->getMemoryVT();
3064 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
3066 if (ExtVT == LoadedVT &&
3067 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy,
3071 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
3072 LN0->getChain(), LN0->getBasePtr(), ExtVT,
3073 LN0->getMemOperand());
3075 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
3076 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3079 // Do not change the width of a volatile load.
3080 // Do not generate loads of non-round integer types since these can
3081 // be expensive (and would be wrong if the type is not byte sized).
3082 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
3083 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy,
3085 EVT PtrType = LN0->getOperand(1).getValueType();
3087 unsigned Alignment = LN0->getAlignment();
3088 SDValue NewPtr = LN0->getBasePtr();
3090 // For big endian targets, we need to add an offset to the pointer
3091 // to load the correct bytes. For little endian systems, we merely
3092 // need to read fewer bytes from the same pointer.
3093 if (TLI.isBigEndian()) {
3094 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
3095 unsigned EVTStoreBytes = ExtVT.getStoreSize();
3096 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
3098 NewPtr = DAG.getNode(ISD::ADD, DL, PtrType,
3099 NewPtr, DAG.getConstant(PtrOff, DL, PtrType));
3100 Alignment = MinAlign(Alignment, PtrOff);
3103 AddToWorklist(NewPtr.getNode());
3106 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
3107 LN0->getChain(), NewPtr,
3108 LN0->getPointerInfo(),
3109 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
3110 LN0->isInvariant(), Alignment, LN0->getAAInfo());
3112 CombineTo(LN0, Load, Load.getValue(1));
3113 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3119 if (SDValue Combined = visitANDLike(N0, N1, N))
3122 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
3123 if (N0.getOpcode() == N1.getOpcode()) {
3124 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3125 if (Tmp.getNode()) return Tmp;
3128 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
3129 // fold (and (sra)) -> (and (srl)) when possible.
3130 if (!VT.isVector() &&
3131 SimplifyDemandedBits(SDValue(N, 0)))
3132 return SDValue(N, 0);
3134 // fold (zext_inreg (extload x)) -> (zextload x)
3135 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
3136 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3137 EVT MemVT = LN0->getMemoryVT();
3138 // If we zero all the possible extended bits, then we can turn this into
3139 // a zextload if we are running before legalize or the operation is legal.
3140 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
3141 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
3142 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
3143 ((!LegalOperations && !LN0->isVolatile()) ||
3144 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
3145 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
3146 LN0->getChain(), LN0->getBasePtr(),
3147 MemVT, LN0->getMemOperand());
3149 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3150 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3153 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
3154 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
3156 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3157 EVT MemVT = LN0->getMemoryVT();
3158 // If we zero all the possible extended bits, then we can turn this into
3159 // a zextload if we are running before legalize or the operation is legal.
3160 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
3161 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
3162 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
3163 ((!LegalOperations && !LN0->isVolatile()) ||
3164 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
3165 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
3166 LN0->getChain(), LN0->getBasePtr(),
3167 MemVT, LN0->getMemOperand());
3169 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
3170 return SDValue(N, 0); // Return N so it doesn't get rechecked!
3173 // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
3174 if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
3175 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
3176 N0.getOperand(1), false);
3177 if (BSwap.getNode())
3184 /// Match (a >> 8) | (a << 8) as (bswap a) >> 16.
3185 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
3186 bool DemandHighBits) {
3187 if (!LegalOperations)
3190 EVT VT = N->getValueType(0);
3191 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
3193 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3196 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
3197 bool LookPassAnd0 = false;
3198 bool LookPassAnd1 = false;
3199 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
3201 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
3203 if (N0.getOpcode() == ISD::AND) {
3204 if (!N0.getNode()->hasOneUse())
3206 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3207 if (!N01C || N01C->getZExtValue() != 0xFF00)
3209 N0 = N0.getOperand(0);
3210 LookPassAnd0 = true;
3213 if (N1.getOpcode() == ISD::AND) {
3214 if (!N1.getNode()->hasOneUse())
3216 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3217 if (!N11C || N11C->getZExtValue() != 0xFF)
3219 N1 = N1.getOperand(0);
3220 LookPassAnd1 = true;
3223 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
3225 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
3227 if (!N0.getNode()->hasOneUse() ||
3228 !N1.getNode()->hasOneUse())
3231 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3232 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3235 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
3238 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
3239 SDValue N00 = N0->getOperand(0);
3240 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
3241 if (!N00.getNode()->hasOneUse())
3243 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
3244 if (!N001C || N001C->getZExtValue() != 0xFF)
3246 N00 = N00.getOperand(0);
3247 LookPassAnd0 = true;
3250 SDValue N10 = N1->getOperand(0);
3251 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
3252 if (!N10.getNode()->hasOneUse())
3254 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
3255 if (!N101C || N101C->getZExtValue() != 0xFF00)
3257 N10 = N10.getOperand(0);
3258 LookPassAnd1 = true;
3264 // Make sure everything beyond the low halfword gets set to zero since the SRL
3265 // 16 will clear the top bits.
3266 unsigned OpSizeInBits = VT.getSizeInBits();
3267 if (DemandHighBits && OpSizeInBits > 16) {
3268 // If the left-shift isn't masked out then the only way this is a bswap is
3269 // if all bits beyond the low 8 are 0. In that case the entire pattern
3270 // reduces to a left shift anyway: leave it for other parts of the combiner.
3274 // However, if the right shift isn't masked out then it might be because
3275 // it's not needed. See if we can spot that too.
3276 if (!LookPassAnd1 &&
3277 !DAG.MaskedValueIsZero(
3278 N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
3282 SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
3283 if (OpSizeInBits > 16) {
3285 Res = DAG.getNode(ISD::SRL, DL, VT, Res,
3286 DAG.getConstant(OpSizeInBits - 16, DL,
3287 getShiftAmountTy(VT)));
3292 /// Return true if the specified node is an element that makes up a 32-bit
3293 /// packed halfword byteswap.
3294 /// ((x & 0x000000ff) << 8) |
3295 /// ((x & 0x0000ff00) >> 8) |
3296 /// ((x & 0x00ff0000) << 8) |
3297 /// ((x & 0xff000000) >> 8)
3298 static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) {
3299 if (!N.getNode()->hasOneUse())
3302 unsigned Opc = N.getOpcode();
3303 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
3306 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3311 switch (N1C->getZExtValue()) {
3314 case 0xFF: Num = 0; break;
3315 case 0xFF00: Num = 1; break;
3316 case 0xFF0000: Num = 2; break;
3317 case 0xFF000000: Num = 3; break;
3320 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
3321 SDValue N0 = N.getOperand(0);
3322 if (Opc == ISD::AND) {
3323 if (Num == 0 || Num == 2) {
3325 // (x >> 8) & 0xff0000
3326 if (N0.getOpcode() != ISD::SRL)
3328 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3329 if (!C || C->getZExtValue() != 8)
3332 // (x << 8) & 0xff00
3333 // (x << 8) & 0xff000000
3334 if (N0.getOpcode() != ISD::SHL)
3336 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3337 if (!C || C->getZExtValue() != 8)
3340 } else if (Opc == ISD::SHL) {
3342 // (x & 0xff0000) << 8
3343 if (Num != 0 && Num != 2)
3345 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3346 if (!C || C->getZExtValue() != 8)
3348 } else { // Opc == ISD::SRL
3349 // (x & 0xff00) >> 8
3350 // (x & 0xff000000) >> 8
3351 if (Num != 1 && Num != 3)
3353 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3354 if (!C || C->getZExtValue() != 8)
3361 Parts[Num] = N0.getOperand(0).getNode();
3365 /// Match a 32-bit packed halfword bswap. That is
3366 /// ((x & 0x000000ff) << 8) |
3367 /// ((x & 0x0000ff00) >> 8) |
3368 /// ((x & 0x00ff0000) << 8) |
3369 /// ((x & 0xff000000) >> 8)
3370 /// => (rotl (bswap x), 16)
3371 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
3372 if (!LegalOperations)
3375 EVT VT = N->getValueType(0);
3378 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3382 // (or (or (and), (and)), (or (and), (and)))
3383 // (or (or (or (and), (and)), (and)), (and))
3384 if (N0.getOpcode() != ISD::OR)
3386 SDValue N00 = N0.getOperand(0);
3387 SDValue N01 = N0.getOperand(1);
3388 SDNode *Parts[4] = {};
3390 if (N1.getOpcode() == ISD::OR &&
3391 N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
3392 // (or (or (and), (and)), (or (and), (and)))
3393 SDValue N000 = N00.getOperand(0);
3394 if (!isBSwapHWordElement(N000, Parts))
3397 SDValue N001 = N00.getOperand(1);
3398 if (!isBSwapHWordElement(N001, Parts))
3400 SDValue N010 = N01.getOperand(0);
3401 if (!isBSwapHWordElement(N010, Parts))
3403 SDValue N011 = N01.getOperand(1);
3404 if (!isBSwapHWordElement(N011, Parts))
3407 // (or (or (or (and), (and)), (and)), (and))
3408 if (!isBSwapHWordElement(N1, Parts))
3410 if (!isBSwapHWordElement(N01, Parts))
3412 if (N00.getOpcode() != ISD::OR)
3414 SDValue N000 = N00.getOperand(0);
3415 if (!isBSwapHWordElement(N000, Parts))
3417 SDValue N001 = N00.getOperand(1);
3418 if (!isBSwapHWordElement(N001, Parts))
3422 // Make sure the parts are all coming from the same node.
3423 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3427 SDValue BSwap = DAG.getNode(ISD::BSWAP, DL, VT,
3428 SDValue(Parts[0], 0));
3430 // Result of the bswap should be rotated by 16. If it's not legal, then
3431 // do (x << 16) | (x >> 16).
3432 SDValue ShAmt = DAG.getConstant(16, DL, getShiftAmountTy(VT));
3433 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3434 return DAG.getNode(ISD::ROTL, DL, VT, BSwap, ShAmt);
3435 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3436 return DAG.getNode(ISD::ROTR, DL, VT, BSwap, ShAmt);
3437 return DAG.getNode(ISD::OR, DL, VT,
3438 DAG.getNode(ISD::SHL, DL, VT, BSwap, ShAmt),
3439 DAG.getNode(ISD::SRL, DL, VT, BSwap, ShAmt));
3442 /// This contains all DAGCombine rules which reduce two values combined by
3443 /// an Or operation to a single value \see visitANDLike().
3444 SDValue DAGCombiner::visitORLike(SDValue N0, SDValue N1, SDNode *LocReference) {
3445 EVT VT = N1.getValueType();
3446 // fold (or x, undef) -> -1
3447 if (!LegalOperations &&
3448 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3449 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3450 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()),
3451 SDLoc(LocReference), VT);
3453 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3454 SDValue LL, LR, RL, RR, CC0, CC1;
3455 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3456 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3457 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3459 if (LR == RR && Op0 == Op1 && LL.getValueType().isInteger()) {
3460 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3461 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3462 if (isNullConstant(LR) && (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3463 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(LR),
3464 LR.getValueType(), LL, RL);
3465 AddToWorklist(ORNode.getNode());
3466 return DAG.getSetCC(SDLoc(LocReference), VT, ORNode, LR, Op1);
3468 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3469 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3470 if (isAllOnesConstant(LR) && (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3471 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(LR),
3472 LR.getValueType(), LL, RL);
3473 AddToWorklist(ANDNode.getNode());
3474 return DAG.getSetCC(SDLoc(LocReference), VT, ANDNode, LR, Op1);
3477 // canonicalize equivalent to ll == rl
3478 if (LL == RR && LR == RL) {
3479 Op1 = ISD::getSetCCSwappedOperands(Op1);
3482 if (LL == RL && LR == RR) {
3483 bool isInteger = LL.getValueType().isInteger();
3484 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3485 if (Result != ISD::SETCC_INVALID &&
3486 (!LegalOperations ||
3487 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
3488 TLI.isOperationLegal(ISD::SETCC,
3489 getSetCCResultType(N0.getValueType())))))
3490 return DAG.getSetCC(SDLoc(LocReference), N0.getValueType(),
3495 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3496 if (N0.getOpcode() == ISD::AND && N1.getOpcode() == ISD::AND &&
3497 // Don't increase # computations.
3498 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3499 // We can only do this xform if we know that bits from X that are set in C2
3500 // but not in C1 are already zero. Likewise for Y.
3501 if (const ConstantSDNode *N0O1C =
3502 getAsNonOpaqueConstant(N0.getOperand(1))) {
3503 if (const ConstantSDNode *N1O1C =
3504 getAsNonOpaqueConstant(N1.getOperand(1))) {
3505 // We can only do this xform if we know that bits from X that are set in
3506 // C2 but not in C1 are already zero. Likewise for Y.
3507 const APInt &LHSMask = N0O1C->getAPIntValue();
3508 const APInt &RHSMask = N1O1C->getAPIntValue();
3510 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3511 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3512 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3513 N0.getOperand(0), N1.getOperand(0));
3514 SDLoc DL(LocReference);
3515 return DAG.getNode(ISD::AND, DL, VT, X,
3516 DAG.getConstant(LHSMask | RHSMask, DL, VT));
3522 // (or (and X, M), (and X, N)) -> (and X, (or M, N))
3523 if (N0.getOpcode() == ISD::AND &&
3524 N1.getOpcode() == ISD::AND &&
3525 N0.getOperand(0) == N1.getOperand(0) &&
3526 // Don't increase # computations.
3527 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3528 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3529 N0.getOperand(1), N1.getOperand(1));
3530 return DAG.getNode(ISD::AND, SDLoc(LocReference), VT, N0.getOperand(0), X);
3536 SDValue DAGCombiner::visitOR(SDNode *N) {
3537 SDValue N0 = N->getOperand(0);
3538 SDValue N1 = N->getOperand(1);
3539 EVT VT = N1.getValueType();
3542 if (VT.isVector()) {
3543 if (SDValue FoldedVOp = SimplifyVBinOp(N))
3546 // fold (or x, 0) -> x, vector edition
3547 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3549 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3552 // fold (or x, -1) -> -1, vector edition
3553 if (ISD::isBuildVectorAllOnes(N0.getNode()))
3554 // do not return N0, because undef node may exist in N0
3555 return DAG.getConstant(
3556 APInt::getAllOnesValue(
3557 N0.getValueType().getScalarType().getSizeInBits()),
3558 SDLoc(N), N0.getValueType());
3559 if (ISD::isBuildVectorAllOnes(N1.getNode()))
3560 // do not return N1, because undef node may exist in N1
3561 return DAG.getConstant(
3562 APInt::getAllOnesValue(
3563 N1.getValueType().getScalarType().getSizeInBits()),
3564 SDLoc(N), N1.getValueType());
3566 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf A, B, Mask1)
3567 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf B, A, Mask2)
3568 // Do this only if the resulting shuffle is legal.
3569 if (isa<ShuffleVectorSDNode>(N0) &&
3570 isa<ShuffleVectorSDNode>(N1) &&
3571 // Avoid folding a node with illegal type.
3572 TLI.isTypeLegal(VT) &&
3573 N0->getOperand(1) == N1->getOperand(1) &&
3574 ISD::isBuildVectorAllZeros(N0.getOperand(1).getNode())) {
3575 bool CanFold = true;
3576 unsigned NumElts = VT.getVectorNumElements();
3577 const ShuffleVectorSDNode *SV0 = cast<ShuffleVectorSDNode>(N0);
3578 const ShuffleVectorSDNode *SV1 = cast<ShuffleVectorSDNode>(N1);
3579 // We construct two shuffle masks:
3580 // - Mask1 is a shuffle mask for a shuffle with N0 as the first operand
3581 // and N1 as the second operand.
3582 // - Mask2 is a shuffle mask for a shuffle with N1 as the first operand
3583 // and N0 as the second operand.
3584 // We do this because OR is commutable and therefore there might be
3585 // two ways to fold this node into a shuffle.
3586 SmallVector<int,4> Mask1;
3587 SmallVector<int,4> Mask2;
3589 for (unsigned i = 0; i != NumElts && CanFold; ++i) {
3590 int M0 = SV0->getMaskElt(i);
3591 int M1 = SV1->getMaskElt(i);
3593 // Both shuffle indexes are undef. Propagate Undef.
3594 if (M0 < 0 && M1 < 0) {
3595 Mask1.push_back(M0);
3596 Mask2.push_back(M0);
3600 if (M0 < 0 || M1 < 0 ||
3601 (M0 < (int)NumElts && M1 < (int)NumElts) ||
3602 (M0 >= (int)NumElts && M1 >= (int)NumElts)) {
3607 Mask1.push_back(M0 < (int)NumElts ? M0 : M1 + NumElts);
3608 Mask2.push_back(M1 < (int)NumElts ? M1 : M0 + NumElts);
3612 // Fold this sequence only if the resulting shuffle is 'legal'.
3613 if (TLI.isShuffleMaskLegal(Mask1, VT))
3614 return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(0),
3615 N1->getOperand(0), &Mask1[0]);
3616 if (TLI.isShuffleMaskLegal(Mask2, VT))
3617 return DAG.getVectorShuffle(VT, SDLoc(N), N1->getOperand(0),
3618 N0->getOperand(0), &Mask2[0]);
3623 // fold (or c1, c2) -> c1|c2
3624 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
3625 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3626 if (N0C && N1C && !N1C->isOpaque())
3627 return DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N), VT, N0C, N1C);
3628 // canonicalize constant to RHS
3629 if (isConstantIntBuildVectorOrConstantInt(N0) &&
3630 !isConstantIntBuildVectorOrConstantInt(N1))
3631 return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
3632 // fold (or x, 0) -> x
3633 if (isNullConstant(N1))
3635 // fold (or x, -1) -> -1
3636 if (isAllOnesConstant(N1))
3638 // fold (or x, c) -> c iff (x & ~c) == 0
3639 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3642 if (SDValue Combined = visitORLike(N0, N1, N))
3645 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3646 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3647 if (BSwap.getNode())
3649 BSwap = MatchBSwapHWordLow(N, N0, N1);
3650 if (BSwap.getNode())
3654 if (SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1))
3656 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3657 // iff (c1 & c2) == 0.
3658 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3659 isa<ConstantSDNode>(N0.getOperand(1))) {
3660 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3661 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0) {
3662 if (SDValue COR = DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N1), VT,
3665 ISD::AND, SDLoc(N), VT,
3666 DAG.getNode(ISD::OR, SDLoc(N0), VT, N0.getOperand(0), N1), COR);
3670 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3671 if (N0.getOpcode() == N1.getOpcode()) {
3672 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3673 if (Tmp.getNode()) return Tmp;
3676 // See if this is some rotate idiom.
3677 if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
3678 return SDValue(Rot, 0);
3680 // Simplify the operands using demanded-bits information.
3681 if (!VT.isVector() &&
3682 SimplifyDemandedBits(SDValue(N, 0)))
3683 return SDValue(N, 0);
3688 /// Match "(X shl/srl V1) & V2" where V2 may not be present.
3689 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3690 if (Op.getOpcode() == ISD::AND) {
3691 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3692 Mask = Op.getOperand(1);
3693 Op = Op.getOperand(0);
3699 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3707 // Return true if we can prove that, whenever Neg and Pos are both in the
3708 // range [0, OpSize), Neg == (Pos == 0 ? 0 : OpSize - Pos). This means that
3709 // for two opposing shifts shift1 and shift2 and a value X with OpBits bits:
3711 // (or (shift1 X, Neg), (shift2 X, Pos))
3713 // reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate
3714 // in direction shift1 by Neg. The range [0, OpSize) means that we only need
3715 // to consider shift amounts with defined behavior.
3716 static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned OpSize) {
3717 // If OpSize is a power of 2 then:
3719 // (a) (Pos == 0 ? 0 : OpSize - Pos) == (OpSize - Pos) & (OpSize - 1)
3720 // (b) Neg == Neg & (OpSize - 1) whenever Neg is in [0, OpSize).
3722 // So if OpSize is a power of 2 and Neg is (and Neg', OpSize-1), we check
3723 // for the stronger condition:
3725 // Neg & (OpSize - 1) == (OpSize - Pos) & (OpSize - 1) [A]
3727 // for all Neg and Pos. Since Neg & (OpSize - 1) == Neg' & (OpSize - 1)
3728 // we can just replace Neg with Neg' for the rest of the function.
3730 // In other cases we check for the even stronger condition:
3732 // Neg == OpSize - Pos [B]
3734 // for all Neg and Pos. Note that the (or ...) then invokes undefined
3735 // behavior if Pos == 0 (and consequently Neg == OpSize).
3737 // We could actually use [A] whenever OpSize is a power of 2, but the
3738 // only extra cases that it would match are those uninteresting ones
3739 // where Neg and Pos are never in range at the same time. E.g. for
3740 // OpSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
3741 // as well as (sub 32, Pos), but:
3743 // (or (shift1 X, (sub 64, Pos)), (shift2 X, Pos))
3745 // always invokes undefined behavior for 32-bit X.
3747 // Below, Mask == OpSize - 1 when using [A] and is all-ones otherwise.
3748 unsigned MaskLoBits = 0;
3749 if (Neg.getOpcode() == ISD::AND &&
3750 isPowerOf2_64(OpSize) &&
3751 Neg.getOperand(1).getOpcode() == ISD::Constant &&
3752 cast<ConstantSDNode>(Neg.getOperand(1))->getAPIntValue() == OpSize - 1) {
3753 Neg = Neg.getOperand(0);
3754 MaskLoBits = Log2_64(OpSize);
3757 // Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
3758 if (Neg.getOpcode() != ISD::SUB)
3760 ConstantSDNode *NegC = dyn_cast<ConstantSDNode>(Neg.getOperand(0));
3763 SDValue NegOp1 = Neg.getOperand(1);
3765 // On the RHS of [A], if Pos is Pos' & (OpSize - 1), just replace Pos with
3766 // Pos'. The truncation is redundant for the purpose of the equality.
3768 Pos.getOpcode() == ISD::AND &&
3769 Pos.getOperand(1).getOpcode() == ISD::Constant &&
3770 cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() == OpSize - 1)
3771 Pos = Pos.getOperand(0);
3773 // The condition we need is now:
3775 // (NegC - NegOp1) & Mask == (OpSize - Pos) & Mask
3777 // If NegOp1 == Pos then we need:
3779 // OpSize & Mask == NegC & Mask
3781 // (because "x & Mask" is a truncation and distributes through subtraction).
3784 Width = NegC->getAPIntValue();
3785 // Check for cases where Pos has the form (add NegOp1, PosC) for some PosC.
3786 // Then the condition we want to prove becomes:
3788 // (NegC - NegOp1) & Mask == (OpSize - (NegOp1 + PosC)) & Mask
3790 // which, again because "x & Mask" is a truncation, becomes:
3792 // NegC & Mask == (OpSize - PosC) & Mask
3793 // OpSize & Mask == (NegC + PosC) & Mask
3794 else if (Pos.getOpcode() == ISD::ADD &&
3795 Pos.getOperand(0) == NegOp1 &&
3796 Pos.getOperand(1).getOpcode() == ISD::Constant)
3797 Width = (cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() +
3798 NegC->getAPIntValue());
3802 // Now we just need to check that OpSize & Mask == Width & Mask.
3804 // Opsize & Mask is 0 since Mask is Opsize - 1.
3805 return Width.getLoBits(MaskLoBits) == 0;
3806 return Width == OpSize;
3809 // A subroutine of MatchRotate used once we have found an OR of two opposite
3810 // shifts of Shifted. If Neg == <operand size> - Pos then the OR reduces
3811 // to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
3812 // former being preferred if supported. InnerPos and InnerNeg are Pos and
3813 // Neg with outer conversions stripped away.
3814 SDNode *DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
3815 SDValue Neg, SDValue InnerPos,
3816 SDValue InnerNeg, unsigned PosOpcode,
3817 unsigned NegOpcode, SDLoc DL) {
3818 // fold (or (shl x, (*ext y)),
3819 // (srl x, (*ext (sub 32, y)))) ->
3820 // (rotl x, y) or (rotr x, (sub 32, y))
3822 // fold (or (shl x, (*ext (sub 32, y))),
3823 // (srl x, (*ext y))) ->
3824 // (rotr x, y) or (rotl x, (sub 32, y))
3825 EVT VT = Shifted.getValueType();
3826 if (matchRotateSub(InnerPos, InnerNeg, VT.getSizeInBits())) {
3827 bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
3828 return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
3829 HasPos ? Pos : Neg).getNode();
3835 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3836 // idioms for rotate, and if the target supports rotation instructions, generate
3838 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL) {
3839 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3840 EVT VT = LHS.getValueType();
3841 if (!TLI.isTypeLegal(VT)) return nullptr;
3843 // The target must have at least one rotate flavor.
3844 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3845 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3846 if (!HasROTL && !HasROTR) return nullptr;
3848 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3849 SDValue LHSShift; // The shift.
3850 SDValue LHSMask; // AND value if any.
3851 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3852 return nullptr; // Not part of a rotate.
3854 SDValue RHSShift; // The shift.
3855 SDValue RHSMask; // AND value if any.
3856 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3857 return nullptr; // Not part of a rotate.
3859 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3860 return nullptr; // Not shifting the same value.
3862 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3863 return nullptr; // Shifts must disagree.
3865 // Canonicalize shl to left side in a shl/srl pair.
3866 if (RHSShift.getOpcode() == ISD::SHL) {
3867 std::swap(LHS, RHS);
3868 std::swap(LHSShift, RHSShift);
3869 std::swap(LHSMask , RHSMask );
3872 unsigned OpSizeInBits = VT.getSizeInBits();
3873 SDValue LHSShiftArg = LHSShift.getOperand(0);
3874 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3875 SDValue RHSShiftArg = RHSShift.getOperand(0);
3876 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3878 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3879 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3880 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3881 RHSShiftAmt.getOpcode() == ISD::Constant) {
3882 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3883 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3884 if ((LShVal + RShVal) != OpSizeInBits)
3887 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3888 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3890 // If there is an AND of either shifted operand, apply it to the result.
3891 if (LHSMask.getNode() || RHSMask.getNode()) {
3892 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3894 if (LHSMask.getNode()) {
3895 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3896 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3898 if (RHSMask.getNode()) {
3899 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3900 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3903 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, DL, VT));
3906 return Rot.getNode();
3909 // If there is a mask here, and we have a variable shift, we can't be sure
3910 // that we're masking out the right stuff.
3911 if (LHSMask.getNode() || RHSMask.getNode())
3914 // If the shift amount is sign/zext/any-extended just peel it off.
3915 SDValue LExtOp0 = LHSShiftAmt;
3916 SDValue RExtOp0 = RHSShiftAmt;
3917 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3918 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3919 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3920 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3921 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3922 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3923 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3924 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3925 LExtOp0 = LHSShiftAmt.getOperand(0);
3926 RExtOp0 = RHSShiftAmt.getOperand(0);
3929 SDNode *TryL = MatchRotatePosNeg(LHSShiftArg, LHSShiftAmt, RHSShiftAmt,
3930 LExtOp0, RExtOp0, ISD::ROTL, ISD::ROTR, DL);
3934 SDNode *TryR = MatchRotatePosNeg(RHSShiftArg, RHSShiftAmt, LHSShiftAmt,
3935 RExtOp0, LExtOp0, ISD::ROTR, ISD::ROTL, DL);
3942 SDValue DAGCombiner::visitXOR(SDNode *N) {
3943 SDValue N0 = N->getOperand(0);
3944 SDValue N1 = N->getOperand(1);
3945 EVT VT = N0.getValueType();
3948 if (VT.isVector()) {
3949 if (SDValue FoldedVOp = SimplifyVBinOp(N))
3952 // fold (xor x, 0) -> x, vector edition
3953 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3955 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3959 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3960 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3961 return DAG.getConstant(0, SDLoc(N), VT);
3962 // fold (xor x, undef) -> undef
3963 if (N0.getOpcode() == ISD::UNDEF)
3965 if (N1.getOpcode() == ISD::UNDEF)
3967 // fold (xor c1, c2) -> c1^c2
3968 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
3969 ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
3971 return DAG.FoldConstantArithmetic(ISD::XOR, SDLoc(N), VT, N0C, N1C);
3972 // canonicalize constant to RHS
3973 if (isConstantIntBuildVectorOrConstantInt(N0) &&
3974 !isConstantIntBuildVectorOrConstantInt(N1))
3975 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
3976 // fold (xor x, 0) -> x
3977 if (isNullConstant(N1))
3980 if (SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1))
3983 // fold !(x cc y) -> (x !cc y)
3984 SDValue LHS, RHS, CC;
3985 if (TLI.isConstTrueVal(N1.getNode()) && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3986 bool isInt = LHS.getValueType().isInteger();
3987 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3990 if (!LegalOperations ||
3991 TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
3992 switch (N0.getOpcode()) {
3994 llvm_unreachable("Unhandled SetCC Equivalent!");
3996 return DAG.getSetCC(SDLoc(N), VT, LHS, RHS, NotCC);
3997 case ISD::SELECT_CC:
3998 return DAG.getSelectCC(SDLoc(N), LHS, RHS, N0.getOperand(2),
3999 N0.getOperand(3), NotCC);
4004 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
4005 if (isOneConstant(N1) && N0.getOpcode() == ISD::ZERO_EXTEND &&
4006 N0.getNode()->hasOneUse() &&
4007 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
4008 SDValue V = N0.getOperand(0);
4010 V = DAG.getNode(ISD::XOR, DL, V.getValueType(), V,
4011 DAG.getConstant(1, DL, V.getValueType()));
4012 AddToWorklist(V.getNode());
4013 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
4016 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
4017 if (isOneConstant(N1) && VT == MVT::i1 &&
4018 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
4019 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4020 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
4021 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
4022 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
4023 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
4024 AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
4025 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
4028 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
4029 if (isAllOnesConstant(N1) &&
4030 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
4031 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4032 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
4033 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
4034 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
4035 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
4036 AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
4037 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
4040 // fold (xor (and x, y), y) -> (and (not x), y)
4041 if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
4042 N0->getOperand(1) == N1) {
4043 SDValue X = N0->getOperand(0);
4044 SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
4045 AddToWorklist(NotX.getNode());
4046 return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
4048 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
4049 if (N1C && N0.getOpcode() == ISD::XOR) {
4050 if (const ConstantSDNode *N00C = getAsNonOpaqueConstant(N0.getOperand(0))) {
4052 return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(1),
4053 DAG.getConstant(N1C->getAPIntValue() ^
4054 N00C->getAPIntValue(), DL, VT));
4056 if (const ConstantSDNode *N01C = getAsNonOpaqueConstant(N0.getOperand(1))) {
4058 return DAG.getNode(ISD::XOR, DL, VT, N0.getOperand(0),
4059 DAG.getConstant(N1C->getAPIntValue() ^
4060 N01C->getAPIntValue(), DL, VT));
4063 // fold (xor x, x) -> 0
4065 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
4067 // fold (xor (shl 1, x), -1) -> (rotl ~1, x)
4068 // Here is a concrete example of this equivalence:
4070 // i16 shl == 1 << 14 == 16384 == 0b0100000000000000
4071 // i16 xor == ~(1 << 14) == 49151 == 0b1011111111111111
4075 // i16 ~1 == 0b1111111111111110
4076 // i16 rol(~1, 14) == 0b1011111111111111
4078 // Some additional tips to help conceptualize this transform:
4079 // - Try to see the operation as placing a single zero in a value of all ones.
4080 // - There exists no value for x which would allow the result to contain zero.
4081 // - Values of x larger than the bitwidth are undefined and do not require a
4082 // consistent result.
4083 // - Pushing the zero left requires shifting one bits in from the right.
4084 // A rotate left of ~1 is a nice way of achieving the desired result.
4085 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT) && N0.getOpcode() == ISD::SHL
4086 && isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0))) {
4088 return DAG.getNode(ISD::ROTL, DL, VT, DAG.getConstant(~1, DL, VT),
4092 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
4093 if (N0.getOpcode() == N1.getOpcode()) {
4094 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
4095 if (Tmp.getNode()) return Tmp;
4098 // Simplify the expression using non-local knowledge.
4099 if (!VT.isVector() &&
4100 SimplifyDemandedBits(SDValue(N, 0)))
4101 return SDValue(N, 0);
4106 /// Handle transforms common to the three shifts, when the shift amount is a
4108 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, ConstantSDNode *Amt) {
4109 SDNode *LHS = N->getOperand(0).getNode();
4110 if (!LHS->hasOneUse()) return SDValue();
4112 // We want to pull some binops through shifts, so that we have (and (shift))
4113 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
4114 // thing happens with address calculations, so it's important to canonicalize
4116 bool HighBitSet = false; // Can we transform this if the high bit is set?
4118 switch (LHS->getOpcode()) {
4119 default: return SDValue();
4122 HighBitSet = false; // We can only transform sra if the high bit is clear.
4125 HighBitSet = true; // We can only transform sra if the high bit is set.
4128 if (N->getOpcode() != ISD::SHL)
4129 return SDValue(); // only shl(add) not sr[al](add).
4130 HighBitSet = false; // We can only transform sra if the high bit is clear.
4134 // We require the RHS of the binop to be a constant and not opaque as well.
4135 ConstantSDNode *BinOpCst = getAsNonOpaqueConstant(LHS->getOperand(1));
4136 if (!BinOpCst) return SDValue();
4138 // FIXME: disable this unless the input to the binop is a shift by a constant.
4139 // If it is not a shift, it pessimizes some common cases like:
4141 // void foo(int *X, int i) { X[i & 1235] = 1; }
4142 // int bar(int *X, int i) { return X[i & 255]; }
4143 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
4144 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
4145 BinOpLHSVal->getOpcode() != ISD::SRA &&
4146 BinOpLHSVal->getOpcode() != ISD::SRL) ||
4147 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
4150 EVT VT = N->getValueType(0);
4152 // If this is a signed shift right, and the high bit is modified by the
4153 // logical operation, do not perform the transformation. The highBitSet
4154 // boolean indicates the value of the high bit of the constant which would
4155 // cause it to be modified for this operation.
4156 if (N->getOpcode() == ISD::SRA) {
4157 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
4158 if (BinOpRHSSignSet != HighBitSet)
4162 if (!TLI.isDesirableToCommuteWithShift(LHS))
4165 // Fold the constants, shifting the binop RHS by the shift amount.
4166 SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
4168 LHS->getOperand(1), N->getOperand(1));
4169 assert(isa<ConstantSDNode>(NewRHS) && "Folding was not successful!");
4171 // Create the new shift.
4172 SDValue NewShift = DAG.getNode(N->getOpcode(),
4173 SDLoc(LHS->getOperand(0)),
4174 VT, LHS->getOperand(0), N->getOperand(1));
4176 // Create the new binop.
4177 return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
4180 SDValue DAGCombiner::distributeTruncateThroughAnd(SDNode *N) {
4181 assert(N->getOpcode() == ISD::TRUNCATE);
4182 assert(N->getOperand(0).getOpcode() == ISD::AND);
4184 // (truncate:TruncVT (and N00, N01C)) -> (and (truncate:TruncVT N00), TruncC)
4185 if (N->hasOneUse() && N->getOperand(0).hasOneUse()) {
4186 SDValue N01 = N->getOperand(0).getOperand(1);
4188 if (ConstantSDNode *N01C = isConstOrConstSplat(N01)) {
4189 if (!N01C->isOpaque()) {
4190 EVT TruncVT = N->getValueType(0);
4191 SDValue N00 = N->getOperand(0).getOperand(0);
4192 APInt TruncC = N01C->getAPIntValue();
4193 TruncC = TruncC.trunc(TruncVT.getScalarSizeInBits());
4196 return DAG.getNode(ISD::AND, DL, TruncVT,
4197 DAG.getNode(ISD::TRUNCATE, DL, TruncVT, N00),
4198 DAG.getConstant(TruncC, DL, TruncVT));
4206 SDValue DAGCombiner::visitRotate(SDNode *N) {
4207 // fold (rot* x, (trunc (and y, c))) -> (rot* x, (and (trunc y), (trunc c))).
4208 if (N->getOperand(1).getOpcode() == ISD::TRUNCATE &&
4209 N->getOperand(1).getOperand(0).getOpcode() == ISD::AND) {
4210 SDValue NewOp1 = distributeTruncateThroughAnd(N->getOperand(1).getNode());
4211 if (NewOp1.getNode())
4212 return DAG.getNode(N->getOpcode(), SDLoc(N), N->getValueType(0),
4213 N->getOperand(0), NewOp1);
4218 SDValue DAGCombiner::visitSHL(SDNode *N) {
4219 SDValue N0 = N->getOperand(0);
4220 SDValue N1 = N->getOperand(1);
4221 EVT VT = N0.getValueType();
4222 unsigned OpSizeInBits = VT.getScalarSizeInBits();
4225 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4226 if (VT.isVector()) {
4227 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4230 BuildVectorSDNode *N1CV = dyn_cast<BuildVectorSDNode>(N1);
4231 // If setcc produces all-one true value then:
4232 // (shl (and (setcc) N01CV) N1CV) -> (and (setcc) N01CV<<N1CV)
4233 if (N1CV && N1CV->isConstant()) {
4234 if (N0.getOpcode() == ISD::AND) {
4235 SDValue N00 = N0->getOperand(0);
4236 SDValue N01 = N0->getOperand(1);
4237 BuildVectorSDNode *N01CV = dyn_cast<BuildVectorSDNode>(N01);
4239 if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC &&
4240 TLI.getBooleanContents(N00.getOperand(0).getValueType()) ==
4241 TargetLowering::ZeroOrNegativeOneBooleanContent) {
4242 if (SDValue C = DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT,
4244 return DAG.getNode(ISD::AND, SDLoc(N), VT, N00, C);
4247 N1C = isConstOrConstSplat(N1);
4252 // fold (shl c1, c2) -> c1<<c2
4253 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4254 if (N0C && N1C && !N1C->isOpaque())
4255 return DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT, N0C, N1C);
4256 // fold (shl 0, x) -> 0
4257 if (isNullConstant(N0))
4259 // fold (shl x, c >= size(x)) -> undef
4260 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4261 return DAG.getUNDEF(VT);
4262 // fold (shl x, 0) -> x
4263 if (N1C && N1C->isNullValue())
4265 // fold (shl undef, x) -> 0
4266 if (N0.getOpcode() == ISD::UNDEF)
4267 return DAG.getConstant(0, SDLoc(N), VT);
4268 // if (shl x, c) is known to be zero, return 0
4269 if (DAG.MaskedValueIsZero(SDValue(N, 0),
4270 APInt::getAllOnesValue(OpSizeInBits)))
4271 return DAG.getConstant(0, SDLoc(N), VT);
4272 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
4273 if (N1.getOpcode() == ISD::TRUNCATE &&
4274 N1.getOperand(0).getOpcode() == ISD::AND) {
4275 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4276 if (NewOp1.getNode())
4277 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0, NewOp1);
4280 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4281 return SDValue(N, 0);
4283 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
4284 if (N1C && N0.getOpcode() == ISD::SHL) {
4285 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4286 uint64_t c1 = N0C1->getZExtValue();
4287 uint64_t c2 = N1C->getZExtValue();
4289 if (c1 + c2 >= OpSizeInBits)
4290 return DAG.getConstant(0, DL, VT);
4291 return DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
4292 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4296 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
4297 // For this to be valid, the second form must not preserve any of the bits
4298 // that are shifted out by the inner shift in the first form. This means
4299 // the outer shift size must be >= the number of bits added by the ext.
4300 // As a corollary, we don't care what kind of ext it is.
4301 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
4302 N0.getOpcode() == ISD::ANY_EXTEND ||
4303 N0.getOpcode() == ISD::SIGN_EXTEND) &&
4304 N0.getOperand(0).getOpcode() == ISD::SHL) {
4305 SDValue N0Op0 = N0.getOperand(0);
4306 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4307 uint64_t c1 = N0Op0C1->getZExtValue();
4308 uint64_t c2 = N1C->getZExtValue();
4309 EVT InnerShiftVT = N0Op0.getValueType();
4310 uint64_t InnerShiftSize = InnerShiftVT.getScalarSizeInBits();
4311 if (c2 >= OpSizeInBits - InnerShiftSize) {
4313 if (c1 + c2 >= OpSizeInBits)
4314 return DAG.getConstant(0, DL, VT);
4315 return DAG.getNode(ISD::SHL, DL, VT,
4316 DAG.getNode(N0.getOpcode(), DL, VT,
4317 N0Op0->getOperand(0)),
4318 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4323 // fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C))
4324 // Only fold this if the inner zext has no other uses to avoid increasing
4325 // the total number of instructions.
4326 if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() &&
4327 N0.getOperand(0).getOpcode() == ISD::SRL) {
4328 SDValue N0Op0 = N0.getOperand(0);
4329 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4330 uint64_t c1 = N0Op0C1->getZExtValue();
4331 if (c1 < VT.getScalarSizeInBits()) {
4332 uint64_t c2 = N1C->getZExtValue();
4334 SDValue NewOp0 = N0.getOperand(0);
4335 EVT CountVT = NewOp0.getOperand(1).getValueType();
4337 SDValue NewSHL = DAG.getNode(ISD::SHL, DL, NewOp0.getValueType(),
4339 DAG.getConstant(c2, DL, CountVT));
4340 AddToWorklist(NewSHL.getNode());
4341 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL);
4347 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
4348 // (and (srl x, (sub c1, c2), MASK)
4349 // Only fold this if the inner shift has no other uses -- if it does, folding
4350 // this will increase the total number of instructions.
4351 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
4352 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4353 uint64_t c1 = N0C1->getZExtValue();
4354 if (c1 < OpSizeInBits) {
4355 uint64_t c2 = N1C->getZExtValue();
4356 APInt Mask = APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - c1);
4359 Mask = Mask.shl(c2 - c1);
4361 Shift = DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
4362 DAG.getConstant(c2 - c1, DL, N1.getValueType()));
4364 Mask = Mask.lshr(c1 - c2);
4366 Shift = DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0),
4367 DAG.getConstant(c1 - c2, DL, N1.getValueType()));
4370 return DAG.getNode(ISD::AND, DL, VT, Shift,
4371 DAG.getConstant(Mask, DL, VT));
4375 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
4376 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
4377 unsigned BitSize = VT.getScalarSizeInBits();
4379 SDValue HiBitsMask =
4380 DAG.getConstant(APInt::getHighBitsSet(BitSize,
4381 BitSize - N1C->getZExtValue()),
4383 return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0),
4387 // fold (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
4388 // Variant of version done on multiply, except mul by a power of 2 is turned
4391 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
4392 (isa<ConstantSDNode>(N0.getOperand(1)) ||
4393 isConstantSplatVector(N0.getOperand(1).getNode(), Val))) {
4394 SDValue Shl0 = DAG.getNode(ISD::SHL, SDLoc(N0), VT, N0.getOperand(0), N1);
4395 SDValue Shl1 = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
4396 return DAG.getNode(ISD::ADD, SDLoc(N), VT, Shl0, Shl1);
4399 if (N1C && !N1C->isOpaque()) {
4400 SDValue NewSHL = visitShiftByConstant(N, N1C);
4401 if (NewSHL.getNode())
4408 SDValue DAGCombiner::visitSRA(SDNode *N) {
4409 SDValue N0 = N->getOperand(0);
4410 SDValue N1 = N->getOperand(1);
4411 EVT VT = N0.getValueType();
4412 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4415 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4416 if (VT.isVector()) {
4417 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4420 N1C = isConstOrConstSplat(N1);
4423 // fold (sra c1, c2) -> (sra c1, c2)
4424 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4425 if (N0C && N1C && !N1C->isOpaque())
4426 return DAG.FoldConstantArithmetic(ISD::SRA, SDLoc(N), VT, N0C, N1C);
4427 // fold (sra 0, x) -> 0
4428 if (isNullConstant(N0))
4430 // fold (sra -1, x) -> -1
4431 if (isAllOnesConstant(N0))
4433 // fold (sra x, (setge c, size(x))) -> undef
4434 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4435 return DAG.getUNDEF(VT);
4436 // fold (sra x, 0) -> x
4437 if (N1C && N1C->isNullValue())
4439 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
4441 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
4442 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
4443 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
4445 ExtVT = EVT::getVectorVT(*DAG.getContext(),
4446 ExtVT, VT.getVectorNumElements());
4447 if ((!LegalOperations ||
4448 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
4449 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
4450 N0.getOperand(0), DAG.getValueType(ExtVT));
4453 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
4454 if (N1C && N0.getOpcode() == ISD::SRA) {
4455 if (ConstantSDNode *C1 = isConstOrConstSplat(N0.getOperand(1))) {
4456 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
4457 if (Sum >= OpSizeInBits)
4458 Sum = OpSizeInBits - 1;
4460 return DAG.getNode(ISD::SRA, DL, VT, N0.getOperand(0),
4461 DAG.getConstant(Sum, DL, N1.getValueType()));
4465 // fold (sra (shl X, m), (sub result_size, n))
4466 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
4467 // result_size - n != m.
4468 // If truncate is free for the target sext(shl) is likely to result in better
4470 if (N0.getOpcode() == ISD::SHL && N1C) {
4471 // Get the two constanst of the shifts, CN0 = m, CN = n.
4472 const ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1));
4474 LLVMContext &Ctx = *DAG.getContext();
4475 // Determine what the truncate's result bitsize and type would be.
4476 EVT TruncVT = EVT::getIntegerVT(Ctx, OpSizeInBits - N1C->getZExtValue());
4479 TruncVT = EVT::getVectorVT(Ctx, TruncVT, VT.getVectorNumElements());
4481 // Determine the residual right-shift amount.
4482 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
4484 // If the shift is not a no-op (in which case this should be just a sign
4485 // extend already), the truncated to type is legal, sign_extend is legal
4486 // on that type, and the truncate to that type is both legal and free,
4487 // perform the transform.
4488 if ((ShiftAmt > 0) &&
4489 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
4490 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
4491 TLI.isTruncateFree(VT, TruncVT)) {
4494 SDValue Amt = DAG.getConstant(ShiftAmt, DL,
4495 getShiftAmountTy(N0.getOperand(0).getValueType()));
4496 SDValue Shift = DAG.getNode(ISD::SRL, DL, VT,
4497 N0.getOperand(0), Amt);
4498 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT,
4500 return DAG.getNode(ISD::SIGN_EXTEND, DL,
4501 N->getValueType(0), Trunc);
4506 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
4507 if (N1.getOpcode() == ISD::TRUNCATE &&
4508 N1.getOperand(0).getOpcode() == ISD::AND) {
4509 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4510 if (NewOp1.getNode())
4511 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0, NewOp1);
4514 // fold (sra (trunc (srl x, c1)), c2) -> (trunc (sra x, c1 + c2))
4515 // if c1 is equal to the number of bits the trunc removes
4516 if (N0.getOpcode() == ISD::TRUNCATE &&
4517 (N0.getOperand(0).getOpcode() == ISD::SRL ||
4518 N0.getOperand(0).getOpcode() == ISD::SRA) &&
4519 N0.getOperand(0).hasOneUse() &&
4520 N0.getOperand(0).getOperand(1).hasOneUse() &&
4522 SDValue N0Op0 = N0.getOperand(0);
4523 if (ConstantSDNode *LargeShift = isConstOrConstSplat(N0Op0.getOperand(1))) {
4524 unsigned LargeShiftVal = LargeShift->getZExtValue();
4525 EVT LargeVT = N0Op0.getValueType();
4527 if (LargeVT.getScalarSizeInBits() - OpSizeInBits == LargeShiftVal) {
4530 DAG.getConstant(LargeShiftVal + N1C->getZExtValue(), DL,
4531 getShiftAmountTy(N0Op0.getOperand(0).getValueType()));
4532 SDValue SRA = DAG.getNode(ISD::SRA, DL, LargeVT,
4533 N0Op0.getOperand(0), Amt);
4534 return DAG.getNode(ISD::TRUNCATE, DL, VT, SRA);
4539 // Simplify, based on bits shifted out of the LHS.
4540 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4541 return SDValue(N, 0);
4544 // If the sign bit is known to be zero, switch this to a SRL.
4545 if (DAG.SignBitIsZero(N0))
4546 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);
4548 if (N1C && !N1C->isOpaque()) {
4549 SDValue NewSRA = visitShiftByConstant(N, N1C);
4550 if (NewSRA.getNode())
4557 SDValue DAGCombiner::visitSRL(SDNode *N) {
4558 SDValue N0 = N->getOperand(0);
4559 SDValue N1 = N->getOperand(1);
4560 EVT VT = N0.getValueType();
4561 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4564 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4565 if (VT.isVector()) {
4566 if (SDValue FoldedVOp = SimplifyVBinOp(N))
4569 N1C = isConstOrConstSplat(N1);
4572 // fold (srl c1, c2) -> c1 >>u c2
4573 ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
4574 if (N0C && N1C && !N1C->isOpaque())
4575 return DAG.FoldConstantArithmetic(ISD::SRL, SDLoc(N), VT, N0C, N1C);
4576 // fold (srl 0, x) -> 0
4577 if (isNullConstant(N0))
4579 // fold (srl x, c >= size(x)) -> undef
4580 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4581 return DAG.getUNDEF(VT);
4582 // fold (srl x, 0) -> x
4583 if (N1C && N1C->isNullValue())
4585 // if (srl x, c) is known to be zero, return 0
4586 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
4587 APInt::getAllOnesValue(OpSizeInBits)))
4588 return DAG.getConstant(0, SDLoc(N), VT);
4590 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
4591 if (N1C && N0.getOpcode() == ISD::SRL) {
4592 if (ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1))) {
4593 uint64_t c1 = N01C->getZExtValue();
4594 uint64_t c2 = N1C->getZExtValue();
4596 if (c1 + c2 >= OpSizeInBits)
4597 return DAG.getConstant(0, DL, VT);
4598 return DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0),
4599 DAG.getConstant(c1 + c2, DL, N1.getValueType()));
4603 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
4604 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
4605 N0.getOperand(0).getOpcode() == ISD::SRL &&
4606 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
4608 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
4609 uint64_t c2 = N1C->getZExtValue();
4610 EVT InnerShiftVT = N0.getOperand(0).getValueType();
4611 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
4612 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
4613 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
4614 if (c1 + OpSizeInBits == InnerShiftSize) {
4616 if (c1 + c2 >= InnerShiftSize)
4617 return DAG.getConstant(0, DL, VT);
4618 return DAG.getNode(ISD::TRUNCATE, DL, VT,
4619 DAG.getNode(ISD::SRL, DL, InnerShiftVT,
4620 N0.getOperand(0)->getOperand(0),
4621 DAG.getConstant(c1 + c2, DL,
4626 // fold (srl (shl x, c), c) -> (and x, cst2)
4627 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1) {
4628 unsigned BitSize = N0.getScalarValueSizeInBits();
4629 if (BitSize <= 64) {
4630 uint64_t ShAmt = N1C->getZExtValue() + 64 - BitSize;
4632 return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0),
4633 DAG.getConstant(~0ULL >> ShAmt, DL, VT));
4637 // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
4638 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
4639 // Shifting in all undef bits?
4640 EVT SmallVT = N0.getOperand(0).getValueType();
4641 unsigned BitSize = SmallVT.getScalarSizeInBits();
4642 if (N1C->getZExtValue() >= BitSize)
4643 return DAG.getUNDEF(VT);
4645 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
4646 uint64_t ShiftAmt = N1C->getZExtValue();
4648 SDValue SmallShift = DAG.getNode(ISD::SRL, DL0, SmallVT,
4650 DAG.getConstant(ShiftAmt, DL0,
4651 getShiftAmountTy(SmallVT)));
4652 AddToWorklist(SmallShift.getNode());
4653 APInt Mask = APInt::getAllOnesValue(OpSizeInBits).lshr(ShiftAmt);
4655 return DAG.getNode(ISD::AND, DL, VT,
4656 DAG.getNode(ISD::ANY_EXTEND, DL, VT, SmallShift),
4657 DAG.getConstant(Mask, DL, VT));
4661 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
4662 // bit, which is unmodified by sra.
4663 if (N1C && N1C->getZExtValue() + 1 == OpSizeInBits) {
4664 if (N0.getOpcode() == ISD::SRA)
4665 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
4668 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
4669 if (N1C && N0.getOpcode() == ISD::CTLZ &&
4670 N1C->getAPIntValue() == Log2_32(OpSizeInBits)) {
4671 APInt KnownZero, KnownOne;
4672 DAG.computeKnownBits(N0.getOperand(0), KnownZero, KnownOne);
4674 // If any of the input bits are KnownOne, then the input couldn't be all
4675 // zeros, thus the result of the srl will always be zero.
4676 if (KnownOne.getBoolValue()) return DAG.getConstant(0, SDLoc(N0), VT);
4678 // If all of the bits input the to ctlz node are known to be zero, then
4679 // the result of the ctlz is "32" and the result of the shift is one.
4680 APInt UnknownBits = ~KnownZero;
4681 if (UnknownBits == 0) return DAG.getConstant(1, SDLoc(N0), VT);
4683 // Otherwise, check to see if there is exactly one bit input to the ctlz.
4684 if ((UnknownBits & (UnknownBits - 1)) == 0) {
4685 // Okay, we know that only that the single bit specified by UnknownBits
4686 // could be set on input to the CTLZ node. If this bit is set, the SRL
4687 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
4688 // to an SRL/XOR pair, which is likely to simplify more.
4689 unsigned ShAmt = UnknownBits.countTrailingZeros();
4690 SDValue Op = N0.getOperand(0);
4694 Op = DAG.getNode(ISD::SRL, DL, VT, Op,
4695 DAG.getConstant(ShAmt, DL,
4696 getShiftAmountTy(Op.getValueType())));
4697 AddToWorklist(Op.getNode());
4701 return DAG.getNode(ISD::XOR, DL, VT,
4702 Op, DAG.getConstant(1, DL, VT));
4706 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
4707 if (N1.getOpcode() == ISD::TRUNCATE &&
4708 N1.getOperand(0).getOpcode() == ISD::AND) {
4709 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4710 if (NewOp1.getNode())
4711 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, NewOp1);
4714 // fold operands of srl based on knowledge that the low bits are not
4716 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4717 return SDValue(N, 0);
4719 if (N1C && !N1C->isOpaque()) {
4720 SDValue NewSRL = visitShiftByConstant(N, N1C);
4721 if (NewSRL.getNode())
4725 // Attempt to convert a srl of a load into a narrower zero-extending load.
4726 SDValue NarrowLoad = ReduceLoadWidth(N);
4727 if (NarrowLoad.getNode())
4730 // Here is a common situation. We want to optimize:
4733 // %b = and i32 %a, 2
4734 // %c = srl i32 %b, 1
4735 // brcond i32 %c ...
4741 // %c = setcc eq %b, 0
4744 // However when after the source operand of SRL is optimized into AND, the SRL
4745 // itself may not be optimized further. Look for it and add the BRCOND into
4747 if (N->hasOneUse()) {
4748 SDNode *Use = *N->use_begin();
4749 if (Use->getOpcode() == ISD::BRCOND)
4751 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
4752 // Also look pass the truncate.
4753 Use = *Use->use_begin();
4754 if (Use->getOpcode() == ISD::BRCOND)
4762 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
4763 SDValue N0 = N->getOperand(0);
4764 EVT VT = N->getValueType(0);
4766 // fold (ctlz c1) -> c2
4767 if (isa<ConstantSDNode>(N0))
4768 return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);
4772 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
4773 SDValue N0 = N->getOperand(0);
4774 EVT VT = N->getValueType(0);
4776 // fold (ctlz_zero_undef c1) -> c2
4777 if (isa<ConstantSDNode>(N0))
4778 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4782 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4783 SDValue N0 = N->getOperand(0);
4784 EVT VT = N->getValueType(0);
4786 // fold (cttz c1) -> c2
4787 if (isa<ConstantSDNode>(N0))
4788 return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);
4792 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4793 SDValue N0 = N->getOperand(0);
4794 EVT VT = N->getValueType(0);
4796 // fold (cttz_zero_undef c1) -> c2
4797 if (isa<ConstantSDNode>(N0))
4798 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4802 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4803 SDValue N0 = N->getOperand(0);
4804 EVT VT = N->getValueType(0);
4806 // fold (ctpop c1) -> c2
4807 if (isa<ConstantSDNode>(N0))
4808 return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
4813 /// \brief Generate Min/Max node
4814 static SDValue combineMinNumMaxNum(SDLoc DL, EVT VT, SDValue LHS, SDValue RHS,
4815 SDValue True, SDValue False,
4816 ISD::CondCode CC, const TargetLowering &TLI,
4817 SelectionDAG &DAG) {
4818 if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
4828 unsigned Opcode = (LHS == True) ? ISD::FMINNUM : ISD::FMAXNUM;
4829 if (TLI.isOperationLegal(Opcode, VT))
4830 return DAG.getNode(Opcode, DL, VT, LHS, RHS);
4839 unsigned Opcode = (LHS == True) ? ISD::FMAXNUM : ISD::FMINNUM;
4840 if (TLI.isOperationLegal(Opcode, VT))
4841 return DAG.getNode(Opcode, DL, VT, LHS, RHS);
4849 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4850 SDValue N0 = N->getOperand(0);
4851 SDValue N1 = N->getOperand(1);
4852 SDValue N2 = N->getOperand(2);
4853 EVT VT = N->getValueType(0);
4854 EVT VT0 = N0.getValueType();
4856 // fold (select C, X, X) -> X
4859 if (const ConstantSDNode *N0C = dyn_cast<const ConstantSDNode>(N0)) {
4860 // fold (select true, X, Y) -> X
4861 // fold (select false, X, Y) -> Y
4862 return !N0C->isNullValue() ? N1 : N2;
4864 // fold (select C, 1, X) -> (or C, X)
4865 if (VT == MVT::i1 && isOneConstant(N1))
4866 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4867 // fold (select C, 0, 1) -> (xor C, 1)
4868 // We can't do this reliably if integer based booleans have different contents
4869 // to floating point based booleans. This is because we can't tell whether we
4870 // have an integer-based boolean or a floating-point-based boolean unless we
4871 // can find the SETCC that produced it and inspect its operands. This is
4872 // fairly easy if C is the SETCC node, but it can potentially be
4873 // undiscoverable (or not reasonably discoverable). For example, it could be
4874 // in another basic block or it could require searching a complicated
4876 if (VT.isInteger() &&
4877 (VT0 == MVT::i1 || (VT0.isInteger() &&
4878 TLI.getBooleanContents(false, false) ==
4879 TLI.getBooleanContents(false, true) &&
4880 TLI.getBooleanContents(false, false) ==
4881 TargetLowering::ZeroOrOneBooleanContent)) &&
4882 isNullConstant(N1) && isOneConstant(N2)) {
4886 return DAG.getNode(ISD::XOR, DL, VT0,
4887 N0, DAG.getConstant(1, DL, VT0));
4890 XORNode = DAG.getNode(ISD::XOR, DL0, VT0,
4891 N0, DAG.getConstant(1, DL0, VT0));
4892 AddToWorklist(XORNode.getNode());
4894 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, XORNode);
4895 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, XORNode);
4897 // fold (select C, 0, X) -> (and (not C), X)
4898 if (VT == VT0 && VT == MVT::i1 && isNullConstant(N1)) {
4899 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4900 AddToWorklist(NOTNode.getNode());
4901 return DAG.getNode(ISD::AND, SDLoc(N), VT, NOTNode, N2);
4903 // fold (select C, X, 1) -> (or (not C), X)
4904 if (VT == VT0 && VT == MVT::i1 && isOneConstant(N2)) {
4905 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4906 AddToWorklist(NOTNode.getNode());
4907 return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
4909 // fold (select C, X, 0) -> (and C, X)
4910 if (VT == MVT::i1 && isNullConstant(N2))
4911 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4912 // fold (select X, X, Y) -> (or X, Y)
4913 // fold (select X, 1, Y) -> (or X, Y)
4914 if (VT == MVT::i1 && (N0 == N1 || isOneConstant(N1)))
4915 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4916 // fold (select X, Y, X) -> (and X, Y)
4917 // fold (select X, Y, 0) -> (and X, Y)
4918 if (VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
4919 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4921 // If we can fold this based on the true/false value, do so.
4922 if (SimplifySelectOps(N, N1, N2))
4923 return SDValue(N, 0); // Don't revisit N.
4925 // fold selects based on a setcc into other things, such as min/max/abs
4926 if (N0.getOpcode() == ISD::SETCC) {
4927 // select x, y (fcmp lt x, y) -> fminnum x, y
4928 // select x, y (fcmp gt x, y) -> fmaxnum x, y
4930 // This is OK if we don't care about what happens if either operand is a
4934 // FIXME: Instead of testing for UnsafeFPMath, this should be checking for
4935 // no signed zeros as well as no nans.
4936 const TargetOptions &Options = DAG.getTarget().Options;
4937 if (Options.UnsafeFPMath &&
4938 VT.isFloatingPoint() && N0.hasOneUse() &&
4939 DAG.isKnownNeverNaN(N1) && DAG.isKnownNeverNaN(N2)) {
4940 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
4943 combineMinNumMaxNum(SDLoc(N), VT, N0.getOperand(0), N0.getOperand(1),
4944 N1, N2, CC, TLI, DAG);
4949 if ((!LegalOperations &&
4950 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT)) ||
4951 TLI.isOperationLegal(ISD::SELECT_CC, VT))
4952 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
4953 N0.getOperand(0), N0.getOperand(1),
4954 N1, N2, N0.getOperand(2));
4955 return SimplifySelect(SDLoc(N), N0, N1, N2);
4958 if (VT0 == MVT::i1) {
4959 if (TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
4960 // select (and Cond0, Cond1), X, Y
4961 // -> select Cond0, (select Cond1, X, Y), Y
4962 if (N0->getOpcode() == ISD::AND && N0->hasOneUse()) {
4963 SDValue Cond0 = N0->getOperand(0);
4964 SDValue Cond1 = N0->getOperand(1);
4965 SDValue InnerSelect = DAG.getNode(ISD::SELECT, SDLoc(N),
4966 N1.getValueType(), Cond1, N1, N2);
4967 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Cond0,
4970 // select (or Cond0, Cond1), X, Y -> select Cond0, X, (select Cond1, X, Y)
4971 if (N0->getOpcode() == ISD::OR && N0->hasOneUse()) {
4972 SDValue Cond0 = N0->getOperand(0);
4973 SDValue Cond1 = N0->getOperand(1);
4974 SDValue InnerSelect = DAG.getNode(ISD::SELECT, SDLoc(N),
4975 N1.getValueType(), Cond1, N1, N2);
4976 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Cond0, N1,
4981 // select Cond0, (select Cond1, X, Y), Y -> select (and Cond0, Cond1), X, Y
4982 if (N1->getOpcode() == ISD::SELECT) {
4983 SDValue N1_0 = N1->getOperand(0);
4984 SDValue N1_1 = N1->getOperand(1);
4985 SDValue N1_2 = N1->getOperand(2);
4986 if (N1_2 == N2 && N0.getValueType() == N1_0.getValueType()) {
4987 // Create the actual and node if we can generate good code for it.
4988 if (!TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
4989 SDValue And = DAG.getNode(ISD::AND, SDLoc(N), N0.getValueType(),
4991 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), And,
4994 // Otherwise see if we can optimize the "and" to a better pattern.
4995 if (SDValue Combined = visitANDLike(N0, N1_0, N))
4996 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Combined,
5000 // select Cond0, X, (select Cond1, X, Y) -> select (or Cond0, Cond1), X, Y
5001 if (N2->getOpcode() == ISD::SELECT) {
5002 SDValue N2_0 = N2->getOperand(0);
5003 SDValue N2_1 = N2->getOperand(1);
5004 SDValue N2_2 = N2->getOperand(2);
5005 if (N2_1 == N1 && N0.getValueType() == N2_0.getValueType()) {
5006 // Create the actual or node if we can generate good code for it.
5007 if (!TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT)) {
5008 SDValue Or = DAG.getNode(ISD::OR, SDLoc(N), N0.getValueType(),
5010 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Or,
5013 // Otherwise see if we can optimize to a better pattern.
5014 if (SDValue Combined = visitORLike(N0, N2_0, N))
5015 return DAG.getNode(ISD::SELECT, SDLoc(N), N1.getValueType(), Combined,
5025 std::pair<SDValue, SDValue> SplitVSETCC(const SDNode *N, SelectionDAG &DAG) {
5028 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
5030 // Split the inputs.
5031 SDValue Lo, Hi, LL, LH, RL, RH;
5032 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 0);
5033 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 1);
5035 Lo = DAG.getNode(N->getOpcode(), DL, LoVT, LL, RL, N->getOperand(2));
5036 Hi = DAG.getNode(N->getOpcode(), DL, HiVT, LH, RH, N->getOperand(2));
5038 return std::make_pair(Lo, Hi);
5041 // This function assumes all the vselect's arguments are CONCAT_VECTOR
5042 // nodes and that the condition is a BV of ConstantSDNodes (or undefs).
5043 static SDValue ConvertSelectToConcatVector(SDNode *N, SelectionDAG &DAG) {
5045 SDValue Cond = N->getOperand(0);
5046 SDValue LHS = N->getOperand(1);
5047 SDValue RHS = N->getOperand(2);
5048 EVT VT = N->getValueType(0);
5049 int NumElems = VT.getVectorNumElements();
5050 assert(LHS.getOpcode() == ISD::CONCAT_VECTORS &&
5051 RHS.getOpcode() == ISD::CONCAT_VECTORS &&
5052 Cond.getOpcode() == ISD::BUILD_VECTOR);
5054 // CONCAT_VECTOR can take an arbitrary number of arguments. We only care about
5055 // binary ones here.
5056 if (LHS->getNumOperands() != 2 || RHS->getNumOperands() != 2)
5059 // We're sure we have an even number of elements due to the
5060 // concat_vectors we have as arguments to vselect.
5061 // Skip BV elements until we find one that's not an UNDEF
5062 // After we find an UNDEF element, keep looping until we get to half the
5063 // length of the BV and see if all the non-undef nodes are the same.
5064 ConstantSDNode *BottomHalf = nullptr;
5065 for (int i = 0; i < NumElems / 2; ++i) {
5066 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
5069 if (BottomHalf == nullptr)
5070 BottomHalf = cast<ConstantSDNode>(Cond.getOperand(i));
5071 else if (Cond->getOperand(i).getNode() != BottomHalf)
5075 // Do the same for the second half of the BuildVector
5076 ConstantSDNode *TopHalf = nullptr;
5077 for (int i = NumElems / 2; i < NumElems; ++i) {
5078 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
5081 if (TopHalf == nullptr)
5082 TopHalf = cast<ConstantSDNode>(Cond.getOperand(i));
5083 else if (Cond->getOperand(i).getNode() != TopHalf)
5087 assert(TopHalf && BottomHalf &&
5088 "One half of the selector was all UNDEFs and the other was all the "
5089 "same value. This should have been addressed before this function.");
5091 ISD::CONCAT_VECTORS, dl, VT,
5092 BottomHalf->isNullValue() ? RHS->getOperand(0) : LHS->getOperand(0),
5093 TopHalf->isNullValue() ? RHS->getOperand(1) : LHS->getOperand(1));
5096 SDValue DAGCombiner::visitMSCATTER(SDNode *N) {
5098 if (Level >= AfterLegalizeTypes)
5101 MaskedScatterSDNode *MSC = cast<MaskedScatterSDNode>(N);
5102 SDValue Mask = MSC->getMask();
5103 SDValue Data = MSC->getValue();
5106 // If the MSCATTER data type requires splitting and the mask is provided by a
5107 // SETCC, then split both nodes and its operands before legalization. This
5108 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5109 // and enables future optimizations (e.g. min/max pattern matching on X86).
5110 if (Mask.getOpcode() != ISD::SETCC)
5113 // Check if any splitting is required.
5114 if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
5115 TargetLowering::TypeSplitVector)
5117 SDValue MaskLo, MaskHi, Lo, Hi;
5118 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5121 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MSC->getValueType(0));
5123 SDValue Chain = MSC->getChain();
5125 EVT MemoryVT = MSC->getMemoryVT();
5126 unsigned Alignment = MSC->getOriginalAlignment();
5128 EVT LoMemVT, HiMemVT;
5129 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5131 SDValue DataLo, DataHi;
5132 std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);
5134 SDValue BasePtr = MSC->getBasePtr();
5135 SDValue IndexLo, IndexHi;
5136 std::tie(IndexLo, IndexHi) = DAG.SplitVector(MSC->getIndex(), DL);
5138 MachineMemOperand *MMO = DAG.getMachineFunction().
5139 getMachineMemOperand(MSC->getPointerInfo(),
5140 MachineMemOperand::MOStore, LoMemVT.getStoreSize(),
5141 Alignment, MSC->getAAInfo(), MSC->getRanges());
5143 SDValue OpsLo[] = { Chain, DataLo, MaskLo, BasePtr, IndexLo };
5144 Lo = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataLo.getValueType(),
5147 SDValue OpsHi[] = {Chain, DataHi, MaskHi, BasePtr, IndexHi};
5148 Hi = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataHi.getValueType(),
5151 AddToWorklist(Lo.getNode());
5152 AddToWorklist(Hi.getNode());
5154 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
5157 SDValue DAGCombiner::visitMSTORE(SDNode *N) {
5159 if (Level >= AfterLegalizeTypes)
5162 MaskedStoreSDNode *MST = dyn_cast<MaskedStoreSDNode>(N);
5163 SDValue Mask = MST->getMask();
5164 SDValue Data = MST->getValue();
5167 // If the MSTORE data type requires splitting and the mask is provided by a
5168 // SETCC, then split both nodes and its operands before legalization. This
5169 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5170 // and enables future optimizations (e.g. min/max pattern matching on X86).
5171 if (Mask.getOpcode() == ISD::SETCC) {
5173 // Check if any splitting is required.
5174 if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
5175 TargetLowering::TypeSplitVector)
5178 SDValue MaskLo, MaskHi, Lo, Hi;
5179 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5182 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MST->getValueType(0));
5184 SDValue Chain = MST->getChain();
5185 SDValue Ptr = MST->getBasePtr();
5187 EVT MemoryVT = MST->getMemoryVT();
5188 unsigned Alignment = MST->getOriginalAlignment();
5190 // if Alignment is equal to the vector size,
5191 // take the half of it for the second part
5192 unsigned SecondHalfAlignment =
5193 (Alignment == Data->getValueType(0).getSizeInBits()/8) ?
5194 Alignment/2 : Alignment;
5196 EVT LoMemVT, HiMemVT;
5197 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5199 SDValue DataLo, DataHi;
5200 std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);
5202 MachineMemOperand *MMO = DAG.getMachineFunction().
5203 getMachineMemOperand(MST->getPointerInfo(),
5204 MachineMemOperand::MOStore, LoMemVT.getStoreSize(),
5205 Alignment, MST->getAAInfo(), MST->getRanges());
5207 Lo = DAG.getMaskedStore(Chain, DL, DataLo, Ptr, MaskLo, LoMemVT, MMO,
5208 MST->isTruncatingStore());
5210 unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
5211 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
5212 DAG.getConstant(IncrementSize, DL, Ptr.getValueType()));
5214 MMO = DAG.getMachineFunction().
5215 getMachineMemOperand(MST->getPointerInfo(),
5216 MachineMemOperand::MOStore, HiMemVT.getStoreSize(),
5217 SecondHalfAlignment, MST->getAAInfo(),
5220 Hi = DAG.getMaskedStore(Chain, DL, DataHi, Ptr, MaskHi, HiMemVT, MMO,
5221 MST->isTruncatingStore());
5223 AddToWorklist(Lo.getNode());
5224 AddToWorklist(Hi.getNode());
5226 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
5231 SDValue DAGCombiner::visitMGATHER(SDNode *N) {
5233 if (Level >= AfterLegalizeTypes)
5236 MaskedGatherSDNode *MGT = dyn_cast<MaskedGatherSDNode>(N);
5237 SDValue Mask = MGT->getMask();
5240 // If the MGATHER result requires splitting and the mask is provided by a
5241 // SETCC, then split both nodes and its operands before legalization. This
5242 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5243 // and enables future optimizations (e.g. min/max pattern matching on X86).
5245 if (Mask.getOpcode() != ISD::SETCC)
5248 EVT VT = N->getValueType(0);
5250 // Check if any splitting is required.
5251 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5252 TargetLowering::TypeSplitVector)
5255 SDValue MaskLo, MaskHi, Lo, Hi;
5256 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5258 SDValue Src0 = MGT->getValue();
5259 SDValue Src0Lo, Src0Hi;
5260 std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);
5263 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
5265 SDValue Chain = MGT->getChain();
5266 EVT MemoryVT = MGT->getMemoryVT();
5267 unsigned Alignment = MGT->getOriginalAlignment();
5269 EVT LoMemVT, HiMemVT;
5270 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5272 SDValue BasePtr = MGT->getBasePtr();
5273 SDValue Index = MGT->getIndex();
5274 SDValue IndexLo, IndexHi;
5275 std::tie(IndexLo, IndexHi) = DAG.SplitVector(Index, DL);
5277 MachineMemOperand *MMO = DAG.getMachineFunction().
5278 getMachineMemOperand(MGT->getPointerInfo(),
5279 MachineMemOperand::MOLoad, LoMemVT.getStoreSize(),
5280 Alignment, MGT->getAAInfo(), MGT->getRanges());
5282 SDValue OpsLo[] = { Chain, Src0Lo, MaskLo, BasePtr, IndexLo };
5283 Lo = DAG.getMaskedGather(DAG.getVTList(LoVT, MVT::Other), LoVT, DL, OpsLo,
5286 SDValue OpsHi[] = {Chain, Src0Hi, MaskHi, BasePtr, IndexHi};
5287 Hi = DAG.getMaskedGather(DAG.getVTList(HiVT, MVT::Other), HiVT, DL, OpsHi,
5290 AddToWorklist(Lo.getNode());
5291 AddToWorklist(Hi.getNode());
5293 // Build a factor node to remember that this load is independent of the
5295 Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
5298 // Legalized the chain result - switch anything that used the old chain to
5300 DAG.ReplaceAllUsesOfValueWith(SDValue(MGT, 1), Chain);
5302 SDValue GatherRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5304 SDValue RetOps[] = { GatherRes, Chain };
5305 return DAG.getMergeValues(RetOps, DL);
5308 SDValue DAGCombiner::visitMLOAD(SDNode *N) {
5310 if (Level >= AfterLegalizeTypes)
5313 MaskedLoadSDNode *MLD = dyn_cast<MaskedLoadSDNode>(N);
5314 SDValue Mask = MLD->getMask();
5317 // If the MLOAD result requires splitting and the mask is provided by a
5318 // SETCC, then split both nodes and its operands before legalization. This
5319 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5320 // and enables future optimizations (e.g. min/max pattern matching on X86).
5322 if (Mask.getOpcode() == ISD::SETCC) {
5323 EVT VT = N->getValueType(0);
5325 // Check if any splitting is required.
5326 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5327 TargetLowering::TypeSplitVector)
5330 SDValue MaskLo, MaskHi, Lo, Hi;
5331 std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);
5333 SDValue Src0 = MLD->getSrc0();
5334 SDValue Src0Lo, Src0Hi;
5335 std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);
5338 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MLD->getValueType(0));
5340 SDValue Chain = MLD->getChain();
5341 SDValue Ptr = MLD->getBasePtr();
5342 EVT MemoryVT = MLD->getMemoryVT();
5343 unsigned Alignment = MLD->getOriginalAlignment();
5345 // if Alignment is equal to the vector size,
5346 // take the half of it for the second part
5347 unsigned SecondHalfAlignment =
5348 (Alignment == MLD->getValueType(0).getSizeInBits()/8) ?
5349 Alignment/2 : Alignment;
5351 EVT LoMemVT, HiMemVT;
5352 std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);
5354 MachineMemOperand *MMO = DAG.getMachineFunction().
5355 getMachineMemOperand(MLD->getPointerInfo(),
5356 MachineMemOperand::MOLoad, LoMemVT.getStoreSize(),
5357 Alignment, MLD->getAAInfo(), MLD->getRanges());
5359 Lo = DAG.getMaskedLoad(LoVT, DL, Chain, Ptr, MaskLo, Src0Lo, LoMemVT, MMO,
5362 unsigned IncrementSize = LoMemVT.getSizeInBits()/8;
5363 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
5364 DAG.getConstant(IncrementSize, DL, Ptr.getValueType()));
5366 MMO = DAG.getMachineFunction().
5367 getMachineMemOperand(MLD->getPointerInfo(),
5368 MachineMemOperand::MOLoad, HiMemVT.getStoreSize(),
5369 SecondHalfAlignment, MLD->getAAInfo(), MLD->getRanges());
5371 Hi = DAG.getMaskedLoad(HiVT, DL, Chain, Ptr, MaskHi, Src0Hi, HiMemVT, MMO,
5374 AddToWorklist(Lo.getNode());
5375 AddToWorklist(Hi.getNode());
5377 // Build a factor node to remember that this load is independent of the
5379 Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
5382 // Legalized the chain result - switch anything that used the old chain to
5384 DAG.ReplaceAllUsesOfValueWith(SDValue(MLD, 1), Chain);
5386 SDValue LoadRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5388 SDValue RetOps[] = { LoadRes, Chain };
5389 return DAG.getMergeValues(RetOps, DL);
5394 SDValue DAGCombiner::visitVSELECT(SDNode *N) {
5395 SDValue N0 = N->getOperand(0);
5396 SDValue N1 = N->getOperand(1);
5397 SDValue N2 = N->getOperand(2);
5400 // Canonicalize integer abs.
5401 // vselect (setg[te] X, 0), X, -X ->
5402 // vselect (setgt X, -1), X, -X ->
5403 // vselect (setl[te] X, 0), -X, X ->
5404 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5405 if (N0.getOpcode() == ISD::SETCC) {
5406 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
5407 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
5409 bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());
5411 if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
5412 (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
5413 N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
5414 isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
5415 else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
5416 N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
5417 isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
5420 EVT VT = LHS.getValueType();
5421 SDValue Shift = DAG.getNode(
5422 ISD::SRA, DL, VT, LHS,
5423 DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, DL, VT));
5424 SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
5425 AddToWorklist(Shift.getNode());
5426 AddToWorklist(Add.getNode());
5427 return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
5431 if (SimplifySelectOps(N, N1, N2))
5432 return SDValue(N, 0); // Don't revisit N.
5434 // If the VSELECT result requires splitting and the mask is provided by a
5435 // SETCC, then split both nodes and its operands before legalization. This
5436 // prevents the type legalizer from unrolling SETCC into scalar comparisons
5437 // and enables future optimizations (e.g. min/max pattern matching on X86).
5438 if (N0.getOpcode() == ISD::SETCC) {
5439 EVT VT = N->getValueType(0);
5441 // Check if any splitting is required.
5442 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
5443 TargetLowering::TypeSplitVector)
5446 SDValue Lo, Hi, CCLo, CCHi, LL, LH, RL, RH;
5447 std::tie(CCLo, CCHi) = SplitVSETCC(N0.getNode(), DAG);
5448 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 1);
5449 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 2);
5451 Lo = DAG.getNode(N->getOpcode(), DL, LL.getValueType(), CCLo, LL, RL);
5452 Hi = DAG.getNode(N->getOpcode(), DL, LH.getValueType(), CCHi, LH, RH);
5454 // Add the new VSELECT nodes to the work list in case they need to be split
5456 AddToWorklist(Lo.getNode());
5457 AddToWorklist(Hi.getNode());
5459 return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
5462 // Fold (vselect (build_vector all_ones), N1, N2) -> N1
5463 if (ISD::isBuildVectorAllOnes(N0.getNode()))
5465 // Fold (vselect (build_vector all_zeros), N1, N2) -> N2
5466 if (ISD::isBuildVectorAllZeros(N0.getNode()))
5469 // The ConvertSelectToConcatVector function is assuming both the above
5470 // checks for (vselect (build_vector all{ones,zeros) ...) have been made
5472 if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
5473 N2.getOpcode() == ISD::CONCAT_VECTORS &&
5474 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
5475 SDValue CV = ConvertSelectToConcatVector(N, DAG);
5483 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
5484 SDValue N0 = N->getOperand(0);
5485 SDValue N1 = N->getOperand(1);
5486 SDValue N2 = N->getOperand(2);
5487 SDValue N3 = N->getOperand(3);
5488 SDValue N4 = N->getOperand(4);
5489 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
5491 // fold select_cc lhs, rhs, x, x, cc -> x
5495 // Determine if the condition we're dealing with is constant
5496 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
5497 N0, N1, CC, SDLoc(N), false);
5498 if (SCC.getNode()) {
5499 AddToWorklist(SCC.getNode());
5501 if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
5502 if (!SCCC->isNullValue())
5503 return N2; // cond always true -> true val
5505 return N3; // cond always false -> false val
5506 } else if (SCC->getOpcode() == ISD::UNDEF) {
5507 // When the condition is UNDEF, just return the first operand. This is
5508 // coherent the DAG creation, no setcc node is created in this case
5510 } else if (SCC.getOpcode() == ISD::SETCC) {
5511 // Fold to a simpler select_cc
5512 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
5513 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
5518 // If we can fold this based on the true/false value, do so.
5519 if (SimplifySelectOps(N, N2, N3))
5520 return SDValue(N, 0); // Don't revisit N.
5522 // fold select_cc into other things, such as min/max/abs
5523 return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
5526 SDValue DAGCombiner::visitSETCC(SDNode *N) {
5527 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
5528 cast<CondCodeSDNode>(N->getOperand(2))->get(),
5532 // tryToFoldExtendOfConstant - Try to fold a sext/zext/aext
5533 // dag node into a ConstantSDNode or a build_vector of constants.
5534 // This function is called by the DAGCombiner when visiting sext/zext/aext
5535 // dag nodes (see for example method DAGCombiner::visitSIGN_EXTEND).
5536 // Vector extends are not folded if operations are legal; this is to
5537 // avoid introducing illegal build_vector dag nodes.
5538 static SDNode *tryToFoldExtendOfConstant(SDNode *N, const TargetLowering &TLI,
5539 SelectionDAG &DAG, bool LegalTypes,
5540 bool LegalOperations) {
5541 unsigned Opcode = N->getOpcode();
5542 SDValue N0 = N->getOperand(0);
5543 EVT VT = N->getValueType(0);
5545 assert((Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND ||
5546 Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG)
5547 && "Expected EXTEND dag node in input!");
5549 // fold (sext c1) -> c1
5550 // fold (zext c1) -> c1
5551 // fold (aext c1) -> c1
5552 if (isa<ConstantSDNode>(N0))
5553 return DAG.getNode(Opcode, SDLoc(N), VT, N0).getNode();
5555 // fold (sext (build_vector AllConstants) -> (build_vector AllConstants)
5556 // fold (zext (build_vector AllConstants) -> (build_vector AllConstants)
5557 // fold (aext (build_vector AllConstants) -> (build_vector AllConstants)
5558 EVT SVT = VT.getScalarType();
5559 if (!(VT.isVector() &&
5560 (!LegalTypes || (!LegalOperations && TLI.isTypeLegal(SVT))) &&
5561 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())))
5564 // We can fold this node into a build_vector.
5565 unsigned VTBits = SVT.getSizeInBits();
5566 unsigned EVTBits = N0->getValueType(0).getScalarType().getSizeInBits();
5567 unsigned ShAmt = VTBits - EVTBits;
5568 SmallVector<SDValue, 8> Elts;
5569 unsigned NumElts = VT.getVectorNumElements();
5572 for (unsigned i=0; i != NumElts; ++i) {
5573 SDValue Op = N0->getOperand(i);
5574 if (Op->getOpcode() == ISD::UNDEF) {
5575 Elts.push_back(DAG.getUNDEF(SVT));
5580 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
5581 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
5582 if (Opcode == ISD::SIGN_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG)
5583 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
5586 Elts.push_back(DAG.getConstant(C.shl(ShAmt).lshr(ShAmt).getZExtValue(),
5590 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Elts).getNode();
5593 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
5594 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
5595 // transformation. Returns true if extension are possible and the above
5596 // mentioned transformation is profitable.
5597 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
5599 SmallVectorImpl<SDNode *> &ExtendNodes,
5600 const TargetLowering &TLI) {
5601 bool HasCopyToRegUses = false;
5602 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
5603 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
5604 UE = N0.getNode()->use_end();
5609 if (UI.getUse().getResNo() != N0.getResNo())
5611 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
5612 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
5613 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
5614 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
5615 // Sign bits will be lost after a zext.
5618 for (unsigned i = 0; i != 2; ++i) {
5619 SDValue UseOp = User->getOperand(i);
5622 if (!isa<ConstantSDNode>(UseOp))
5627 ExtendNodes.push_back(User);
5630 // If truncates aren't free and there are users we can't
5631 // extend, it isn't worthwhile.
5634 // Remember if this value is live-out.
5635 if (User->getOpcode() == ISD::CopyToReg)
5636 HasCopyToRegUses = true;
5639 if (HasCopyToRegUses) {
5640 bool BothLiveOut = false;
5641 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
5643 SDUse &Use = UI.getUse();
5644 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
5650 // Both unextended and extended values are live out. There had better be
5651 // a good reason for the transformation.
5652 return ExtendNodes.size();
5657 void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
5658 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
5659 ISD::NodeType ExtType) {
5660 // Extend SetCC uses if necessary.
5661 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
5662 SDNode *SetCC = SetCCs[i];
5663 SmallVector<SDValue, 4> Ops;
5665 for (unsigned j = 0; j != 2; ++j) {
5666 SDValue SOp = SetCC->getOperand(j);
5668 Ops.push_back(ExtLoad);
5670 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
5673 Ops.push_back(SetCC->getOperand(2));
5674 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0), Ops));
5678 // FIXME: Bring more similar combines here, common to sext/zext (maybe aext?).
5679 SDValue DAGCombiner::CombineExtLoad(SDNode *N) {
5680 SDValue N0 = N->getOperand(0);
5681 EVT DstVT = N->getValueType(0);
5682 EVT SrcVT = N0.getValueType();
5684 assert((N->getOpcode() == ISD::SIGN_EXTEND ||
5685 N->getOpcode() == ISD::ZERO_EXTEND) &&
5686 "Unexpected node type (not an extend)!");
5688 // fold (sext (load x)) to multiple smaller sextloads; same for zext.
5689 // For example, on a target with legal v4i32, but illegal v8i32, turn:
5690 // (v8i32 (sext (v8i16 (load x))))
5692 // (v8i32 (concat_vectors (v4i32 (sextload x)),
5693 // (v4i32 (sextload (x + 16)))))
5694 // Where uses of the original load, i.e.:
5696 // are replaced with:
5698 // (v8i32 (concat_vectors (v4i32 (sextload x)),
5699 // (v4i32 (sextload (x + 16)))))))
5701 // This combine is only applicable to illegal, but splittable, vectors.
5702 // All legal types, and illegal non-vector types, are handled elsewhere.
5703 // This combine is controlled by TargetLowering::isVectorLoadExtDesirable.
5705 if (N0->getOpcode() != ISD::LOAD)
5708 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5710 if (!ISD::isNON_EXTLoad(LN0) || !ISD::isUNINDEXEDLoad(LN0) ||
5711 !N0.hasOneUse() || LN0->isVolatile() || !DstVT.isVector() ||
5712 !DstVT.isPow2VectorType() || !TLI.isVectorLoadExtDesirable(SDValue(N, 0)))
5715 SmallVector<SDNode *, 4> SetCCs;
5716 if (!ExtendUsesToFormExtLoad(N, N0, N->getOpcode(), SetCCs, TLI))
5719 ISD::LoadExtType ExtType =
5720 N->getOpcode() == ISD::SIGN_EXTEND ? ISD::SEXTLOAD : ISD::ZEXTLOAD;
5722 // Try to split the vector types to get down to legal types.
5723 EVT SplitSrcVT = SrcVT;
5724 EVT SplitDstVT = DstVT;
5725 while (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT) &&
5726 SplitSrcVT.getVectorNumElements() > 1) {
5727 SplitDstVT = DAG.GetSplitDestVTs(SplitDstVT).first;
5728 SplitSrcVT = DAG.GetSplitDestVTs(SplitSrcVT).first;
5731 if (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT))
5735 const unsigned NumSplits =
5736 DstVT.getVectorNumElements() / SplitDstVT.getVectorNumElements();
5737 const unsigned Stride = SplitSrcVT.getStoreSize();
5738 SmallVector<SDValue, 4> Loads;
5739 SmallVector<SDValue, 4> Chains;
5741 SDValue BasePtr = LN0->getBasePtr();
5742 for (unsigned Idx = 0; Idx < NumSplits; Idx++) {
5743 const unsigned Offset = Idx * Stride;
5744 const unsigned Align = MinAlign(LN0->getAlignment(), Offset);
5746 SDValue SplitLoad = DAG.getExtLoad(
5747 ExtType, DL, SplitDstVT, LN0->getChain(), BasePtr,
5748 LN0->getPointerInfo().getWithOffset(Offset), SplitSrcVT,
5749 LN0->isVolatile(), LN0->isNonTemporal(), LN0->isInvariant(),
5750 Align, LN0->getAAInfo());
5752 BasePtr = DAG.getNode(ISD::ADD, DL, BasePtr.getValueType(), BasePtr,
5753 DAG.getConstant(Stride, DL, BasePtr.getValueType()));
5755 Loads.push_back(SplitLoad.getValue(0));
5756 Chains.push_back(SplitLoad.getValue(1));
5759 SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
5760 SDValue NewValue = DAG.getNode(ISD::CONCAT_VECTORS, DL, DstVT, Loads);
5762 CombineTo(N, NewValue);
5764 // Replace uses of the original load (before extension)
5765 // with a truncate of the concatenated sextloaded vectors.
5767 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(), NewValue);
5768 CombineTo(N0.getNode(), Trunc, NewChain);
5769 ExtendSetCCUses(SetCCs, Trunc, NewValue, DL,
5770 (ISD::NodeType)N->getOpcode());
5771 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5774 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
5775 SDValue N0 = N->getOperand(0);
5776 EVT VT = N->getValueType(0);
5778 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
5780 return SDValue(Res, 0);
5782 // fold (sext (sext x)) -> (sext x)
5783 // fold (sext (aext x)) -> (sext x)
5784 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
5785 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT,
5788 if (N0.getOpcode() == ISD::TRUNCATE) {
5789 // fold (sext (truncate (load x))) -> (sext (smaller load x))
5790 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
5791 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
5792 if (NarrowLoad.getNode()) {
5793 SDNode* oye = N0.getNode()->getOperand(0).getNode();
5794 if (NarrowLoad.getNode() != N0.getNode()) {
5795 CombineTo(N0.getNode(), NarrowLoad);
5796 // CombineTo deleted the truncate, if needed, but not what's under it.
5799 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5802 // See if the value being truncated is already sign extended. If so, just
5803 // eliminate the trunc/sext pair.
5804 SDValue Op = N0.getOperand(0);
5805 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
5806 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
5807 unsigned DestBits = VT.getScalarType().getSizeInBits();
5808 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
5810 if (OpBits == DestBits) {
5811 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
5812 // bits, it is already ready.
5813 if (NumSignBits > DestBits-MidBits)
5815 } else if (OpBits < DestBits) {
5816 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
5817 // bits, just sext from i32.
5818 if (NumSignBits > OpBits-MidBits)
5819 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, Op);
5821 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
5822 // bits, just truncate to i32.
5823 if (NumSignBits > OpBits-MidBits)
5824 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
5827 // fold (sext (truncate x)) -> (sextinreg x).
5828 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
5829 N0.getValueType())) {
5830 if (OpBits < DestBits)
5831 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
5832 else if (OpBits > DestBits)
5833 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
5834 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, Op,
5835 DAG.getValueType(N0.getValueType()));
5839 // fold (sext (load x)) -> (sext (truncate (sextload x)))
5840 // Only generate vector extloads when 1) they're legal, and 2) they are
5841 // deemed desirable by the target.
5842 if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5843 ((!LegalOperations && !VT.isVector() &&
5844 !cast<LoadSDNode>(N0)->isVolatile()) ||
5845 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, N0.getValueType()))) {
5846 bool DoXform = true;
5847 SmallVector<SDNode*, 4> SetCCs;
5848 if (!N0.hasOneUse())
5849 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
5851 DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
5853 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5854 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5856 LN0->getBasePtr(), N0.getValueType(),
5857 LN0->getMemOperand());
5858 CombineTo(N, ExtLoad);
5859 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5860 N0.getValueType(), ExtLoad);
5861 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5862 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5864 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5868 // fold (sext (load x)) to multiple smaller sextloads.
5869 // Only on illegal but splittable vectors.
5870 if (SDValue ExtLoad = CombineExtLoad(N))
5873 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
5874 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
5875 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
5876 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
5877 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5878 EVT MemVT = LN0->getMemoryVT();
5879 if ((!LegalOperations && !LN0->isVolatile()) ||
5880 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, MemVT)) {
5881 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5883 LN0->getBasePtr(), MemVT,
5884 LN0->getMemOperand());
5885 CombineTo(N, ExtLoad);
5886 CombineTo(N0.getNode(),
5887 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5888 N0.getValueType(), ExtLoad),
5889 ExtLoad.getValue(1));
5890 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5894 // fold (sext (and/or/xor (load x), cst)) ->
5895 // (and/or/xor (sextload x), (sext cst))
5896 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
5897 N0.getOpcode() == ISD::XOR) &&
5898 isa<LoadSDNode>(N0.getOperand(0)) &&
5899 N0.getOperand(1).getOpcode() == ISD::Constant &&
5900 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, N0.getValueType()) &&
5901 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
5902 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
5903 if (LN0->getExtensionType() != ISD::ZEXTLOAD && LN0->isUnindexed()) {
5904 bool DoXform = true;
5905 SmallVector<SDNode*, 4> SetCCs;
5906 if (!N0.hasOneUse())
5907 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
5910 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
5911 LN0->getChain(), LN0->getBasePtr(),
5913 LN0->getMemOperand());
5914 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5915 Mask = Mask.sext(VT.getSizeInBits());
5917 SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
5918 ExtLoad, DAG.getConstant(Mask, DL, VT));
5919 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
5920 SDLoc(N0.getOperand(0)),
5921 N0.getOperand(0).getValueType(), ExtLoad);
5923 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
5924 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL,
5926 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5931 if (N0.getOpcode() == ISD::SETCC) {
5932 EVT N0VT = N0.getOperand(0).getValueType();
5933 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
5934 // Only do this before legalize for now.
5935 if (VT.isVector() && !LegalOperations &&
5936 TLI.getBooleanContents(N0VT) ==
5937 TargetLowering::ZeroOrNegativeOneBooleanContent) {
5938 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
5939 // of the same size as the compared operands. Only optimize sext(setcc())
5940 // if this is the case.
5941 EVT SVT = getSetCCResultType(N0VT);
5943 // We know that the # elements of the results is the same as the
5944 // # elements of the compare (and the # elements of the compare result
5945 // for that matter). Check to see that they are the same size. If so,
5946 // we know that the element size of the sext'd result matches the
5947 // element size of the compare operands.
5948 if (VT.getSizeInBits() == SVT.getSizeInBits())
5949 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5951 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5953 // If the desired elements are smaller or larger than the source
5954 // elements we can use a matching integer vector type and then
5955 // truncate/sign extend
5956 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
5957 if (SVT == MatchingVectorType) {
5958 SDValue VsetCC = DAG.getSetCC(SDLoc(N), MatchingVectorType,
5959 N0.getOperand(0), N0.getOperand(1),
5960 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5961 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
5965 // sext(setcc x, y, cc) -> (select (setcc x, y, cc), -1, 0)
5966 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
5969 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), DL, VT);
5971 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
5972 NegOne, DAG.getConstant(0, DL, VT),
5973 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5974 if (SCC.getNode()) return SCC;
5976 if (!VT.isVector()) {
5977 EVT SetCCVT = getSetCCResultType(N0.getOperand(0).getValueType());
5978 if (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, SetCCVT)) {
5980 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
5981 SDValue SetCC = DAG.getSetCC(DL, SetCCVT,
5982 N0.getOperand(0), N0.getOperand(1), CC);
5983 return DAG.getSelect(DL, VT, SetCC,
5984 NegOne, DAG.getConstant(0, DL, VT));
5989 // fold (sext x) -> (zext x) if the sign bit is known zero.
5990 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
5991 DAG.SignBitIsZero(N0))
5992 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
5997 // isTruncateOf - If N is a truncate of some other value, return true, record
5998 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
5999 // This function computes KnownZero to avoid a duplicated call to
6000 // computeKnownBits in the caller.
6001 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
6004 if (N->getOpcode() == ISD::TRUNCATE) {
6005 Op = N->getOperand(0);
6006 DAG.computeKnownBits(Op, KnownZero, KnownOne);
6010 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
6011 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
6014 SDValue Op0 = N->getOperand(0);
6015 SDValue Op1 = N->getOperand(1);
6016 assert(Op0.getValueType() == Op1.getValueType());
6018 if (isNullConstant(Op0))
6020 else if (isNullConstant(Op1))
6025 DAG.computeKnownBits(Op, KnownZero, KnownOne);
6027 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
6033 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
6034 SDValue N0 = N->getOperand(0);
6035 EVT VT = N->getValueType(0);
6037 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6039 return SDValue(Res, 0);
6041 // fold (zext (zext x)) -> (zext x)
6042 // fold (zext (aext x)) -> (zext x)
6043 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
6044 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
6047 // fold (zext (truncate x)) -> (zext x) or
6048 // (zext (truncate x)) -> (truncate x)
6049 // This is valid when the truncated bits of x are already zero.
6050 // FIXME: We should extend this to work for vectors too.
6053 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
6054 APInt TruncatedBits =
6055 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
6056 APInt(Op.getValueSizeInBits(), 0) :
6057 APInt::getBitsSet(Op.getValueSizeInBits(),
6058 N0.getValueSizeInBits(),
6059 std::min(Op.getValueSizeInBits(),
6060 VT.getSizeInBits()));
6061 if (TruncatedBits == (KnownZero & TruncatedBits)) {
6062 if (VT.bitsGT(Op.getValueType()))
6063 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, Op);
6064 if (VT.bitsLT(Op.getValueType()))
6065 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
6071 // fold (zext (truncate (load x))) -> (zext (smaller load x))
6072 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
6073 if (N0.getOpcode() == ISD::TRUNCATE) {
6074 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6075 if (NarrowLoad.getNode()) {
6076 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6077 if (NarrowLoad.getNode() != N0.getNode()) {
6078 CombineTo(N0.getNode(), NarrowLoad);
6079 // CombineTo deleted the truncate, if needed, but not what's under it.
6082 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6086 // fold (zext (truncate x)) -> (and x, mask)
6087 if (N0.getOpcode() == ISD::TRUNCATE &&
6088 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
6090 // fold (zext (truncate (load x))) -> (zext (smaller load x))
6091 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
6092 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6093 if (NarrowLoad.getNode()) {
6094 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6095 if (NarrowLoad.getNode() != N0.getNode()) {
6096 CombineTo(N0.getNode(), NarrowLoad);
6097 // CombineTo deleted the truncate, if needed, but not what's under it.
6100 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6103 SDValue Op = N0.getOperand(0);
6104 if (Op.getValueType().bitsLT(VT)) {
6105 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Op);
6106 AddToWorklist(Op.getNode());
6107 } else if (Op.getValueType().bitsGT(VT)) {
6108 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
6109 AddToWorklist(Op.getNode());
6111 return DAG.getZeroExtendInReg(Op, SDLoc(N),
6112 N0.getValueType().getScalarType());
6115 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
6116 // if either of the casts is not free.
6117 if (N0.getOpcode() == ISD::AND &&
6118 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
6119 N0.getOperand(1).getOpcode() == ISD::Constant &&
6120 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
6121 N0.getValueType()) ||
6122 !TLI.isZExtFree(N0.getValueType(), VT))) {
6123 SDValue X = N0.getOperand(0).getOperand(0);
6124 if (X.getValueType().bitsLT(VT)) {
6125 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(X), VT, X);
6126 } else if (X.getValueType().bitsGT(VT)) {
6127 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
6129 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6130 Mask = Mask.zext(VT.getSizeInBits());
6132 return DAG.getNode(ISD::AND, DL, VT,
6133 X, DAG.getConstant(Mask, DL, VT));
6136 // fold (zext (load x)) -> (zext (truncate (zextload x)))
6137 // Only generate vector extloads when 1) they're legal, and 2) they are
6138 // deemed desirable by the target.
6139 if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6140 ((!LegalOperations && !VT.isVector() &&
6141 !cast<LoadSDNode>(N0)->isVolatile()) ||
6142 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, N0.getValueType()))) {
6143 bool DoXform = true;
6144 SmallVector<SDNode*, 4> SetCCs;
6145 if (!N0.hasOneUse())
6146 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
6148 DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
6150 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6151 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
6153 LN0->getBasePtr(), N0.getValueType(),
6154 LN0->getMemOperand());
6155 CombineTo(N, ExtLoad);
6156 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6157 N0.getValueType(), ExtLoad);
6158 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
6160 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
6162 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6166 // fold (zext (load x)) to multiple smaller zextloads.
6167 // Only on illegal but splittable vectors.
6168 if (SDValue ExtLoad = CombineExtLoad(N))
6171 // fold (zext (and/or/xor (load x), cst)) ->
6172 // (and/or/xor (zextload x), (zext cst))
6173 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
6174 N0.getOpcode() == ISD::XOR) &&
6175 isa<LoadSDNode>(N0.getOperand(0)) &&
6176 N0.getOperand(1).getOpcode() == ISD::Constant &&
6177 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, N0.getValueType()) &&
6178 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
6179 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
6180 if (LN0->getExtensionType() != ISD::SEXTLOAD && LN0->isUnindexed()) {
6181 bool DoXform = true;
6182 SmallVector<SDNode*, 4> SetCCs;
6183 if (!N0.hasOneUse())
6184 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
6187 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
6188 LN0->getChain(), LN0->getBasePtr(),
6190 LN0->getMemOperand());
6191 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6192 Mask = Mask.zext(VT.getSizeInBits());
6194 SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
6195 ExtLoad, DAG.getConstant(Mask, DL, VT));
6196 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
6197 SDLoc(N0.getOperand(0)),
6198 N0.getOperand(0).getValueType(), ExtLoad);
6200 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
6201 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL,
6203 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6208 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
6209 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
6210 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
6211 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
6212 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6213 EVT MemVT = LN0->getMemoryVT();
6214 if ((!LegalOperations && !LN0->isVolatile()) ||
6215 TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT)) {
6216 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
6218 LN0->getBasePtr(), MemVT,
6219 LN0->getMemOperand());
6220 CombineTo(N, ExtLoad);
6221 CombineTo(N0.getNode(),
6222 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
6224 ExtLoad.getValue(1));
6225 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6229 if (N0.getOpcode() == ISD::SETCC) {
6230 if (!LegalOperations && VT.isVector() &&
6231 N0.getValueType().getVectorElementType() == MVT::i1) {
6232 EVT N0VT = N0.getOperand(0).getValueType();
6233 if (getSetCCResultType(N0VT) == N0.getValueType())
6236 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
6237 // Only do this before legalize for now.
6238 EVT EltVT = VT.getVectorElementType();
6240 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
6241 DAG.getConstant(1, DL, EltVT));
6242 if (VT.getSizeInBits() == N0VT.getSizeInBits())
6243 // We know that the # elements of the results is the same as the
6244 // # elements of the compare (and the # elements of the compare result
6245 // for that matter). Check to see that they are the same size. If so,
6246 // we know that the element size of the sext'd result matches the
6247 // element size of the compare operands.
6248 return DAG.getNode(ISD::AND, DL, VT,
6249 DAG.getSetCC(DL, VT, N0.getOperand(0),
6251 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
6252 DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
6255 // If the desired elements are smaller or larger than the source
6256 // elements we can use a matching integer vector type and then
6257 // truncate/sign extend
6258 EVT MatchingElementType =
6259 EVT::getIntegerVT(*DAG.getContext(),
6260 N0VT.getScalarType().getSizeInBits());
6261 EVT MatchingVectorType =
6262 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
6263 N0VT.getVectorNumElements());
6265 DAG.getSetCC(DL, MatchingVectorType, N0.getOperand(0),
6267 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6268 return DAG.getNode(ISD::AND, DL, VT,
6269 DAG.getSExtOrTrunc(VsetCC, DL, VT),
6270 DAG.getNode(ISD::BUILD_VECTOR, DL, VT, OneOps));
6273 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
6276 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
6277 DAG.getConstant(1, DL, VT), DAG.getConstant(0, DL, VT),
6278 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
6279 if (SCC.getNode()) return SCC;
6282 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
6283 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
6284 isa<ConstantSDNode>(N0.getOperand(1)) &&
6285 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
6287 SDValue ShAmt = N0.getOperand(1);
6288 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
6289 if (N0.getOpcode() == ISD::SHL) {
6290 SDValue InnerZExt = N0.getOperand(0);
6291 // If the original shl may be shifting out bits, do not perform this
6293 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
6294 InnerZExt.getOperand(0).getValueType().getSizeInBits();
6295 if (ShAmtVal > KnownZeroBits)
6301 // Ensure that the shift amount is wide enough for the shifted value.
6302 if (VT.getSizeInBits() >= 256)
6303 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
6305 return DAG.getNode(N0.getOpcode(), DL, VT,
6306 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
6313 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
6314 SDValue N0 = N->getOperand(0);
6315 EVT VT = N->getValueType(0);
6317 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6319 return SDValue(Res, 0);
6321 // fold (aext (aext x)) -> (aext x)
6322 // fold (aext (zext x)) -> (zext x)
6323 // fold (aext (sext x)) -> (sext x)
6324 if (N0.getOpcode() == ISD::ANY_EXTEND ||
6325 N0.getOpcode() == ISD::ZERO_EXTEND ||
6326 N0.getOpcode() == ISD::SIGN_EXTEND)
6327 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
6329 // fold (aext (truncate (load x))) -> (aext (smaller load x))
6330 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
6331 if (N0.getOpcode() == ISD::TRUNCATE) {
6332 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
6333 if (NarrowLoad.getNode()) {
6334 SDNode* oye = N0.getNode()->getOperand(0).getNode();
6335 if (NarrowLoad.getNode() != N0.getNode()) {
6336 CombineTo(N0.getNode(), NarrowLoad);
6337 // CombineTo deleted the truncate, if needed, but not what's under it.
6340 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6344 // fold (aext (truncate x))
6345 if (N0.getOpcode() == ISD::TRUNCATE) {
6346 SDValue TruncOp = N0.getOperand(0);
6347 if (TruncOp.getValueType() == VT)
6348 return TruncOp; // x iff x size == zext size.
6349 if (TruncOp.getValueType().bitsGT(VT))
6350 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, TruncOp);
6351 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, TruncOp);
6354 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
6355 // if the trunc is not free.
6356 if (N0.getOpcode() == ISD::AND &&
6357 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
6358 N0.getOperand(1).getOpcode() == ISD::Constant &&
6359 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
6360 N0.getValueType())) {
6361 SDValue X = N0.getOperand(0).getOperand(0);
6362 if (X.getValueType().bitsLT(VT)) {
6363 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, X);
6364 } else if (X.getValueType().bitsGT(VT)) {
6365 X = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, X);
6367 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
6368 Mask = Mask.zext(VT.getSizeInBits());
6370 return DAG.getNode(ISD::AND, DL, VT,
6371 X, DAG.getConstant(Mask, DL, VT));
6374 // fold (aext (load x)) -> (aext (truncate (extload x)))
6375 // None of the supported targets knows how to perform load and any_ext
6376 // on vectors in one instruction. We only perform this transformation on
6378 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
6379 ISD::isUNINDEXEDLoad(N0.getNode()) &&
6380 TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
6381 bool DoXform = true;
6382 SmallVector<SDNode*, 4> SetCCs;
6383 if (!N0.hasOneUse())
6384 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
6386 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6387 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
6389 LN0->getBasePtr(), N0.getValueType(),
6390 LN0->getMemOperand());
6391 CombineTo(N, ExtLoad);
6392 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6393 N0.getValueType(), ExtLoad);
6394 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
6395 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
6397 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6401 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
6402 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
6403 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
6404 if (N0.getOpcode() == ISD::LOAD &&
6405 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6407 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6408 ISD::LoadExtType ExtType = LN0->getExtensionType();
6409 EVT MemVT = LN0->getMemoryVT();
6410 if (!LegalOperations || TLI.isLoadExtLegal(ExtType, VT, MemVT)) {
6411 SDValue ExtLoad = DAG.getExtLoad(ExtType, SDLoc(N),
6412 VT, LN0->getChain(), LN0->getBasePtr(),
6413 MemVT, LN0->getMemOperand());
6414 CombineTo(N, ExtLoad);
6415 CombineTo(N0.getNode(),
6416 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
6417 N0.getValueType(), ExtLoad),
6418 ExtLoad.getValue(1));
6419 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6423 if (N0.getOpcode() == ISD::SETCC) {
6425 // aext(setcc) -> vsetcc
6426 // aext(setcc) -> truncate(vsetcc)
6427 // aext(setcc) -> aext(vsetcc)
6428 // Only do this before legalize for now.
6429 if (VT.isVector() && !LegalOperations) {
6430 EVT N0VT = N0.getOperand(0).getValueType();
6431 // We know that the # elements of the results is the same as the
6432 // # elements of the compare (and the # elements of the compare result
6433 // for that matter). Check to see that they are the same size. If so,
6434 // we know that the element size of the sext'd result matches the
6435 // element size of the compare operands.
6436 if (VT.getSizeInBits() == N0VT.getSizeInBits())
6437 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
6439 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6440 // If the desired elements are smaller or larger than the source
6441 // elements we can use a matching integer vector type and then
6442 // truncate/any extend
6444 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
6446 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
6448 cast<CondCodeSDNode>(N0.getOperand(2))->get());
6449 return DAG.getAnyExtOrTrunc(VsetCC, SDLoc(N), VT);
6453 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
6456 SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1),
6457 DAG.getConstant(1, DL, VT), DAG.getConstant(0, DL, VT),
6458 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
6466 /// See if the specified operand can be simplified with the knowledge that only
6467 /// the bits specified by Mask are used. If so, return the simpler operand,
6468 /// otherwise return a null SDValue.
6469 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
6470 switch (V.getOpcode()) {
6472 case ISD::Constant: {
6473 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
6474 assert(CV && "Const value should be ConstSDNode.");
6475 const APInt &CVal = CV->getAPIntValue();
6476 APInt NewVal = CVal & Mask;
6478 return DAG.getConstant(NewVal, SDLoc(V), V.getValueType());
6483 // If the LHS or RHS don't contribute bits to the or, drop them.
6484 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
6485 return V.getOperand(1);
6486 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
6487 return V.getOperand(0);
6490 // Only look at single-use SRLs.
6491 if (!V.getNode()->hasOneUse())
6493 if (ConstantSDNode *RHSC = getAsNonOpaqueConstant(V.getOperand(1))) {
6494 // See if we can recursively simplify the LHS.
6495 unsigned Amt = RHSC->getZExtValue();
6497 // Watch out for shift count overflow though.
6498 if (Amt >= Mask.getBitWidth()) break;
6499 APInt NewMask = Mask << Amt;
6500 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
6501 if (SimplifyLHS.getNode())
6502 return DAG.getNode(ISD::SRL, SDLoc(V), V.getValueType(),
6503 SimplifyLHS, V.getOperand(1));
6509 /// If the result of a wider load is shifted to right of N bits and then
6510 /// truncated to a narrower type and where N is a multiple of number of bits of
6511 /// the narrower type, transform it to a narrower load from address + N / num of
6512 /// bits of new type. If the result is to be extended, also fold the extension
6513 /// to form a extending load.
6514 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
6515 unsigned Opc = N->getOpcode();
6517 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
6518 SDValue N0 = N->getOperand(0);
6519 EVT VT = N->getValueType(0);
6522 // This transformation isn't valid for vector loads.
6526 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
6528 if (Opc == ISD::SIGN_EXTEND_INREG) {
6529 ExtType = ISD::SEXTLOAD;
6530 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6531 } else if (Opc == ISD::SRL) {
6532 // Another special-case: SRL is basically zero-extending a narrower value.
6533 ExtType = ISD::ZEXTLOAD;
6535 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
6536 if (!N01) return SDValue();
6537 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
6538 VT.getSizeInBits() - N01->getZExtValue());
6540 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, VT, ExtVT))
6543 unsigned EVTBits = ExtVT.getSizeInBits();
6545 // Do not generate loads of non-round integer types since these can
6546 // be expensive (and would be wrong if the type is not byte sized).
6547 if (!ExtVT.isRound())
6551 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
6552 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
6553 ShAmt = N01->getZExtValue();
6554 // Is the shift amount a multiple of size of VT?
6555 if ((ShAmt & (EVTBits-1)) == 0) {
6556 N0 = N0.getOperand(0);
6557 // Is the load width a multiple of size of VT?
6558 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
6562 // At this point, we must have a load or else we can't do the transform.
6563 if (!isa<LoadSDNode>(N0)) return SDValue();
6565 // Because a SRL must be assumed to *need* to zero-extend the high bits
6566 // (as opposed to anyext the high bits), we can't combine the zextload
6567 // lowering of SRL and an sextload.
6568 if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
6571 // If the shift amount is larger than the input type then we're not
6572 // accessing any of the loaded bytes. If the load was a zextload/extload
6573 // then the result of the shift+trunc is zero/undef (handled elsewhere).
6574 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
6579 // If the load is shifted left (and the result isn't shifted back right),
6580 // we can fold the truncate through the shift.
6581 unsigned ShLeftAmt = 0;
6582 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
6583 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
6584 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
6585 ShLeftAmt = N01->getZExtValue();
6586 N0 = N0.getOperand(0);
6590 // If we haven't found a load, we can't narrow it. Don't transform one with
6591 // multiple uses, this would require adding a new load.
6592 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse())
6595 // Don't change the width of a volatile load.
6596 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6597 if (LN0->isVolatile())
6600 // Verify that we are actually reducing a load width here.
6601 if (LN0->getMemoryVT().getSizeInBits() < EVTBits)
6604 // For the transform to be legal, the load must produce only two values
6605 // (the value loaded and the chain). Don't transform a pre-increment
6606 // load, for example, which produces an extra value. Otherwise the
6607 // transformation is not equivalent, and the downstream logic to replace
6608 // uses gets things wrong.
6609 if (LN0->getNumValues() > 2)
6612 // If the load that we're shrinking is an extload and we're not just
6613 // discarding the extension we can't simply shrink the load. Bail.
6614 // TODO: It would be possible to merge the extensions in some cases.
6615 if (LN0->getExtensionType() != ISD::NON_EXTLOAD &&
6616 LN0->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
6619 if (!TLI.shouldReduceLoadWidth(LN0, ExtType, ExtVT))
6622 EVT PtrType = N0.getOperand(1).getValueType();
6624 if (PtrType == MVT::Untyped || PtrType.isExtended())
6625 // It's not possible to generate a constant of extended or untyped type.
6628 // For big endian targets, we need to adjust the offset to the pointer to
6629 // load the correct bytes.
6630 if (TLI.isBigEndian()) {
6631 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
6632 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
6633 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
6636 uint64_t PtrOff = ShAmt / 8;
6637 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
6639 SDValue NewPtr = DAG.getNode(ISD::ADD, DL,
6640 PtrType, LN0->getBasePtr(),
6641 DAG.getConstant(PtrOff, DL, PtrType));
6642 AddToWorklist(NewPtr.getNode());
6645 if (ExtType == ISD::NON_EXTLOAD)
6646 Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
6647 LN0->getPointerInfo().getWithOffset(PtrOff),
6648 LN0->isVolatile(), LN0->isNonTemporal(),
6649 LN0->isInvariant(), NewAlign, LN0->getAAInfo());
6651 Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
6652 LN0->getPointerInfo().getWithOffset(PtrOff),
6653 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
6654 LN0->isInvariant(), NewAlign, LN0->getAAInfo());
6656 // Replace the old load's chain with the new load's chain.
6657 WorklistRemover DeadNodes(*this);
6658 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
6660 // Shift the result left, if we've swallowed a left shift.
6661 SDValue Result = Load;
6662 if (ShLeftAmt != 0) {
6663 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
6664 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
6666 // If the shift amount is as large as the result size (but, presumably,
6667 // no larger than the source) then the useful bits of the result are
6668 // zero; we can't simply return the shortened shift, because the result
6669 // of that operation is undefined.
6671 if (ShLeftAmt >= VT.getSizeInBits())
6672 Result = DAG.getConstant(0, DL, VT);
6674 Result = DAG.getNode(ISD::SHL, DL, VT,
6675 Result, DAG.getConstant(ShLeftAmt, DL, ShImmTy));
6678 // Return the new loaded value.
6682 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
6683 SDValue N0 = N->getOperand(0);
6684 SDValue N1 = N->getOperand(1);
6685 EVT VT = N->getValueType(0);
6686 EVT EVT = cast<VTSDNode>(N1)->getVT();
6687 unsigned VTBits = VT.getScalarType().getSizeInBits();
6688 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
6690 // fold (sext_in_reg c1) -> c1
6691 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
6692 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);
6694 // If the input is already sign extended, just drop the extension.
6695 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
6698 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
6699 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
6700 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
6701 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
6702 N0.getOperand(0), N1);
6704 // fold (sext_in_reg (sext x)) -> (sext x)
6705 // fold (sext_in_reg (aext x)) -> (sext x)
6706 // if x is small enough.
6707 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
6708 SDValue N00 = N0.getOperand(0);
6709 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
6710 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
6711 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
6714 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
6715 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
6716 return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT);
6718 // fold operands of sext_in_reg based on knowledge that the top bits are not
6720 if (SimplifyDemandedBits(SDValue(N, 0)))
6721 return SDValue(N, 0);
6723 // fold (sext_in_reg (load x)) -> (smaller sextload x)
6724 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
6725 SDValue NarrowLoad = ReduceLoadWidth(N);
6726 if (NarrowLoad.getNode())
6729 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
6730 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
6731 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
6732 if (N0.getOpcode() == ISD::SRL) {
6733 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
6734 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
6735 // We can turn this into an SRA iff the input to the SRL is already sign
6737 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
6738 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
6739 return DAG.getNode(ISD::SRA, SDLoc(N), VT,
6740 N0.getOperand(0), N0.getOperand(1));
6744 // fold (sext_inreg (extload x)) -> (sextload x)
6745 if (ISD::isEXTLoad(N0.getNode()) &&
6746 ISD::isUNINDEXEDLoad(N0.getNode()) &&
6747 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
6748 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6749 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
6750 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6751 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
6753 LN0->getBasePtr(), EVT,
6754 LN0->getMemOperand());
6755 CombineTo(N, ExtLoad);
6756 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
6757 AddToWorklist(ExtLoad.getNode());
6758 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6760 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
6761 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
6763 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
6764 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6765 TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
6766 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6767 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
6769 LN0->getBasePtr(), EVT,
6770 LN0->getMemOperand());
6771 CombineTo(N, ExtLoad);
6772 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
6773 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6776 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
6777 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
6778 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
6779 N0.getOperand(1), false);
6780 if (BSwap.getNode())
6781 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
6785 // Fold a sext_inreg of a build_vector of ConstantSDNodes or undefs
6786 // into a build_vector.
6787 if (ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
6788 SmallVector<SDValue, 8> Elts;
6789 unsigned NumElts = N0->getNumOperands();
6790 unsigned ShAmt = VTBits - EVTBits;
6792 for (unsigned i = 0; i != NumElts; ++i) {
6793 SDValue Op = N0->getOperand(i);
6794 if (Op->getOpcode() == ISD::UNDEF) {
6799 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
6800 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
6801 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
6802 SDLoc(Op), Op.getValueType()));
6805 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Elts);
6811 SDValue DAGCombiner::visitSIGN_EXTEND_VECTOR_INREG(SDNode *N) {
6812 SDValue N0 = N->getOperand(0);
6813 EVT VT = N->getValueType(0);
6815 if (N0.getOpcode() == ISD::UNDEF)
6816 return DAG.getUNDEF(VT);
6818 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
6820 return SDValue(Res, 0);
6825 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
6826 SDValue N0 = N->getOperand(0);
6827 EVT VT = N->getValueType(0);
6828 bool isLE = TLI.isLittleEndian();
6831 if (N0.getValueType() == N->getValueType(0))
6833 // fold (truncate c1) -> c1
6834 if (isConstantIntBuildVectorOrConstantInt(N0))
6835 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
6836 // fold (truncate (truncate x)) -> (truncate x)
6837 if (N0.getOpcode() == ISD::TRUNCATE)
6838 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
6839 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
6840 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
6841 N0.getOpcode() == ISD::SIGN_EXTEND ||
6842 N0.getOpcode() == ISD::ANY_EXTEND) {
6843 if (N0.getOperand(0).getValueType().bitsLT(VT))
6844 // if the source is smaller than the dest, we still need an extend
6845 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
6847 if (N0.getOperand(0).getValueType().bitsGT(VT))
6848 // if the source is larger than the dest, than we just need the truncate
6849 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
6850 // if the source and dest are the same type, we can drop both the extend
6851 // and the truncate.
6852 return N0.getOperand(0);
6855 // Fold extract-and-trunc into a narrow extract. For example:
6856 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
6857 // i32 y = TRUNCATE(i64 x)
6859 // v16i8 b = BITCAST (v2i64 val)
6860 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
6862 // Note: We only run this optimization after type legalization (which often
6863 // creates this pattern) and before operation legalization after which
6864 // we need to be more careful about the vector instructions that we generate.
6865 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
6866 LegalTypes && !LegalOperations && N0->hasOneUse() && VT != MVT::i1) {
6868 EVT VecTy = N0.getOperand(0).getValueType();
6869 EVT ExTy = N0.getValueType();
6870 EVT TrTy = N->getValueType(0);
6872 unsigned NumElem = VecTy.getVectorNumElements();
6873 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
6875 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
6876 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
6878 SDValue EltNo = N0->getOperand(1);
6879 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
6880 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
6881 EVT IndexTy = TLI.getVectorIdxTy();
6882 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
6884 SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
6885 NVT, N0.getOperand(0));
6888 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
6890 DAG.getConstant(Index, DL, IndexTy));
6894 // trunc (select c, a, b) -> select c, (trunc a), (trunc b)
6895 if (N0.getOpcode() == ISD::SELECT) {
6896 EVT SrcVT = N0.getValueType();
6897 if ((!LegalOperations || TLI.isOperationLegal(ISD::SELECT, SrcVT)) &&
6898 TLI.isTruncateFree(SrcVT, VT)) {
6900 SDValue Cond = N0.getOperand(0);
6901 SDValue TruncOp0 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
6902 SDValue TruncOp1 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(2));
6903 return DAG.getNode(ISD::SELECT, SDLoc(N), VT, Cond, TruncOp0, TruncOp1);
6907 // Fold a series of buildvector, bitcast, and truncate if possible.
6909 // (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
6910 // (2xi32 (buildvector x, y)).
6911 if (Level == AfterLegalizeVectorOps && VT.isVector() &&
6912 N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
6913 N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
6914 N0.getOperand(0).hasOneUse()) {
6916 SDValue BuildVect = N0.getOperand(0);
6917 EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
6918 EVT TruncVecEltTy = VT.getVectorElementType();
6920 // Check that the element types match.
6921 if (BuildVectEltTy == TruncVecEltTy) {
6922 // Now we only need to compute the offset of the truncated elements.
6923 unsigned BuildVecNumElts = BuildVect.getNumOperands();
6924 unsigned TruncVecNumElts = VT.getVectorNumElements();
6925 unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;
6927 assert((BuildVecNumElts % TruncVecNumElts) == 0 &&
6928 "Invalid number of elements");
6930 SmallVector<SDValue, 8> Opnds;
6931 for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
6932 Opnds.push_back(BuildVect.getOperand(i));
6934 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
6938 // See if we can simplify the input to this truncate through knowledge that
6939 // only the low bits are being used.
6940 // For example "trunc (or (shl x, 8), y)" // -> trunc y
6941 // Currently we only perform this optimization on scalars because vectors
6942 // may have different active low bits.
6943 if (!VT.isVector()) {
6945 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
6946 VT.getSizeInBits()));
6947 if (Shorter.getNode())
6948 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
6950 // fold (truncate (load x)) -> (smaller load x)
6951 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
6952 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
6953 SDValue Reduced = ReduceLoadWidth(N);
6954 if (Reduced.getNode())
6956 // Handle the case where the load remains an extending load even
6957 // after truncation.
6958 if (N0.hasOneUse() && ISD::isUNINDEXEDLoad(N0.getNode())) {
6959 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6960 if (!LN0->isVolatile() &&
6961 LN0->getMemoryVT().getStoreSizeInBits() < VT.getSizeInBits()) {
6962 SDValue NewLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(LN0),
6963 VT, LN0->getChain(), LN0->getBasePtr(),
6965 LN0->getMemOperand());
6966 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLoad.getValue(1));
6971 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
6972 // where ... are all 'undef'.
6973 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
6974 SmallVector<EVT, 8> VTs;
6977 unsigned NumDefs = 0;
6979 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
6980 SDValue X = N0.getOperand(i);
6981 if (X.getOpcode() != ISD::UNDEF) {
6986 // Stop if more than one members are non-undef.
6989 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
6990 VT.getVectorElementType(),
6991 X.getValueType().getVectorNumElements()));
6995 return DAG.getUNDEF(VT);
6998 assert(V.getNode() && "The single defined operand is empty!");
6999 SmallVector<SDValue, 8> Opnds;
7000 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
7002 Opnds.push_back(DAG.getUNDEF(VTs[i]));
7005 SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
7006 AddToWorklist(NV.getNode());
7007 Opnds.push_back(NV);
7009 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Opnds);
7013 // Simplify the operands using demanded-bits information.
7014 if (!VT.isVector() &&
7015 SimplifyDemandedBits(SDValue(N, 0)))
7016 return SDValue(N, 0);
7021 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
7022 SDValue Elt = N->getOperand(i);
7023 if (Elt.getOpcode() != ISD::MERGE_VALUES)
7024 return Elt.getNode();
7025 return Elt.getOperand(Elt.getResNo()).getNode();
7028 /// build_pair (load, load) -> load
7029 /// if load locations are consecutive.
7030 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
7031 assert(N->getOpcode() == ISD::BUILD_PAIR);
7033 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
7034 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
7035 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
7036 LD1->getAddressSpace() != LD2->getAddressSpace())
7038 EVT LD1VT = LD1->getValueType(0);
7040 if (ISD::isNON_EXTLoad(LD2) &&
7042 // If both are volatile this would reduce the number of volatile loads.
7043 // If one is volatile it might be ok, but play conservative and bail out.
7044 !LD1->isVolatile() &&
7045 !LD2->isVolatile() &&
7046 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
7047 unsigned Align = LD1->getAlignment();
7048 unsigned NewAlign = TLI.getDataLayout()->
7049 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
7051 if (NewAlign <= Align &&
7052 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
7053 return DAG.getLoad(VT, SDLoc(N), LD1->getChain(),
7054 LD1->getBasePtr(), LD1->getPointerInfo(),
7055 false, false, false, Align);
7061 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
7062 SDValue N0 = N->getOperand(0);
7063 EVT VT = N->getValueType(0);
7065 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
7066 // Only do this before legalize, since afterward the target may be depending
7067 // on the bitconvert.
7068 // First check to see if this is all constant.
7070 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
7072 bool isSimple = cast<BuildVectorSDNode>(N0)->isConstant();
7074 EVT DestEltVT = N->getValueType(0).getVectorElementType();
7075 assert(!DestEltVT.isVector() &&
7076 "Element type of vector ValueType must not be vector!");
7078 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
7081 // If the input is a constant, let getNode fold it.
7082 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
7083 // If we can't allow illegal operations, we need to check that this is just
7084 // a fp -> int or int -> conversion and that the resulting operation will
7086 if (!LegalOperations ||
7087 (isa<ConstantSDNode>(N0) && VT.isFloatingPoint() && !VT.isVector() &&
7088 TLI.isOperationLegal(ISD::ConstantFP, VT)) ||
7089 (isa<ConstantFPSDNode>(N0) && VT.isInteger() && !VT.isVector() &&
7090 TLI.isOperationLegal(ISD::Constant, VT)))
7091 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, N0);
7094 // (conv (conv x, t1), t2) -> (conv x, t2)
7095 if (N0.getOpcode() == ISD::BITCAST)
7096 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT,
7099 // fold (conv (load x)) -> (load (conv*)x)
7100 // If the resultant load doesn't need a higher alignment than the original!
7101 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7102 // Do not change the width of a volatile load.
7103 !cast<LoadSDNode>(N0)->isVolatile() &&
7104 // Do not remove the cast if the types differ in endian layout.
7105 TLI.hasBigEndianPartOrdering(N0.getValueType()) ==
7106 TLI.hasBigEndianPartOrdering(VT) &&
7107 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)) &&
7108 TLI.isLoadBitCastBeneficial(N0.getValueType(), VT)) {
7109 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
7110 unsigned Align = TLI.getDataLayout()->
7111 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
7112 unsigned OrigAlign = LN0->getAlignment();
7114 if (Align <= OrigAlign) {
7115 SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
7116 LN0->getBasePtr(), LN0->getPointerInfo(),
7117 LN0->isVolatile(), LN0->isNonTemporal(),
7118 LN0->isInvariant(), OrigAlign,
7120 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
7125 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
7126 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
7127 // This often reduces constant pool loads.
7128 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
7129 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
7130 N0.getNode()->hasOneUse() && VT.isInteger() &&
7131 !VT.isVector() && !N0.getValueType().isVector()) {
7132 SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
7134 AddToWorklist(NewConv.getNode());
7137 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
7138 if (N0.getOpcode() == ISD::FNEG)
7139 return DAG.getNode(ISD::XOR, DL, VT,
7140 NewConv, DAG.getConstant(SignBit, DL, VT));
7141 assert(N0.getOpcode() == ISD::FABS);
7142 return DAG.getNode(ISD::AND, DL, VT,
7143 NewConv, DAG.getConstant(~SignBit, DL, VT));
7146 // fold (bitconvert (fcopysign cst, x)) ->
7147 // (or (and (bitconvert x), sign), (and cst, (not sign)))
7148 // Note that we don't handle (copysign x, cst) because this can always be
7149 // folded to an fneg or fabs.
7150 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
7151 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
7152 VT.isInteger() && !VT.isVector()) {
7153 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
7154 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
7155 if (isTypeLegal(IntXVT)) {
7156 SDValue X = DAG.getNode(ISD::BITCAST, SDLoc(N0),
7157 IntXVT, N0.getOperand(1));
7158 AddToWorklist(X.getNode());
7160 // If X has a different width than the result/lhs, sext it or truncate it.
7161 unsigned VTWidth = VT.getSizeInBits();
7162 if (OrigXWidth < VTWidth) {
7163 X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
7164 AddToWorklist(X.getNode());
7165 } else if (OrigXWidth > VTWidth) {
7166 // To get the sign bit in the right place, we have to shift it right
7167 // before truncating.
7169 X = DAG.getNode(ISD::SRL, DL,
7170 X.getValueType(), X,
7171 DAG.getConstant(OrigXWidth-VTWidth, DL,
7173 AddToWorklist(X.getNode());
7174 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
7175 AddToWorklist(X.getNode());
7178 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
7179 X = DAG.getNode(ISD::AND, SDLoc(X), VT,
7180 X, DAG.getConstant(SignBit, SDLoc(X), VT));
7181 AddToWorklist(X.getNode());
7183 SDValue Cst = DAG.getNode(ISD::BITCAST, SDLoc(N0),
7184 VT, N0.getOperand(0));
7185 Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
7186 Cst, DAG.getConstant(~SignBit, SDLoc(Cst), VT));
7187 AddToWorklist(Cst.getNode());
7189 return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
7193 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
7194 if (N0.getOpcode() == ISD::BUILD_PAIR) {
7195 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
7196 if (CombineLD.getNode())
7200 // Remove double bitcasts from shuffles - this is often a legacy of
7201 // XformToShuffleWithZero being used to combine bitmaskings (of
7202 // float vectors bitcast to integer vectors) into shuffles.
7203 // bitcast(shuffle(bitcast(s0),bitcast(s1))) -> shuffle(s0,s1)
7204 if (Level < AfterLegalizeDAG && TLI.isTypeLegal(VT) && VT.isVector() &&
7205 N0->getOpcode() == ISD::VECTOR_SHUFFLE &&
7206 VT.getVectorNumElements() >= N0.getValueType().getVectorNumElements() &&
7207 !(VT.getVectorNumElements() % N0.getValueType().getVectorNumElements())) {
7208 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N0);
7210 // If operands are a bitcast, peek through if it casts the original VT.
7211 // If operands are a UNDEF or constant, just bitcast back to original VT.
7212 auto PeekThroughBitcast = [&](SDValue Op) {
7213 if (Op.getOpcode() == ISD::BITCAST &&
7214 Op.getOperand(0)->getValueType(0) == VT)
7215 return SDValue(Op.getOperand(0));
7216 if (ISD::isBuildVectorOfConstantSDNodes(Op.getNode()) ||
7217 ISD::isBuildVectorOfConstantFPSDNodes(Op.getNode()))
7218 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
7222 SDValue SV0 = PeekThroughBitcast(N0->getOperand(0));
7223 SDValue SV1 = PeekThroughBitcast(N0->getOperand(1));
7228 VT.getVectorNumElements() / N0.getValueType().getVectorNumElements();
7229 SmallVector<int, 8> NewMask;
7230 for (int M : SVN->getMask())
7231 for (int i = 0; i != MaskScale; ++i)
7232 NewMask.push_back(M < 0 ? -1 : M * MaskScale + i);
7234 bool LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
7236 std::swap(SV0, SV1);
7237 ShuffleVectorSDNode::commuteMask(NewMask);
7238 LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
7242 return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, NewMask);
7248 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
7249 EVT VT = N->getValueType(0);
7250 return CombineConsecutiveLoads(N, VT);
7253 /// We know that BV is a build_vector node with Constant, ConstantFP or Undef
7254 /// operands. DstEltVT indicates the destination element value type.
7255 SDValue DAGCombiner::
7256 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
7257 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
7259 // If this is already the right type, we're done.
7260 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
7262 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
7263 unsigned DstBitSize = DstEltVT.getSizeInBits();
7265 // If this is a conversion of N elements of one type to N elements of another
7266 // type, convert each element. This handles FP<->INT cases.
7267 if (SrcBitSize == DstBitSize) {
7268 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
7269 BV->getValueType(0).getVectorNumElements());
7271 // Due to the FP element handling below calling this routine recursively,
7272 // we can end up with a scalar-to-vector node here.
7273 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
7274 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
7275 DAG.getNode(ISD::BITCAST, SDLoc(BV),
7276 DstEltVT, BV->getOperand(0)));
7278 SmallVector<SDValue, 8> Ops;
7279 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
7280 SDValue Op = BV->getOperand(i);
7281 // If the vector element type is not legal, the BUILD_VECTOR operands
7282 // are promoted and implicitly truncated. Make that explicit here.
7283 if (Op.getValueType() != SrcEltVT)
7284 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
7285 Ops.push_back(DAG.getNode(ISD::BITCAST, SDLoc(BV),
7287 AddToWorklist(Ops.back().getNode());
7289 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT, Ops);
7292 // Otherwise, we're growing or shrinking the elements. To avoid having to
7293 // handle annoying details of growing/shrinking FP values, we convert them to
7295 if (SrcEltVT.isFloatingPoint()) {
7296 // Convert the input float vector to a int vector where the elements are the
7298 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
7299 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
7303 // Now we know the input is an integer vector. If the output is a FP type,
7304 // convert to integer first, then to FP of the right size.
7305 if (DstEltVT.isFloatingPoint()) {
7306 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
7307 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
7309 // Next, convert to FP elements of the same size.
7310 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
7315 // Okay, we know the src/dst types are both integers of differing types.
7316 // Handling growing first.
7317 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
7318 if (SrcBitSize < DstBitSize) {
7319 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
7321 SmallVector<SDValue, 8> Ops;
7322 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
7323 i += NumInputsPerOutput) {
7324 bool isLE = TLI.isLittleEndian();
7325 APInt NewBits = APInt(DstBitSize, 0);
7326 bool EltIsUndef = true;
7327 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
7328 // Shift the previously computed bits over.
7329 NewBits <<= SrcBitSize;
7330 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
7331 if (Op.getOpcode() == ISD::UNDEF) continue;
7334 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
7335 zextOrTrunc(SrcBitSize).zext(DstBitSize);
7339 Ops.push_back(DAG.getUNDEF(DstEltVT));
7341 Ops.push_back(DAG.getConstant(NewBits, DL, DstEltVT));
7344 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
7345 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
7348 // Finally, this must be the case where we are shrinking elements: each input
7349 // turns into multiple outputs.
7350 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
7351 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
7352 NumOutputsPerInput*BV->getNumOperands());
7353 SmallVector<SDValue, 8> Ops;
7355 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
7356 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
7357 Ops.append(NumOutputsPerInput, DAG.getUNDEF(DstEltVT));
7361 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
7362 getAPIntValue().zextOrTrunc(SrcBitSize);
7364 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
7365 APInt ThisVal = OpVal.trunc(DstBitSize);
7366 Ops.push_back(DAG.getConstant(ThisVal, DL, DstEltVT));
7367 OpVal = OpVal.lshr(DstBitSize);
7370 // For big endian targets, swap the order of the pieces of each element.
7371 if (TLI.isBigEndian())
7372 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
7375 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
7378 /// Try to perform FMA combining on a given FADD node.
7379 SDValue DAGCombiner::visitFADDForFMACombine(SDNode *N) {
7380 SDValue N0 = N->getOperand(0);
7381 SDValue N1 = N->getOperand(1);
7382 EVT VT = N->getValueType(0);
7385 const TargetOptions &Options = DAG.getTarget().Options;
7386 bool UnsafeFPMath = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
7387 Options.UnsafeFPMath);
7389 // Floating-point multiply-add with intermediate rounding.
7390 bool HasFMAD = (LegalOperations &&
7391 TLI.isOperationLegal(ISD::FMAD, VT));
7393 // Floating-point multiply-add without intermediate rounding.
7394 bool HasFMA = ((!LegalOperations ||
7395 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) &&
7396 TLI.isFMAFasterThanFMulAndFAdd(VT) &&
7399 // No valid opcode, do not combine.
7400 if (!HasFMAD && !HasFMA)
7403 // Always prefer FMAD to FMA for precision.
7404 unsigned int PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
7405 bool Aggressive = TLI.enableAggressiveFMAFusion(VT);
7406 bool LookThroughFPExt = TLI.isFPExtFree(VT);
7408 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
7409 if (N0.getOpcode() == ISD::FMUL &&
7410 (Aggressive || N0->hasOneUse())) {
7411 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7412 N0.getOperand(0), N0.getOperand(1), N1);
7415 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
7416 // Note: Commutes FADD operands.
7417 if (N1.getOpcode() == ISD::FMUL &&
7418 (Aggressive || N1->hasOneUse())) {
7419 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7420 N1.getOperand(0), N1.getOperand(1), N0);
7423 // Look through FP_EXTEND nodes to do more combining.
7424 if (UnsafeFPMath && LookThroughFPExt) {
7425 // fold (fadd (fpext (fmul x, y)), z) -> (fma (fpext x), (fpext y), z)
7426 if (N0.getOpcode() == ISD::FP_EXTEND) {
7427 SDValue N00 = N0.getOperand(0);
7428 if (N00.getOpcode() == ISD::FMUL)
7429 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7430 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7432 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7433 N00.getOperand(1)), N1);
7436 // fold (fadd x, (fpext (fmul y, z))) -> (fma (fpext y), (fpext z), x)
7437 // Note: Commutes FADD operands.
7438 if (N1.getOpcode() == ISD::FP_EXTEND) {
7439 SDValue N10 = N1.getOperand(0);
7440 if (N10.getOpcode() == ISD::FMUL)
7441 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7442 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7444 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7445 N10.getOperand(1)), N0);
7449 // More folding opportunities when target permits.
7450 if ((UnsafeFPMath || HasFMAD) && Aggressive) {
7451 // fold (fadd (fma x, y, (fmul u, v)), z) -> (fma x, y (fma u, v, z))
7452 if (N0.getOpcode() == PreferredFusedOpcode &&
7453 N0.getOperand(2).getOpcode() == ISD::FMUL) {
7454 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7455 N0.getOperand(0), N0.getOperand(1),
7456 DAG.getNode(PreferredFusedOpcode, SL, VT,
7457 N0.getOperand(2).getOperand(0),
7458 N0.getOperand(2).getOperand(1),
7462 // fold (fadd x, (fma y, z, (fmul u, v)) -> (fma y, z (fma u, v, x))
7463 if (N1->getOpcode() == PreferredFusedOpcode &&
7464 N1.getOperand(2).getOpcode() == ISD::FMUL) {
7465 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7466 N1.getOperand(0), N1.getOperand(1),
7467 DAG.getNode(PreferredFusedOpcode, SL, VT,
7468 N1.getOperand(2).getOperand(0),
7469 N1.getOperand(2).getOperand(1),
7473 if (UnsafeFPMath && LookThroughFPExt) {
7474 // fold (fadd (fma x, y, (fpext (fmul u, v))), z)
7475 // -> (fma x, y, (fma (fpext u), (fpext v), z))
7476 auto FoldFAddFMAFPExtFMul = [&] (
7477 SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
7478 return DAG.getNode(PreferredFusedOpcode, SL, VT, X, Y,
7479 DAG.getNode(PreferredFusedOpcode, SL, VT,
7480 DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
7481 DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
7484 if (N0.getOpcode() == PreferredFusedOpcode) {
7485 SDValue N02 = N0.getOperand(2);
7486 if (N02.getOpcode() == ISD::FP_EXTEND) {
7487 SDValue N020 = N02.getOperand(0);
7488 if (N020.getOpcode() == ISD::FMUL)
7489 return FoldFAddFMAFPExtFMul(N0.getOperand(0), N0.getOperand(1),
7490 N020.getOperand(0), N020.getOperand(1),
7495 // fold (fadd (fpext (fma x, y, (fmul u, v))), z)
7496 // -> (fma (fpext x), (fpext y), (fma (fpext u), (fpext v), z))
7497 // FIXME: This turns two single-precision and one double-precision
7498 // operation into two double-precision operations, which might not be
7499 // interesting for all targets, especially GPUs.
7500 auto FoldFAddFPExtFMAFMul = [&] (
7501 SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
7502 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7503 DAG.getNode(ISD::FP_EXTEND, SL, VT, X),
7504 DAG.getNode(ISD::FP_EXTEND, SL, VT, Y),
7505 DAG.getNode(PreferredFusedOpcode, SL, VT,
7506 DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
7507 DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
7510 if (N0.getOpcode() == ISD::FP_EXTEND) {
7511 SDValue N00 = N0.getOperand(0);
7512 if (N00.getOpcode() == PreferredFusedOpcode) {
7513 SDValue N002 = N00.getOperand(2);
7514 if (N002.getOpcode() == ISD::FMUL)
7515 return FoldFAddFPExtFMAFMul(N00.getOperand(0), N00.getOperand(1),
7516 N002.getOperand(0), N002.getOperand(1),
7521 // fold (fadd x, (fma y, z, (fpext (fmul u, v)))
7522 // -> (fma y, z, (fma (fpext u), (fpext v), x))
7523 if (N1.getOpcode() == PreferredFusedOpcode) {
7524 SDValue N12 = N1.getOperand(2);
7525 if (N12.getOpcode() == ISD::FP_EXTEND) {
7526 SDValue N120 = N12.getOperand(0);
7527 if (N120.getOpcode() == ISD::FMUL)
7528 return FoldFAddFMAFPExtFMul(N1.getOperand(0), N1.getOperand(1),
7529 N120.getOperand(0), N120.getOperand(1),
7534 // fold (fadd x, (fpext (fma y, z, (fmul u, v)))
7535 // -> (fma (fpext y), (fpext z), (fma (fpext u), (fpext v), x))
7536 // FIXME: This turns two single-precision and one double-precision
7537 // operation into two double-precision operations, which might not be
7538 // interesting for all targets, especially GPUs.
7539 if (N1.getOpcode() == ISD::FP_EXTEND) {
7540 SDValue N10 = N1.getOperand(0);
7541 if (N10.getOpcode() == PreferredFusedOpcode) {
7542 SDValue N102 = N10.getOperand(2);
7543 if (N102.getOpcode() == ISD::FMUL)
7544 return FoldFAddFPExtFMAFMul(N10.getOperand(0), N10.getOperand(1),
7545 N102.getOperand(0), N102.getOperand(1),
7555 /// Try to perform FMA combining on a given FSUB node.
7556 SDValue DAGCombiner::visitFSUBForFMACombine(SDNode *N) {
7557 SDValue N0 = N->getOperand(0);
7558 SDValue N1 = N->getOperand(1);
7559 EVT VT = N->getValueType(0);
7562 const TargetOptions &Options = DAG.getTarget().Options;
7563 bool UnsafeFPMath = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
7564 Options.UnsafeFPMath);
7566 // Floating-point multiply-add with intermediate rounding.
7567 bool HasFMAD = (LegalOperations &&
7568 TLI.isOperationLegal(ISD::FMAD, VT));
7570 // Floating-point multiply-add without intermediate rounding.
7571 bool HasFMA = ((!LegalOperations ||
7572 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) &&
7573 TLI.isFMAFasterThanFMulAndFAdd(VT) &&
7576 // No valid opcode, do not combine.
7577 if (!HasFMAD && !HasFMA)
7580 // Always prefer FMAD to FMA for precision.
7581 unsigned int PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
7582 bool Aggressive = TLI.enableAggressiveFMAFusion(VT);
7583 bool LookThroughFPExt = TLI.isFPExtFree(VT);
7585 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
7586 if (N0.getOpcode() == ISD::FMUL &&
7587 (Aggressive || N0->hasOneUse())) {
7588 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7589 N0.getOperand(0), N0.getOperand(1),
7590 DAG.getNode(ISD::FNEG, SL, VT, N1));
7593 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
7594 // Note: Commutes FSUB operands.
7595 if (N1.getOpcode() == ISD::FMUL &&
7596 (Aggressive || N1->hasOneUse()))
7597 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7598 DAG.getNode(ISD::FNEG, SL, VT,
7600 N1.getOperand(1), N0);
7602 // fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
7603 if (N0.getOpcode() == ISD::FNEG &&
7604 N0.getOperand(0).getOpcode() == ISD::FMUL &&
7605 (Aggressive || (N0->hasOneUse() && N0.getOperand(0).hasOneUse()))) {
7606 SDValue N00 = N0.getOperand(0).getOperand(0);
7607 SDValue N01 = N0.getOperand(0).getOperand(1);
7608 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7609 DAG.getNode(ISD::FNEG, SL, VT, N00), N01,
7610 DAG.getNode(ISD::FNEG, SL, VT, N1));
7613 // Look through FP_EXTEND nodes to do more combining.
7614 if (UnsafeFPMath && LookThroughFPExt) {
7615 // fold (fsub (fpext (fmul x, y)), z)
7616 // -> (fma (fpext x), (fpext y), (fneg z))
7617 if (N0.getOpcode() == ISD::FP_EXTEND) {
7618 SDValue N00 = N0.getOperand(0);
7619 if (N00.getOpcode() == ISD::FMUL)
7620 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7621 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7623 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7625 DAG.getNode(ISD::FNEG, SL, VT, N1));
7628 // fold (fsub x, (fpext (fmul y, z)))
7629 // -> (fma (fneg (fpext y)), (fpext z), x)
7630 // Note: Commutes FSUB operands.
7631 if (N1.getOpcode() == ISD::FP_EXTEND) {
7632 SDValue N10 = N1.getOperand(0);
7633 if (N10.getOpcode() == ISD::FMUL)
7634 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7635 DAG.getNode(ISD::FNEG, SL, VT,
7636 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7637 N10.getOperand(0))),
7638 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7643 // fold (fsub (fpext (fneg (fmul, x, y))), z)
7644 // -> (fneg (fma (fpext x), (fpext y), z))
7645 // Note: This could be removed with appropriate canonicalization of the
7646 // input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
7647 // orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
7648 // from implementing the canonicalization in visitFSUB.
7649 if (N0.getOpcode() == ISD::FP_EXTEND) {
7650 SDValue N00 = N0.getOperand(0);
7651 if (N00.getOpcode() == ISD::FNEG) {
7652 SDValue N000 = N00.getOperand(0);
7653 if (N000.getOpcode() == ISD::FMUL) {
7654 return DAG.getNode(ISD::FNEG, SL, VT,
7655 DAG.getNode(PreferredFusedOpcode, SL, VT,
7656 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7657 N000.getOperand(0)),
7658 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7659 N000.getOperand(1)),
7665 // fold (fsub (fneg (fpext (fmul, x, y))), z)
7666 // -> (fneg (fma (fpext x)), (fpext y), z)
7667 // Note: This could be removed with appropriate canonicalization of the
7668 // input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
7669 // orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
7670 // from implementing the canonicalization in visitFSUB.
7671 if (N0.getOpcode() == ISD::FNEG) {
7672 SDValue N00 = N0.getOperand(0);
7673 if (N00.getOpcode() == ISD::FP_EXTEND) {
7674 SDValue N000 = N00.getOperand(0);
7675 if (N000.getOpcode() == ISD::FMUL) {
7676 return DAG.getNode(ISD::FNEG, SL, VT,
7677 DAG.getNode(PreferredFusedOpcode, SL, VT,
7678 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7679 N000.getOperand(0)),
7680 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7681 N000.getOperand(1)),
7689 // More folding opportunities when target permits.
7690 if ((UnsafeFPMath || HasFMAD) && Aggressive) {
7691 // fold (fsub (fma x, y, (fmul u, v)), z)
7692 // -> (fma x, y (fma u, v, (fneg z)))
7693 if (N0.getOpcode() == PreferredFusedOpcode &&
7694 N0.getOperand(2).getOpcode() == ISD::FMUL) {
7695 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7696 N0.getOperand(0), N0.getOperand(1),
7697 DAG.getNode(PreferredFusedOpcode, SL, VT,
7698 N0.getOperand(2).getOperand(0),
7699 N0.getOperand(2).getOperand(1),
7700 DAG.getNode(ISD::FNEG, SL, VT,
7704 // fold (fsub x, (fma y, z, (fmul u, v)))
7705 // -> (fma (fneg y), z, (fma (fneg u), v, x))
7706 if (N1.getOpcode() == PreferredFusedOpcode &&
7707 N1.getOperand(2).getOpcode() == ISD::FMUL) {
7708 SDValue N20 = N1.getOperand(2).getOperand(0);
7709 SDValue N21 = N1.getOperand(2).getOperand(1);
7710 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7711 DAG.getNode(ISD::FNEG, SL, VT,
7714 DAG.getNode(PreferredFusedOpcode, SL, VT,
7715 DAG.getNode(ISD::FNEG, SL, VT, N20),
7720 if (UnsafeFPMath && LookThroughFPExt) {
7721 // fold (fsub (fma x, y, (fpext (fmul u, v))), z)
7722 // -> (fma x, y (fma (fpext u), (fpext v), (fneg z)))
7723 if (N0.getOpcode() == PreferredFusedOpcode) {
7724 SDValue N02 = N0.getOperand(2);
7725 if (N02.getOpcode() == ISD::FP_EXTEND) {
7726 SDValue N020 = N02.getOperand(0);
7727 if (N020.getOpcode() == ISD::FMUL)
7728 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7729 N0.getOperand(0), N0.getOperand(1),
7730 DAG.getNode(PreferredFusedOpcode, SL, VT,
7731 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7732 N020.getOperand(0)),
7733 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7734 N020.getOperand(1)),
7735 DAG.getNode(ISD::FNEG, SL, VT,
7740 // fold (fsub (fpext (fma x, y, (fmul u, v))), z)
7741 // -> (fma (fpext x), (fpext y),
7742 // (fma (fpext u), (fpext v), (fneg z)))
7743 // FIXME: This turns two single-precision and one double-precision
7744 // operation into two double-precision operations, which might not be
7745 // interesting for all targets, especially GPUs.
7746 if (N0.getOpcode() == ISD::FP_EXTEND) {
7747 SDValue N00 = N0.getOperand(0);
7748 if (N00.getOpcode() == PreferredFusedOpcode) {
7749 SDValue N002 = N00.getOperand(2);
7750 if (N002.getOpcode() == ISD::FMUL)
7751 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7752 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7754 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7756 DAG.getNode(PreferredFusedOpcode, SL, VT,
7757 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7758 N002.getOperand(0)),
7759 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7760 N002.getOperand(1)),
7761 DAG.getNode(ISD::FNEG, SL, VT,
7766 // fold (fsub x, (fma y, z, (fpext (fmul u, v))))
7767 // -> (fma (fneg y), z, (fma (fneg (fpext u)), (fpext v), x))
7768 if (N1.getOpcode() == PreferredFusedOpcode &&
7769 N1.getOperand(2).getOpcode() == ISD::FP_EXTEND) {
7770 SDValue N120 = N1.getOperand(2).getOperand(0);
7771 if (N120.getOpcode() == ISD::FMUL) {
7772 SDValue N1200 = N120.getOperand(0);
7773 SDValue N1201 = N120.getOperand(1);
7774 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7775 DAG.getNode(ISD::FNEG, SL, VT, N1.getOperand(0)),
7777 DAG.getNode(PreferredFusedOpcode, SL, VT,
7778 DAG.getNode(ISD::FNEG, SL, VT,
7779 DAG.getNode(ISD::FP_EXTEND, SL,
7781 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7787 // fold (fsub x, (fpext (fma y, z, (fmul u, v))))
7788 // -> (fma (fneg (fpext y)), (fpext z),
7789 // (fma (fneg (fpext u)), (fpext v), x))
7790 // FIXME: This turns two single-precision and one double-precision
7791 // operation into two double-precision operations, which might not be
7792 // interesting for all targets, especially GPUs.
7793 if (N1.getOpcode() == ISD::FP_EXTEND &&
7794 N1.getOperand(0).getOpcode() == PreferredFusedOpcode) {
7795 SDValue N100 = N1.getOperand(0).getOperand(0);
7796 SDValue N101 = N1.getOperand(0).getOperand(1);
7797 SDValue N102 = N1.getOperand(0).getOperand(2);
7798 if (N102.getOpcode() == ISD::FMUL) {
7799 SDValue N1020 = N102.getOperand(0);
7800 SDValue N1021 = N102.getOperand(1);
7801 return DAG.getNode(PreferredFusedOpcode, SL, VT,
7802 DAG.getNode(ISD::FNEG, SL, VT,
7803 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7805 DAG.getNode(ISD::FP_EXTEND, SL, VT, N101),
7806 DAG.getNode(PreferredFusedOpcode, SL, VT,
7807 DAG.getNode(ISD::FNEG, SL, VT,
7808 DAG.getNode(ISD::FP_EXTEND, SL,
7810 DAG.getNode(ISD::FP_EXTEND, SL, VT,
7821 SDValue DAGCombiner::visitFADD(SDNode *N) {
7822 SDValue N0 = N->getOperand(0);
7823 SDValue N1 = N->getOperand(1);
7824 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7825 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
7826 EVT VT = N->getValueType(0);
7828 const TargetOptions &Options = DAG.getTarget().Options;
7832 if (SDValue FoldedVOp = SimplifyVBinOp(N))
7835 // fold (fadd c1, c2) -> c1 + c2
7837 return DAG.getNode(ISD::FADD, DL, VT, N0, N1);
7839 // canonicalize constant to RHS
7840 if (N0CFP && !N1CFP)
7841 return DAG.getNode(ISD::FADD, DL, VT, N1, N0);
7843 // fold (fadd A, (fneg B)) -> (fsub A, B)
7844 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
7845 isNegatibleForFree(N1, LegalOperations, TLI, &Options) == 2)
7846 return DAG.getNode(ISD::FSUB, DL, VT, N0,
7847 GetNegatedExpression(N1, DAG, LegalOperations));
7849 // fold (fadd (fneg A), B) -> (fsub B, A)
7850 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
7851 isNegatibleForFree(N0, LegalOperations, TLI, &Options) == 2)
7852 return DAG.getNode(ISD::FSUB, DL, VT, N1,
7853 GetNegatedExpression(N0, DAG, LegalOperations));
7855 // If 'unsafe math' is enabled, fold lots of things.
7856 if (Options.UnsafeFPMath) {
7857 // No FP constant should be created after legalization as Instruction
7858 // Selection pass has a hard time dealing with FP constants.
7859 bool AllowNewConst = (Level < AfterLegalizeDAG);
7861 // fold (fadd A, 0) -> A
7862 if (N1CFP && N1CFP->getValueAPF().isZero())
7865 // fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
7866 if (N1CFP && N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
7867 isa<ConstantFPSDNode>(N0.getOperand(1)))
7868 return DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(0),
7869 DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(1), N1));
7871 // If allowed, fold (fadd (fneg x), x) -> 0.0
7872 if (AllowNewConst && N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
7873 return DAG.getConstantFP(0.0, DL, VT);
7875 // If allowed, fold (fadd x, (fneg x)) -> 0.0
7876 if (AllowNewConst && N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
7877 return DAG.getConstantFP(0.0, DL, VT);
7879 // We can fold chains of FADD's of the same value into multiplications.
7880 // This transform is not safe in general because we are reducing the number
7881 // of rounding steps.
7882 if (TLI.isOperationLegalOrCustom(ISD::FMUL, VT) && !N0CFP && !N1CFP) {
7883 if (N0.getOpcode() == ISD::FMUL) {
7884 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
7885 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
7887 // (fadd (fmul x, c), x) -> (fmul x, c+1)
7888 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
7889 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP01, 0),
7890 DAG.getConstantFP(1.0, DL, VT));
7891 return DAG.getNode(ISD::FMUL, DL, VT, N1, NewCFP);
7894 // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
7895 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
7896 N1.getOperand(0) == N1.getOperand(1) &&
7897 N0.getOperand(0) == N1.getOperand(0)) {
7898 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP01, 0),
7899 DAG.getConstantFP(2.0, DL, VT));
7900 return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), NewCFP);
7904 if (N1.getOpcode() == ISD::FMUL) {
7905 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
7906 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
7908 // (fadd x, (fmul x, c)) -> (fmul x, c+1)
7909 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
7910 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP11, 0),
7911 DAG.getConstantFP(1.0, DL, VT));
7912 return DAG.getNode(ISD::FMUL, DL, VT, N0, NewCFP);
7915 // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
7916 if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
7917 N0.getOperand(0) == N0.getOperand(1) &&
7918 N1.getOperand(0) == N0.getOperand(0)) {
7919 SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, SDValue(CFP11, 0),
7920 DAG.getConstantFP(2.0, DL, VT));
7921 return DAG.getNode(ISD::FMUL, DL, VT, N1.getOperand(0), NewCFP);
7925 if (N0.getOpcode() == ISD::FADD && AllowNewConst) {
7926 ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
7927 // (fadd (fadd x, x), x) -> (fmul x, 3.0)
7928 if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
7929 (N0.getOperand(0) == N1)) {
7930 return DAG.getNode(ISD::FMUL, DL, VT,
7931 N1, DAG.getConstantFP(3.0, DL, VT));
7935 if (N1.getOpcode() == ISD::FADD && AllowNewConst) {
7936 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
7937 // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
7938 if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
7939 N1.getOperand(0) == N0) {
7940 return DAG.getNode(ISD::FMUL, DL, VT,
7941 N0, DAG.getConstantFP(3.0, DL, VT));
7945 // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
7946 if (AllowNewConst &&
7947 N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
7948 N0.getOperand(0) == N0.getOperand(1) &&
7949 N1.getOperand(0) == N1.getOperand(1) &&
7950 N0.getOperand(0) == N1.getOperand(0)) {
7951 return DAG.getNode(ISD::FMUL, DL, VT,
7952 N0.getOperand(0), DAG.getConstantFP(4.0, DL, VT));
7955 } // enable-unsafe-fp-math
7957 // FADD -> FMA combines:
7958 SDValue Fused = visitFADDForFMACombine(N);
7960 AddToWorklist(Fused.getNode());
7967 SDValue DAGCombiner::visitFSUB(SDNode *N) {
7968 SDValue N0 = N->getOperand(0);
7969 SDValue N1 = N->getOperand(1);
7970 ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
7971 ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
7972 EVT VT = N->getValueType(0);
7974 const TargetOptions &Options = DAG.getTarget().Options;
7978 if (SDValue FoldedVOp = SimplifyVBinOp(N))
7981 // fold (fsub c1, c2) -> c1-c2
7983 return DAG.getNode(ISD::FSUB, dl, VT, N0, N1);
7985 // fold (fsub A, (fneg B)) -> (fadd A, B)
7986 if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
7987 return DAG.getNode(ISD::FADD, dl, VT, N0,
7988 GetNegatedExpression(N1, DAG, LegalOperations));
7990 // If 'unsafe math' is enabled, fold lots of things.
7991 if (Options.UnsafeFPMath) {
7993 if (N1CFP && N1CFP->getValueAPF().isZero())
7996 // (fsub 0, B) -> -B
7997 if (N0CFP && N0CFP->getValueAPF().isZero()) {
7998 if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
7999 return GetNegatedExpression(N1, DAG, LegalOperations);
8000 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8001 return DAG.getNode(ISD::FNEG, dl, VT, N1);
8004 // (fsub x, x) -> 0.0
8006 return DAG.getConstantFP(0.0f, dl, VT);
8008 // (fsub x, (fadd x, y)) -> (fneg y)
8009 // (fsub x, (fadd y, x)) -> (fneg y)
8010 if (N1.getOpcode() == ISD::FADD) {
8011 SDValue N10 = N1->getOperand(0);
8012 SDValue N11 = N1->getOperand(1);
8014 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI, &Options))
8015 return GetNegatedExpression(N11, DAG, LegalOperations);
8017 if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI, &Options))
8018 return GetNegatedExpression(N10, DAG, LegalOperations);
8022 // FSUB -> FMA combines:
8023 SDValue Fused = visitFSUBForFMACombine(N);
8025 AddToWorklist(Fused.getNode());
8032 SDValue DAGCombiner::visitFMUL(SDNode *N) {
8033 SDValue N0 = N->getOperand(0);
8034 SDValue N1 = N->getOperand(1);
8035 ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
8036 ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
8037 EVT VT = N->getValueType(0);
8039 const TargetOptions &Options = DAG.getTarget().Options;
8042 if (VT.isVector()) {
8043 // This just handles C1 * C2 for vectors. Other vector folds are below.
8044 if (SDValue FoldedVOp = SimplifyVBinOp(N))
8048 // fold (fmul c1, c2) -> c1*c2
8050 return DAG.getNode(ISD::FMUL, DL, VT, N0, N1);
8052 // canonicalize constant to RHS
8053 if (isConstantFPBuildVectorOrConstantFP(N0) &&
8054 !isConstantFPBuildVectorOrConstantFP(N1))
8055 return DAG.getNode(ISD::FMUL, DL, VT, N1, N0);
8057 // fold (fmul A, 1.0) -> A
8058 if (N1CFP && N1CFP->isExactlyValue(1.0))
8061 if (Options.UnsafeFPMath) {
8062 // fold (fmul A, 0) -> 0
8063 if (N1CFP && N1CFP->getValueAPF().isZero())
8066 // fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
8067 if (N0.getOpcode() == ISD::FMUL) {
8068 // Fold scalars or any vector constants (not just splats).
8069 // This fold is done in general by InstCombine, but extra fmul insts
8070 // may have been generated during lowering.
8071 SDValue N00 = N0.getOperand(0);
8072 SDValue N01 = N0.getOperand(1);
8073 auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
8074 auto *BV00 = dyn_cast<BuildVectorSDNode>(N00);
8075 auto *BV01 = dyn_cast<BuildVectorSDNode>(N01);
8077 // Check 1: Make sure that the first operand of the inner multiply is NOT
8078 // a constant. Otherwise, we may induce infinite looping.
8079 if (!(isConstOrConstSplatFP(N00) || (BV00 && BV00->isConstant()))) {
8080 // Check 2: Make sure that the second operand of the inner multiply and
8081 // the second operand of the outer multiply are constants.
8082 if ((N1CFP && isConstOrConstSplatFP(N01)) ||
8083 (BV1 && BV01 && BV1->isConstant() && BV01->isConstant())) {
8084 SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, N01, N1);
8085 return DAG.getNode(ISD::FMUL, DL, VT, N00, MulConsts);
8090 // fold (fmul (fadd x, x), c) -> (fmul x, (fmul 2.0, c))
8091 // Undo the fmul 2.0, x -> fadd x, x transformation, since if it occurs
8092 // during an early run of DAGCombiner can prevent folding with fmuls
8093 // inserted during lowering.
8094 if (N0.getOpcode() == ISD::FADD && N0.getOperand(0) == N0.getOperand(1)) {
8095 const SDValue Two = DAG.getConstantFP(2.0, DL, VT);
8096 SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, Two, N1);
8097 return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), MulConsts);
8101 // fold (fmul X, 2.0) -> (fadd X, X)
8102 if (N1CFP && N1CFP->isExactlyValue(+2.0))
8103 return DAG.getNode(ISD::FADD, DL, VT, N0, N0);
8105 // fold (fmul X, -1.0) -> (fneg X)
8106 if (N1CFP && N1CFP->isExactlyValue(-1.0))
8107 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8108 return DAG.getNode(ISD::FNEG, DL, VT, N0);
8110 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
8111 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
8112 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
8113 // Both can be negated for free, check to see if at least one is cheaper
8115 if (LHSNeg == 2 || RHSNeg == 2)
8116 return DAG.getNode(ISD::FMUL, DL, VT,
8117 GetNegatedExpression(N0, DAG, LegalOperations),
8118 GetNegatedExpression(N1, DAG, LegalOperations));
8125 SDValue DAGCombiner::visitFMA(SDNode *N) {
8126 SDValue N0 = N->getOperand(0);
8127 SDValue N1 = N->getOperand(1);
8128 SDValue N2 = N->getOperand(2);
8129 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8130 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8131 EVT VT = N->getValueType(0);
8133 const TargetOptions &Options = DAG.getTarget().Options;
8135 // Constant fold FMA.
8136 if (isa<ConstantFPSDNode>(N0) &&
8137 isa<ConstantFPSDNode>(N1) &&
8138 isa<ConstantFPSDNode>(N2)) {
8139 return DAG.getNode(ISD::FMA, dl, VT, N0, N1, N2);
8142 if (Options.UnsafeFPMath) {
8143 if (N0CFP && N0CFP->isZero())
8145 if (N1CFP && N1CFP->isZero())
8148 if (N0CFP && N0CFP->isExactlyValue(1.0))
8149 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
8150 if (N1CFP && N1CFP->isExactlyValue(1.0))
8151 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);
8153 // Canonicalize (fma c, x, y) -> (fma x, c, y)
8154 if (N0CFP && !N1CFP)
8155 return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
8157 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
8158 if (Options.UnsafeFPMath && N1CFP &&
8159 N2.getOpcode() == ISD::FMUL &&
8160 N0 == N2.getOperand(0) &&
8161 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
8162 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8163 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
8167 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
8168 if (Options.UnsafeFPMath &&
8169 N0.getOpcode() == ISD::FMUL && N1CFP &&
8170 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
8171 return DAG.getNode(ISD::FMA, dl, VT,
8173 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
8177 // (fma x, 1, y) -> (fadd x, y)
8178 // (fma x, -1, y) -> (fadd (fneg x), y)
8180 if (N1CFP->isExactlyValue(1.0))
8181 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
8183 if (N1CFP->isExactlyValue(-1.0) &&
8184 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
8185 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
8186 AddToWorklist(RHSNeg.getNode());
8187 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
8191 // (fma x, c, x) -> (fmul x, (c+1))
8192 if (Options.UnsafeFPMath && N1CFP && N0 == N2)
8193 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8194 DAG.getNode(ISD::FADD, dl, VT,
8195 N1, DAG.getConstantFP(1.0, dl, VT)));
8197 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
8198 if (Options.UnsafeFPMath && N1CFP &&
8199 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
8200 return DAG.getNode(ISD::FMUL, dl, VT, N0,
8201 DAG.getNode(ISD::FADD, dl, VT,
8202 N1, DAG.getConstantFP(-1.0, dl, VT)));
8208 SDValue DAGCombiner::visitFDIV(SDNode *N) {
8209 SDValue N0 = N->getOperand(0);
8210 SDValue N1 = N->getOperand(1);
8211 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8212 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8213 EVT VT = N->getValueType(0);
8215 const TargetOptions &Options = DAG.getTarget().Options;
8219 if (SDValue FoldedVOp = SimplifyVBinOp(N))
8222 // fold (fdiv c1, c2) -> c1/c2
8224 return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
8226 if (Options.UnsafeFPMath) {
8227 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
8229 // Compute the reciprocal 1.0 / c2.
8230 APFloat N1APF = N1CFP->getValueAPF();
8231 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
8232 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
8233 // Only do the transform if the reciprocal is a legal fp immediate that
8234 // isn't too nasty (eg NaN, denormal, ...).
8235 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
8236 (!LegalOperations ||
8237 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
8238 // backend)... we should handle this gracefully after Legalize.
8239 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
8240 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
8241 TLI.isFPImmLegal(Recip, VT)))
8242 return DAG.getNode(ISD::FMUL, DL, VT, N0,
8243 DAG.getConstantFP(Recip, DL, VT));
8246 // If this FDIV is part of a reciprocal square root, it may be folded
8247 // into a target-specific square root estimate instruction.
8248 if (N1.getOpcode() == ISD::FSQRT) {
8249 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0))) {
8250 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8252 } else if (N1.getOpcode() == ISD::FP_EXTEND &&
8253 N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8254 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
8255 RV = DAG.getNode(ISD::FP_EXTEND, SDLoc(N1), VT, RV);
8256 AddToWorklist(RV.getNode());
8257 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8259 } else if (N1.getOpcode() == ISD::FP_ROUND &&
8260 N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8261 if (SDValue RV = BuildRsqrtEstimate(N1.getOperand(0).getOperand(0))) {
8262 RV = DAG.getNode(ISD::FP_ROUND, SDLoc(N1), VT, RV, N1.getOperand(1));
8263 AddToWorklist(RV.getNode());
8264 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8266 } else if (N1.getOpcode() == ISD::FMUL) {
8267 // Look through an FMUL. Even though this won't remove the FDIV directly,
8268 // it's still worthwhile to get rid of the FSQRT if possible.
8271 if (N1.getOperand(0).getOpcode() == ISD::FSQRT) {
8272 SqrtOp = N1.getOperand(0);
8273 OtherOp = N1.getOperand(1);
8274 } else if (N1.getOperand(1).getOpcode() == ISD::FSQRT) {
8275 SqrtOp = N1.getOperand(1);
8276 OtherOp = N1.getOperand(0);
8278 if (SqrtOp.getNode()) {
8279 // We found a FSQRT, so try to make this fold:
8280 // x / (y * sqrt(z)) -> x * (rsqrt(z) / y)
8281 if (SDValue RV = BuildRsqrtEstimate(SqrtOp.getOperand(0))) {
8282 RV = DAG.getNode(ISD::FDIV, SDLoc(N1), VT, RV, OtherOp);
8283 AddToWorklist(RV.getNode());
8284 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8289 // Fold into a reciprocal estimate and multiply instead of a real divide.
8290 if (SDValue RV = BuildReciprocalEstimate(N1)) {
8291 AddToWorklist(RV.getNode());
8292 return DAG.getNode(ISD::FMUL, DL, VT, N0, RV);
8296 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
8297 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
8298 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
8299 // Both can be negated for free, check to see if at least one is cheaper
8301 if (LHSNeg == 2 || RHSNeg == 2)
8302 return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
8303 GetNegatedExpression(N0, DAG, LegalOperations),
8304 GetNegatedExpression(N1, DAG, LegalOperations));
8308 // Combine multiple FDIVs with the same divisor into multiple FMULs by the
8310 // E.g., (a / D; b / D;) -> (recip = 1.0 / D; a * recip; b * recip)
8311 // Notice that this is not always beneficial. One reason is different target
8312 // may have different costs for FDIV and FMUL, so sometimes the cost of two
8313 // FDIVs may be lower than the cost of one FDIV and two FMULs. Another reason
8314 // is the critical path is increased from "one FDIV" to "one FDIV + one FMUL".
8315 if (Options.UnsafeFPMath) {
8316 // Skip if current node is a reciprocal.
8317 if (N0CFP && N0CFP->isExactlyValue(1.0))
8320 SmallVector<SDNode *, 4> Users;
8321 // Find all FDIV users of the same divisor.
8322 for (auto *U : N1->uses()) {
8323 if (U->getOpcode() == ISD::FDIV && U->getOperand(1) == N1)
8327 if (TLI.combineRepeatedFPDivisors(Users.size())) {
8328 SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);
8329 SDValue Reciprocal = DAG.getNode(ISD::FDIV, DL, VT, FPOne, N1);
8331 // Dividend / Divisor -> Dividend * Reciprocal
8332 for (auto *U : Users) {
8333 SDValue Dividend = U->getOperand(0);
8334 if (Dividend != FPOne) {
8335 SDValue NewNode = DAG.getNode(ISD::FMUL, SDLoc(U), VT, Dividend,
8337 DAG.ReplaceAllUsesWith(U, NewNode.getNode());
8347 SDValue DAGCombiner::visitFREM(SDNode *N) {
8348 SDValue N0 = N->getOperand(0);
8349 SDValue N1 = N->getOperand(1);
8350 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8351 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8352 EVT VT = N->getValueType(0);
8354 // fold (frem c1, c2) -> fmod(c1,c2)
8356 return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1);
8361 SDValue DAGCombiner::visitFSQRT(SDNode *N) {
8362 if (DAG.getTarget().Options.UnsafeFPMath &&
8363 !TLI.isFsqrtCheap()) {
8364 // Compute this as X * (1/sqrt(X)) = X * (X ** -0.5)
8365 if (SDValue RV = BuildRsqrtEstimate(N->getOperand(0))) {
8366 EVT VT = RV.getValueType();
8368 RV = DAG.getNode(ISD::FMUL, DL, VT, N->getOperand(0), RV);
8369 AddToWorklist(RV.getNode());
8371 // Unfortunately, RV is now NaN if the input was exactly 0.
8372 // Select out this case and force the answer to 0.
8373 SDValue Zero = DAG.getConstantFP(0.0, DL, VT);
8375 DAG.getSetCC(DL, TLI.getSetCCResultType(*DAG.getContext(), VT),
8376 N->getOperand(0), Zero, ISD::SETEQ);
8377 AddToWorklist(ZeroCmp.getNode());
8378 AddToWorklist(RV.getNode());
8380 RV = DAG.getNode(VT.isVector() ? ISD::VSELECT : ISD::SELECT,
8381 DL, VT, ZeroCmp, Zero, RV);
8388 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
8389 SDValue N0 = N->getOperand(0);
8390 SDValue N1 = N->getOperand(1);
8391 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8392 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8393 EVT VT = N->getValueType(0);
8395 if (N0CFP && N1CFP) // Constant fold
8396 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);
8399 const APFloat& V = N1CFP->getValueAPF();
8400 // copysign(x, c1) -> fabs(x) iff ispos(c1)
8401 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
8402 if (!V.isNegative()) {
8403 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
8404 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8406 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
8407 return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
8408 DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
8412 // copysign(fabs(x), y) -> copysign(x, y)
8413 // copysign(fneg(x), y) -> copysign(x, y)
8414 // copysign(copysign(x,z), y) -> copysign(x, y)
8415 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
8416 N0.getOpcode() == ISD::FCOPYSIGN)
8417 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8418 N0.getOperand(0), N1);
8420 // copysign(x, abs(y)) -> abs(x)
8421 if (N1.getOpcode() == ISD::FABS)
8422 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8424 // copysign(x, copysign(y,z)) -> copysign(x, z)
8425 if (N1.getOpcode() == ISD::FCOPYSIGN)
8426 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8427 N0, N1.getOperand(1));
8429 // copysign(x, fp_extend(y)) -> copysign(x, y)
8430 // copysign(x, fp_round(y)) -> copysign(x, y)
8431 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
8432 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8433 N0, N1.getOperand(0));
8438 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
8439 SDValue N0 = N->getOperand(0);
8440 EVT VT = N->getValueType(0);
8441 EVT OpVT = N0.getValueType();
8443 // fold (sint_to_fp c1) -> c1fp
8444 if (isConstantIntBuildVectorOrConstantInt(N0) &&
8445 // ...but only if the target supports immediate floating-point values
8446 (!LegalOperations ||
8447 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
8448 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
8450 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
8451 // but UINT_TO_FP is legal on this target, try to convert.
8452 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
8453 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
8454 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
8455 if (DAG.SignBitIsZero(N0))
8456 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
8459 // The next optimizations are desirable only if SELECT_CC can be lowered.
8460 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
8461 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
8462 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
8464 (!LegalOperations ||
8465 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8468 { N0.getOperand(0), N0.getOperand(1),
8469 DAG.getConstantFP(-1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8471 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8474 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
8475 // (select_cc x, y, 1.0, 0.0,, cc)
8476 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
8477 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
8478 (!LegalOperations ||
8479 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8482 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
8483 DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8484 N0.getOperand(0).getOperand(2) };
8485 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8492 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
8493 SDValue N0 = N->getOperand(0);
8494 EVT VT = N->getValueType(0);
8495 EVT OpVT = N0.getValueType();
8497 // fold (uint_to_fp c1) -> c1fp
8498 if (isConstantIntBuildVectorOrConstantInt(N0) &&
8499 // ...but only if the target supports immediate floating-point values
8500 (!LegalOperations ||
8501 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
8502 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
8504 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
8505 // but SINT_TO_FP is legal on this target, try to convert.
8506 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
8507 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
8508 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
8509 if (DAG.SignBitIsZero(N0))
8510 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
8513 // The next optimizations are desirable only if SELECT_CC can be lowered.
8514 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
8515 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
8517 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
8518 (!LegalOperations ||
8519 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
8522 { N0.getOperand(0), N0.getOperand(1),
8523 DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
8525 return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
8532 // Fold (fp_to_{s/u}int ({s/u}int_to_fpx)) -> zext x, sext x, trunc x, or x
8533 static SDValue FoldIntToFPToInt(SDNode *N, SelectionDAG &DAG) {
8534 SDValue N0 = N->getOperand(0);
8535 EVT VT = N->getValueType(0);
8537 if (N0.getOpcode() != ISD::UINT_TO_FP && N0.getOpcode() != ISD::SINT_TO_FP)
8540 SDValue Src = N0.getOperand(0);
8541 EVT SrcVT = Src.getValueType();
8542 bool IsInputSigned = N0.getOpcode() == ISD::SINT_TO_FP;
8543 bool IsOutputSigned = N->getOpcode() == ISD::FP_TO_SINT;
8545 // We can safely assume the conversion won't overflow the output range,
8546 // because (for example) (uint8_t)18293.f is undefined behavior.
8548 // Since we can assume the conversion won't overflow, our decision as to
8549 // whether the input will fit in the float should depend on the minimum
8550 // of the input range and output range.
8552 // This means this is also safe for a signed input and unsigned output, since
8553 // a negative input would lead to undefined behavior.
8554 unsigned InputSize = (int)SrcVT.getScalarSizeInBits() - IsInputSigned;
8555 unsigned OutputSize = (int)VT.getScalarSizeInBits() - IsOutputSigned;
8556 unsigned ActualSize = std::min(InputSize, OutputSize);
8557 const fltSemantics &sem = DAG.EVTToAPFloatSemantics(N0.getValueType());
8559 // We can only fold away the float conversion if the input range can be
8560 // represented exactly in the float range.
8561 if (APFloat::semanticsPrecision(sem) >= ActualSize) {
8562 if (VT.getScalarSizeInBits() > SrcVT.getScalarSizeInBits()) {
8563 unsigned ExtOp = IsInputSigned && IsOutputSigned ? ISD::SIGN_EXTEND
8565 return DAG.getNode(ExtOp, SDLoc(N), VT, Src);
8567 if (VT.getScalarSizeInBits() < SrcVT.getScalarSizeInBits())
8568 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Src);
8571 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Src);
8576 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
8577 SDValue N0 = N->getOperand(0);
8578 EVT VT = N->getValueType(0);
8580 // fold (fp_to_sint c1fp) -> c1
8581 if (isConstantFPBuildVectorOrConstantFP(N0))
8582 return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
8584 return FoldIntToFPToInt(N, DAG);
8587 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
8588 SDValue N0 = N->getOperand(0);
8589 EVT VT = N->getValueType(0);
8591 // fold (fp_to_uint c1fp) -> c1
8592 if (isConstantFPBuildVectorOrConstantFP(N0))
8593 return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);
8595 return FoldIntToFPToInt(N, DAG);
8598 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
8599 SDValue N0 = N->getOperand(0);
8600 SDValue N1 = N->getOperand(1);
8601 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8602 EVT VT = N->getValueType(0);
8604 // fold (fp_round c1fp) -> c1fp
8606 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);
8608 // fold (fp_round (fp_extend x)) -> x
8609 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
8610 return N0.getOperand(0);
8612 // fold (fp_round (fp_round x)) -> (fp_round x)
8613 if (N0.getOpcode() == ISD::FP_ROUND) {
8614 const bool NIsTrunc = N->getConstantOperandVal(1) == 1;
8615 const bool N0IsTrunc = N0.getNode()->getConstantOperandVal(1) == 1;
8616 // If the first fp_round isn't a value preserving truncation, it might
8617 // introduce a tie in the second fp_round, that wouldn't occur in the
8618 // single-step fp_round we want to fold to.
8619 // In other words, double rounding isn't the same as rounding.
8620 // Also, this is a value preserving truncation iff both fp_round's are.
8621 if (DAG.getTarget().Options.UnsafeFPMath || N0IsTrunc) {
8623 return DAG.getNode(ISD::FP_ROUND, DL, VT, N0.getOperand(0),
8624 DAG.getIntPtrConstant(NIsTrunc && N0IsTrunc, DL));
8628 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
8629 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
8630 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
8631 N0.getOperand(0), N1);
8632 AddToWorklist(Tmp.getNode());
8633 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
8634 Tmp, N0.getOperand(1));
8640 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
8641 SDValue N0 = N->getOperand(0);
8642 EVT VT = N->getValueType(0);
8643 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
8644 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8646 // fold (fp_round_inreg c1fp) -> c1fp
8647 if (N0CFP && isTypeLegal(EVT)) {
8649 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), DL, EVT);
8650 return DAG.getNode(ISD::FP_EXTEND, DL, VT, Round);
8656 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
8657 SDValue N0 = N->getOperand(0);
8658 EVT VT = N->getValueType(0);
8660 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
8661 if (N->hasOneUse() &&
8662 N->use_begin()->getOpcode() == ISD::FP_ROUND)
8665 // fold (fp_extend c1fp) -> c1fp
8666 if (isConstantFPBuildVectorOrConstantFP(N0))
8667 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);
8669 // fold (fp_extend (fp16_to_fp op)) -> (fp16_to_fp op)
8670 if (N0.getOpcode() == ISD::FP16_TO_FP &&
8671 TLI.getOperationAction(ISD::FP16_TO_FP, VT) == TargetLowering::Legal)
8672 return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), VT, N0.getOperand(0));
8674 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
8676 if (N0.getOpcode() == ISD::FP_ROUND
8677 && N0.getNode()->getConstantOperandVal(1) == 1) {
8678 SDValue In = N0.getOperand(0);
8679 if (In.getValueType() == VT) return In;
8680 if (VT.bitsLT(In.getValueType()))
8681 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
8682 In, N0.getOperand(1));
8683 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
8686 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
8687 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
8688 TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
8689 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
8690 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
8692 LN0->getBasePtr(), N0.getValueType(),
8693 LN0->getMemOperand());
8694 CombineTo(N, ExtLoad);
8695 CombineTo(N0.getNode(),
8696 DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
8697 N0.getValueType(), ExtLoad,
8698 DAG.getIntPtrConstant(1, SDLoc(N0))),
8699 ExtLoad.getValue(1));
8700 return SDValue(N, 0); // Return N so it doesn't get rechecked!
8706 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
8707 SDValue N0 = N->getOperand(0);
8708 EVT VT = N->getValueType(0);
8710 // fold (fceil c1) -> fceil(c1)
8711 if (isConstantFPBuildVectorOrConstantFP(N0))
8712 return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
8717 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
8718 SDValue N0 = N->getOperand(0);
8719 EVT VT = N->getValueType(0);
8721 // fold (ftrunc c1) -> ftrunc(c1)
8722 if (isConstantFPBuildVectorOrConstantFP(N0))
8723 return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
8728 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
8729 SDValue N0 = N->getOperand(0);
8730 EVT VT = N->getValueType(0);
8732 // fold (ffloor c1) -> ffloor(c1)
8733 if (isConstantFPBuildVectorOrConstantFP(N0))
8734 return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
8739 // FIXME: FNEG and FABS have a lot in common; refactor.
8740 SDValue DAGCombiner::visitFNEG(SDNode *N) {
8741 SDValue N0 = N->getOperand(0);
8742 EVT VT = N->getValueType(0);
8744 // Constant fold FNEG.
8745 if (isConstantFPBuildVectorOrConstantFP(N0))
8746 return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
8748 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
8749 &DAG.getTarget().Options))
8750 return GetNegatedExpression(N0, DAG, LegalOperations);
8752 // Transform fneg(bitconvert(x)) -> bitconvert(x ^ sign) to avoid loading
8753 // constant pool values.
8754 if (!TLI.isFNegFree(VT) &&
8755 N0.getOpcode() == ISD::BITCAST &&
8756 N0.getNode()->hasOneUse()) {
8757 SDValue Int = N0.getOperand(0);
8758 EVT IntVT = Int.getValueType();
8759 if (IntVT.isInteger() && !IntVT.isVector()) {
8761 if (N0.getValueType().isVector()) {
8762 // For a vector, get a mask such as 0x80... per scalar element
8764 SignMask = APInt::getSignBit(N0.getValueType().getScalarSizeInBits());
8765 SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
8767 // For a scalar, just generate 0x80...
8768 SignMask = APInt::getSignBit(IntVT.getSizeInBits());
8771 Int = DAG.getNode(ISD::XOR, DL0, IntVT, Int,
8772 DAG.getConstant(SignMask, DL0, IntVT));
8773 AddToWorklist(Int.getNode());
8774 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Int);
8778 // (fneg (fmul c, x)) -> (fmul -c, x)
8779 if (N0.getOpcode() == ISD::FMUL) {
8780 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
8782 APFloat CVal = CFP1->getValueAPF();
8784 if (Level >= AfterLegalizeDAG &&
8785 (TLI.isFPImmLegal(CVal, N->getValueType(0)) ||
8786 TLI.isOperationLegal(ISD::ConstantFP, N->getValueType(0))))
8788 ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
8789 DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0.getOperand(1)));
8796 SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
8797 SDValue N0 = N->getOperand(0);
8798 SDValue N1 = N->getOperand(1);
8799 const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8800 const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8802 if (N0CFP && N1CFP) {
8803 const APFloat &C0 = N0CFP->getValueAPF();
8804 const APFloat &C1 = N1CFP->getValueAPF();
8805 return DAG.getConstantFP(minnum(C0, C1), SDLoc(N), N->getValueType(0));
8809 EVT VT = N->getValueType(0);
8810 // Canonicalize to constant on RHS.
8811 return DAG.getNode(ISD::FMINNUM, SDLoc(N), VT, N1, N0);
8817 SDValue DAGCombiner::visitFMAXNUM(SDNode *N) {
8818 SDValue N0 = N->getOperand(0);
8819 SDValue N1 = N->getOperand(1);
8820 const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
8821 const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
8823 if (N0CFP && N1CFP) {
8824 const APFloat &C0 = N0CFP->getValueAPF();
8825 const APFloat &C1 = N1CFP->getValueAPF();
8826 return DAG.getConstantFP(maxnum(C0, C1), SDLoc(N), N->getValueType(0));
8830 EVT VT = N->getValueType(0);
8831 // Canonicalize to constant on RHS.
8832 return DAG.getNode(ISD::FMAXNUM, SDLoc(N), VT, N1, N0);
8838 SDValue DAGCombiner::visitFABS(SDNode *N) {
8839 SDValue N0 = N->getOperand(0);
8840 EVT VT = N->getValueType(0);
8842 // fold (fabs c1) -> fabs(c1)
8843 if (isConstantFPBuildVectorOrConstantFP(N0))
8844 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
8846 // fold (fabs (fabs x)) -> (fabs x)
8847 if (N0.getOpcode() == ISD::FABS)
8848 return N->getOperand(0);
8850 // fold (fabs (fneg x)) -> (fabs x)
8851 // fold (fabs (fcopysign x, y)) -> (fabs x)
8852 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
8853 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));
8855 // Transform fabs(bitconvert(x)) -> bitconvert(x & ~sign) to avoid loading
8856 // constant pool values.
8857 if (!TLI.isFAbsFree(VT) &&
8858 N0.getOpcode() == ISD::BITCAST &&
8859 N0.getNode()->hasOneUse()) {
8860 SDValue Int = N0.getOperand(0);
8861 EVT IntVT = Int.getValueType();
8862 if (IntVT.isInteger() && !IntVT.isVector()) {
8864 if (N0.getValueType().isVector()) {
8865 // For a vector, get a mask such as 0x7f... per scalar element
8867 SignMask = ~APInt::getSignBit(N0.getValueType().getScalarSizeInBits());
8868 SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
8870 // For a scalar, just generate 0x7f...
8871 SignMask = ~APInt::getSignBit(IntVT.getSizeInBits());
8874 Int = DAG.getNode(ISD::AND, DL, IntVT, Int,
8875 DAG.getConstant(SignMask, DL, IntVT));
8876 AddToWorklist(Int.getNode());
8877 return DAG.getNode(ISD::BITCAST, SDLoc(N), N->getValueType(0), Int);
8884 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
8885 SDValue Chain = N->getOperand(0);
8886 SDValue N1 = N->getOperand(1);
8887 SDValue N2 = N->getOperand(2);
8889 // If N is a constant we could fold this into a fallthrough or unconditional
8890 // branch. However that doesn't happen very often in normal code, because
8891 // Instcombine/SimplifyCFG should have handled the available opportunities.
8892 // If we did this folding here, it would be necessary to update the
8893 // MachineBasicBlock CFG, which is awkward.
8895 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
8897 if (N1.getOpcode() == ISD::SETCC &&
8898 TLI.isOperationLegalOrCustom(ISD::BR_CC,
8899 N1.getOperand(0).getValueType())) {
8900 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
8901 Chain, N1.getOperand(2),
8902 N1.getOperand(0), N1.getOperand(1), N2);
8905 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
8906 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
8907 (N1.getOperand(0).hasOneUse() &&
8908 N1.getOperand(0).getOpcode() == ISD::SRL))) {
8909 SDNode *Trunc = nullptr;
8910 if (N1.getOpcode() == ISD::TRUNCATE) {
8911 // Look pass the truncate.
8912 Trunc = N1.getNode();
8913 N1 = N1.getOperand(0);
8916 // Match this pattern so that we can generate simpler code:
8919 // %b = and i32 %a, 2
8920 // %c = srl i32 %b, 1
8921 // brcond i32 %c ...
8926 // %b = and i32 %a, 2
8927 // %c = setcc eq %b, 0
8930 // This applies only when the AND constant value has one bit set and the
8931 // SRL constant is equal to the log2 of the AND constant. The back-end is
8932 // smart enough to convert the result into a TEST/JMP sequence.
8933 SDValue Op0 = N1.getOperand(0);
8934 SDValue Op1 = N1.getOperand(1);
8936 if (Op0.getOpcode() == ISD::AND &&
8937 Op1.getOpcode() == ISD::Constant) {
8938 SDValue AndOp1 = Op0.getOperand(1);
8940 if (AndOp1.getOpcode() == ISD::Constant) {
8941 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
8943 if (AndConst.isPowerOf2() &&
8944 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
8948 getSetCCResultType(Op0.getValueType()),
8949 Op0, DAG.getConstant(0, DL, Op0.getValueType()),
8952 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, DL,
8953 MVT::Other, Chain, SetCC, N2);
8954 // Don't add the new BRCond into the worklist or else SimplifySelectCC
8955 // will convert it back to (X & C1) >> C2.
8956 CombineTo(N, NewBRCond, false);
8957 // Truncate is dead.
8959 deleteAndRecombine(Trunc);
8960 // Replace the uses of SRL with SETCC
8961 WorklistRemover DeadNodes(*this);
8962 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
8963 deleteAndRecombine(N1.getNode());
8964 return SDValue(N, 0); // Return N so it doesn't get rechecked!
8970 // Restore N1 if the above transformation doesn't match.
8971 N1 = N->getOperand(1);
8974 // Transform br(xor(x, y)) -> br(x != y)
8975 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
8976 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
8977 SDNode *TheXor = N1.getNode();
8978 SDValue Op0 = TheXor->getOperand(0);
8979 SDValue Op1 = TheXor->getOperand(1);
8980 if (Op0.getOpcode() == Op1.getOpcode()) {
8981 // Avoid missing important xor optimizations.
8982 SDValue Tmp = visitXOR(TheXor);
8983 if (Tmp.getNode()) {
8984 if (Tmp.getNode() != TheXor) {
8985 DEBUG(dbgs() << "\nReplacing.8 ";
8987 dbgs() << "\nWith: ";
8988 Tmp.getNode()->dump(&DAG);
8990 WorklistRemover DeadNodes(*this);
8991 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
8992 deleteAndRecombine(TheXor);
8993 return DAG.getNode(ISD::BRCOND, SDLoc(N),
8994 MVT::Other, Chain, Tmp, N2);
8997 // visitXOR has changed XOR's operands or replaced the XOR completely,
8999 return SDValue(N, 0);
9003 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
9005 if (isOneConstant(Op0) && Op0.hasOneUse() &&
9006 Op0.getOpcode() == ISD::XOR) {
9007 TheXor = Op0.getNode();
9011 EVT SetCCVT = N1.getValueType();
9013 SetCCVT = getSetCCResultType(SetCCVT);
9014 SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
9017 Equal ? ISD::SETEQ : ISD::SETNE);
9018 // Replace the uses of XOR with SETCC
9019 WorklistRemover DeadNodes(*this);
9020 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
9021 deleteAndRecombine(N1.getNode());
9022 return DAG.getNode(ISD::BRCOND, SDLoc(N),
9023 MVT::Other, Chain, SetCC, N2);
9030 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
9032 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
9033 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
9034 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
9036 // If N is a constant we could fold this into a fallthrough or unconditional
9037 // branch. However that doesn't happen very often in normal code, because
9038 // Instcombine/SimplifyCFG should have handled the available opportunities.
9039 // If we did this folding here, it would be necessary to update the
9040 // MachineBasicBlock CFG, which is awkward.
9042 // Use SimplifySetCC to simplify SETCC's.
9043 SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
9044 CondLHS, CondRHS, CC->get(), SDLoc(N),
9046 if (Simp.getNode()) AddToWorklist(Simp.getNode());
9048 // fold to a simpler setcc
9049 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
9050 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
9051 N->getOperand(0), Simp.getOperand(2),
9052 Simp.getOperand(0), Simp.getOperand(1),
9058 /// Return true if 'Use' is a load or a store that uses N as its base pointer
9059 /// and that N may be folded in the load / store addressing mode.
9060 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
9062 const TargetLowering &TLI) {
9066 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
9067 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
9069 VT = LD->getMemoryVT();
9070 AS = LD->getAddressSpace();
9071 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
9072 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
9074 VT = ST->getMemoryVT();
9075 AS = ST->getAddressSpace();
9079 TargetLowering::AddrMode AM;
9080 if (N->getOpcode() == ISD::ADD) {
9081 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
9084 AM.BaseOffs = Offset->getSExtValue();
9088 } else if (N->getOpcode() == ISD::SUB) {
9089 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
9092 AM.BaseOffs = -Offset->getSExtValue();
9099 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()), AS);
9102 /// Try turning a load/store into a pre-indexed load/store when the base
9103 /// pointer is an add or subtract and it has other uses besides the load/store.
9104 /// After the transformation, the new indexed load/store has effectively folded
9105 /// the add/subtract in and all of its other uses are redirected to the
9107 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
9108 if (Level < AfterLegalizeDAG)
9114 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
9115 if (LD->isIndexed())
9117 VT = LD->getMemoryVT();
9118 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
9119 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
9121 Ptr = LD->getBasePtr();
9122 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
9123 if (ST->isIndexed())
9125 VT = ST->getMemoryVT();
9126 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
9127 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
9129 Ptr = ST->getBasePtr();
9135 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
9136 // out. There is no reason to make this a preinc/predec.
9137 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
9138 Ptr.getNode()->hasOneUse())
9141 // Ask the target to do addressing mode selection.
9144 ISD::MemIndexedMode AM = ISD::UNINDEXED;
9145 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
9148 // Backends without true r+i pre-indexed forms may need to pass a
9149 // constant base with a variable offset so that constant coercion
9150 // will work with the patterns in canonical form.
9151 bool Swapped = false;
9152 if (isa<ConstantSDNode>(BasePtr)) {
9153 std::swap(BasePtr, Offset);
9157 // Don't create a indexed load / store with zero offset.
9158 if (isNullConstant(Offset))
9161 // Try turning it into a pre-indexed load / store except when:
9162 // 1) The new base ptr is a frame index.
9163 // 2) If N is a store and the new base ptr is either the same as or is a
9164 // predecessor of the value being stored.
9165 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
9166 // that would create a cycle.
9167 // 4) All uses are load / store ops that use it as old base ptr.
9169 // Check #1. Preinc'ing a frame index would require copying the stack pointer
9170 // (plus the implicit offset) to a register to preinc anyway.
9171 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
9176 SDValue Val = cast<StoreSDNode>(N)->getValue();
9177 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
9181 // If the offset is a constant, there may be other adds of constants that
9182 // can be folded with this one. We should do this to avoid having to keep
9183 // a copy of the original base pointer.
9184 SmallVector<SDNode *, 16> OtherUses;
9185 if (isa<ConstantSDNode>(Offset))
9186 for (SDNode::use_iterator UI = BasePtr.getNode()->use_begin(),
9187 UE = BasePtr.getNode()->use_end();
9189 SDUse &Use = UI.getUse();
9190 // Skip the use that is Ptr and uses of other results from BasePtr's
9191 // node (important for nodes that return multiple results).
9192 if (Use.getUser() == Ptr.getNode() || Use != BasePtr)
9195 if (Use.getUser()->isPredecessorOf(N))
9198 if (Use.getUser()->getOpcode() != ISD::ADD &&
9199 Use.getUser()->getOpcode() != ISD::SUB) {
9204 SDValue Op1 = Use.getUser()->getOperand((UI.getOperandNo() + 1) & 1);
9205 if (!isa<ConstantSDNode>(Op1)) {
9210 // FIXME: In some cases, we can be smarter about this.
9211 if (Op1.getValueType() != Offset.getValueType()) {
9216 OtherUses.push_back(Use.getUser());
9220 std::swap(BasePtr, Offset);
9222 // Now check for #3 and #4.
9223 bool RealUse = false;
9225 // Caches for hasPredecessorHelper
9226 SmallPtrSet<const SDNode *, 32> Visited;
9227 SmallVector<const SDNode *, 16> Worklist;
9229 for (SDNode *Use : Ptr.getNode()->uses()) {
9232 if (N->hasPredecessorHelper(Use, Visited, Worklist))
9235 // If Ptr may be folded in addressing mode of other use, then it's
9236 // not profitable to do this transformation.
9237 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
9246 Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
9247 BasePtr, Offset, AM);
9249 Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
9250 BasePtr, Offset, AM);
9253 DEBUG(dbgs() << "\nReplacing.4 ";
9255 dbgs() << "\nWith: ";
9256 Result.getNode()->dump(&DAG);
9258 WorklistRemover DeadNodes(*this);
9260 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
9261 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
9263 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
9266 // Finally, since the node is now dead, remove it from the graph.
9267 deleteAndRecombine(N);
9270 std::swap(BasePtr, Offset);
9272 // Replace other uses of BasePtr that can be updated to use Ptr
9273 for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
9274 unsigned OffsetIdx = 1;
9275 if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
9277 assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==
9278 BasePtr.getNode() && "Expected BasePtr operand");
9280 // We need to replace ptr0 in the following expression:
9281 // x0 * offset0 + y0 * ptr0 = t0
9283 // x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
9285 // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
9286 // indexed load/store and the expresion that needs to be re-written.
9288 // Therefore, we have:
9289 // t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1
9291 ConstantSDNode *CN =
9292 cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
9294 APInt Offset0 = CN->getAPIntValue();
9295 APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();
9297 X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
9298 Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
9299 X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
9300 Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;
9302 unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;
9304 APInt CNV = Offset0;
9305 if (X0 < 0) CNV = -CNV;
9306 if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
9307 else CNV = CNV - Offset1;
9309 SDLoc DL(OtherUses[i]);
9311 // We can now generate the new expression.
9312 SDValue NewOp1 = DAG.getConstant(CNV, DL, CN->getValueType(0));
9313 SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);
9315 SDValue NewUse = DAG.getNode(Opcode,
9317 OtherUses[i]->getValueType(0), NewOp1, NewOp2);
9318 DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
9319 deleteAndRecombine(OtherUses[i]);
9322 // Replace the uses of Ptr with uses of the updated base value.
9323 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
9324 deleteAndRecombine(Ptr.getNode());
9329 /// Try to combine a load/store with a add/sub of the base pointer node into a
9330 /// post-indexed load/store. The transformation folded the add/subtract into the
9331 /// new indexed load/store effectively and all of its uses are redirected to the
9333 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
9334 if (Level < AfterLegalizeDAG)
9340 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
9341 if (LD->isIndexed())
9343 VT = LD->getMemoryVT();
9344 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
9345 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
9347 Ptr = LD->getBasePtr();
9348 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
9349 if (ST->isIndexed())
9351 VT = ST->getMemoryVT();
9352 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
9353 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
9355 Ptr = ST->getBasePtr();
9361 if (Ptr.getNode()->hasOneUse())
9364 for (SDNode *Op : Ptr.getNode()->uses()) {
9366 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
9371 ISD::MemIndexedMode AM = ISD::UNINDEXED;
9372 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
9373 // Don't create a indexed load / store with zero offset.
9374 if (isNullConstant(Offset))
9377 // Try turning it into a post-indexed load / store except when
9378 // 1) All uses are load / store ops that use it as base ptr (and
9379 // it may be folded as addressing mmode).
9380 // 2) Op must be independent of N, i.e. Op is neither a predecessor
9381 // nor a successor of N. Otherwise, if Op is folded that would
9384 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
9388 bool TryNext = false;
9389 for (SDNode *Use : BasePtr.getNode()->uses()) {
9390 if (Use == Ptr.getNode())
9393 // If all the uses are load / store addresses, then don't do the
9395 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
9396 bool RealUse = false;
9397 for (SDNode *UseUse : Use->uses()) {
9398 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
9413 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
9414 SDValue Result = isLoad
9415 ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
9416 BasePtr, Offset, AM)
9417 : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
9418 BasePtr, Offset, AM);
9421 DEBUG(dbgs() << "\nReplacing.5 ";
9423 dbgs() << "\nWith: ";
9424 Result.getNode()->dump(&DAG);
9426 WorklistRemover DeadNodes(*this);
9428 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
9429 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
9431 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
9434 // Finally, since the node is now dead, remove it from the graph.
9435 deleteAndRecombine(N);
9437 // Replace the uses of Use with uses of the updated base value.
9438 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
9439 Result.getValue(isLoad ? 1 : 0));
9440 deleteAndRecombine(Op);
9449 /// \brief Return the base-pointer arithmetic from an indexed \p LD.
9450 SDValue DAGCombiner::SplitIndexingFromLoad(LoadSDNode *LD) {
9451 ISD::MemIndexedMode AM = LD->getAddressingMode();
9452 assert(AM != ISD::UNINDEXED);
9453 SDValue BP = LD->getOperand(1);
9454 SDValue Inc = LD->getOperand(2);
9456 // Some backends use TargetConstants for load offsets, but don't expect
9457 // TargetConstants in general ADD nodes. We can convert these constants into
9458 // regular Constants (if the constant is not opaque).
9459 assert((Inc.getOpcode() != ISD::TargetConstant ||
9460 !cast<ConstantSDNode>(Inc)->isOpaque()) &&
9461 "Cannot split out indexing using opaque target constants");
9462 if (Inc.getOpcode() == ISD::TargetConstant) {
9463 ConstantSDNode *ConstInc = cast<ConstantSDNode>(Inc);
9464 Inc = DAG.getConstant(*ConstInc->getConstantIntValue(), SDLoc(Inc),
9465 ConstInc->getValueType(0));
9469 (AM == ISD::PRE_INC || AM == ISD::POST_INC ? ISD::ADD : ISD::SUB);
9470 return DAG.getNode(Opc, SDLoc(LD), BP.getSimpleValueType(), BP, Inc);
9473 SDValue DAGCombiner::visitLOAD(SDNode *N) {
9474 LoadSDNode *LD = cast<LoadSDNode>(N);
9475 SDValue Chain = LD->getChain();
9476 SDValue Ptr = LD->getBasePtr();
9478 // If load is not volatile and there are no uses of the loaded value (and
9479 // the updated indexed value in case of indexed loads), change uses of the
9480 // chain value into uses of the chain input (i.e. delete the dead load).
9481 if (!LD->isVolatile()) {
9482 if (N->getValueType(1) == MVT::Other) {
9484 if (!N->hasAnyUseOfValue(0)) {
9485 // It's not safe to use the two value CombineTo variant here. e.g.
9486 // v1, chain2 = load chain1, loc
9487 // v2, chain3 = load chain2, loc
9489 // Now we replace use of chain2 with chain1. This makes the second load
9490 // isomorphic to the one we are deleting, and thus makes this load live.
9491 DEBUG(dbgs() << "\nReplacing.6 ";
9493 dbgs() << "\nWith chain: ";
9494 Chain.getNode()->dump(&DAG);
9496 WorklistRemover DeadNodes(*this);
9497 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
9500 deleteAndRecombine(N);
9502 return SDValue(N, 0); // Return N so it doesn't get rechecked!
9506 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
9508 // If this load has an opaque TargetConstant offset, then we cannot split
9509 // the indexing into an add/sub directly (that TargetConstant may not be
9510 // valid for a different type of node, and we cannot convert an opaque
9511 // target constant into a regular constant).
9512 bool HasOTCInc = LD->getOperand(2).getOpcode() == ISD::TargetConstant &&
9513 cast<ConstantSDNode>(LD->getOperand(2))->isOpaque();
9515 if (!N->hasAnyUseOfValue(0) &&
9516 ((MaySplitLoadIndex && !HasOTCInc) || !N->hasAnyUseOfValue(1))) {
9517 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
9519 if (N->hasAnyUseOfValue(1) && MaySplitLoadIndex && !HasOTCInc) {
9520 Index = SplitIndexingFromLoad(LD);
9521 // Try to fold the base pointer arithmetic into subsequent loads and
9523 AddUsersToWorklist(N);
9525 Index = DAG.getUNDEF(N->getValueType(1));
9526 DEBUG(dbgs() << "\nReplacing.7 ";
9528 dbgs() << "\nWith: ";
9529 Undef.getNode()->dump(&DAG);
9530 dbgs() << " and 2 other values\n");
9531 WorklistRemover DeadNodes(*this);
9532 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
9533 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Index);
9534 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
9535 deleteAndRecombine(N);
9536 return SDValue(N, 0); // Return N so it doesn't get rechecked!
9541 // If this load is directly stored, replace the load value with the stored
9543 // TODO: Handle store large -> read small portion.
9544 // TODO: Handle TRUNCSTORE/LOADEXT
9545 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
9546 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
9547 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
9548 if (PrevST->getBasePtr() == Ptr &&
9549 PrevST->getValue().getValueType() == N->getValueType(0))
9550 return CombineTo(N, Chain.getOperand(1), Chain);
9554 // Try to infer better alignment information than the load already has.
9555 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
9556 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
9557 if (Align > LD->getMemOperand()->getBaseAlignment()) {
9559 DAG.getExtLoad(LD->getExtensionType(), SDLoc(N),
9560 LD->getValueType(0),
9561 Chain, Ptr, LD->getPointerInfo(),
9563 LD->isVolatile(), LD->isNonTemporal(),
9564 LD->isInvariant(), Align, LD->getAAInfo());
9565 if (NewLoad.getNode() != N)
9566 return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
9571 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
9572 : DAG.getSubtarget().useAA();
9574 if (CombinerAAOnlyFunc.getNumOccurrences() &&
9575 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
9578 if (UseAA && LD->isUnindexed()) {
9579 // Walk up chain skipping non-aliasing memory nodes.
9580 SDValue BetterChain = FindBetterChain(N, Chain);
9582 // If there is a better chain.
9583 if (Chain != BetterChain) {
9586 // Replace the chain to void dependency.
9587 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
9588 ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
9589 BetterChain, Ptr, LD->getMemOperand());
9591 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
9592 LD->getValueType(0),
9593 BetterChain, Ptr, LD->getMemoryVT(),
9594 LD->getMemOperand());
9597 // Create token factor to keep old chain connected.
9598 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
9599 MVT::Other, Chain, ReplLoad.getValue(1));
9601 // Make sure the new and old chains are cleaned up.
9602 AddToWorklist(Token.getNode());
9604 // Replace uses with load result and token factor. Don't add users
9606 return CombineTo(N, ReplLoad.getValue(0), Token, false);
9610 // Try transforming N to an indexed load.
9611 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
9612 return SDValue(N, 0);
9614 // Try to slice up N to more direct loads if the slices are mapped to
9615 // different register banks or pairing can take place.
9617 return SDValue(N, 0);
9623 /// \brief Helper structure used to slice a load in smaller loads.
9624 /// Basically a slice is obtained from the following sequence:
9625 /// Origin = load Ty1, Base
9626 /// Shift = srl Ty1 Origin, CstTy Amount
9627 /// Inst = trunc Shift to Ty2
9629 /// Then, it will be rewriten into:
9630 /// Slice = load SliceTy, Base + SliceOffset
9631 /// [Inst = zext Slice to Ty2], only if SliceTy <> Ty2
9633 /// SliceTy is deduced from the number of bits that are actually used to
9635 struct LoadedSlice {
9636 /// \brief Helper structure used to compute the cost of a slice.
9638 /// Are we optimizing for code size.
9643 unsigned CrossRegisterBanksCopies;
9647 Cost(bool ForCodeSize = false)
9648 : ForCodeSize(ForCodeSize), Loads(0), Truncates(0),
9649 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {}
9651 /// \brief Get the cost of one isolated slice.
9652 Cost(const LoadedSlice &LS, bool ForCodeSize = false)
9653 : ForCodeSize(ForCodeSize), Loads(1), Truncates(0),
9654 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {
9655 EVT TruncType = LS.Inst->getValueType(0);
9656 EVT LoadedType = LS.getLoadedType();
9657 if (TruncType != LoadedType &&
9658 !LS.DAG->getTargetLoweringInfo().isZExtFree(LoadedType, TruncType))
9662 /// \brief Account for slicing gain in the current cost.
9663 /// Slicing provide a few gains like removing a shift or a
9664 /// truncate. This method allows to grow the cost of the original
9665 /// load with the gain from this slice.
9666 void addSliceGain(const LoadedSlice &LS) {
9667 // Each slice saves a truncate.
9668 const TargetLowering &TLI = LS.DAG->getTargetLoweringInfo();
9669 if (!TLI.isTruncateFree(LS.Inst->getValueType(0),
9670 LS.Inst->getOperand(0).getValueType()))
9672 // If there is a shift amount, this slice gets rid of it.
9675 // If this slice can merge a cross register bank copy, account for it.
9676 if (LS.canMergeExpensiveCrossRegisterBankCopy())
9677 ++CrossRegisterBanksCopies;
9680 Cost &operator+=(const Cost &RHS) {
9682 Truncates += RHS.Truncates;
9683 CrossRegisterBanksCopies += RHS.CrossRegisterBanksCopies;
9689 bool operator==(const Cost &RHS) const {
9690 return Loads == RHS.Loads && Truncates == RHS.Truncates &&
9691 CrossRegisterBanksCopies == RHS.CrossRegisterBanksCopies &&
9692 ZExts == RHS.ZExts && Shift == RHS.Shift;
9695 bool operator!=(const Cost &RHS) const { return !(*this == RHS); }
9697 bool operator<(const Cost &RHS) const {
9698 // Assume cross register banks copies are as expensive as loads.
9699 // FIXME: Do we want some more target hooks?
9700 unsigned ExpensiveOpsLHS = Loads + CrossRegisterBanksCopies;
9701 unsigned ExpensiveOpsRHS = RHS.Loads + RHS.CrossRegisterBanksCopies;
9702 // Unless we are optimizing for code size, consider the
9703 // expensive operation first.
9704 if (!ForCodeSize && ExpensiveOpsLHS != ExpensiveOpsRHS)
9705 return ExpensiveOpsLHS < ExpensiveOpsRHS;
9706 return (Truncates + ZExts + Shift + ExpensiveOpsLHS) <
9707 (RHS.Truncates + RHS.ZExts + RHS.Shift + ExpensiveOpsRHS);
9710 bool operator>(const Cost &RHS) const { return RHS < *this; }
9712 bool operator<=(const Cost &RHS) const { return !(RHS < *this); }
9714 bool operator>=(const Cost &RHS) const { return !(*this < RHS); }
9716 // The last instruction that represent the slice. This should be a
9717 // truncate instruction.
9719 // The original load instruction.
9721 // The right shift amount in bits from the original load.
9723 // The DAG from which Origin came from.
9724 // This is used to get some contextual information about legal types, etc.
9727 LoadedSlice(SDNode *Inst = nullptr, LoadSDNode *Origin = nullptr,
9728 unsigned Shift = 0, SelectionDAG *DAG = nullptr)
9729 : Inst(Inst), Origin(Origin), Shift(Shift), DAG(DAG) {}
9731 /// \brief Get the bits used in a chunk of bits \p BitWidth large.
9732 /// \return Result is \p BitWidth and has used bits set to 1 and
9733 /// not used bits set to 0.
9734 APInt getUsedBits() const {
9735 // Reproduce the trunc(lshr) sequence:
9736 // - Start from the truncated value.
9737 // - Zero extend to the desired bit width.
9739 assert(Origin && "No original load to compare against.");
9740 unsigned BitWidth = Origin->getValueSizeInBits(0);
9741 assert(Inst && "This slice is not bound to an instruction");
9742 assert(Inst->getValueSizeInBits(0) <= BitWidth &&
9743 "Extracted slice is bigger than the whole type!");
9744 APInt UsedBits(Inst->getValueSizeInBits(0), 0);
9745 UsedBits.setAllBits();
9746 UsedBits = UsedBits.zext(BitWidth);
9751 /// \brief Get the size of the slice to be loaded in bytes.
9752 unsigned getLoadedSize() const {
9753 unsigned SliceSize = getUsedBits().countPopulation();
9754 assert(!(SliceSize & 0x7) && "Size is not a multiple of a byte.");
9755 return SliceSize / 8;
9758 /// \brief Get the type that will be loaded for this slice.
9759 /// Note: This may not be the final type for the slice.
9760 EVT getLoadedType() const {
9761 assert(DAG && "Missing context");
9762 LLVMContext &Ctxt = *DAG->getContext();
9763 return EVT::getIntegerVT(Ctxt, getLoadedSize() * 8);
9766 /// \brief Get the alignment of the load used for this slice.
9767 unsigned getAlignment() const {
9768 unsigned Alignment = Origin->getAlignment();
9769 unsigned Offset = getOffsetFromBase();
9771 Alignment = MinAlign(Alignment, Alignment + Offset);
9775 /// \brief Check if this slice can be rewritten with legal operations.
9776 bool isLegal() const {
9777 // An invalid slice is not legal.
9778 if (!Origin || !Inst || !DAG)
9781 // Offsets are for indexed load only, we do not handle that.
9782 if (Origin->getOffset().getOpcode() != ISD::UNDEF)
9785 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
9787 // Check that the type is legal.
9788 EVT SliceType = getLoadedType();
9789 if (!TLI.isTypeLegal(SliceType))
9792 // Check that the load is legal for this type.
9793 if (!TLI.isOperationLegal(ISD::LOAD, SliceType))
9796 // Check that the offset can be computed.
9797 // 1. Check its type.
9798 EVT PtrType = Origin->getBasePtr().getValueType();
9799 if (PtrType == MVT::Untyped || PtrType.isExtended())
9802 // 2. Check that it fits in the immediate.
9803 if (!TLI.isLegalAddImmediate(getOffsetFromBase()))
9806 // 3. Check that the computation is legal.
9807 if (!TLI.isOperationLegal(ISD::ADD, PtrType))
9810 // Check that the zext is legal if it needs one.
9811 EVT TruncateType = Inst->getValueType(0);
9812 if (TruncateType != SliceType &&
9813 !TLI.isOperationLegal(ISD::ZERO_EXTEND, TruncateType))
9819 /// \brief Get the offset in bytes of this slice in the original chunk of
9821 /// \pre DAG != nullptr.
9822 uint64_t getOffsetFromBase() const {
9823 assert(DAG && "Missing context.");
9825 DAG->getTargetLoweringInfo().getDataLayout()->isBigEndian();
9826 assert(!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported.");
9827 uint64_t Offset = Shift / 8;
9828 unsigned TySizeInBytes = Origin->getValueSizeInBits(0) / 8;
9829 assert(!(Origin->getValueSizeInBits(0) & 0x7) &&
9830 "The size of the original loaded type is not a multiple of a"
9832 // If Offset is bigger than TySizeInBytes, it means we are loading all
9833 // zeros. This should have been optimized before in the process.
9834 assert(TySizeInBytes > Offset &&
9835 "Invalid shift amount for given loaded size");
9837 Offset = TySizeInBytes - Offset - getLoadedSize();
9841 /// \brief Generate the sequence of instructions to load the slice
9842 /// represented by this object and redirect the uses of this slice to
9843 /// this new sequence of instructions.
9844 /// \pre this->Inst && this->Origin are valid Instructions and this
9845 /// object passed the legal check: LoadedSlice::isLegal returned true.
9846 /// \return The last instruction of the sequence used to load the slice.
9847 SDValue loadSlice() const {
9848 assert(Inst && Origin && "Unable to replace a non-existing slice.");
9849 const SDValue &OldBaseAddr = Origin->getBasePtr();
9850 SDValue BaseAddr = OldBaseAddr;
9851 // Get the offset in that chunk of bytes w.r.t. the endianess.
9852 int64_t Offset = static_cast<int64_t>(getOffsetFromBase());
9853 assert(Offset >= 0 && "Offset too big to fit in int64_t!");
9855 // BaseAddr = BaseAddr + Offset.
9856 EVT ArithType = BaseAddr.getValueType();
9858 BaseAddr = DAG->getNode(ISD::ADD, DL, ArithType, BaseAddr,
9859 DAG->getConstant(Offset, DL, ArithType));
9862 // Create the type of the loaded slice according to its size.
9863 EVT SliceType = getLoadedType();
9865 // Create the load for the slice.
9866 SDValue LastInst = DAG->getLoad(
9867 SliceType, SDLoc(Origin), Origin->getChain(), BaseAddr,
9868 Origin->getPointerInfo().getWithOffset(Offset), Origin->isVolatile(),
9869 Origin->isNonTemporal(), Origin->isInvariant(), getAlignment());
9870 // If the final type is not the same as the loaded type, this means that
9871 // we have to pad with zero. Create a zero extend for that.
9872 EVT FinalType = Inst->getValueType(0);
9873 if (SliceType != FinalType)
9875 DAG->getNode(ISD::ZERO_EXTEND, SDLoc(LastInst), FinalType, LastInst);
9879 /// \brief Check if this slice can be merged with an expensive cross register
9880 /// bank copy. E.g.,
9882 /// f = bitcast i32 i to float
9883 bool canMergeExpensiveCrossRegisterBankCopy() const {
9884 if (!Inst || !Inst->hasOneUse())
9886 SDNode *Use = *Inst->use_begin();
9887 if (Use->getOpcode() != ISD::BITCAST)
9889 assert(DAG && "Missing context");
9890 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
9891 EVT ResVT = Use->getValueType(0);
9892 const TargetRegisterClass *ResRC = TLI.getRegClassFor(ResVT.getSimpleVT());
9893 const TargetRegisterClass *ArgRC =
9894 TLI.getRegClassFor(Use->getOperand(0).getValueType().getSimpleVT());
9895 if (ArgRC == ResRC || !TLI.isOperationLegal(ISD::LOAD, ResVT))
9898 // At this point, we know that we perform a cross-register-bank copy.
9899 // Check if it is expensive.
9900 const TargetRegisterInfo *TRI = DAG->getSubtarget().getRegisterInfo();
9901 // Assume bitcasts are cheap, unless both register classes do not
9902 // explicitly share a common sub class.
9903 if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
9906 // Check if it will be merged with the load.
9907 // 1. Check the alignment constraint.
9908 unsigned RequiredAlignment = TLI.getDataLayout()->getABITypeAlignment(
9909 ResVT.getTypeForEVT(*DAG->getContext()));
9911 if (RequiredAlignment > getAlignment())
9914 // 2. Check that the load is a legal operation for that type.
9915 if (!TLI.isOperationLegal(ISD::LOAD, ResVT))
9918 // 3. Check that we do not have a zext in the way.
9919 if (Inst->getValueType(0) != getLoadedType())
9927 /// \brief Check that all bits set in \p UsedBits form a dense region, i.e.,
9928 /// \p UsedBits looks like 0..0 1..1 0..0.
9929 static bool areUsedBitsDense(const APInt &UsedBits) {
9930 // If all the bits are one, this is dense!
9931 if (UsedBits.isAllOnesValue())
9934 // Get rid of the unused bits on the right.
9935 APInt NarrowedUsedBits = UsedBits.lshr(UsedBits.countTrailingZeros());
9936 // Get rid of the unused bits on the left.
9937 if (NarrowedUsedBits.countLeadingZeros())
9938 NarrowedUsedBits = NarrowedUsedBits.trunc(NarrowedUsedBits.getActiveBits());
9939 // Check that the chunk of bits is completely used.
9940 return NarrowedUsedBits.isAllOnesValue();
9943 /// \brief Check whether or not \p First and \p Second are next to each other
9944 /// in memory. This means that there is no hole between the bits loaded
9945 /// by \p First and the bits loaded by \p Second.
9946 static bool areSlicesNextToEachOther(const LoadedSlice &First,
9947 const LoadedSlice &Second) {
9948 assert(First.Origin == Second.Origin && First.Origin &&
9949 "Unable to match different memory origins.");
9950 APInt UsedBits = First.getUsedBits();
9951 assert((UsedBits & Second.getUsedBits()) == 0 &&
9952 "Slices are not supposed to overlap.");
9953 UsedBits |= Second.getUsedBits();
9954 return areUsedBitsDense(UsedBits);
9957 /// \brief Adjust the \p GlobalLSCost according to the target
9958 /// paring capabilities and the layout of the slices.
9959 /// \pre \p GlobalLSCost should account for at least as many loads as
9960 /// there is in the slices in \p LoadedSlices.
9961 static void adjustCostForPairing(SmallVectorImpl<LoadedSlice> &LoadedSlices,
9962 LoadedSlice::Cost &GlobalLSCost) {
9963 unsigned NumberOfSlices = LoadedSlices.size();
9964 // If there is less than 2 elements, no pairing is possible.
9965 if (NumberOfSlices < 2)
9968 // Sort the slices so that elements that are likely to be next to each
9969 // other in memory are next to each other in the list.
9970 std::sort(LoadedSlices.begin(), LoadedSlices.end(),
9971 [](const LoadedSlice &LHS, const LoadedSlice &RHS) {
9972 assert(LHS.Origin == RHS.Origin && "Different bases not implemented.");
9973 return LHS.getOffsetFromBase() < RHS.getOffsetFromBase();
9975 const TargetLowering &TLI = LoadedSlices[0].DAG->getTargetLoweringInfo();
9976 // First (resp. Second) is the first (resp. Second) potentially candidate
9977 // to be placed in a paired load.
9978 const LoadedSlice *First = nullptr;
9979 const LoadedSlice *Second = nullptr;
9980 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice,
9981 // Set the beginning of the pair.
9984 Second = &LoadedSlices[CurrSlice];
9986 // If First is NULL, it means we start a new pair.
9987 // Get to the next slice.
9991 EVT LoadedType = First->getLoadedType();
9993 // If the types of the slices are different, we cannot pair them.
9994 if (LoadedType != Second->getLoadedType())
9997 // Check if the target supplies paired loads for this type.
9998 unsigned RequiredAlignment = 0;
9999 if (!TLI.hasPairedLoad(LoadedType, RequiredAlignment)) {
10000 // move to the next pair, this type is hopeless.
10004 // Check if we meet the alignment requirement.
10005 if (RequiredAlignment > First->getAlignment())
10008 // Check that both loads are next to each other in memory.
10009 if (!areSlicesNextToEachOther(*First, *Second))
10012 assert(GlobalLSCost.Loads > 0 && "We save more loads than we created!");
10013 --GlobalLSCost.Loads;
10014 // Move to the next pair.
10019 /// \brief Check the profitability of all involved LoadedSlice.
10020 /// Currently, it is considered profitable if there is exactly two
10021 /// involved slices (1) which are (2) next to each other in memory, and
10022 /// whose cost (\see LoadedSlice::Cost) is smaller than the original load (3).
10024 /// Note: The order of the elements in \p LoadedSlices may be modified, but not
10025 /// the elements themselves.
10027 /// FIXME: When the cost model will be mature enough, we can relax
10028 /// constraints (1) and (2).
10029 static bool isSlicingProfitable(SmallVectorImpl<LoadedSlice> &LoadedSlices,
10030 const APInt &UsedBits, bool ForCodeSize) {
10031 unsigned NumberOfSlices = LoadedSlices.size();
10032 if (StressLoadSlicing)
10033 return NumberOfSlices > 1;
10036 if (NumberOfSlices != 2)
10040 if (!areUsedBitsDense(UsedBits))
10044 LoadedSlice::Cost OrigCost(ForCodeSize), GlobalSlicingCost(ForCodeSize);
10045 // The original code has one big load.
10046 OrigCost.Loads = 1;
10047 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice) {
10048 const LoadedSlice &LS = LoadedSlices[CurrSlice];
10049 // Accumulate the cost of all the slices.
10050 LoadedSlice::Cost SliceCost(LS, ForCodeSize);
10051 GlobalSlicingCost += SliceCost;
10053 // Account as cost in the original configuration the gain obtained
10054 // with the current slices.
10055 OrigCost.addSliceGain(LS);
10058 // If the target supports paired load, adjust the cost accordingly.
10059 adjustCostForPairing(LoadedSlices, GlobalSlicingCost);
10060 return OrigCost > GlobalSlicingCost;
10063 /// \brief If the given load, \p LI, is used only by trunc or trunc(lshr)
10064 /// operations, split it in the various pieces being extracted.
10066 /// This sort of thing is introduced by SROA.
10067 /// This slicing takes care not to insert overlapping loads.
10068 /// \pre LI is a simple load (i.e., not an atomic or volatile load).
10069 bool DAGCombiner::SliceUpLoad(SDNode *N) {
10070 if (Level < AfterLegalizeDAG)
10073 LoadSDNode *LD = cast<LoadSDNode>(N);
10074 if (LD->isVolatile() || !ISD::isNormalLoad(LD) ||
10075 !LD->getValueType(0).isInteger())
10078 // Keep track of already used bits to detect overlapping values.
10079 // In that case, we will just abort the transformation.
10080 APInt UsedBits(LD->getValueSizeInBits(0), 0);
10082 SmallVector<LoadedSlice, 4> LoadedSlices;
10084 // Check if this load is used as several smaller chunks of bits.
10085 // Basically, look for uses in trunc or trunc(lshr) and record a new chain
10086 // of computation for each trunc.
10087 for (SDNode::use_iterator UI = LD->use_begin(), UIEnd = LD->use_end();
10088 UI != UIEnd; ++UI) {
10089 // Skip the uses of the chain.
10090 if (UI.getUse().getResNo() != 0)
10093 SDNode *User = *UI;
10094 unsigned Shift = 0;
10096 // Check if this is a trunc(lshr).
10097 if (User->getOpcode() == ISD::SRL && User->hasOneUse() &&
10098 isa<ConstantSDNode>(User->getOperand(1))) {
10099 Shift = cast<ConstantSDNode>(User->getOperand(1))->getZExtValue();
10100 User = *User->use_begin();
10103 // At this point, User is a Truncate, iff we encountered, trunc or
10105 if (User->getOpcode() != ISD::TRUNCATE)
10108 // The width of the type must be a power of 2 and greater than 8-bits.
10109 // Otherwise the load cannot be represented in LLVM IR.
10110 // Moreover, if we shifted with a non-8-bits multiple, the slice
10111 // will be across several bytes. We do not support that.
10112 unsigned Width = User->getValueSizeInBits(0);
10113 if (Width < 8 || !isPowerOf2_32(Width) || (Shift & 0x7))
10116 // Build the slice for this chain of computations.
10117 LoadedSlice LS(User, LD, Shift, &DAG);
10118 APInt CurrentUsedBits = LS.getUsedBits();
10120 // Check if this slice overlaps with another.
10121 if ((CurrentUsedBits & UsedBits) != 0)
10123 // Update the bits used globally.
10124 UsedBits |= CurrentUsedBits;
10126 // Check if the new slice would be legal.
10130 // Record the slice.
10131 LoadedSlices.push_back(LS);
10134 // Abort slicing if it does not seem to be profitable.
10135 if (!isSlicingProfitable(LoadedSlices, UsedBits, ForCodeSize))
10140 // Rewrite each chain to use an independent load.
10141 // By construction, each chain can be represented by a unique load.
10143 // Prepare the argument for the new token factor for all the slices.
10144 SmallVector<SDValue, 8> ArgChains;
10145 for (SmallVectorImpl<LoadedSlice>::const_iterator
10146 LSIt = LoadedSlices.begin(),
10147 LSItEnd = LoadedSlices.end();
10148 LSIt != LSItEnd; ++LSIt) {
10149 SDValue SliceInst = LSIt->loadSlice();
10150 CombineTo(LSIt->Inst, SliceInst, true);
10151 if (SliceInst.getNode()->getOpcode() != ISD::LOAD)
10152 SliceInst = SliceInst.getOperand(0);
10153 assert(SliceInst->getOpcode() == ISD::LOAD &&
10154 "It takes more than a zext to get to the loaded slice!!");
10155 ArgChains.push_back(SliceInst.getValue(1));
10158 SDValue Chain = DAG.getNode(ISD::TokenFactor, SDLoc(LD), MVT::Other,
10160 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
10164 /// Check to see if V is (and load (ptr), imm), where the load is having
10165 /// specific bytes cleared out. If so, return the byte size being masked out
10166 /// and the shift amount.
10167 static std::pair<unsigned, unsigned>
10168 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
10169 std::pair<unsigned, unsigned> Result(0, 0);
10171 // Check for the structure we're looking for.
10172 if (V->getOpcode() != ISD::AND ||
10173 !isa<ConstantSDNode>(V->getOperand(1)) ||
10174 !ISD::isNormalLoad(V->getOperand(0).getNode()))
10177 // Check the chain and pointer.
10178 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
10179 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
10181 // The store should be chained directly to the load or be an operand of a
10183 if (LD == Chain.getNode())
10185 else if (Chain->getOpcode() != ISD::TokenFactor)
10186 return Result; // Fail.
10189 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
10190 if (Chain->getOperand(i).getNode() == LD) {
10194 if (!isOk) return Result;
10197 // This only handles simple types.
10198 if (V.getValueType() != MVT::i16 &&
10199 V.getValueType() != MVT::i32 &&
10200 V.getValueType() != MVT::i64)
10203 // Check the constant mask. Invert it so that the bits being masked out are
10204 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
10205 // follow the sign bit for uniformity.
10206 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
10207 unsigned NotMaskLZ = countLeadingZeros(NotMask);
10208 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
10209 unsigned NotMaskTZ = countTrailingZeros(NotMask);
10210 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
10211 if (NotMaskLZ == 64) return Result; // All zero mask.
10213 // See if we have a continuous run of bits. If so, we have 0*1+0*
10214 if (countTrailingOnes(NotMask >> NotMaskTZ) + NotMaskTZ + NotMaskLZ != 64)
10217 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
10218 if (V.getValueType() != MVT::i64 && NotMaskLZ)
10219 NotMaskLZ -= 64-V.getValueSizeInBits();
10221 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
10222 switch (MaskedBytes) {
10226 default: return Result; // All one mask, or 5-byte mask.
10229 // Verify that the first bit starts at a multiple of mask so that the access
10230 // is aligned the same as the access width.
10231 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
10233 Result.first = MaskedBytes;
10234 Result.second = NotMaskTZ/8;
10239 /// Check to see if IVal is something that provides a value as specified by
10240 /// MaskInfo. If so, replace the specified store with a narrower store of
10241 /// truncated IVal.
10243 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
10244 SDValue IVal, StoreSDNode *St,
10246 unsigned NumBytes = MaskInfo.first;
10247 unsigned ByteShift = MaskInfo.second;
10248 SelectionDAG &DAG = DC->getDAG();
10250 // Check to see if IVal is all zeros in the part being masked in by the 'or'
10251 // that uses this. If not, this is not a replacement.
10252 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
10253 ByteShift*8, (ByteShift+NumBytes)*8);
10254 if (!DAG.MaskedValueIsZero(IVal, Mask)) return nullptr;
10256 // Check that it is legal on the target to do this. It is legal if the new
10257 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
10259 MVT VT = MVT::getIntegerVT(NumBytes*8);
10260 if (!DC->isTypeLegal(VT))
10263 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
10264 // shifted by ByteShift and truncated down to NumBytes.
10267 IVal = DAG.getNode(ISD::SRL, DL, IVal.getValueType(), IVal,
10268 DAG.getConstant(ByteShift*8, DL,
10269 DC->getShiftAmountTy(IVal.getValueType())));
10272 // Figure out the offset for the store and the alignment of the access.
10274 unsigned NewAlign = St->getAlignment();
10276 if (DAG.getTargetLoweringInfo().isLittleEndian())
10277 StOffset = ByteShift;
10279 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
10281 SDValue Ptr = St->getBasePtr();
10284 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(),
10285 Ptr, DAG.getConstant(StOffset, DL, Ptr.getValueType()));
10286 NewAlign = MinAlign(NewAlign, StOffset);
10289 // Truncate down to the new size.
10290 IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);
10293 return DAG.getStore(St->getChain(), SDLoc(St), IVal, Ptr,
10294 St->getPointerInfo().getWithOffset(StOffset),
10295 false, false, NewAlign).getNode();
10299 /// Look for sequence of load / op / store where op is one of 'or', 'xor', and
10300 /// 'and' of immediates. If 'op' is only touching some of the loaded bits, try
10301 /// narrowing the load and store if it would end up being a win for performance
10303 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
10304 StoreSDNode *ST = cast<StoreSDNode>(N);
10305 if (ST->isVolatile())
10308 SDValue Chain = ST->getChain();
10309 SDValue Value = ST->getValue();
10310 SDValue Ptr = ST->getBasePtr();
10311 EVT VT = Value.getValueType();
10313 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
10316 unsigned Opc = Value.getOpcode();
10318 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
10319 // is a byte mask indicating a consecutive number of bytes, check to see if
10320 // Y is known to provide just those bytes. If so, we try to replace the
10321 // load + replace + store sequence with a single (narrower) store, which makes
10323 if (Opc == ISD::OR) {
10324 std::pair<unsigned, unsigned> MaskedLoad;
10325 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
10326 if (MaskedLoad.first)
10327 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
10328 Value.getOperand(1), ST,this))
10329 return SDValue(NewST, 0);
10331 // Or is commutative, so try swapping X and Y.
10332 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
10333 if (MaskedLoad.first)
10334 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
10335 Value.getOperand(0), ST,this))
10336 return SDValue(NewST, 0);
10339 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
10340 Value.getOperand(1).getOpcode() != ISD::Constant)
10343 SDValue N0 = Value.getOperand(0);
10344 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
10345 Chain == SDValue(N0.getNode(), 1)) {
10346 LoadSDNode *LD = cast<LoadSDNode>(N0);
10347 if (LD->getBasePtr() != Ptr ||
10348 LD->getPointerInfo().getAddrSpace() !=
10349 ST->getPointerInfo().getAddrSpace())
10352 // Find the type to narrow it the load / op / store to.
10353 SDValue N1 = Value.getOperand(1);
10354 unsigned BitWidth = N1.getValueSizeInBits();
10355 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
10356 if (Opc == ISD::AND)
10357 Imm ^= APInt::getAllOnesValue(BitWidth);
10358 if (Imm == 0 || Imm.isAllOnesValue())
10360 unsigned ShAmt = Imm.countTrailingZeros();
10361 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
10362 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
10363 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
10364 // The narrowing should be profitable, the load/store operation should be
10365 // legal (or custom) and the store size should be equal to the NewVT width.
10366 while (NewBW < BitWidth &&
10367 (NewVT.getStoreSizeInBits() != NewBW ||
10368 !TLI.isOperationLegalOrCustom(Opc, NewVT) ||
10369 !TLI.isNarrowingProfitable(VT, NewVT))) {
10370 NewBW = NextPowerOf2(NewBW);
10371 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
10373 if (NewBW >= BitWidth)
10376 // If the lsb changed does not start at the type bitwidth boundary,
10377 // start at the previous one.
10379 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
10380 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
10381 std::min(BitWidth, ShAmt + NewBW));
10382 if ((Imm & Mask) == Imm) {
10383 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
10384 if (Opc == ISD::AND)
10385 NewImm ^= APInt::getAllOnesValue(NewBW);
10386 uint64_t PtrOff = ShAmt / 8;
10387 // For big endian targets, we need to adjust the offset to the pointer to
10388 // load the correct bytes.
10389 if (TLI.isBigEndian())
10390 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
10392 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
10393 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
10394 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
10397 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
10398 Ptr.getValueType(), Ptr,
10399 DAG.getConstant(PtrOff, SDLoc(LD),
10400 Ptr.getValueType()));
10401 SDValue NewLD = DAG.getLoad(NewVT, SDLoc(N0),
10402 LD->getChain(), NewPtr,
10403 LD->getPointerInfo().getWithOffset(PtrOff),
10404 LD->isVolatile(), LD->isNonTemporal(),
10405 LD->isInvariant(), NewAlign,
10407 SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
10408 DAG.getConstant(NewImm, SDLoc(Value),
10410 SDValue NewST = DAG.getStore(Chain, SDLoc(N),
10412 ST->getPointerInfo().getWithOffset(PtrOff),
10413 false, false, NewAlign);
10415 AddToWorklist(NewPtr.getNode());
10416 AddToWorklist(NewLD.getNode());
10417 AddToWorklist(NewVal.getNode());
10418 WorklistRemover DeadNodes(*this);
10419 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
10428 /// For a given floating point load / store pair, if the load value isn't used
10429 /// by any other operations, then consider transforming the pair to integer
10430 /// load / store operations if the target deems the transformation profitable.
10431 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
10432 StoreSDNode *ST = cast<StoreSDNode>(N);
10433 SDValue Chain = ST->getChain();
10434 SDValue Value = ST->getValue();
10435 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
10436 Value.hasOneUse() &&
10437 Chain == SDValue(Value.getNode(), 1)) {
10438 LoadSDNode *LD = cast<LoadSDNode>(Value);
10439 EVT VT = LD->getMemoryVT();
10440 if (!VT.isFloatingPoint() ||
10441 VT != ST->getMemoryVT() ||
10442 LD->isNonTemporal() ||
10443 ST->isNonTemporal() ||
10444 LD->getPointerInfo().getAddrSpace() != 0 ||
10445 ST->getPointerInfo().getAddrSpace() != 0)
10448 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
10449 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
10450 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
10451 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
10452 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
10455 unsigned LDAlign = LD->getAlignment();
10456 unsigned STAlign = ST->getAlignment();
10457 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
10458 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
10459 if (LDAlign < ABIAlign || STAlign < ABIAlign)
10462 SDValue NewLD = DAG.getLoad(IntVT, SDLoc(Value),
10463 LD->getChain(), LD->getBasePtr(),
10464 LD->getPointerInfo(),
10465 false, false, false, LDAlign);
10467 SDValue NewST = DAG.getStore(NewLD.getValue(1), SDLoc(N),
10468 NewLD, ST->getBasePtr(),
10469 ST->getPointerInfo(),
10470 false, false, STAlign);
10472 AddToWorklist(NewLD.getNode());
10473 AddToWorklist(NewST.getNode());
10474 WorklistRemover DeadNodes(*this);
10475 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
10484 /// Helper struct to parse and store a memory address as base + index + offset.
10485 /// We ignore sign extensions when it is safe to do so.
10486 /// The following two expressions are not equivalent. To differentiate we need
10487 /// to store whether there was a sign extension involved in the index
10489 /// (load (i64 add (i64 copyfromreg %c)
10490 /// (i64 signextend (add (i8 load %index)
10494 /// (load (i64 add (i64 copyfromreg %c)
10495 /// (i64 signextend (i32 add (i32 signextend (i8 load %index))
10497 struct BaseIndexOffset {
10501 bool IsIndexSignExt;
10503 BaseIndexOffset() : Offset(0), IsIndexSignExt(false) {}
10505 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
10506 bool IsIndexSignExt) :
10507 Base(Base), Index(Index), Offset(Offset), IsIndexSignExt(IsIndexSignExt) {}
10509 bool equalBaseIndex(const BaseIndexOffset &Other) {
10510 return Other.Base == Base && Other.Index == Index &&
10511 Other.IsIndexSignExt == IsIndexSignExt;
10514 /// Parses tree in Ptr for base, index, offset addresses.
10515 static BaseIndexOffset match(SDValue Ptr) {
10516 bool IsIndexSignExt = false;
10518 // We only can pattern match BASE + INDEX + OFFSET. If Ptr is not an ADD
10519 // instruction, then it could be just the BASE or everything else we don't
10520 // know how to handle. Just use Ptr as BASE and give up.
10521 if (Ptr->getOpcode() != ISD::ADD)
10522 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10524 // We know that we have at least an ADD instruction. Try to pattern match
10525 // the simple case of BASE + OFFSET.
10526 if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
10527 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
10528 return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
10532 // Inside a loop the current BASE pointer is calculated using an ADD and a
10533 // MUL instruction. In this case Ptr is the actual BASE pointer.
10534 // (i64 add (i64 %array_ptr)
10535 // (i64 mul (i64 %induction_var)
10536 // (i64 %element_size)))
10537 if (Ptr->getOperand(1)->getOpcode() == ISD::MUL)
10538 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10540 // Look at Base + Index + Offset cases.
10541 SDValue Base = Ptr->getOperand(0);
10542 SDValue IndexOffset = Ptr->getOperand(1);
10544 // Skip signextends.
10545 if (IndexOffset->getOpcode() == ISD::SIGN_EXTEND) {
10546 IndexOffset = IndexOffset->getOperand(0);
10547 IsIndexSignExt = true;
10550 // Either the case of Base + Index (no offset) or something else.
10551 if (IndexOffset->getOpcode() != ISD::ADD)
10552 return BaseIndexOffset(Base, IndexOffset, 0, IsIndexSignExt);
10554 // Now we have the case of Base + Index + offset.
10555 SDValue Index = IndexOffset->getOperand(0);
10556 SDValue Offset = IndexOffset->getOperand(1);
10558 if (!isa<ConstantSDNode>(Offset))
10559 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
10561 // Ignore signextends.
10562 if (Index->getOpcode() == ISD::SIGN_EXTEND) {
10563 Index = Index->getOperand(0);
10564 IsIndexSignExt = true;
10565 } else IsIndexSignExt = false;
10567 int64_t Off = cast<ConstantSDNode>(Offset)->getSExtValue();
10568 return BaseIndexOffset(Base, Index, Off, IsIndexSignExt);
10573 bool DAGCombiner::MergeStoresOfConstantsOrVecElts(
10574 SmallVectorImpl<MemOpLink> &StoreNodes, EVT MemVT,
10575 unsigned NumElem, bool IsConstantSrc, bool UseVector) {
10576 // Make sure we have something to merge.
10580 int64_t ElementSizeBytes = MemVT.getSizeInBits() / 8;
10581 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
10582 unsigned LatestNodeUsed = 0;
10584 for (unsigned i=0; i < NumElem; ++i) {
10585 // Find a chain for the new wide-store operand. Notice that some
10586 // of the store nodes that we found may not be selected for inclusion
10587 // in the wide store. The chain we use needs to be the chain of the
10588 // latest store node which is *used* and replaced by the wide store.
10589 if (StoreNodes[i].SequenceNum < StoreNodes[LatestNodeUsed].SequenceNum)
10590 LatestNodeUsed = i;
10593 // The latest Node in the DAG.
10594 LSBaseSDNode *LatestOp = StoreNodes[LatestNodeUsed].MemNode;
10595 SDLoc DL(StoreNodes[0].MemNode);
10599 // Find a legal type for the vector store.
10600 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
10601 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
10602 if (IsConstantSrc) {
10603 // A vector store with a constant source implies that the constant is
10604 // zero; we only handle merging stores of constant zeros because the zero
10605 // can be materialized without a load.
10606 // It may be beneficial to loosen this restriction to allow non-zero
10608 StoredVal = DAG.getConstant(0, DL, Ty);
10610 SmallVector<SDValue, 8> Ops;
10611 for (unsigned i = 0; i < NumElem ; ++i) {
10612 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10613 SDValue Val = St->getValue();
10614 // All of the operands of a BUILD_VECTOR must have the same type.
10615 if (Val.getValueType() != MemVT)
10617 Ops.push_back(Val);
10620 // Build the extracted vector elements back into a vector.
10621 StoredVal = DAG.getNode(ISD::BUILD_VECTOR, DL, Ty, Ops);
10624 // We should always use a vector store when merging extracted vector
10625 // elements, so this path implies a store of constants.
10626 assert(IsConstantSrc && "Merged vector elements should use vector store");
10628 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
10629 APInt StoreInt(StoreBW, 0);
10631 // Construct a single integer constant which is made of the smaller
10632 // constant inputs.
10633 bool IsLE = TLI.isLittleEndian();
10634 for (unsigned i = 0; i < NumElem ; ++i) {
10635 unsigned Idx = IsLE ? (NumElem - 1 - i) : i;
10636 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
10637 SDValue Val = St->getValue();
10638 StoreInt <<= ElementSizeBytes*8;
10639 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
10640 StoreInt |= C->getAPIntValue().zext(StoreBW);
10641 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
10642 StoreInt |= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
10644 llvm_unreachable("Invalid constant element type");
10648 // Create the new Load and Store operations.
10649 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
10650 StoredVal = DAG.getConstant(StoreInt, DL, StoreTy);
10653 SDValue NewStore = DAG.getStore(LatestOp->getChain(), DL, StoredVal,
10654 FirstInChain->getBasePtr(),
10655 FirstInChain->getPointerInfo(),
10657 FirstInChain->getAlignment());
10659 // Replace the last store with the new store
10660 CombineTo(LatestOp, NewStore);
10661 // Erase all other stores.
10662 for (unsigned i = 0; i < NumElem ; ++i) {
10663 if (StoreNodes[i].MemNode == LatestOp)
10665 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10666 // ReplaceAllUsesWith will replace all uses that existed when it was
10667 // called, but graph optimizations may cause new ones to appear. For
10668 // example, the case in pr14333 looks like
10670 // St's chain -> St -> another store -> X
10672 // And the only difference from St to the other store is the chain.
10673 // When we change it's chain to be St's chain they become identical,
10674 // get CSEed and the net result is that X is now a use of St.
10675 // Since we know that St is redundant, just iterate.
10676 while (!St->use_empty())
10677 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
10678 deleteAndRecombine(St);
10684 static bool allowableAlignment(const SelectionDAG &DAG,
10685 const TargetLowering &TLI, EVT EVTTy,
10686 unsigned AS, unsigned Align) {
10687 if (TLI.allowsMisalignedMemoryAccesses(EVTTy, AS, Align))
10690 Type *Ty = EVTTy.getTypeForEVT(*DAG.getContext());
10691 unsigned ABIAlignment = TLI.getDataLayout()->getPrefTypeAlignment(Ty);
10692 return (Align >= ABIAlignment);
10695 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
10696 if (OptLevel == CodeGenOpt::None)
10699 EVT MemVT = St->getMemoryVT();
10700 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
10701 bool NoVectors = DAG.getMachineFunction().getFunction()->hasFnAttribute(
10702 Attribute::NoImplicitFloat);
10704 // This function cannot currently deal with non-byte-sized memory sizes.
10705 if (ElementSizeBytes * 8 != MemVT.getSizeInBits())
10708 // Don't merge vectors into wider inputs.
10709 if (MemVT.isVector() || !MemVT.isSimple())
10712 // Perform an early exit check. Do not bother looking at stored values that
10713 // are not constants, loads, or extracted vector elements.
10714 SDValue StoredVal = St->getValue();
10715 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
10716 bool IsConstantSrc = isa<ConstantSDNode>(StoredVal) ||
10717 isa<ConstantFPSDNode>(StoredVal);
10718 bool IsExtractVecEltSrc = (StoredVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT);
10720 if (!IsConstantSrc && !IsLoadSrc && !IsExtractVecEltSrc)
10723 // Only look at ends of store sequences.
10724 SDValue Chain = SDValue(St, 0);
10725 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
10728 // This holds the base pointer, index, and the offset in bytes from the base
10730 BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
10732 // We must have a base and an offset.
10733 if (!BasePtr.Base.getNode())
10736 // Do not handle stores to undef base pointers.
10737 if (BasePtr.Base.getOpcode() == ISD::UNDEF)
10740 // Save the LoadSDNodes that we find in the chain.
10741 // We need to make sure that these nodes do not interfere with
10742 // any of the store nodes.
10743 SmallVector<LSBaseSDNode*, 8> AliasLoadNodes;
10745 // Save the StoreSDNodes that we find in the chain.
10746 SmallVector<MemOpLink, 8> StoreNodes;
10748 // Walk up the chain and look for nodes with offsets from the same
10749 // base pointer. Stop when reaching an instruction with a different kind
10750 // or instruction which has a different base pointer.
10752 StoreSDNode *Index = St;
10754 // If the chain has more than one use, then we can't reorder the mem ops.
10755 if (Index != St && !SDValue(Index, 0)->hasOneUse())
10758 // Find the base pointer and offset for this memory node.
10759 BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
10761 // Check that the base pointer is the same as the original one.
10762 if (!Ptr.equalBaseIndex(BasePtr))
10765 // The memory operands must not be volatile.
10766 if (Index->isVolatile() || Index->isIndexed())
10770 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
10771 if (St->isTruncatingStore())
10774 // The stored memory type must be the same.
10775 if (Index->getMemoryVT() != MemVT)
10778 // We found a potential memory operand to merge.
10779 StoreNodes.push_back(MemOpLink(Index, Ptr.Offset, Seq++));
10781 // Find the next memory operand in the chain. If the next operand in the
10782 // chain is a store then move up and continue the scan with the next
10783 // memory operand. If the next operand is a load save it and use alias
10784 // information to check if it interferes with anything.
10785 SDNode *NextInChain = Index->getChain().getNode();
10787 if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
10788 // We found a store node. Use it for the next iteration.
10791 } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
10792 if (Ldn->isVolatile()) {
10797 // Save the load node for later. Continue the scan.
10798 AliasLoadNodes.push_back(Ldn);
10799 NextInChain = Ldn->getChain().getNode();
10808 // Check if there is anything to merge.
10809 if (StoreNodes.size() < 2)
10812 // Sort the memory operands according to their distance from the base pointer.
10813 std::sort(StoreNodes.begin(), StoreNodes.end(),
10814 [](MemOpLink LHS, MemOpLink RHS) {
10815 return LHS.OffsetFromBase < RHS.OffsetFromBase ||
10816 (LHS.OffsetFromBase == RHS.OffsetFromBase &&
10817 LHS.SequenceNum > RHS.SequenceNum);
10820 // Scan the memory operations on the chain and find the first non-consecutive
10821 // store memory address.
10822 unsigned LastConsecutiveStore = 0;
10823 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
10824 for (unsigned i = 0, e = StoreNodes.size(); i < e; ++i) {
10826 // Check that the addresses are consecutive starting from the second
10827 // element in the list of stores.
10829 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
10830 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
10834 bool Alias = false;
10835 // Check if this store interferes with any of the loads that we found.
10836 for (unsigned ld = 0, lde = AliasLoadNodes.size(); ld < lde; ++ld)
10837 if (isAlias(AliasLoadNodes[ld], StoreNodes[i].MemNode)) {
10841 // We found a load that alias with this store. Stop the sequence.
10845 // Mark this node as useful.
10846 LastConsecutiveStore = i;
10849 // The node with the lowest store address.
10850 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
10851 unsigned FirstStoreAS = FirstInChain->getAddressSpace();
10852 unsigned FirstStoreAlign = FirstInChain->getAlignment();
10854 // Store the constants into memory as one consecutive store.
10855 if (IsConstantSrc) {
10856 unsigned LastLegalType = 0;
10857 unsigned LastLegalVectorType = 0;
10858 bool NonZero = false;
10859 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
10860 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10861 SDValue StoredVal = St->getValue();
10863 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
10864 NonZero |= !C->isNullValue();
10865 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
10866 NonZero |= !C->getConstantFPValue()->isNullValue();
10872 // Find a legal type for the constant store.
10873 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
10874 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
10875 if (TLI.isTypeLegal(StoreTy) &&
10876 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS,
10877 FirstStoreAlign)) {
10878 LastLegalType = i+1;
10879 // Or check whether a truncstore is legal.
10880 } else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
10881 TargetLowering::TypePromoteInteger) {
10882 EVT LegalizedStoredValueTy =
10883 TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
10884 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
10885 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstStoreAS,
10886 FirstStoreAlign)) {
10887 LastLegalType = i + 1;
10891 // Find a legal type for the vector store.
10892 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
10893 if (TLI.isTypeLegal(Ty) &&
10894 allowableAlignment(DAG, TLI, Ty, FirstStoreAS, FirstStoreAlign)) {
10895 LastLegalVectorType = i + 1;
10900 // We only use vectors if the constant is known to be zero or the target
10901 // allows it and the function is not marked with the noimplicitfloat
10904 LastLegalVectorType = 0;
10905 } else if (NonZero && !TLI.storeOfVectorConstantIsCheap(MemVT,
10906 LastLegalVectorType,
10908 LastLegalVectorType = 0;
10911 // Check if we found a legal integer type to store.
10912 if (LastLegalType == 0 && LastLegalVectorType == 0)
10915 bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
10916 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
10918 return MergeStoresOfConstantsOrVecElts(StoreNodes, MemVT, NumElem,
10922 // When extracting multiple vector elements, try to store them
10923 // in one vector store rather than a sequence of scalar stores.
10924 if (IsExtractVecEltSrc) {
10925 unsigned NumElem = 0;
10926 for (unsigned i = 0; i < LastConsecutiveStore + 1; ++i) {
10927 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10928 SDValue StoredVal = St->getValue();
10929 // This restriction could be loosened.
10930 // Bail out if any stored values are not elements extracted from a vector.
10931 // It should be possible to handle mixed sources, but load sources need
10932 // more careful handling (see the block of code below that handles
10933 // consecutive loads).
10934 if (StoredVal.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
10937 // Find a legal type for the vector store.
10938 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
10939 if (TLI.isTypeLegal(Ty) &&
10940 allowableAlignment(DAG, TLI, Ty, FirstStoreAS, FirstStoreAlign))
10944 return MergeStoresOfConstantsOrVecElts(StoreNodes, MemVT, NumElem,
10948 // Below we handle the case of multiple consecutive stores that
10949 // come from multiple consecutive loads. We merge them into a single
10950 // wide load and a single wide store.
10952 // Look for load nodes which are used by the stored values.
10953 SmallVector<MemOpLink, 8> LoadNodes;
10955 // Find acceptable loads. Loads need to have the same chain (token factor),
10956 // must not be zext, volatile, indexed, and they must be consecutive.
10957 BaseIndexOffset LdBasePtr;
10958 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
10959 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
10960 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
10963 // Loads must only have one use.
10964 if (!Ld->hasNUsesOfValue(1, 0))
10967 // The memory operands must not be volatile.
10968 if (Ld->isVolatile() || Ld->isIndexed())
10971 // We do not accept ext loads.
10972 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
10975 // The stored memory type must be the same.
10976 if (Ld->getMemoryVT() != MemVT)
10979 BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
10980 // If this is not the first ptr that we check.
10981 if (LdBasePtr.Base.getNode()) {
10982 // The base ptr must be the same.
10983 if (!LdPtr.equalBaseIndex(LdBasePtr))
10986 // Check that all other base pointers are the same as this one.
10990 // We found a potential memory operand to merge.
10991 LoadNodes.push_back(MemOpLink(Ld, LdPtr.Offset, 0));
10994 if (LoadNodes.size() < 2)
10997 // If we have load/store pair instructions and we only have two values,
10999 unsigned RequiredAlignment;
11000 if (LoadNodes.size() == 2 && TLI.hasPairedLoad(MemVT, RequiredAlignment) &&
11001 St->getAlignment() >= RequiredAlignment)
11004 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
11005 unsigned FirstLoadAS = FirstLoad->getAddressSpace();
11006 unsigned FirstLoadAlign = FirstLoad->getAlignment();
11008 // Scan the memory operations on the chain and find the first non-consecutive
11009 // load memory address. These variables hold the index in the store node
11011 unsigned LastConsecutiveLoad = 0;
11012 // This variable refers to the size and not index in the array.
11013 unsigned LastLegalVectorType = 0;
11014 unsigned LastLegalIntegerType = 0;
11015 StartAddress = LoadNodes[0].OffsetFromBase;
11016 SDValue FirstChain = FirstLoad->getChain();
11017 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
11018 // All loads much share the same chain.
11019 if (LoadNodes[i].MemNode->getChain() != FirstChain)
11022 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
11023 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
11025 LastConsecutiveLoad = i;
11027 // Find a legal type for the vector store.
11028 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
11029 if (TLI.isTypeLegal(StoreTy) &&
11030 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS, FirstStoreAlign) &&
11031 allowableAlignment(DAG, TLI, StoreTy, FirstLoadAS, FirstLoadAlign)) {
11032 LastLegalVectorType = i + 1;
11035 // Find a legal type for the integer store.
11036 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
11037 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
11038 if (TLI.isTypeLegal(StoreTy) &&
11039 allowableAlignment(DAG, TLI, StoreTy, FirstStoreAS, FirstStoreAlign) &&
11040 allowableAlignment(DAG, TLI, StoreTy, FirstLoadAS, FirstLoadAlign))
11041 LastLegalIntegerType = i + 1;
11042 // Or check whether a truncstore and extload is legal.
11043 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
11044 TargetLowering::TypePromoteInteger) {
11045 EVT LegalizedStoredValueTy =
11046 TLI.getTypeToTransformTo(*DAG.getContext(), StoreTy);
11047 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
11048 TLI.isLoadExtLegal(ISD::ZEXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11049 TLI.isLoadExtLegal(ISD::SEXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11050 TLI.isLoadExtLegal(ISD::EXTLOAD, LegalizedStoredValueTy, StoreTy) &&
11051 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstStoreAS,
11052 FirstStoreAlign) &&
11053 allowableAlignment(DAG, TLI, LegalizedStoredValueTy, FirstLoadAS,
11055 LastLegalIntegerType = i+1;
11059 // Only use vector types if the vector type is larger than the integer type.
11060 // If they are the same, use integers.
11061 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
11062 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
11064 // We add +1 here because the LastXXX variables refer to location while
11065 // the NumElem refers to array/index size.
11066 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
11067 NumElem = std::min(LastLegalType, NumElem);
11072 // The latest Node in the DAG.
11073 unsigned LatestNodeUsed = 0;
11074 for (unsigned i=1; i<NumElem; ++i) {
11075 // Find a chain for the new wide-store operand. Notice that some
11076 // of the store nodes that we found may not be selected for inclusion
11077 // in the wide store. The chain we use needs to be the chain of the
11078 // latest store node which is *used* and replaced by the wide store.
11079 if (StoreNodes[i].SequenceNum < StoreNodes[LatestNodeUsed].SequenceNum)
11080 LatestNodeUsed = i;
11083 LSBaseSDNode *LatestOp = StoreNodes[LatestNodeUsed].MemNode;
11085 // Find if it is better to use vectors or integers to load and store
11089 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
11091 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
11092 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
11095 SDLoc LoadDL(LoadNodes[0].MemNode);
11096 SDLoc StoreDL(StoreNodes[0].MemNode);
11098 SDValue NewLoad = DAG.getLoad(
11099 JointMemOpVT, LoadDL, FirstLoad->getChain(), FirstLoad->getBasePtr(),
11100 FirstLoad->getPointerInfo(), false, false, false, FirstLoadAlign);
11102 SDValue NewStore = DAG.getStore(
11103 LatestOp->getChain(), StoreDL, NewLoad, FirstInChain->getBasePtr(),
11104 FirstInChain->getPointerInfo(), false, false, FirstStoreAlign);
11106 // Replace one of the loads with the new load.
11107 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
11108 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
11109 SDValue(NewLoad.getNode(), 1));
11111 // Remove the rest of the load chains.
11112 for (unsigned i = 1; i < NumElem ; ++i) {
11113 // Replace all chain users of the old load nodes with the chain of the new
11115 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
11116 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
11119 // Replace the last store with the new store.
11120 CombineTo(LatestOp, NewStore);
11121 // Erase all other stores.
11122 for (unsigned i = 0; i < NumElem ; ++i) {
11123 // Remove all Store nodes.
11124 if (StoreNodes[i].MemNode == LatestOp)
11126 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
11127 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
11128 deleteAndRecombine(St);
11134 SDValue DAGCombiner::visitSTORE(SDNode *N) {
11135 StoreSDNode *ST = cast<StoreSDNode>(N);
11136 SDValue Chain = ST->getChain();
11137 SDValue Value = ST->getValue();
11138 SDValue Ptr = ST->getBasePtr();
11140 // If this is a store of a bit convert, store the input value if the
11141 // resultant store does not need a higher alignment than the original.
11142 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
11143 ST->isUnindexed()) {
11144 unsigned OrigAlign = ST->getAlignment();
11145 EVT SVT = Value.getOperand(0).getValueType();
11146 unsigned Align = TLI.getDataLayout()->
11147 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
11148 if (Align <= OrigAlign &&
11149 ((!LegalOperations && !ST->isVolatile()) ||
11150 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
11151 return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
11152 Ptr, ST->getPointerInfo(), ST->isVolatile(),
11153 ST->isNonTemporal(), OrigAlign,
11157 // Turn 'store undef, Ptr' -> nothing.
11158 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
11161 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
11162 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
11163 // NOTE: If the original store is volatile, this transform must not increase
11164 // the number of stores. For example, on x86-32 an f64 can be stored in one
11165 // processor operation but an i64 (which is not legal) requires two. So the
11166 // transform should not be done in this case.
11167 if (Value.getOpcode() != ISD::TargetConstantFP) {
11169 switch (CFP->getSimpleValueType(0).SimpleTy) {
11170 default: llvm_unreachable("Unknown FP type");
11171 case MVT::f16: // We don't do this for these yet.
11177 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
11178 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
11180 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
11181 bitcastToAPInt().getZExtValue(), SDLoc(CFP),
11183 return DAG.getStore(Chain, SDLoc(N), Tmp,
11184 Ptr, ST->getMemOperand());
11188 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
11189 !ST->isVolatile()) ||
11190 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
11192 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
11193 getZExtValue(), SDLoc(CFP), MVT::i64);
11194 return DAG.getStore(Chain, SDLoc(N), Tmp,
11195 Ptr, ST->getMemOperand());
11198 if (!ST->isVolatile() &&
11199 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
11200 // Many FP stores are not made apparent until after legalize, e.g. for
11201 // argument passing. Since this is so common, custom legalize the
11202 // 64-bit integer store into two 32-bit stores.
11203 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
11204 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, SDLoc(CFP), MVT::i32);
11205 SDValue Hi = DAG.getConstant(Val >> 32, SDLoc(CFP), MVT::i32);
11206 if (TLI.isBigEndian()) std::swap(Lo, Hi);
11208 unsigned Alignment = ST->getAlignment();
11209 bool isVolatile = ST->isVolatile();
11210 bool isNonTemporal = ST->isNonTemporal();
11211 AAMDNodes AAInfo = ST->getAAInfo();
11215 SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
11216 Ptr, ST->getPointerInfo(),
11217 isVolatile, isNonTemporal,
11218 ST->getAlignment(), AAInfo);
11219 Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
11220 DAG.getConstant(4, DL, Ptr.getValueType()));
11221 Alignment = MinAlign(Alignment, 4U);
11222 SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
11223 Ptr, ST->getPointerInfo().getWithOffset(4),
11224 isVolatile, isNonTemporal,
11225 Alignment, AAInfo);
11226 return DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
11235 // Try to infer better alignment information than the store already has.
11236 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
11237 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
11238 if (Align > ST->getAlignment()) {
11240 DAG.getTruncStore(Chain, SDLoc(N), Value,
11241 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
11242 ST->isVolatile(), ST->isNonTemporal(), Align,
11244 if (NewStore.getNode() != N)
11245 return CombineTo(ST, NewStore, true);
11250 // Try transforming a pair floating point load / store ops to integer
11251 // load / store ops.
11252 SDValue NewST = TransformFPLoadStorePair(N);
11253 if (NewST.getNode())
11256 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA
11257 : DAG.getSubtarget().useAA();
11259 if (CombinerAAOnlyFunc.getNumOccurrences() &&
11260 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
11263 if (UseAA && ST->isUnindexed()) {
11264 // Walk up chain skipping non-aliasing memory nodes.
11265 SDValue BetterChain = FindBetterChain(N, Chain);
11267 // If there is a better chain.
11268 if (Chain != BetterChain) {
11271 // Replace the chain to avoid dependency.
11272 if (ST->isTruncatingStore()) {
11273 ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
11274 ST->getMemoryVT(), ST->getMemOperand());
11276 ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
11277 ST->getMemOperand());
11280 // Create token to keep both nodes around.
11281 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
11282 MVT::Other, Chain, ReplStore);
11284 // Make sure the new and old chains are cleaned up.
11285 AddToWorklist(Token.getNode());
11287 // Don't add users to work list.
11288 return CombineTo(N, Token, false);
11292 // Try transforming N to an indexed store.
11293 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
11294 return SDValue(N, 0);
11296 // FIXME: is there such a thing as a truncating indexed store?
11297 if (ST->isTruncatingStore() && ST->isUnindexed() &&
11298 Value.getValueType().isInteger()) {
11299 // See if we can simplify the input to this truncstore with knowledge that
11300 // only the low bits are being used. For example:
11301 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
11303 GetDemandedBits(Value,
11304 APInt::getLowBitsSet(
11305 Value.getValueType().getScalarType().getSizeInBits(),
11306 ST->getMemoryVT().getScalarType().getSizeInBits()));
11307 AddToWorklist(Value.getNode());
11308 if (Shorter.getNode())
11309 return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
11310 Ptr, ST->getMemoryVT(), ST->getMemOperand());
11312 // Otherwise, see if we can simplify the operation with
11313 // SimplifyDemandedBits, which only works if the value has a single use.
11314 if (SimplifyDemandedBits(Value,
11315 APInt::getLowBitsSet(
11316 Value.getValueType().getScalarType().getSizeInBits(),
11317 ST->getMemoryVT().getScalarType().getSizeInBits())))
11318 return SDValue(N, 0);
11321 // If this is a load followed by a store to the same location, then the store
11323 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
11324 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
11325 ST->isUnindexed() && !ST->isVolatile() &&
11326 // There can't be any side effects between the load and store, such as
11327 // a call or store.
11328 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
11329 // The store is dead, remove it.
11334 // If this is a store followed by a store with the same value to the same
11335 // location, then the store is dead/noop.
11336 if (StoreSDNode *ST1 = dyn_cast<StoreSDNode>(Chain)) {
11337 if (ST1->getBasePtr() == Ptr && ST->getMemoryVT() == ST1->getMemoryVT() &&
11338 ST1->getValue() == Value && ST->isUnindexed() && !ST->isVolatile() &&
11339 ST1->isUnindexed() && !ST1->isVolatile()) {
11340 // The store is dead, remove it.
11345 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
11346 // truncating store. We can do this even if this is already a truncstore.
11347 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
11348 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
11349 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
11350 ST->getMemoryVT())) {
11351 return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
11352 Ptr, ST->getMemoryVT(), ST->getMemOperand());
11355 // Only perform this optimization before the types are legal, because we
11356 // don't want to perform this optimization on every DAGCombine invocation.
11358 bool EverChanged = false;
11361 // There can be multiple store sequences on the same chain.
11362 // Keep trying to merge store sequences until we are unable to do so
11363 // or until we merge the last store on the chain.
11364 bool Changed = MergeConsecutiveStores(ST);
11365 EverChanged |= Changed;
11366 if (!Changed) break;
11367 } while (ST->getOpcode() != ISD::DELETED_NODE);
11370 return SDValue(N, 0);
11373 return ReduceLoadOpStoreWidth(N);
11376 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
11377 SDValue InVec = N->getOperand(0);
11378 SDValue InVal = N->getOperand(1);
11379 SDValue EltNo = N->getOperand(2);
11382 // If the inserted element is an UNDEF, just use the input vector.
11383 if (InVal.getOpcode() == ISD::UNDEF)
11386 EVT VT = InVec.getValueType();
11388 // If we can't generate a legal BUILD_VECTOR, exit
11389 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
11392 // Check that we know which element is being inserted
11393 if (!isa<ConstantSDNode>(EltNo))
11395 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11397 // Canonicalize insert_vector_elt dag nodes.
11399 // (insert_vector_elt (insert_vector_elt A, Idx0), Idx1)
11400 // -> (insert_vector_elt (insert_vector_elt A, Idx1), Idx0)
11402 // Do this only if the child insert_vector node has one use; also
11403 // do this only if indices are both constants and Idx1 < Idx0.
11404 if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT && InVec.hasOneUse()
11405 && isa<ConstantSDNode>(InVec.getOperand(2))) {
11406 unsigned OtherElt =
11407 cast<ConstantSDNode>(InVec.getOperand(2))->getZExtValue();
11408 if (Elt < OtherElt) {
11410 SDValue NewOp = DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(N), VT,
11411 InVec.getOperand(0), InVal, EltNo);
11412 AddToWorklist(NewOp.getNode());
11413 return DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(InVec.getNode()),
11414 VT, NewOp, InVec.getOperand(1), InVec.getOperand(2));
11418 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
11419 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
11420 // vector elements.
11421 SmallVector<SDValue, 8> Ops;
11422 // Do not combine these two vectors if the output vector will not replace
11423 // the input vector.
11424 if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
11425 Ops.append(InVec.getNode()->op_begin(),
11426 InVec.getNode()->op_end());
11427 } else if (InVec.getOpcode() == ISD::UNDEF) {
11428 unsigned NElts = VT.getVectorNumElements();
11429 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
11434 // Insert the element
11435 if (Elt < Ops.size()) {
11436 // All the operands of BUILD_VECTOR must have the same type;
11437 // we enforce that here.
11438 EVT OpVT = Ops[0].getValueType();
11439 if (InVal.getValueType() != OpVT)
11440 InVal = OpVT.bitsGT(InVal.getValueType()) ?
11441 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
11442 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
11446 // Return the new vector
11447 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
11450 SDValue DAGCombiner::ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
11451 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad) {
11452 EVT ResultVT = EVE->getValueType(0);
11453 EVT VecEltVT = InVecVT.getVectorElementType();
11454 unsigned Align = OriginalLoad->getAlignment();
11455 unsigned NewAlign = TLI.getDataLayout()->getABITypeAlignment(
11456 VecEltVT.getTypeForEVT(*DAG.getContext()));
11458 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, VecEltVT))
11463 SDValue NewPtr = OriginalLoad->getBasePtr();
11465 EVT PtrType = NewPtr.getValueType();
11466 MachinePointerInfo MPI;
11468 if (auto *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo)) {
11469 int Elt = ConstEltNo->getZExtValue();
11470 unsigned PtrOff = VecEltVT.getSizeInBits() * Elt / 8;
11471 Offset = DAG.getConstant(PtrOff, DL, PtrType);
11472 MPI = OriginalLoad->getPointerInfo().getWithOffset(PtrOff);
11474 Offset = DAG.getZExtOrTrunc(EltNo, DL, PtrType);
11475 Offset = DAG.getNode(
11476 ISD::MUL, DL, PtrType, Offset,
11477 DAG.getConstant(VecEltVT.getStoreSize(), DL, PtrType));
11478 MPI = OriginalLoad->getPointerInfo();
11480 NewPtr = DAG.getNode(ISD::ADD, DL, PtrType, NewPtr, Offset);
11482 // The replacement we need to do here is a little tricky: we need to
11483 // replace an extractelement of a load with a load.
11484 // Use ReplaceAllUsesOfValuesWith to do the replacement.
11485 // Note that this replacement assumes that the extractvalue is the only
11486 // use of the load; that's okay because we don't want to perform this
11487 // transformation in other cases anyway.
11490 if (ResultVT.bitsGT(VecEltVT)) {
11491 // If the result type of vextract is wider than the load, then issue an
11492 // extending load instead.
11493 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, ResultVT,
11497 Load = DAG.getExtLoad(
11498 ExtType, SDLoc(EVE), ResultVT, OriginalLoad->getChain(), NewPtr, MPI,
11499 VecEltVT, OriginalLoad->isVolatile(), OriginalLoad->isNonTemporal(),
11500 OriginalLoad->isInvariant(), Align, OriginalLoad->getAAInfo());
11501 Chain = Load.getValue(1);
11503 Load = DAG.getLoad(
11504 VecEltVT, SDLoc(EVE), OriginalLoad->getChain(), NewPtr, MPI,
11505 OriginalLoad->isVolatile(), OriginalLoad->isNonTemporal(),
11506 OriginalLoad->isInvariant(), Align, OriginalLoad->getAAInfo());
11507 Chain = Load.getValue(1);
11508 if (ResultVT.bitsLT(VecEltVT))
11509 Load = DAG.getNode(ISD::TRUNCATE, SDLoc(EVE), ResultVT, Load);
11511 Load = DAG.getNode(ISD::BITCAST, SDLoc(EVE), ResultVT, Load);
11513 WorklistRemover DeadNodes(*this);
11514 SDValue From[] = { SDValue(EVE, 0), SDValue(OriginalLoad, 1) };
11515 SDValue To[] = { Load, Chain };
11516 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
11517 // Since we're explicitly calling ReplaceAllUses, add the new node to the
11518 // worklist explicitly as well.
11519 AddToWorklist(Load.getNode());
11520 AddUsersToWorklist(Load.getNode()); // Add users too
11521 // Make sure to revisit this node to clean it up; it will usually be dead.
11522 AddToWorklist(EVE);
11524 return SDValue(EVE, 0);
11527 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
11528 // (vextract (scalar_to_vector val, 0) -> val
11529 SDValue InVec = N->getOperand(0);
11530 EVT VT = InVec.getValueType();
11531 EVT NVT = N->getValueType(0);
11533 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
11534 // Check if the result type doesn't match the inserted element type. A
11535 // SCALAR_TO_VECTOR may truncate the inserted element and the
11536 // EXTRACT_VECTOR_ELT may widen the extracted vector.
11537 SDValue InOp = InVec.getOperand(0);
11538 if (InOp.getValueType() != NVT) {
11539 assert(InOp.getValueType().isInteger() && NVT.isInteger());
11540 return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
11545 SDValue EltNo = N->getOperand(1);
11546 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
11548 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
11549 // We only perform this optimization before the op legalization phase because
11550 // we may introduce new vector instructions which are not backed by TD
11551 // patterns. For example on AVX, extracting elements from a wide vector
11552 // without using extract_subvector. However, if we can find an underlying
11553 // scalar value, then we can always use that.
11554 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
11556 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11557 int NumElem = VT.getVectorNumElements();
11558 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
11559 // Find the new index to extract from.
11560 int OrigElt = SVOp->getMaskElt(Elt);
11562 // Extracting an undef index is undef.
11564 return DAG.getUNDEF(NVT);
11566 // Select the right vector half to extract from.
11568 if (OrigElt < NumElem) {
11569 SVInVec = InVec->getOperand(0);
11571 SVInVec = InVec->getOperand(1);
11572 OrigElt -= NumElem;
11575 if (SVInVec.getOpcode() == ISD::BUILD_VECTOR) {
11576 SDValue InOp = SVInVec.getOperand(OrigElt);
11577 if (InOp.getValueType() != NVT) {
11578 assert(InOp.getValueType().isInteger() && NVT.isInteger());
11579 InOp = DAG.getSExtOrTrunc(InOp, SDLoc(SVInVec), NVT);
11585 // FIXME: We should handle recursing on other vector shuffles and
11586 // scalar_to_vector here as well.
11588 if (!LegalOperations) {
11589 EVT IndexTy = TLI.getVectorIdxTy();
11590 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT, SVInVec,
11591 DAG.getConstant(OrigElt, SDLoc(SVOp), IndexTy));
11595 bool BCNumEltsChanged = false;
11596 EVT ExtVT = VT.getVectorElementType();
11599 // If the result of load has to be truncated, then it's not necessarily
11601 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
11604 if (InVec.getOpcode() == ISD::BITCAST) {
11605 // Don't duplicate a load with other uses.
11606 if (!InVec.hasOneUse())
11609 EVT BCVT = InVec.getOperand(0).getValueType();
11610 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
11612 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
11613 BCNumEltsChanged = true;
11614 InVec = InVec.getOperand(0);
11615 ExtVT = BCVT.getVectorElementType();
11618 // (vextract (vN[if]M load $addr), i) -> ([if]M load $addr + i * size)
11619 if (!LegalOperations && !ConstEltNo && InVec.hasOneUse() &&
11620 ISD::isNormalLoad(InVec.getNode()) &&
11621 !N->getOperand(1)->hasPredecessor(InVec.getNode())) {
11622 SDValue Index = N->getOperand(1);
11623 if (LoadSDNode *OrigLoad = dyn_cast<LoadSDNode>(InVec))
11624 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, Index,
11628 // Perform only after legalization to ensure build_vector / vector_shuffle
11629 // optimizations have already been done.
11630 if (!LegalOperations) return SDValue();
11632 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
11633 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
11634 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
11637 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
11639 LoadSDNode *LN0 = nullptr;
11640 const ShuffleVectorSDNode *SVN = nullptr;
11641 if (ISD::isNormalLoad(InVec.getNode())) {
11642 LN0 = cast<LoadSDNode>(InVec);
11643 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
11644 InVec.getOperand(0).getValueType() == ExtVT &&
11645 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
11646 // Don't duplicate a load with other uses.
11647 if (!InVec.hasOneUse())
11650 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
11651 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
11652 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
11654 // (load $addr+1*size)
11656 // Don't duplicate a load with other uses.
11657 if (!InVec.hasOneUse())
11660 // If the bit convert changed the number of elements, it is unsafe
11661 // to examine the mask.
11662 if (BCNumEltsChanged)
11665 // Select the input vector, guarding against out of range extract vector.
11666 unsigned NumElems = VT.getVectorNumElements();
11667 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
11668 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
11670 if (InVec.getOpcode() == ISD::BITCAST) {
11671 // Don't duplicate a load with other uses.
11672 if (!InVec.hasOneUse())
11675 InVec = InVec.getOperand(0);
11677 if (ISD::isNormalLoad(InVec.getNode())) {
11678 LN0 = cast<LoadSDNode>(InVec);
11679 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
11680 EltNo = DAG.getConstant(Elt, SDLoc(EltNo), EltNo.getValueType());
11684 // Make sure we found a non-volatile load and the extractelement is
11686 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
11689 // If Idx was -1 above, Elt is going to be -1, so just return undef.
11691 return DAG.getUNDEF(LVT);
11693 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, EltNo, LN0);
11699 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
11700 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
11701 // We perform this optimization post type-legalization because
11702 // the type-legalizer often scalarizes integer-promoted vectors.
11703 // Performing this optimization before may create bit-casts which
11704 // will be type-legalized to complex code sequences.
11705 // We perform this optimization only before the operation legalizer because we
11706 // may introduce illegal operations.
11707 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
11710 unsigned NumInScalars = N->getNumOperands();
11712 EVT VT = N->getValueType(0);
11714 // Check to see if this is a BUILD_VECTOR of a bunch of values
11715 // which come from any_extend or zero_extend nodes. If so, we can create
11716 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
11717 // optimizations. We do not handle sign-extend because we can't fill the sign
11719 EVT SourceType = MVT::Other;
11720 bool AllAnyExt = true;
11722 for (unsigned i = 0; i != NumInScalars; ++i) {
11723 SDValue In = N->getOperand(i);
11724 // Ignore undef inputs.
11725 if (In.getOpcode() == ISD::UNDEF) continue;
11727 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
11728 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
11730 // Abort if the element is not an extension.
11731 if (!ZeroExt && !AnyExt) {
11732 SourceType = MVT::Other;
11736 // The input is a ZeroExt or AnyExt. Check the original type.
11737 EVT InTy = In.getOperand(0).getValueType();
11739 // Check that all of the widened source types are the same.
11740 if (SourceType == MVT::Other)
11743 else if (InTy != SourceType) {
11744 // Multiple income types. Abort.
11745 SourceType = MVT::Other;
11749 // Check if all of the extends are ANY_EXTENDs.
11750 AllAnyExt &= AnyExt;
11753 // In order to have valid types, all of the inputs must be extended from the
11754 // same source type and all of the inputs must be any or zero extend.
11755 // Scalar sizes must be a power of two.
11756 EVT OutScalarTy = VT.getScalarType();
11757 bool ValidTypes = SourceType != MVT::Other &&
11758 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
11759 isPowerOf2_32(SourceType.getSizeInBits());
11761 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
11762 // turn into a single shuffle instruction.
11766 bool isLE = TLI.isLittleEndian();
11767 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
11768 assert(ElemRatio > 1 && "Invalid element size ratio");
11769 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
11770 DAG.getConstant(0, SDLoc(N), SourceType);
11772 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
11773 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
11775 // Populate the new build_vector
11776 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
11777 SDValue Cast = N->getOperand(i);
11778 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
11779 Cast.getOpcode() == ISD::ZERO_EXTEND ||
11780 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
11782 if (Cast.getOpcode() == ISD::UNDEF)
11783 In = DAG.getUNDEF(SourceType);
11785 In = Cast->getOperand(0);
11786 unsigned Index = isLE ? (i * ElemRatio) :
11787 (i * ElemRatio + (ElemRatio - 1));
11789 assert(Index < Ops.size() && "Invalid index");
11793 // The type of the new BUILD_VECTOR node.
11794 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
11795 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
11796 "Invalid vector size");
11797 // Check if the new vector type is legal.
11798 if (!isTypeLegal(VecVT)) return SDValue();
11800 // Make the new BUILD_VECTOR.
11801 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, Ops);
11803 // The new BUILD_VECTOR node has the potential to be further optimized.
11804 AddToWorklist(BV.getNode());
11805 // Bitcast to the desired type.
11806 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
11809 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
11810 EVT VT = N->getValueType(0);
11812 unsigned NumInScalars = N->getNumOperands();
11815 EVT SrcVT = MVT::Other;
11816 unsigned Opcode = ISD::DELETED_NODE;
11817 unsigned NumDefs = 0;
11819 for (unsigned i = 0; i != NumInScalars; ++i) {
11820 SDValue In = N->getOperand(i);
11821 unsigned Opc = In.getOpcode();
11823 if (Opc == ISD::UNDEF)
11826 // If all scalar values are floats and converted from integers.
11827 if (Opcode == ISD::DELETED_NODE &&
11828 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
11835 EVT InVT = In.getOperand(0).getValueType();
11837 // If all scalar values are typed differently, bail out. It's chosen to
11838 // simplify BUILD_VECTOR of integer types.
11839 if (SrcVT == MVT::Other)
11846 // If the vector has just one element defined, it's not worth to fold it into
11847 // a vectorized one.
11851 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
11852 && "Should only handle conversion from integer to float.");
11853 assert(SrcVT != MVT::Other && "Cannot determine source type!");
11855 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
11857 if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
11860 // Just because the floating-point vector type is legal does not necessarily
11861 // mean that the corresponding integer vector type is.
11862 if (!isTypeLegal(NVT))
11865 SmallVector<SDValue, 8> Opnds;
11866 for (unsigned i = 0; i != NumInScalars; ++i) {
11867 SDValue In = N->getOperand(i);
11869 if (In.getOpcode() == ISD::UNDEF)
11870 Opnds.push_back(DAG.getUNDEF(SrcVT));
11872 Opnds.push_back(In.getOperand(0));
11874 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Opnds);
11875 AddToWorklist(BV.getNode());
11877 return DAG.getNode(Opcode, dl, VT, BV);
11880 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
11881 unsigned NumInScalars = N->getNumOperands();
11883 EVT VT = N->getValueType(0);
11885 // A vector built entirely of undefs is undef.
11886 if (ISD::allOperandsUndef(N))
11887 return DAG.getUNDEF(VT);
11889 if (SDValue V = reduceBuildVecExtToExtBuildVec(N))
11892 if (SDValue V = reduceBuildVecConvertToConvertBuildVec(N))
11895 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
11896 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
11897 // at most two distinct vectors, turn this into a shuffle node.
11899 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
11900 if (!isTypeLegal(VT))
11903 // May only combine to shuffle after legalize if shuffle is legal.
11904 if (LegalOperations && !TLI.isOperationLegal(ISD::VECTOR_SHUFFLE, VT))
11907 SDValue VecIn1, VecIn2;
11908 bool UsesZeroVector = false;
11909 for (unsigned i = 0; i != NumInScalars; ++i) {
11910 SDValue Op = N->getOperand(i);
11911 // Ignore undef inputs.
11912 if (Op.getOpcode() == ISD::UNDEF) continue;
11914 // See if we can combine this build_vector into a blend with a zero vector.
11915 if (!VecIn2.getNode() && (isNullConstant(Op) ||
11916 (Op.getOpcode() == ISD::ConstantFP &&
11917 cast<ConstantFPSDNode>(Op.getNode())->getValueAPF().isZero()))) {
11918 UsesZeroVector = true;
11922 // If this input is something other than a EXTRACT_VECTOR_ELT with a
11923 // constant index, bail out.
11924 if (Op.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
11925 !isa<ConstantSDNode>(Op.getOperand(1))) {
11926 VecIn1 = VecIn2 = SDValue(nullptr, 0);
11930 // We allow up to two distinct input vectors.
11931 SDValue ExtractedFromVec = Op.getOperand(0);
11932 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
11935 if (!VecIn1.getNode()) {
11936 VecIn1 = ExtractedFromVec;
11937 } else if (!VecIn2.getNode() && !UsesZeroVector) {
11938 VecIn2 = ExtractedFromVec;
11940 // Too many inputs.
11941 VecIn1 = VecIn2 = SDValue(nullptr, 0);
11946 // If everything is good, we can make a shuffle operation.
11947 if (VecIn1.getNode()) {
11948 unsigned InNumElements = VecIn1.getValueType().getVectorNumElements();
11949 SmallVector<int, 8> Mask;
11950 for (unsigned i = 0; i != NumInScalars; ++i) {
11951 unsigned Opcode = N->getOperand(i).getOpcode();
11952 if (Opcode == ISD::UNDEF) {
11953 Mask.push_back(-1);
11957 // Operands can also be zero.
11958 if (Opcode != ISD::EXTRACT_VECTOR_ELT) {
11959 assert(UsesZeroVector &&
11960 (Opcode == ISD::Constant || Opcode == ISD::ConstantFP) &&
11961 "Unexpected node found!");
11962 Mask.push_back(NumInScalars+i);
11966 // If extracting from the first vector, just use the index directly.
11967 SDValue Extract = N->getOperand(i);
11968 SDValue ExtVal = Extract.getOperand(1);
11969 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
11970 if (Extract.getOperand(0) == VecIn1) {
11971 Mask.push_back(ExtIndex);
11975 // Otherwise, use InIdx + InputVecSize
11976 Mask.push_back(InNumElements + ExtIndex);
11979 // Avoid introducing illegal shuffles with zero.
11980 if (UsesZeroVector && !TLI.isVectorClearMaskLegal(Mask, VT))
11983 // We can't generate a shuffle node with mismatched input and output types.
11984 // Attempt to transform a single input vector to the correct type.
11985 if ((VT != VecIn1.getValueType())) {
11986 // If the input vector type has a different base type to the output
11987 // vector type, bail out.
11988 EVT VTElemType = VT.getVectorElementType();
11989 if ((VecIn1.getValueType().getVectorElementType() != VTElemType) ||
11990 (VecIn2.getNode() &&
11991 (VecIn2.getValueType().getVectorElementType() != VTElemType)))
11994 // If the input vector is too small, widen it.
11995 // We only support widening of vectors which are half the size of the
11996 // output registers. For example XMM->YMM widening on X86 with AVX.
11997 EVT VecInT = VecIn1.getValueType();
11998 if (VecInT.getSizeInBits() * 2 == VT.getSizeInBits()) {
11999 // If we only have one small input, widen it by adding undef values.
12000 if (!VecIn2.getNode())
12001 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, VecIn1,
12002 DAG.getUNDEF(VecIn1.getValueType()));
12003 else if (VecIn1.getValueType() == VecIn2.getValueType()) {
12004 // If we have two small inputs of the same type, try to concat them.
12005 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, VecIn1, VecIn2);
12006 VecIn2 = SDValue(nullptr, 0);
12009 } else if (VecInT.getSizeInBits() == VT.getSizeInBits() * 2) {
12010 // If the input vector is too large, try to split it.
12011 // We don't support having two input vectors that are too large.
12012 // If the zero vector was used, we can not split the vector,
12013 // since we'd need 3 inputs.
12014 if (UsesZeroVector || VecIn2.getNode())
12017 if (!TLI.isExtractSubvectorCheap(VT, VT.getVectorNumElements()))
12020 // Try to replace VecIn1 with two extract_subvectors
12021 // No need to update the masks, they should still be correct.
12022 VecIn2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, VecIn1,
12023 DAG.getConstant(VT.getVectorNumElements(), dl, TLI.getVectorIdxTy()));
12024 VecIn1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, VecIn1,
12025 DAG.getConstant(0, dl, TLI.getVectorIdxTy()));
12030 if (UsesZeroVector)
12031 VecIn2 = VT.isInteger() ? DAG.getConstant(0, dl, VT) :
12032 DAG.getConstantFP(0.0, dl, VT);
12034 // If VecIn2 is unused then change it to undef.
12035 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
12037 // Check that we were able to transform all incoming values to the same
12039 if (VecIn2.getValueType() != VecIn1.getValueType() ||
12040 VecIn1.getValueType() != VT)
12043 // Return the new VECTOR_SHUFFLE node.
12047 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
12053 static SDValue combineConcatVectorOfScalars(SDNode *N, SelectionDAG &DAG) {
12054 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
12055 EVT OpVT = N->getOperand(0).getValueType();
12057 // If the operands are legal vectors, leave them alone.
12058 if (TLI.isTypeLegal(OpVT))
12062 EVT VT = N->getValueType(0);
12063 SmallVector<SDValue, 8> Ops;
12065 EVT SVT = EVT::getIntegerVT(*DAG.getContext(), OpVT.getSizeInBits());
12066 SDValue ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);
12068 // Keep track of what we encounter.
12069 bool AnyInteger = false;
12070 bool AnyFP = false;
12071 for (const SDValue &Op : N->ops()) {
12072 if (ISD::BITCAST == Op.getOpcode() &&
12073 !Op.getOperand(0).getValueType().isVector())
12074 Ops.push_back(Op.getOperand(0));
12075 else if (ISD::UNDEF == Op.getOpcode())
12076 Ops.push_back(ScalarUndef);
12080 // Note whether we encounter an integer or floating point scalar.
12081 // If it's neither, bail out, it could be something weird like x86mmx.
12082 EVT LastOpVT = Ops.back().getValueType();
12083 if (LastOpVT.isFloatingPoint())
12085 else if (LastOpVT.isInteger())
12091 // If any of the operands is a floating point scalar bitcast to a vector,
12092 // use floating point types throughout, and bitcast everything.
12093 // Replace UNDEFs by another scalar UNDEF node, of the final desired type.
12095 SVT = EVT::getFloatingPointVT(OpVT.getSizeInBits());
12096 ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);
12098 for (SDValue &Op : Ops) {
12099 if (Op.getValueType() == SVT)
12101 if (Op.getOpcode() == ISD::UNDEF)
12104 Op = DAG.getNode(ISD::BITCAST, DL, SVT, Op);
12109 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SVT,
12110 VT.getSizeInBits() / SVT.getSizeInBits());
12111 return DAG.getNode(ISD::BITCAST, DL, VT,
12112 DAG.getNode(ISD::BUILD_VECTOR, DL, VecVT, Ops));
12115 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
12116 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
12117 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
12118 // inputs come from at most two distinct vectors, turn this into a shuffle
12121 // If we only have one input vector, we don't need to do any concatenation.
12122 if (N->getNumOperands() == 1)
12123 return N->getOperand(0);
12125 // Check if all of the operands are undefs.
12126 EVT VT = N->getValueType(0);
12127 if (ISD::allOperandsUndef(N))
12128 return DAG.getUNDEF(VT);
12130 // Optimize concat_vectors where all but the first of the vectors are undef.
12131 if (std::all_of(std::next(N->op_begin()), N->op_end(), [](const SDValue &Op) {
12132 return Op.getOpcode() == ISD::UNDEF;
12134 SDValue In = N->getOperand(0);
12135 assert(In.getValueType().isVector() && "Must concat vectors");
12137 // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
12138 if (In->getOpcode() == ISD::BITCAST &&
12139 !In->getOperand(0)->getValueType(0).isVector()) {
12140 SDValue Scalar = In->getOperand(0);
12142 // If the bitcast type isn't legal, it might be a trunc of a legal type;
12143 // look through the trunc so we can still do the transform:
12144 // concat_vectors(trunc(scalar), undef) -> scalar_to_vector(scalar)
12145 if (Scalar->getOpcode() == ISD::TRUNCATE &&
12146 !TLI.isTypeLegal(Scalar.getValueType()) &&
12147 TLI.isTypeLegal(Scalar->getOperand(0).getValueType()))
12148 Scalar = Scalar->getOperand(0);
12150 EVT SclTy = Scalar->getValueType(0);
12152 if (!SclTy.isFloatingPoint() && !SclTy.isInteger())
12155 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SclTy,
12156 VT.getSizeInBits() / SclTy.getSizeInBits());
12157 if (!TLI.isTypeLegal(NVT) || !TLI.isTypeLegal(Scalar.getValueType()))
12160 SDLoc dl = SDLoc(N);
12161 SDValue Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, NVT, Scalar);
12162 return DAG.getNode(ISD::BITCAST, dl, VT, Res);
12166 // Fold any combination of BUILD_VECTOR or UNDEF nodes into one BUILD_VECTOR.
12167 // We have already tested above for an UNDEF only concatenation.
12168 // fold (concat_vectors (BUILD_VECTOR A, B, ...), (BUILD_VECTOR C, D, ...))
12169 // -> (BUILD_VECTOR A, B, ..., C, D, ...)
12170 auto IsBuildVectorOrUndef = [](const SDValue &Op) {
12171 return ISD::UNDEF == Op.getOpcode() || ISD::BUILD_VECTOR == Op.getOpcode();
12173 bool AllBuildVectorsOrUndefs =
12174 std::all_of(N->op_begin(), N->op_end(), IsBuildVectorOrUndef);
12175 if (AllBuildVectorsOrUndefs) {
12176 SmallVector<SDValue, 8> Opnds;
12177 EVT SVT = VT.getScalarType();
12180 if (!SVT.isFloatingPoint()) {
12181 // If BUILD_VECTOR are from built from integer, they may have different
12182 // operand types. Get the smallest type and truncate all operands to it.
12183 bool FoundMinVT = false;
12184 for (const SDValue &Op : N->ops())
12185 if (ISD::BUILD_VECTOR == Op.getOpcode()) {
12186 EVT OpSVT = Op.getOperand(0)->getValueType(0);
12187 MinVT = (!FoundMinVT || OpSVT.bitsLE(MinVT)) ? OpSVT : MinVT;
12190 assert(FoundMinVT && "Concat vector type mismatch");
12193 for (const SDValue &Op : N->ops()) {
12194 EVT OpVT = Op.getValueType();
12195 unsigned NumElts = OpVT.getVectorNumElements();
12197 if (ISD::UNDEF == Op.getOpcode())
12198 Opnds.append(NumElts, DAG.getUNDEF(MinVT));
12200 if (ISD::BUILD_VECTOR == Op.getOpcode()) {
12201 if (SVT.isFloatingPoint()) {
12202 assert(SVT == OpVT.getScalarType() && "Concat vector type mismatch");
12203 Opnds.append(Op->op_begin(), Op->op_begin() + NumElts);
12205 for (unsigned i = 0; i != NumElts; ++i)
12207 DAG.getNode(ISD::TRUNCATE, SDLoc(N), MinVT, Op.getOperand(i)));
12212 assert(VT.getVectorNumElements() == Opnds.size() &&
12213 "Concat vector type mismatch");
12214 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
12217 // Fold CONCAT_VECTORS of only bitcast scalars (or undef) to BUILD_VECTOR.
12218 if (SDValue V = combineConcatVectorOfScalars(N, DAG))
12221 // Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
12222 // nodes often generate nop CONCAT_VECTOR nodes.
12223 // Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
12224 // place the incoming vectors at the exact same location.
12225 SDValue SingleSource = SDValue();
12226 unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();
12228 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
12229 SDValue Op = N->getOperand(i);
12231 if (Op.getOpcode() == ISD::UNDEF)
12234 // Check if this is the identity extract:
12235 if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
12238 // Find the single incoming vector for the extract_subvector.
12239 if (SingleSource.getNode()) {
12240 if (Op.getOperand(0) != SingleSource)
12243 SingleSource = Op.getOperand(0);
12245 // Check the source type is the same as the type of the result.
12246 // If not, this concat may extend the vector, so we can not
12247 // optimize it away.
12248 if (SingleSource.getValueType() != N->getValueType(0))
12252 unsigned IdentityIndex = i * PartNumElem;
12253 ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
12254 // The extract index must be constant.
12258 // Check that we are reading from the identity index.
12259 if (CS->getZExtValue() != IdentityIndex)
12263 if (SingleSource.getNode())
12264 return SingleSource;
12269 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
12270 EVT NVT = N->getValueType(0);
12271 SDValue V = N->getOperand(0);
12273 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
12275 // (extract_subvec (concat V1, V2, ...), i)
12278 // Only operand 0 is checked as 'concat' assumes all inputs of the same
12280 if (V->getOperand(0).getValueType() != NVT)
12282 unsigned Idx = N->getConstantOperandVal(1);
12283 unsigned NumElems = NVT.getVectorNumElements();
12284 assert((Idx % NumElems) == 0 &&
12285 "IDX in concat is not a multiple of the result vector length.");
12286 return V->getOperand(Idx / NumElems);
12290 if (V->getOpcode() == ISD::BITCAST)
12291 V = V.getOperand(0);
12293 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
12295 // Handle only simple case where vector being inserted and vector
12296 // being extracted are of same type, and are half size of larger vectors.
12297 EVT BigVT = V->getOperand(0).getValueType();
12298 EVT SmallVT = V->getOperand(1).getValueType();
12299 if (!NVT.bitsEq(SmallVT) || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
12302 // Only handle cases where both indexes are constants with the same type.
12303 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
12304 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
12306 if (InsIdx && ExtIdx &&
12307 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
12308 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
12310 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
12312 // indices are equal or bit offsets are equal => V1
12313 // otherwise => (extract_subvec V1, ExtIdx)
12314 if (InsIdx->getZExtValue() * SmallVT.getScalarType().getSizeInBits() ==
12315 ExtIdx->getZExtValue() * NVT.getScalarType().getSizeInBits())
12316 return DAG.getNode(ISD::BITCAST, dl, NVT, V->getOperand(1));
12317 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT,
12318 DAG.getNode(ISD::BITCAST, dl,
12319 N->getOperand(0).getValueType(),
12320 V->getOperand(0)), N->getOperand(1));
12327 static SDValue simplifyShuffleOperandRecursively(SmallBitVector &UsedElements,
12328 SDValue V, SelectionDAG &DAG) {
12330 EVT VT = V.getValueType();
12332 switch (V.getOpcode()) {
12336 case ISD::CONCAT_VECTORS: {
12337 EVT OpVT = V->getOperand(0).getValueType();
12338 int OpSize = OpVT.getVectorNumElements();
12339 SmallBitVector OpUsedElements(OpSize, false);
12340 bool FoundSimplification = false;
12341 SmallVector<SDValue, 4> NewOps;
12342 NewOps.reserve(V->getNumOperands());
12343 for (int i = 0, NumOps = V->getNumOperands(); i < NumOps; ++i) {
12344 SDValue Op = V->getOperand(i);
12345 bool OpUsed = false;
12346 for (int j = 0; j < OpSize; ++j)
12347 if (UsedElements[i * OpSize + j]) {
12348 OpUsedElements[j] = true;
12352 OpUsed ? simplifyShuffleOperandRecursively(OpUsedElements, Op, DAG)
12353 : DAG.getUNDEF(OpVT));
12354 FoundSimplification |= Op == NewOps.back();
12355 OpUsedElements.reset();
12357 if (FoundSimplification)
12358 V = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, NewOps);
12362 case ISD::INSERT_SUBVECTOR: {
12363 SDValue BaseV = V->getOperand(0);
12364 SDValue SubV = V->getOperand(1);
12365 auto *IdxN = dyn_cast<ConstantSDNode>(V->getOperand(2));
12369 int SubSize = SubV.getValueType().getVectorNumElements();
12370 int Idx = IdxN->getZExtValue();
12371 bool SubVectorUsed = false;
12372 SmallBitVector SubUsedElements(SubSize, false);
12373 for (int i = 0; i < SubSize; ++i)
12374 if (UsedElements[i + Idx]) {
12375 SubVectorUsed = true;
12376 SubUsedElements[i] = true;
12377 UsedElements[i + Idx] = false;
12380 // Now recurse on both the base and sub vectors.
12381 SDValue SimplifiedSubV =
12383 ? simplifyShuffleOperandRecursively(SubUsedElements, SubV, DAG)
12384 : DAG.getUNDEF(SubV.getValueType());
12385 SDValue SimplifiedBaseV = simplifyShuffleOperandRecursively(UsedElements, BaseV, DAG);
12386 if (SimplifiedSubV != SubV || SimplifiedBaseV != BaseV)
12387 V = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
12388 SimplifiedBaseV, SimplifiedSubV, V->getOperand(2));
12394 static SDValue simplifyShuffleOperands(ShuffleVectorSDNode *SVN, SDValue N0,
12395 SDValue N1, SelectionDAG &DAG) {
12396 EVT VT = SVN->getValueType(0);
12397 int NumElts = VT.getVectorNumElements();
12398 SmallBitVector N0UsedElements(NumElts, false), N1UsedElements(NumElts, false);
12399 for (int M : SVN->getMask())
12400 if (M >= 0 && M < NumElts)
12401 N0UsedElements[M] = true;
12402 else if (M >= NumElts)
12403 N1UsedElements[M - NumElts] = true;
12405 SDValue S0 = simplifyShuffleOperandRecursively(N0UsedElements, N0, DAG);
12406 SDValue S1 = simplifyShuffleOperandRecursively(N1UsedElements, N1, DAG);
12407 if (S0 == N0 && S1 == N1)
12410 return DAG.getVectorShuffle(VT, SDLoc(SVN), S0, S1, SVN->getMask());
12413 // Tries to turn a shuffle of two CONCAT_VECTORS into a single concat,
12414 // or turn a shuffle of a single concat into simpler shuffle then concat.
12415 static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
12416 EVT VT = N->getValueType(0);
12417 unsigned NumElts = VT.getVectorNumElements();
12419 SDValue N0 = N->getOperand(0);
12420 SDValue N1 = N->getOperand(1);
12421 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
12423 SmallVector<SDValue, 4> Ops;
12424 EVT ConcatVT = N0.getOperand(0).getValueType();
12425 unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
12426 unsigned NumConcats = NumElts / NumElemsPerConcat;
12428 // Special case: shuffle(concat(A,B)) can be more efficiently represented
12429 // as concat(shuffle(A,B),UNDEF) if the shuffle doesn't set any of the high
12430 // half vector elements.
12431 if (NumElemsPerConcat * 2 == NumElts && N1.getOpcode() == ISD::UNDEF &&
12432 std::all_of(SVN->getMask().begin() + NumElemsPerConcat,
12433 SVN->getMask().end(), [](int i) { return i == -1; })) {
12434 N0 = DAG.getVectorShuffle(ConcatVT, SDLoc(N), N0.getOperand(0), N0.getOperand(1),
12435 ArrayRef<int>(SVN->getMask().begin(), NumElemsPerConcat));
12436 N1 = DAG.getUNDEF(ConcatVT);
12437 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, N0, N1);
12440 // Look at every vector that's inserted. We're looking for exact
12441 // subvector-sized copies from a concatenated vector
12442 for (unsigned I = 0; I != NumConcats; ++I) {
12443 // Make sure we're dealing with a copy.
12444 unsigned Begin = I * NumElemsPerConcat;
12445 bool AllUndef = true, NoUndef = true;
12446 for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
12447 if (SVN->getMaskElt(J) >= 0)
12454 if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
12457 for (unsigned J = 1; J != NumElemsPerConcat; ++J)
12458 if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
12461 unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
12462 if (FirstElt < N0.getNumOperands())
12463 Ops.push_back(N0.getOperand(FirstElt));
12465 Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));
12467 } else if (AllUndef) {
12468 Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
12469 } else { // Mixed with general masks and undefs, can't do optimization.
12474 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops);
12477 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
12478 EVT VT = N->getValueType(0);
12479 unsigned NumElts = VT.getVectorNumElements();
12481 SDValue N0 = N->getOperand(0);
12482 SDValue N1 = N->getOperand(1);
12484 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
12486 // Canonicalize shuffle undef, undef -> undef
12487 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
12488 return DAG.getUNDEF(VT);
12490 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
12492 // Canonicalize shuffle v, v -> v, undef
12494 SmallVector<int, 8> NewMask;
12495 for (unsigned i = 0; i != NumElts; ++i) {
12496 int Idx = SVN->getMaskElt(i);
12497 if (Idx >= (int)NumElts) Idx -= NumElts;
12498 NewMask.push_back(Idx);
12500 return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT),
12504 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
12505 if (N0.getOpcode() == ISD::UNDEF) {
12506 SmallVector<int, 8> NewMask;
12507 for (unsigned i = 0; i != NumElts; ++i) {
12508 int Idx = SVN->getMaskElt(i);
12510 if (Idx >= (int)NumElts)
12513 Idx = -1; // remove reference to lhs
12515 NewMask.push_back(Idx);
12517 return DAG.getVectorShuffle(VT, SDLoc(N), N1, DAG.getUNDEF(VT),
12521 // Remove references to rhs if it is undef
12522 if (N1.getOpcode() == ISD::UNDEF) {
12523 bool Changed = false;
12524 SmallVector<int, 8> NewMask;
12525 for (unsigned i = 0; i != NumElts; ++i) {
12526 int Idx = SVN->getMaskElt(i);
12527 if (Idx >= (int)NumElts) {
12531 NewMask.push_back(Idx);
12534 return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, &NewMask[0]);
12537 // If it is a splat, check if the argument vector is another splat or a
12539 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
12540 SDNode *V = N0.getNode();
12542 // If this is a bit convert that changes the element type of the vector but
12543 // not the number of vector elements, look through it. Be careful not to
12544 // look though conversions that change things like v4f32 to v2f64.
12545 if (V->getOpcode() == ISD::BITCAST) {
12546 SDValue ConvInput = V->getOperand(0);
12547 if (ConvInput.getValueType().isVector() &&
12548 ConvInput.getValueType().getVectorNumElements() == NumElts)
12549 V = ConvInput.getNode();
12552 if (V->getOpcode() == ISD::BUILD_VECTOR) {
12553 assert(V->getNumOperands() == NumElts &&
12554 "BUILD_VECTOR has wrong number of operands");
12556 bool AllSame = true;
12557 for (unsigned i = 0; i != NumElts; ++i) {
12558 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
12559 Base = V->getOperand(i);
12563 // Splat of <u, u, u, u>, return <u, u, u, u>
12564 if (!Base.getNode())
12566 for (unsigned i = 0; i != NumElts; ++i) {
12567 if (V->getOperand(i) != Base) {
12572 // Splat of <x, x, x, x>, return <x, x, x, x>
12576 // Canonicalize any other splat as a build_vector.
12577 const SDValue &Splatted = V->getOperand(SVN->getSplatIndex());
12578 SmallVector<SDValue, 8> Ops(NumElts, Splatted);
12579 SDValue NewBV = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
12580 V->getValueType(0), Ops);
12582 // We may have jumped through bitcasts, so the type of the
12583 // BUILD_VECTOR may not match the type of the shuffle.
12584 if (V->getValueType(0) != VT)
12585 NewBV = DAG.getNode(ISD::BITCAST, SDLoc(N), VT, NewBV);
12590 // There are various patterns used to build up a vector from smaller vectors,
12591 // subvectors, or elements. Scan chains of these and replace unused insertions
12592 // or components with undef.
12593 if (SDValue S = simplifyShuffleOperands(SVN, N0, N1, DAG))
12596 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
12597 Level < AfterLegalizeVectorOps &&
12598 (N1.getOpcode() == ISD::UNDEF ||
12599 (N1.getOpcode() == ISD::CONCAT_VECTORS &&
12600 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
12601 SDValue V = partitionShuffleOfConcats(N, DAG);
12607 // Attempt to combine a shuffle of 2 inputs of 'scalar sources' -
12608 // BUILD_VECTOR or SCALAR_TO_VECTOR into a single BUILD_VECTOR.
12609 if (Level < AfterLegalizeVectorOps && TLI.isTypeLegal(VT)) {
12610 SmallVector<SDValue, 8> Ops;
12611 for (int M : SVN->getMask()) {
12612 SDValue Op = DAG.getUNDEF(VT.getScalarType());
12614 int Idx = M % NumElts;
12615 SDValue &S = (M < (int)NumElts ? N0 : N1);
12616 if (S.getOpcode() == ISD::BUILD_VECTOR && S.hasOneUse()) {
12617 Op = S.getOperand(Idx);
12618 } else if (S.getOpcode() == ISD::SCALAR_TO_VECTOR && S.hasOneUse()) {
12620 Op = S.getOperand(0);
12622 // Operand can't be combined - bail out.
12628 if (Ops.size() == VT.getVectorNumElements()) {
12629 // BUILD_VECTOR requires all inputs to be of the same type, find the
12630 // maximum type and extend them all.
12631 EVT SVT = VT.getScalarType();
12632 if (SVT.isInteger())
12633 for (SDValue &Op : Ops)
12634 SVT = (SVT.bitsLT(Op.getValueType()) ? Op.getValueType() : SVT);
12635 if (SVT != VT.getScalarType())
12636 for (SDValue &Op : Ops)
12637 Op = TLI.isZExtFree(Op.getValueType(), SVT)
12638 ? DAG.getZExtOrTrunc(Op, SDLoc(N), SVT)
12639 : DAG.getSExtOrTrunc(Op, SDLoc(N), SVT);
12640 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Ops);
12644 // If this shuffle only has a single input that is a bitcasted shuffle,
12645 // attempt to merge the 2 shuffles and suitably bitcast the inputs/output
12646 // back to their original types.
12647 if (N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
12648 N1.getOpcode() == ISD::UNDEF && Level < AfterLegalizeVectorOps &&
12649 TLI.isTypeLegal(VT)) {
12651 // Peek through the bitcast only if there is one user.
12653 while (BC0.getOpcode() == ISD::BITCAST) {
12654 if (!BC0.hasOneUse())
12656 BC0 = BC0.getOperand(0);
12659 auto ScaleShuffleMask = [](ArrayRef<int> Mask, int Scale) {
12661 return SmallVector<int, 8>(Mask.begin(), Mask.end());
12663 SmallVector<int, 8> NewMask;
12665 for (int s = 0; s != Scale; ++s)
12666 NewMask.push_back(M < 0 ? -1 : Scale * M + s);
12670 if (BC0.getOpcode() == ISD::VECTOR_SHUFFLE && BC0.hasOneUse()) {
12671 EVT SVT = VT.getScalarType();
12672 EVT InnerVT = BC0->getValueType(0);
12673 EVT InnerSVT = InnerVT.getScalarType();
12675 // Determine which shuffle works with the smaller scalar type.
12676 EVT ScaleVT = SVT.bitsLT(InnerSVT) ? VT : InnerVT;
12677 EVT ScaleSVT = ScaleVT.getScalarType();
12679 if (TLI.isTypeLegal(ScaleVT) &&
12680 0 == (InnerSVT.getSizeInBits() % ScaleSVT.getSizeInBits()) &&
12681 0 == (SVT.getSizeInBits() % ScaleSVT.getSizeInBits())) {
12683 int InnerScale = InnerSVT.getSizeInBits() / ScaleSVT.getSizeInBits();
12684 int OuterScale = SVT.getSizeInBits() / ScaleSVT.getSizeInBits();
12686 // Scale the shuffle masks to the smaller scalar type.
12687 ShuffleVectorSDNode *InnerSVN = cast<ShuffleVectorSDNode>(BC0);
12688 SmallVector<int, 8> InnerMask =
12689 ScaleShuffleMask(InnerSVN->getMask(), InnerScale);
12690 SmallVector<int, 8> OuterMask =
12691 ScaleShuffleMask(SVN->getMask(), OuterScale);
12693 // Merge the shuffle masks.
12694 SmallVector<int, 8> NewMask;
12695 for (int M : OuterMask)
12696 NewMask.push_back(M < 0 ? -1 : InnerMask[M]);
12698 // Test for shuffle mask legality over both commutations.
12699 SDValue SV0 = BC0->getOperand(0);
12700 SDValue SV1 = BC0->getOperand(1);
12701 bool LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
12703 std::swap(SV0, SV1);
12704 ShuffleVectorSDNode::commuteMask(NewMask);
12705 LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
12709 SV0 = DAG.getNode(ISD::BITCAST, SDLoc(N), ScaleVT, SV0);
12710 SV1 = DAG.getNode(ISD::BITCAST, SDLoc(N), ScaleVT, SV1);
12711 return DAG.getNode(
12712 ISD::BITCAST, SDLoc(N), VT,
12713 DAG.getVectorShuffle(ScaleVT, SDLoc(N), SV0, SV1, NewMask));
12719 // Canonicalize shuffles according to rules:
12720 // shuffle(A, shuffle(A, B)) -> shuffle(shuffle(A,B), A)
12721 // shuffle(B, shuffle(A, B)) -> shuffle(shuffle(A,B), B)
12722 // shuffle(B, shuffle(A, Undef)) -> shuffle(shuffle(A, Undef), B)
12723 if (N1.getOpcode() == ISD::VECTOR_SHUFFLE &&
12724 N0.getOpcode() != ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
12725 TLI.isTypeLegal(VT)) {
12726 // The incoming shuffle must be of the same type as the result of the
12727 // current shuffle.
12728 assert(N1->getOperand(0).getValueType() == VT &&
12729 "Shuffle types don't match");
12731 SDValue SV0 = N1->getOperand(0);
12732 SDValue SV1 = N1->getOperand(1);
12733 bool HasSameOp0 = N0 == SV0;
12734 bool IsSV1Undef = SV1.getOpcode() == ISD::UNDEF;
12735 if (HasSameOp0 || IsSV1Undef || N0 == SV1)
12736 // Commute the operands of this shuffle so that next rule
12738 return DAG.getCommutedVectorShuffle(*SVN);
12741 // Try to fold according to rules:
12742 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
12743 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
12744 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
12745 // Don't try to fold shuffles with illegal type.
12746 // Only fold if this shuffle is the only user of the other shuffle.
12747 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && N->isOnlyUserOf(N0.getNode()) &&
12748 Level < AfterLegalizeDAG && TLI.isTypeLegal(VT)) {
12749 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
12751 // The incoming shuffle must be of the same type as the result of the
12752 // current shuffle.
12753 assert(OtherSV->getOperand(0).getValueType() == VT &&
12754 "Shuffle types don't match");
12757 SmallVector<int, 4> Mask;
12758 // Compute the combined shuffle mask for a shuffle with SV0 as the first
12759 // operand, and SV1 as the second operand.
12760 for (unsigned i = 0; i != NumElts; ++i) {
12761 int Idx = SVN->getMaskElt(i);
12763 // Propagate Undef.
12764 Mask.push_back(Idx);
12768 SDValue CurrentVec;
12769 if (Idx < (int)NumElts) {
12770 // This shuffle index refers to the inner shuffle N0. Lookup the inner
12771 // shuffle mask to identify which vector is actually referenced.
12772 Idx = OtherSV->getMaskElt(Idx);
12774 // Propagate Undef.
12775 Mask.push_back(Idx);
12779 CurrentVec = (Idx < (int) NumElts) ? OtherSV->getOperand(0)
12780 : OtherSV->getOperand(1);
12782 // This shuffle index references an element within N1.
12786 // Simple case where 'CurrentVec' is UNDEF.
12787 if (CurrentVec.getOpcode() == ISD::UNDEF) {
12788 Mask.push_back(-1);
12792 // Canonicalize the shuffle index. We don't know yet if CurrentVec
12793 // will be the first or second operand of the combined shuffle.
12794 Idx = Idx % NumElts;
12795 if (!SV0.getNode() || SV0 == CurrentVec) {
12796 // Ok. CurrentVec is the left hand side.
12797 // Update the mask accordingly.
12799 Mask.push_back(Idx);
12803 // Bail out if we cannot convert the shuffle pair into a single shuffle.
12804 if (SV1.getNode() && SV1 != CurrentVec)
12807 // Ok. CurrentVec is the right hand side.
12808 // Update the mask accordingly.
12810 Mask.push_back(Idx + NumElts);
12813 // Check if all indices in Mask are Undef. In case, propagate Undef.
12814 bool isUndefMask = true;
12815 for (unsigned i = 0; i != NumElts && isUndefMask; ++i)
12816 isUndefMask &= Mask[i] < 0;
12819 return DAG.getUNDEF(VT);
12821 if (!SV0.getNode())
12822 SV0 = DAG.getUNDEF(VT);
12823 if (!SV1.getNode())
12824 SV1 = DAG.getUNDEF(VT);
12826 // Avoid introducing shuffles with illegal mask.
12827 if (!TLI.isShuffleMaskLegal(Mask, VT)) {
12828 ShuffleVectorSDNode::commuteMask(Mask);
12830 if (!TLI.isShuffleMaskLegal(Mask, VT))
12833 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, A, M2)
12834 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, A, M2)
12835 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, B, M2)
12836 std::swap(SV0, SV1);
12839 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
12840 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
12841 // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
12842 return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, &Mask[0]);
12848 SDValue DAGCombiner::visitSCALAR_TO_VECTOR(SDNode *N) {
12849 SDValue InVal = N->getOperand(0);
12850 EVT VT = N->getValueType(0);
12852 // Replace a SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(V,C0)) pattern
12853 // with a VECTOR_SHUFFLE.
12854 if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
12855 SDValue InVec = InVal->getOperand(0);
12856 SDValue EltNo = InVal->getOperand(1);
12858 // FIXME: We could support implicit truncation if the shuffle can be
12859 // scaled to a smaller vector scalar type.
12860 ConstantSDNode *C0 = dyn_cast<ConstantSDNode>(EltNo);
12861 if (C0 && VT == InVec.getValueType() &&
12862 VT.getScalarType() == InVal.getValueType()) {
12863 SmallVector<int, 8> NewMask(VT.getVectorNumElements(), -1);
12864 int Elt = C0->getZExtValue();
12867 if (TLI.isShuffleMaskLegal(NewMask, VT))
12868 return DAG.getVectorShuffle(VT, SDLoc(N), InVec, DAG.getUNDEF(VT),
12876 SDValue DAGCombiner::visitINSERT_SUBVECTOR(SDNode *N) {
12877 SDValue N0 = N->getOperand(0);
12878 SDValue N2 = N->getOperand(2);
12880 // If the input vector is a concatenation, and the insert replaces
12881 // one of the halves, we can optimize into a single concat_vectors.
12882 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
12883 N0->getNumOperands() == 2 && N2.getOpcode() == ISD::Constant) {
12884 APInt InsIdx = cast<ConstantSDNode>(N2)->getAPIntValue();
12885 EVT VT = N->getValueType(0);
12887 // Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
12888 // (concat_vectors Z, Y)
12890 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
12891 N->getOperand(1), N0.getOperand(1));
12893 // Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
12894 // (concat_vectors X, Z)
12895 if (InsIdx == VT.getVectorNumElements()/2)
12896 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
12897 N0.getOperand(0), N->getOperand(1));
12903 SDValue DAGCombiner::visitFP_TO_FP16(SDNode *N) {
12904 SDValue N0 = N->getOperand(0);
12906 // fold (fp_to_fp16 (fp16_to_fp op)) -> op
12907 if (N0->getOpcode() == ISD::FP16_TO_FP)
12908 return N0->getOperand(0);
12913 /// Returns a vector_shuffle if it able to transform an AND to a vector_shuffle
12914 /// with the destination vector and a zero vector.
12915 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
12916 /// vector_shuffle V, Zero, <0, 4, 2, 4>
12917 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
12918 EVT VT = N->getValueType(0);
12919 SDValue LHS = N->getOperand(0);
12920 SDValue RHS = N->getOperand(1);
12923 // Make sure we're not running after operation legalization where it
12924 // may have custom lowered the vector shuffles.
12925 if (LegalOperations)
12928 if (N->getOpcode() != ISD::AND)
12931 if (RHS.getOpcode() == ISD::BITCAST)
12932 RHS = RHS.getOperand(0);
12934 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
12935 SmallVector<int, 8> Indices;
12936 unsigned NumElts = RHS.getNumOperands();
12938 for (unsigned i = 0; i != NumElts; ++i) {
12939 SDValue Elt = RHS.getOperand(i);
12940 if (isAllOnesConstant(Elt))
12941 Indices.push_back(i);
12942 else if (isNullConstant(Elt))
12943 Indices.push_back(NumElts+i);
12948 // Let's see if the target supports this vector_shuffle.
12949 EVT RVT = RHS.getValueType();
12950 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
12953 // Return the new VECTOR_SHUFFLE node.
12954 EVT EltVT = RVT.getVectorElementType();
12955 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
12956 DAG.getConstant(0, dl, EltVT));
12957 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, dl, RVT, ZeroOps);
12958 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
12959 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
12960 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
12966 /// Visit a binary vector operation, like ADD.
12967 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
12968 assert(N->getValueType(0).isVector() &&
12969 "SimplifyVBinOp only works on vectors!");
12971 SDValue LHS = N->getOperand(0);
12972 SDValue RHS = N->getOperand(1);
12974 if (SDValue Shuffle = XformToShuffleWithZero(N))
12977 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
12979 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
12980 RHS.getOpcode() == ISD::BUILD_VECTOR) {
12981 // Check if both vectors are constants. If not bail out.
12982 if (!(cast<BuildVectorSDNode>(LHS)->isConstant() &&
12983 cast<BuildVectorSDNode>(RHS)->isConstant()))
12986 SmallVector<SDValue, 8> Ops;
12987 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
12988 SDValue LHSOp = LHS.getOperand(i);
12989 SDValue RHSOp = RHS.getOperand(i);
12991 // Can't fold divide by zero.
12992 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
12993 N->getOpcode() == ISD::FDIV) {
12994 if (isNullConstant(RHSOp) || (RHSOp.getOpcode() == ISD::ConstantFP &&
12995 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
12999 EVT VT = LHSOp.getValueType();
13000 EVT RVT = RHSOp.getValueType();
13002 // Integer BUILD_VECTOR operands may have types larger than the element
13003 // size (e.g., when the element type is not legal). Prior to type
13004 // legalization, the types may not match between the two BUILD_VECTORS.
13005 // Truncate one of the operands to make them match.
13006 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
13007 RHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, RHSOp);
13009 LHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), RVT, LHSOp);
13013 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(LHS), VT,
13015 if (FoldOp.getOpcode() != ISD::UNDEF &&
13016 FoldOp.getOpcode() != ISD::Constant &&
13017 FoldOp.getOpcode() != ISD::ConstantFP)
13019 Ops.push_back(FoldOp);
13020 AddToWorklist(FoldOp.getNode());
13023 if (Ops.size() == LHS.getNumOperands())
13024 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), LHS.getValueType(), Ops);
13027 // Type legalization might introduce new shuffles in the DAG.
13028 // Fold (VBinOp (shuffle (A, Undef, Mask)), (shuffle (B, Undef, Mask)))
13029 // -> (shuffle (VBinOp (A, B)), Undef, Mask).
13030 if (LegalTypes && isa<ShuffleVectorSDNode>(LHS) &&
13031 isa<ShuffleVectorSDNode>(RHS) && LHS.hasOneUse() && RHS.hasOneUse() &&
13032 LHS.getOperand(1).getOpcode() == ISD::UNDEF &&
13033 RHS.getOperand(1).getOpcode() == ISD::UNDEF) {
13034 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(LHS);
13035 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(RHS);
13037 if (SVN0->getMask().equals(SVN1->getMask())) {
13038 EVT VT = N->getValueType(0);
13039 SDValue UndefVector = LHS.getOperand(1);
13040 SDValue NewBinOp = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
13041 LHS.getOperand(0), RHS.getOperand(0));
13042 AddUsersToWorklist(N);
13043 return DAG.getVectorShuffle(VT, SDLoc(N), NewBinOp, UndefVector,
13044 &SVN0->getMask()[0]);
13051 SDValue DAGCombiner::SimplifySelect(SDLoc DL, SDValue N0,
13052 SDValue N1, SDValue N2){
13053 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
13055 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
13056 cast<CondCodeSDNode>(N0.getOperand(2))->get());
13058 // If we got a simplified select_cc node back from SimplifySelectCC, then
13059 // break it down into a new SETCC node, and a new SELECT node, and then return
13060 // the SELECT node, since we were called with a SELECT node.
13061 if (SCC.getNode()) {
13062 // Check to see if we got a select_cc back (to turn into setcc/select).
13063 // Otherwise, just return whatever node we got back, like fabs.
13064 if (SCC.getOpcode() == ISD::SELECT_CC) {
13065 SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
13067 SCC.getOperand(0), SCC.getOperand(1),
13068 SCC.getOperand(4));
13069 AddToWorklist(SETCC.getNode());
13070 return DAG.getSelect(SDLoc(SCC), SCC.getValueType(), SETCC,
13071 SCC.getOperand(2), SCC.getOperand(3));
13079 /// Given a SELECT or a SELECT_CC node, where LHS and RHS are the two values
13080 /// being selected between, see if we can simplify the select. Callers of this
13081 /// should assume that TheSelect is deleted if this returns true. As such, they
13082 /// should return the appropriate thing (e.g. the node) back to the top-level of
13083 /// the DAG combiner loop to avoid it being looked at.
13084 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
13087 // fold (select (setcc x, -0.0, *lt), NaN, (fsqrt x))
13088 // The select + setcc is redundant, because fsqrt returns NaN for X < -0.
13089 if (const ConstantFPSDNode *NaN = isConstOrConstSplatFP(LHS)) {
13090 if (NaN->isNaN() && RHS.getOpcode() == ISD::FSQRT) {
13091 // We have: (select (setcc ?, ?, ?), NaN, (fsqrt ?))
13092 SDValue Sqrt = RHS;
13095 const ConstantFPSDNode *NegZero = nullptr;
13097 if (TheSelect->getOpcode() == ISD::SELECT_CC) {
13098 CC = dyn_cast<CondCodeSDNode>(TheSelect->getOperand(4))->get();
13099 CmpLHS = TheSelect->getOperand(0);
13100 NegZero = isConstOrConstSplatFP(TheSelect->getOperand(1));
13102 // SELECT or VSELECT
13103 SDValue Cmp = TheSelect->getOperand(0);
13104 if (Cmp.getOpcode() == ISD::SETCC) {
13105 CC = dyn_cast<CondCodeSDNode>(Cmp.getOperand(2))->get();
13106 CmpLHS = Cmp.getOperand(0);
13107 NegZero = isConstOrConstSplatFP(Cmp.getOperand(1));
13110 if (NegZero && NegZero->isNegative() && NegZero->isZero() &&
13111 Sqrt.getOperand(0) == CmpLHS && (CC == ISD::SETOLT ||
13112 CC == ISD::SETULT || CC == ISD::SETLT)) {
13113 // We have: (select (setcc x, -0.0, *lt), NaN, (fsqrt x))
13114 CombineTo(TheSelect, Sqrt);
13119 // Cannot simplify select with vector condition
13120 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
13122 // If this is a select from two identical things, try to pull the operation
13123 // through the select.
13124 if (LHS.getOpcode() != RHS.getOpcode() ||
13125 !LHS.hasOneUse() || !RHS.hasOneUse())
13128 // If this is a load and the token chain is identical, replace the select
13129 // of two loads with a load through a select of the address to load from.
13130 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
13131 // constants have been dropped into the constant pool.
13132 if (LHS.getOpcode() == ISD::LOAD) {
13133 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
13134 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
13136 // Token chains must be identical.
13137 if (LHS.getOperand(0) != RHS.getOperand(0) ||
13138 // Do not let this transformation reduce the number of volatile loads.
13139 LLD->isVolatile() || RLD->isVolatile() ||
13140 // FIXME: If either is a pre/post inc/dec load,
13141 // we'd need to split out the address adjustment.
13142 LLD->isIndexed() || RLD->isIndexed() ||
13143 // If this is an EXTLOAD, the VT's must match.
13144 LLD->getMemoryVT() != RLD->getMemoryVT() ||
13145 // If this is an EXTLOAD, the kind of extension must match.
13146 (LLD->getExtensionType() != RLD->getExtensionType() &&
13147 // The only exception is if one of the extensions is anyext.
13148 LLD->getExtensionType() != ISD::EXTLOAD &&
13149 RLD->getExtensionType() != ISD::EXTLOAD) ||
13150 // FIXME: this discards src value information. This is
13151 // over-conservative. It would be beneficial to be able to remember
13152 // both potential memory locations. Since we are discarding
13153 // src value info, don't do the transformation if the memory
13154 // locations are not in the default address space.
13155 LLD->getPointerInfo().getAddrSpace() != 0 ||
13156 RLD->getPointerInfo().getAddrSpace() != 0 ||
13157 !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
13158 LLD->getBasePtr().getValueType()))
13161 // Check that the select condition doesn't reach either load. If so,
13162 // folding this will induce a cycle into the DAG. If not, this is safe to
13163 // xform, so create a select of the addresses.
13165 if (TheSelect->getOpcode() == ISD::SELECT) {
13166 SDNode *CondNode = TheSelect->getOperand(0).getNode();
13167 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
13168 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
13170 // The loads must not depend on one another.
13171 if (LLD->isPredecessorOf(RLD) ||
13172 RLD->isPredecessorOf(LLD))
13174 Addr = DAG.getSelect(SDLoc(TheSelect),
13175 LLD->getBasePtr().getValueType(),
13176 TheSelect->getOperand(0), LLD->getBasePtr(),
13177 RLD->getBasePtr());
13178 } else { // Otherwise SELECT_CC
13179 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
13180 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
13182 if ((LLD->hasAnyUseOfValue(1) &&
13183 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
13184 (RLD->hasAnyUseOfValue(1) &&
13185 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
13188 Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
13189 LLD->getBasePtr().getValueType(),
13190 TheSelect->getOperand(0),
13191 TheSelect->getOperand(1),
13192 LLD->getBasePtr(), RLD->getBasePtr(),
13193 TheSelect->getOperand(4));
13197 // It is safe to replace the two loads if they have different alignments,
13198 // but the new load must be the minimum (most restrictive) alignment of the
13200 bool isInvariant = LLD->isInvariant() & RLD->isInvariant();
13201 unsigned Alignment = std::min(LLD->getAlignment(), RLD->getAlignment());
13202 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
13203 Load = DAG.getLoad(TheSelect->getValueType(0),
13205 // FIXME: Discards pointer and AA info.
13206 LLD->getChain(), Addr, MachinePointerInfo(),
13207 LLD->isVolatile(), LLD->isNonTemporal(),
13208 isInvariant, Alignment);
13210 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
13211 RLD->getExtensionType() : LLD->getExtensionType(),
13213 TheSelect->getValueType(0),
13214 // FIXME: Discards pointer and AA info.
13215 LLD->getChain(), Addr, MachinePointerInfo(),
13216 LLD->getMemoryVT(), LLD->isVolatile(),
13217 LLD->isNonTemporal(), isInvariant, Alignment);
13220 // Users of the select now use the result of the load.
13221 CombineTo(TheSelect, Load);
13223 // Users of the old loads now use the new load's chain. We know the
13224 // old-load value is dead now.
13225 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
13226 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
13233 /// Simplify an expression of the form (N0 cond N1) ? N2 : N3
13234 /// where 'cond' is the comparison specified by CC.
13235 SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
13236 SDValue N2, SDValue N3,
13237 ISD::CondCode CC, bool NotExtCompare) {
13238 // (x ? y : y) -> y.
13239 if (N2 == N3) return N2;
13241 EVT VT = N2.getValueType();
13242 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
13243 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
13245 // Determine if the condition we're dealing with is constant
13246 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
13247 N0, N1, CC, DL, false);
13248 if (SCC.getNode()) AddToWorklist(SCC.getNode());
13250 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
13251 // fold select_cc true, x, y -> x
13252 // fold select_cc false, x, y -> y
13253 return !SCCC->isNullValue() ? N2 : N3;
13256 // Check to see if we can simplify the select into an fabs node
13257 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
13258 // Allow either -0.0 or 0.0
13259 if (CFP->getValueAPF().isZero()) {
13260 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
13261 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
13262 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
13263 N2 == N3.getOperand(0))
13264 return DAG.getNode(ISD::FABS, DL, VT, N0);
13266 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
13267 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
13268 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
13269 N2.getOperand(0) == N3)
13270 return DAG.getNode(ISD::FABS, DL, VT, N3);
13274 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
13275 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
13276 // in it. This is a win when the constant is not otherwise available because
13277 // it replaces two constant pool loads with one. We only do this if the FP
13278 // type is known to be legal, because if it isn't, then we are before legalize
13279 // types an we want the other legalization to happen first (e.g. to avoid
13280 // messing with soft float) and if the ConstantFP is not legal, because if
13281 // it is legal, we may not need to store the FP constant in a constant pool.
13282 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
13283 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
13284 if (TLI.isTypeLegal(N2.getValueType()) &&
13285 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
13286 TargetLowering::Legal &&
13287 !TLI.isFPImmLegal(TV->getValueAPF(), TV->getValueType(0)) &&
13288 !TLI.isFPImmLegal(FV->getValueAPF(), FV->getValueType(0))) &&
13289 // If both constants have multiple uses, then we won't need to do an
13290 // extra load, they are likely around in registers for other users.
13291 (TV->hasOneUse() || FV->hasOneUse())) {
13292 Constant *Elts[] = {
13293 const_cast<ConstantFP*>(FV->getConstantFPValue()),
13294 const_cast<ConstantFP*>(TV->getConstantFPValue())
13296 Type *FPTy = Elts[0]->getType();
13297 const DataLayout &TD = *TLI.getDataLayout();
13299 // Create a ConstantArray of the two constants.
13300 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
13301 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
13302 TD.getPrefTypeAlignment(FPTy));
13303 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
13305 // Get the offsets to the 0 and 1 element of the array so that we can
13306 // select between them.
13307 SDValue Zero = DAG.getIntPtrConstant(0, DL);
13308 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
13309 SDValue One = DAG.getIntPtrConstant(EltSize, SDLoc(FV));
13311 SDValue Cond = DAG.getSetCC(DL,
13312 getSetCCResultType(N0.getValueType()),
13314 AddToWorklist(Cond.getNode());
13315 SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
13317 AddToWorklist(CstOffset.getNode());
13318 CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
13320 AddToWorklist(CPIdx.getNode());
13321 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
13322 MachinePointerInfo::getConstantPool(), false,
13323 false, false, Alignment);
13327 // Check to see if we can perform the "gzip trick", transforming
13328 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
13329 if (isNullConstant(N3) && CC == ISD::SETLT &&
13330 (isNullConstant(N1) || // (a < 0) ? b : 0
13331 (isOneConstant(N1) && N0 == N2))) { // (a < 1) ? a : 0
13332 EVT XType = N0.getValueType();
13333 EVT AType = N2.getValueType();
13334 if (XType.bitsGE(AType)) {
13335 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
13336 // single-bit constant.
13337 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue() - 1)) == 0)) {
13338 unsigned ShCtV = N2C->getAPIntValue().logBase2();
13339 ShCtV = XType.getSizeInBits() - ShCtV - 1;
13340 SDValue ShCt = DAG.getConstant(ShCtV, SDLoc(N0),
13341 getShiftAmountTy(N0.getValueType()));
13342 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0),
13344 AddToWorklist(Shift.getNode());
13346 if (XType.bitsGT(AType)) {
13347 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
13348 AddToWorklist(Shift.getNode());
13351 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
13354 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0),
13356 DAG.getConstant(XType.getSizeInBits() - 1,
13358 getShiftAmountTy(N0.getValueType())));
13359 AddToWorklist(Shift.getNode());
13361 if (XType.bitsGT(AType)) {
13362 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
13363 AddToWorklist(Shift.getNode());
13366 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
13370 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
13371 // where y is has a single bit set.
13372 // A plaintext description would be, we can turn the SELECT_CC into an AND
13373 // when the condition can be materialized as an all-ones register. Any
13374 // single bit-test can be materialized as an all-ones register with
13375 // shift-left and shift-right-arith.
13376 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
13377 N0->getValueType(0) == VT && isNullConstant(N1) && isNullConstant(N2)) {
13378 SDValue AndLHS = N0->getOperand(0);
13379 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
13380 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
13381 // Shift the tested bit over the sign bit.
13382 APInt AndMask = ConstAndRHS->getAPIntValue();
13384 DAG.getConstant(AndMask.countLeadingZeros(), SDLoc(AndLHS),
13385 getShiftAmountTy(AndLHS.getValueType()));
13386 SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);
13388 // Now arithmetic right shift it all the way over, so the result is either
13389 // all-ones, or zero.
13391 DAG.getConstant(AndMask.getBitWidth() - 1, SDLoc(Shl),
13392 getShiftAmountTy(Shl.getValueType()));
13393 SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);
13395 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
13399 // fold select C, 16, 0 -> shl C, 4
13400 if (N2C && isNullConstant(N3) && N2C->getAPIntValue().isPowerOf2() &&
13401 TLI.getBooleanContents(N0.getValueType()) ==
13402 TargetLowering::ZeroOrOneBooleanContent) {
13404 // If the caller doesn't want us to simplify this into a zext of a compare,
13406 if (NotExtCompare && N2C->isOne())
13409 // Get a SetCC of the condition
13410 // NOTE: Don't create a SETCC if it's not legal on this target.
13411 if (!LegalOperations ||
13412 TLI.isOperationLegal(ISD::SETCC,
13413 LegalTypes ? getSetCCResultType(N0.getValueType()) : MVT::i1)) {
13415 // cast from setcc result type to select result type
13417 SCC = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
13419 if (N2.getValueType().bitsLT(SCC.getValueType()))
13420 Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
13421 N2.getValueType());
13423 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
13424 N2.getValueType(), SCC);
13426 SCC = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
13427 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
13428 N2.getValueType(), SCC);
13431 AddToWorklist(SCC.getNode());
13432 AddToWorklist(Temp.getNode());
13437 // shl setcc result by log2 n2c
13438 return DAG.getNode(
13439 ISD::SHL, DL, N2.getValueType(), Temp,
13440 DAG.getConstant(N2C->getAPIntValue().logBase2(), SDLoc(Temp),
13441 getShiftAmountTy(Temp.getValueType())));
13445 // Check to see if this is the equivalent of setcc
13446 // FIXME: Turn all of these into setcc if setcc if setcc is legal
13447 // otherwise, go ahead with the folds.
13448 if (0 && isNullConstant(N3) && isOneConstant(N2)) {
13449 EVT XType = N0.getValueType();
13450 if (!LegalOperations ||
13451 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(XType))) {
13452 SDValue Res = DAG.getSetCC(DL, getSetCCResultType(XType), N0, N1, CC);
13453 if (Res.getValueType() != VT)
13454 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
13458 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
13459 if (isNullConstant(N1) && CC == ISD::SETEQ &&
13460 (!LegalOperations ||
13461 TLI.isOperationLegal(ISD::CTLZ, XType))) {
13462 SDValue Ctlz = DAG.getNode(ISD::CTLZ, SDLoc(N0), XType, N0);
13463 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
13464 DAG.getConstant(Log2_32(XType.getSizeInBits()),
13466 getShiftAmountTy(Ctlz.getValueType())));
13468 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
13469 if (isNullConstant(N1) && CC == ISD::SETGT) {
13471 SDValue NegN0 = DAG.getNode(ISD::SUB, DL,
13472 XType, DAG.getConstant(0, DL, XType), N0);
13473 SDValue NotN0 = DAG.getNOT(DL, N0, XType);
13474 return DAG.getNode(ISD::SRL, DL, XType,
13475 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
13476 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13477 getShiftAmountTy(XType)));
13479 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
13480 if (isAllOnesConstant(N1) && CC == ISD::SETGT) {
13482 SDValue Sign = DAG.getNode(ISD::SRL, DL, XType, N0,
13483 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13484 getShiftAmountTy(N0.getValueType())));
13485 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, DL,
13490 // Check to see if this is an integer abs.
13491 // select_cc setg[te] X, 0, X, -X ->
13492 // select_cc setgt X, -1, X, -X ->
13493 // select_cc setl[te] X, 0, -X, X ->
13494 // select_cc setlt X, 1, -X, X ->
13495 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
13497 ConstantSDNode *SubC = nullptr;
13498 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
13499 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
13500 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
13501 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
13502 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
13503 (N1C->isOne() && CC == ISD::SETLT)) &&
13504 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
13505 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
13507 EVT XType = N0.getValueType();
13508 if (SubC && SubC->isNullValue() && XType.isInteger()) {
13510 SDValue Shift = DAG.getNode(ISD::SRA, DL, XType,
13512 DAG.getConstant(XType.getSizeInBits() - 1, DL,
13513 getShiftAmountTy(N0.getValueType())));
13514 SDValue Add = DAG.getNode(ISD::ADD, DL,
13516 AddToWorklist(Shift.getNode());
13517 AddToWorklist(Add.getNode());
13518 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
13525 /// This is a stub for TargetLowering::SimplifySetCC.
13526 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
13527 SDValue N1, ISD::CondCode Cond,
13528 SDLoc DL, bool foldBooleans) {
13529 TargetLowering::DAGCombinerInfo
13530 DagCombineInfo(DAG, Level, false, this);
13531 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
13534 /// Given an ISD::SDIV node expressing a divide by constant, return
13535 /// a DAG expression to select that will generate the same value by multiplying
13536 /// by a magic number.
13537 /// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
13538 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
13539 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13543 // Avoid division by zero.
13544 if (C->isNullValue())
13547 std::vector<SDNode*> Built;
13549 TLI.BuildSDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
13551 for (SDNode *N : Built)
13556 /// Given an ISD::SDIV node expressing a divide by constant power of 2, return a
13557 /// DAG expression that will generate the same value by right shifting.
13558 SDValue DAGCombiner::BuildSDIVPow2(SDNode *N) {
13559 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13563 // Avoid division by zero.
13564 if (C->isNullValue())
13567 std::vector<SDNode *> Built;
13568 SDValue S = TLI.BuildSDIVPow2(N, C->getAPIntValue(), DAG, &Built);
13570 for (SDNode *N : Built)
13575 /// Given an ISD::UDIV node expressing a divide by constant, return a DAG
13576 /// expression that will generate the same value by multiplying by a magic
13578 /// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
13579 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
13580 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
13584 // Avoid division by zero.
13585 if (C->isNullValue())
13588 std::vector<SDNode*> Built;
13590 TLI.BuildUDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
13592 for (SDNode *N : Built)
13597 SDValue DAGCombiner::BuildReciprocalEstimate(SDValue Op) {
13598 if (Level >= AfterLegalizeDAG)
13601 // Expose the DAG combiner to the target combiner implementations.
13602 TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
13604 unsigned Iterations = 0;
13605 if (SDValue Est = TLI.getRecipEstimate(Op, DCI, Iterations)) {
13607 // Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13608 // For the reciprocal, we need to find the zero of the function:
13609 // F(X) = A X - 1 [which has a zero at X = 1/A]
13611 // X_{i+1} = X_i (2 - A X_i) = X_i + X_i (1 - A X_i) [this second form
13612 // does not require additional intermediate precision]
13613 EVT VT = Op.getValueType();
13615 SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);
13617 AddToWorklist(Est.getNode());
13619 // Newton iterations: Est = Est + Est (1 - Arg * Est)
13620 for (unsigned i = 0; i < Iterations; ++i) {
13621 SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Op, Est);
13622 AddToWorklist(NewEst.getNode());
13624 NewEst = DAG.getNode(ISD::FSUB, DL, VT, FPOne, NewEst);
13625 AddToWorklist(NewEst.getNode());
13627 NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
13628 AddToWorklist(NewEst.getNode());
13630 Est = DAG.getNode(ISD::FADD, DL, VT, Est, NewEst);
13631 AddToWorklist(Est.getNode());
13640 /// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13641 /// For the reciprocal sqrt, we need to find the zero of the function:
13642 /// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
13644 /// X_{i+1} = X_i (1.5 - A X_i^2 / 2)
13645 /// As a result, we precompute A/2 prior to the iteration loop.
13646 SDValue DAGCombiner::BuildRsqrtNROneConst(SDValue Arg, SDValue Est,
13647 unsigned Iterations) {
13648 EVT VT = Arg.getValueType();
13650 SDValue ThreeHalves = DAG.getConstantFP(1.5, DL, VT);
13652 // We now need 0.5 * Arg which we can write as (1.5 * Arg - Arg) so that
13653 // this entire sequence requires only one FP constant.
13654 SDValue HalfArg = DAG.getNode(ISD::FMUL, DL, VT, ThreeHalves, Arg);
13655 AddToWorklist(HalfArg.getNode());
13657 HalfArg = DAG.getNode(ISD::FSUB, DL, VT, HalfArg, Arg);
13658 AddToWorklist(HalfArg.getNode());
13660 // Newton iterations: Est = Est * (1.5 - HalfArg * Est * Est)
13661 for (unsigned i = 0; i < Iterations; ++i) {
13662 SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
13663 AddToWorklist(NewEst.getNode());
13665 NewEst = DAG.getNode(ISD::FMUL, DL, VT, HalfArg, NewEst);
13666 AddToWorklist(NewEst.getNode());
13668 NewEst = DAG.getNode(ISD::FSUB, DL, VT, ThreeHalves, NewEst);
13669 AddToWorklist(NewEst.getNode());
13671 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst);
13672 AddToWorklist(Est.getNode());
13677 /// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
13678 /// For the reciprocal sqrt, we need to find the zero of the function:
13679 /// F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
13681 /// X_{i+1} = (-0.5 * X_i) * (A * X_i * X_i + (-3.0))
13682 SDValue DAGCombiner::BuildRsqrtNRTwoConst(SDValue Arg, SDValue Est,
13683 unsigned Iterations) {
13684 EVT VT = Arg.getValueType();
13686 SDValue MinusThree = DAG.getConstantFP(-3.0, DL, VT);
13687 SDValue MinusHalf = DAG.getConstantFP(-0.5, DL, VT);
13689 // Newton iterations: Est = -0.5 * Est * (-3.0 + Arg * Est * Est)
13690 for (unsigned i = 0; i < Iterations; ++i) {
13691 SDValue HalfEst = DAG.getNode(ISD::FMUL, DL, VT, Est, MinusHalf);
13692 AddToWorklist(HalfEst.getNode());
13694 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Est);
13695 AddToWorklist(Est.getNode());
13697 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Arg);
13698 AddToWorklist(Est.getNode());
13700 Est = DAG.getNode(ISD::FADD, DL, VT, Est, MinusThree);
13701 AddToWorklist(Est.getNode());
13703 Est = DAG.getNode(ISD::FMUL, DL, VT, Est, HalfEst);
13704 AddToWorklist(Est.getNode());
13709 SDValue DAGCombiner::BuildRsqrtEstimate(SDValue Op) {
13710 if (Level >= AfterLegalizeDAG)
13713 // Expose the DAG combiner to the target combiner implementations.
13714 TargetLowering::DAGCombinerInfo DCI(DAG, Level, false, this);
13715 unsigned Iterations = 0;
13716 bool UseOneConstNR = false;
13717 if (SDValue Est = TLI.getRsqrtEstimate(Op, DCI, Iterations, UseOneConstNR)) {
13718 AddToWorklist(Est.getNode());
13720 Est = UseOneConstNR ?
13721 BuildRsqrtNROneConst(Op, Est, Iterations) :
13722 BuildRsqrtNRTwoConst(Op, Est, Iterations);
13730 /// Return true if base is a frame index, which is known not to alias with
13731 /// anything but itself. Provides base object and offset as results.
13732 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
13733 const GlobalValue *&GV, const void *&CV) {
13734 // Assume it is a primitive operation.
13735 Base = Ptr; Offset = 0; GV = nullptr; CV = nullptr;
13737 // If it's an adding a simple constant then integrate the offset.
13738 if (Base.getOpcode() == ISD::ADD) {
13739 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
13740 Base = Base.getOperand(0);
13741 Offset += C->getZExtValue();
13745 // Return the underlying GlobalValue, and update the Offset. Return false
13746 // for GlobalAddressSDNode since the same GlobalAddress may be represented
13747 // by multiple nodes with different offsets.
13748 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
13749 GV = G->getGlobal();
13750 Offset += G->getOffset();
13754 // Return the underlying Constant value, and update the Offset. Return false
13755 // for ConstantSDNodes since the same constant pool entry may be represented
13756 // by multiple nodes with different offsets.
13757 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
13758 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
13759 : (const void *)C->getConstVal();
13760 Offset += C->getOffset();
13763 // If it's any of the following then it can't alias with anything but itself.
13764 return isa<FrameIndexSDNode>(Base);
13767 /// Return true if there is any possibility that the two addresses overlap.
13768 bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
13769 // If they are the same then they must be aliases.
13770 if (Op0->getBasePtr() == Op1->getBasePtr()) return true;
13772 // If they are both volatile then they cannot be reordered.
13773 if (Op0->isVolatile() && Op1->isVolatile()) return true;
13775 // Gather base node and offset information.
13776 SDValue Base1, Base2;
13777 int64_t Offset1, Offset2;
13778 const GlobalValue *GV1, *GV2;
13779 const void *CV1, *CV2;
13780 bool isFrameIndex1 = FindBaseOffset(Op0->getBasePtr(),
13781 Base1, Offset1, GV1, CV1);
13782 bool isFrameIndex2 = FindBaseOffset(Op1->getBasePtr(),
13783 Base2, Offset2, GV2, CV2);
13785 // If they have a same base address then check to see if they overlap.
13786 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
13787 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
13788 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
13790 // It is possible for different frame indices to alias each other, mostly
13791 // when tail call optimization reuses return address slots for arguments.
13792 // To catch this case, look up the actual index of frame indices to compute
13793 // the real alias relationship.
13794 if (isFrameIndex1 && isFrameIndex2) {
13795 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
13796 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
13797 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
13798 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
13799 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
13802 // Otherwise, if we know what the bases are, and they aren't identical, then
13803 // we know they cannot alias.
13804 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
13807 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
13808 // compared to the size and offset of the access, we may be able to prove they
13809 // do not alias. This check is conservative for now to catch cases created by
13810 // splitting vector types.
13811 if ((Op0->getOriginalAlignment() == Op1->getOriginalAlignment()) &&
13812 (Op0->getSrcValueOffset() != Op1->getSrcValueOffset()) &&
13813 (Op0->getMemoryVT().getSizeInBits() >> 3 ==
13814 Op1->getMemoryVT().getSizeInBits() >> 3) &&
13815 (Op0->getOriginalAlignment() > Op0->getMemoryVT().getSizeInBits()) >> 3) {
13816 int64_t OffAlign1 = Op0->getSrcValueOffset() % Op0->getOriginalAlignment();
13817 int64_t OffAlign2 = Op1->getSrcValueOffset() % Op1->getOriginalAlignment();
13819 // There is no overlap between these relatively aligned accesses of similar
13820 // size, return no alias.
13821 if ((OffAlign1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign2 ||
13822 (OffAlign2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign1)
13826 bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0
13828 : DAG.getSubtarget().useAA();
13830 if (CombinerAAOnlyFunc.getNumOccurrences() &&
13831 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
13835 Op0->getMemOperand()->getValue() && Op1->getMemOperand()->getValue()) {
13836 // Use alias analysis information.
13837 int64_t MinOffset = std::min(Op0->getSrcValueOffset(),
13838 Op1->getSrcValueOffset());
13839 int64_t Overlap1 = (Op0->getMemoryVT().getSizeInBits() >> 3) +
13840 Op0->getSrcValueOffset() - MinOffset;
13841 int64_t Overlap2 = (Op1->getMemoryVT().getSizeInBits() >> 3) +
13842 Op1->getSrcValueOffset() - MinOffset;
13843 AliasAnalysis::AliasResult AAResult =
13844 AA.alias(AliasAnalysis::Location(Op0->getMemOperand()->getValue(),
13846 UseTBAA ? Op0->getAAInfo() : AAMDNodes()),
13847 AliasAnalysis::Location(Op1->getMemOperand()->getValue(),
13849 UseTBAA ? Op1->getAAInfo() : AAMDNodes()));
13850 if (AAResult == AliasAnalysis::NoAlias)
13854 // Otherwise we have to assume they alias.
13858 /// Walk up chain skipping non-aliasing memory nodes,
13859 /// looking for aliasing nodes and adding them to the Aliases vector.
13860 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
13861 SmallVectorImpl<SDValue> &Aliases) {
13862 SmallVector<SDValue, 8> Chains; // List of chains to visit.
13863 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
13865 // Get alias information for node.
13866 bool IsLoad = isa<LoadSDNode>(N) && !cast<LSBaseSDNode>(N)->isVolatile();
13869 Chains.push_back(OriginalChain);
13870 unsigned Depth = 0;
13872 // Look at each chain and determine if it is an alias. If so, add it to the
13873 // aliases list. If not, then continue up the chain looking for the next
13875 while (!Chains.empty()) {
13876 SDValue Chain = Chains.back();
13879 // For TokenFactor nodes, look at each operand and only continue up the
13880 // chain until we find two aliases. If we've seen two aliases, assume we'll
13881 // find more and revert to original chain since the xform is unlikely to be
13884 // FIXME: The depth check could be made to return the last non-aliasing
13885 // chain we found before we hit a tokenfactor rather than the original
13887 if (Depth > 6 || Aliases.size() == 2) {
13889 Aliases.push_back(OriginalChain);
13893 // Don't bother if we've been before.
13894 if (!Visited.insert(Chain.getNode()).second)
13897 switch (Chain.getOpcode()) {
13898 case ISD::EntryToken:
13899 // Entry token is ideal chain operand, but handled in FindBetterChain.
13904 // Get alias information for Chain.
13905 bool IsOpLoad = isa<LoadSDNode>(Chain.getNode()) &&
13906 !cast<LSBaseSDNode>(Chain.getNode())->isVolatile();
13908 // If chain is alias then stop here.
13909 if (!(IsLoad && IsOpLoad) &&
13910 isAlias(cast<LSBaseSDNode>(N), cast<LSBaseSDNode>(Chain.getNode()))) {
13911 Aliases.push_back(Chain);
13913 // Look further up the chain.
13914 Chains.push_back(Chain.getOperand(0));
13920 case ISD::TokenFactor:
13921 // We have to check each of the operands of the token factor for "small"
13922 // token factors, so we queue them up. Adding the operands to the queue
13923 // (stack) in reverse order maintains the original order and increases the
13924 // likelihood that getNode will find a matching token factor (CSE.)
13925 if (Chain.getNumOperands() > 16) {
13926 Aliases.push_back(Chain);
13929 for (unsigned n = Chain.getNumOperands(); n;)
13930 Chains.push_back(Chain.getOperand(--n));
13935 // For all other instructions we will just have to take what we can get.
13936 Aliases.push_back(Chain);
13941 // We need to be careful here to also search for aliases through the
13942 // value operand of a store, etc. Consider the following situation:
13944 // L1 = load Token1, %52
13945 // S1 = store Token1, L1, %51
13946 // L2 = load Token1, %52+8
13947 // S2 = store Token1, L2, %51+8
13948 // Token2 = Token(S1, S2)
13949 // L3 = load Token2, %53
13950 // S3 = store Token2, L3, %52
13951 // L4 = load Token2, %53+8
13952 // S4 = store Token2, L4, %52+8
13953 // If we search for aliases of S3 (which loads address %52), and we look
13954 // only through the chain, then we'll miss the trivial dependence on L1
13955 // (which also loads from %52). We then might change all loads and
13956 // stores to use Token1 as their chain operand, which could result in
13957 // copying %53 into %52 before copying %52 into %51 (which should
13960 // The problem is, however, that searching for such data dependencies
13961 // can become expensive, and the cost is not directly related to the
13962 // chain depth. Instead, we'll rule out such configurations here by
13963 // insisting that we've visited all chain users (except for users
13964 // of the original chain, which is not necessary). When doing this,
13965 // we need to look through nodes we don't care about (otherwise, things
13966 // like register copies will interfere with trivial cases).
13968 SmallVector<const SDNode *, 16> Worklist;
13969 for (const SDNode *N : Visited)
13970 if (N != OriginalChain.getNode())
13971 Worklist.push_back(N);
13973 while (!Worklist.empty()) {
13974 const SDNode *M = Worklist.pop_back_val();
13976 // We have already visited M, and want to make sure we've visited any uses
13977 // of M that we care about. For uses that we've not visisted, and don't
13978 // care about, queue them to the worklist.
13980 for (SDNode::use_iterator UI = M->use_begin(),
13981 UIE = M->use_end(); UI != UIE; ++UI)
13982 if (UI.getUse().getValueType() == MVT::Other &&
13983 Visited.insert(*UI).second) {
13984 if (isa<MemIntrinsicSDNode>(*UI) || isa<MemSDNode>(*UI)) {
13985 // We've not visited this use, and we care about it (it could have an
13986 // ordering dependency with the original node).
13988 Aliases.push_back(OriginalChain);
13992 // We've not visited this use, but we don't care about it. Mark it as
13993 // visited and enqueue it to the worklist.
13994 Worklist.push_back(*UI);
13999 /// Walk up chain skipping non-aliasing memory nodes, looking for a better chain
14000 /// (aliasing node.)
14001 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
14002 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
14004 // Accumulate all the aliases to this node.
14005 GatherAllAliases(N, OldChain, Aliases);
14007 // If no operands then chain to entry token.
14008 if (Aliases.size() == 0)
14009 return DAG.getEntryNode();
14011 // If a single operand then chain to it. We don't need to revisit it.
14012 if (Aliases.size() == 1)
14015 // Construct a custom tailored token factor.
14016 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Aliases);
14019 /// This is the entry point for the file.
14020 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
14021 CodeGenOpt::Level OptLevel) {
14022 /// This is the main entry point to this class.
14023 DAGCombiner(*this, AA, OptLevel).Run(Level);