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/SmallPtrSet.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/Analysis/AliasAnalysis.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/DerivedTypes.h"
27 #include "llvm/IR/Function.h"
28 #include "llvm/IR/LLVMContext.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Target/TargetLowering.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetOptions.h"
37 #include "llvm/Target/TargetRegisterInfo.h"
38 #include "llvm/Target/TargetSubtargetInfo.h"
42 #define DEBUG_TYPE "dagcombine"
44 STATISTIC(NodesCombined , "Number of dag nodes combined");
45 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
46 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
47 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
48 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
49 STATISTIC(SlicedLoads, "Number of load sliced");
53 CombinerAA("combiner-alias-analysis", cl::Hidden,
54 cl::desc("Enable DAG combiner alias-analysis heuristics"));
57 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
58 cl::desc("Enable DAG combiner's use of IR alias analysis"));
61 UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(true),
62 cl::desc("Enable DAG combiner's use of TBAA"));
65 static cl::opt<std::string>
66 CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden,
67 cl::desc("Only use DAG-combiner alias analysis in this"
71 /// Hidden option to stress test load slicing, i.e., when this option
72 /// is enabled, load slicing bypasses most of its profitability guards.
74 StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden,
75 cl::desc("Bypass the profitability model of load "
79 //------------------------------ DAGCombiner ---------------------------------//
83 const TargetLowering &TLI;
85 CodeGenOpt::Level OptLevel;
90 // Worklist of all of the nodes that need to be simplified.
92 // This has the semantics that when adding to the worklist,
93 // the item added must be next to be processed. It should
94 // also only appear once. The naive approach to this takes
97 // To reduce the insert/remove time to logarithmic, we use
98 // a set and a vector to maintain our worklist.
100 // The set contains the items on the worklist, but does not
101 // maintain the order they should be visited.
103 // The vector maintains the order nodes should be visited, but may
104 // contain duplicate or removed nodes. When choosing a node to
105 // visit, we pop off the order stack until we find an item that is
106 // also in the contents set. All operations are O(log N).
107 SmallPtrSet<SDNode*, 64> WorkListContents;
108 SmallVector<SDNode*, 64> WorkListOrder;
110 // AA - Used for DAG load/store alias analysis.
113 /// AddUsersToWorkList - When an instruction is simplified, add all users of
114 /// the instruction to the work lists because they might get more simplified
117 void AddUsersToWorkList(SDNode *N) {
118 for (SDNode *Node : N->uses())
122 /// visit - call the node-specific routine that knows how to fold each
123 /// particular type of node.
124 SDValue visit(SDNode *N);
127 /// AddToWorkList - Add to the work list making sure its instance is at the
128 /// back (next to be processed.)
129 void AddToWorkList(SDNode *N) {
130 WorkListContents.insert(N);
131 WorkListOrder.push_back(N);
134 /// removeFromWorkList - remove all instances of N from the worklist.
136 void removeFromWorkList(SDNode *N) {
137 WorkListContents.erase(N);
140 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
143 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
144 return CombineTo(N, &Res, 1, AddTo);
147 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
149 SDValue To[] = { Res0, Res1 };
150 return CombineTo(N, To, 2, AddTo);
153 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
157 /// SimplifyDemandedBits - Check the specified integer node value to see if
158 /// it can be simplified or if things it uses can be simplified by bit
159 /// propagation. If so, return true.
160 bool SimplifyDemandedBits(SDValue Op) {
161 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
162 APInt Demanded = APInt::getAllOnesValue(BitWidth);
163 return SimplifyDemandedBits(Op, Demanded);
166 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
168 bool CombineToPreIndexedLoadStore(SDNode *N);
169 bool CombineToPostIndexedLoadStore(SDNode *N);
170 bool SliceUpLoad(SDNode *N);
172 /// \brief Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed
175 /// \param EVE ISD::EXTRACT_VECTOR_ELT to be replaced.
176 /// \param InVecVT type of the input vector to EVE with bitcasts resolved.
177 /// \param EltNo index of the vector element to load.
178 /// \param OriginalLoad load that EVE came from to be replaced.
179 /// \returns EVE on success SDValue() on failure.
180 SDValue ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
181 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad);
182 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
183 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
184 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
185 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
186 SDValue PromoteIntBinOp(SDValue Op);
187 SDValue PromoteIntShiftOp(SDValue Op);
188 SDValue PromoteExtend(SDValue Op);
189 bool PromoteLoad(SDValue Op);
191 void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
192 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
193 ISD::NodeType ExtType);
195 /// combine - call the node-specific routine that knows how to fold each
196 /// particular type of node. If that doesn't do anything, try the
197 /// target-specific DAG combines.
198 SDValue combine(SDNode *N);
200 // Visitation implementation - Implement dag node combining for different
201 // node types. The semantics are as follows:
203 // SDValue.getNode() == 0 - No change was made
204 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
205 // otherwise - N should be replaced by the returned Operand.
207 SDValue visitTokenFactor(SDNode *N);
208 SDValue visitMERGE_VALUES(SDNode *N);
209 SDValue visitADD(SDNode *N);
210 SDValue visitSUB(SDNode *N);
211 SDValue visitADDC(SDNode *N);
212 SDValue visitSUBC(SDNode *N);
213 SDValue visitADDE(SDNode *N);
214 SDValue visitSUBE(SDNode *N);
215 SDValue visitMUL(SDNode *N);
216 SDValue visitSDIV(SDNode *N);
217 SDValue visitUDIV(SDNode *N);
218 SDValue visitSREM(SDNode *N);
219 SDValue visitUREM(SDNode *N);
220 SDValue visitMULHU(SDNode *N);
221 SDValue visitMULHS(SDNode *N);
222 SDValue visitSMUL_LOHI(SDNode *N);
223 SDValue visitUMUL_LOHI(SDNode *N);
224 SDValue visitSMULO(SDNode *N);
225 SDValue visitUMULO(SDNode *N);
226 SDValue visitSDIVREM(SDNode *N);
227 SDValue visitUDIVREM(SDNode *N);
228 SDValue visitAND(SDNode *N);
229 SDValue visitOR(SDNode *N);
230 SDValue visitXOR(SDNode *N);
231 SDValue SimplifyVBinOp(SDNode *N);
232 SDValue SimplifyVUnaryOp(SDNode *N);
233 SDValue visitSHL(SDNode *N);
234 SDValue visitSRA(SDNode *N);
235 SDValue visitSRL(SDNode *N);
236 SDValue visitRotate(SDNode *N);
237 SDValue visitCTLZ(SDNode *N);
238 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
239 SDValue visitCTTZ(SDNode *N);
240 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
241 SDValue visitCTPOP(SDNode *N);
242 SDValue visitSELECT(SDNode *N);
243 SDValue visitVSELECT(SDNode *N);
244 SDValue visitSELECT_CC(SDNode *N);
245 SDValue visitSETCC(SDNode *N);
246 SDValue visitSIGN_EXTEND(SDNode *N);
247 SDValue visitZERO_EXTEND(SDNode *N);
248 SDValue visitANY_EXTEND(SDNode *N);
249 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
250 SDValue visitTRUNCATE(SDNode *N);
251 SDValue visitBITCAST(SDNode *N);
252 SDValue visitBUILD_PAIR(SDNode *N);
253 SDValue visitFADD(SDNode *N);
254 SDValue visitFSUB(SDNode *N);
255 SDValue visitFMUL(SDNode *N);
256 SDValue visitFMA(SDNode *N);
257 SDValue visitFDIV(SDNode *N);
258 SDValue visitFREM(SDNode *N);
259 SDValue visitFCOPYSIGN(SDNode *N);
260 SDValue visitSINT_TO_FP(SDNode *N);
261 SDValue visitUINT_TO_FP(SDNode *N);
262 SDValue visitFP_TO_SINT(SDNode *N);
263 SDValue visitFP_TO_UINT(SDNode *N);
264 SDValue visitFP_ROUND(SDNode *N);
265 SDValue visitFP_ROUND_INREG(SDNode *N);
266 SDValue visitFP_EXTEND(SDNode *N);
267 SDValue visitFNEG(SDNode *N);
268 SDValue visitFABS(SDNode *N);
269 SDValue visitFCEIL(SDNode *N);
270 SDValue visitFTRUNC(SDNode *N);
271 SDValue visitFFLOOR(SDNode *N);
272 SDValue visitBRCOND(SDNode *N);
273 SDValue visitBR_CC(SDNode *N);
274 SDValue visitLOAD(SDNode *N);
275 SDValue visitSTORE(SDNode *N);
276 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
277 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
278 SDValue visitBUILD_VECTOR(SDNode *N);
279 SDValue visitCONCAT_VECTORS(SDNode *N);
280 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
281 SDValue visitVECTOR_SHUFFLE(SDNode *N);
282 SDValue visitINSERT_SUBVECTOR(SDNode *N);
284 SDValue XformToShuffleWithZero(SDNode *N);
285 SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
287 SDValue visitShiftByConstant(SDNode *N, ConstantSDNode *Amt);
289 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
290 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
291 SDValue SimplifySelect(SDLoc DL, SDValue N0, SDValue N1, SDValue N2);
292 SDValue SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1, SDValue N2,
293 SDValue N3, ISD::CondCode CC,
294 bool NotExtCompare = false);
295 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
296 SDLoc DL, bool foldBooleans = true);
298 bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
300 bool isOneUseSetCC(SDValue N) const;
302 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
304 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
305 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
306 SDValue BuildSDIV(SDNode *N);
307 SDValue BuildUDIV(SDNode *N);
308 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
309 bool DemandHighBits = true);
310 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
311 SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
312 SDValue InnerPos, SDValue InnerNeg,
313 unsigned PosOpcode, unsigned NegOpcode,
315 SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
316 SDValue ReduceLoadWidth(SDNode *N);
317 SDValue ReduceLoadOpStoreWidth(SDNode *N);
318 SDValue TransformFPLoadStorePair(SDNode *N);
319 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
320 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
322 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
324 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
325 /// looking for aliasing nodes and adding them to the Aliases vector.
326 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
327 SmallVectorImpl<SDValue> &Aliases);
329 /// isAlias - Return true if there is any possibility that the two addresses
331 bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const;
333 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
334 /// looking for a better chain (aliasing node.)
335 SDValue FindBetterChain(SDNode *N, SDValue Chain);
337 /// Merge consecutive store operations into a wide store.
338 /// This optimization uses wide integers or vectors when possible.
339 /// \return True if some memory operations were changed.
340 bool MergeConsecutiveStores(StoreSDNode *N);
342 /// \brief Try to transform a truncation where C is a constant:
343 /// (trunc (and X, C)) -> (and (trunc X), (trunc C))
345 /// \p N needs to be a truncation and its first operand an AND. Other
346 /// requirements are checked by the function (e.g. that trunc is
347 /// single-use) and if missed an empty SDValue is returned.
348 SDValue distributeTruncateThroughAnd(SDNode *N);
351 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
352 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
353 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {
354 AttributeSet FnAttrs =
355 DAG.getMachineFunction().getFunction()->getAttributes();
357 FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
358 Attribute::OptimizeForSize) ||
359 FnAttrs.hasAttribute(AttributeSet::FunctionIndex, Attribute::MinSize);
362 /// Run - runs the dag combiner on all nodes in the work list
363 void Run(CombineLevel AtLevel);
365 SelectionDAG &getDAG() const { return DAG; }
367 /// getShiftAmountTy - Returns a type large enough to hold any valid
368 /// shift amount - before type legalization these can be huge.
369 EVT getShiftAmountTy(EVT LHSTy) {
370 assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
371 if (LHSTy.isVector())
373 return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy)
374 : TLI.getPointerTy();
377 /// isTypeLegal - This method returns true if we are running before type
378 /// legalization or if the specified VT is legal.
379 bool isTypeLegal(const EVT &VT) {
380 if (!LegalTypes) return true;
381 return TLI.isTypeLegal(VT);
384 /// getSetCCResultType - Convenience wrapper around
385 /// TargetLowering::getSetCCResultType
386 EVT getSetCCResultType(EVT VT) const {
387 return TLI.getSetCCResultType(*DAG.getContext(), VT);
394 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
395 /// nodes from the worklist.
396 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
399 explicit WorkListRemover(DAGCombiner &dc)
400 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
402 void NodeDeleted(SDNode *N, SDNode *E) override {
403 DC.removeFromWorkList(N);
408 //===----------------------------------------------------------------------===//
409 // TargetLowering::DAGCombinerInfo implementation
410 //===----------------------------------------------------------------------===//
412 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
413 ((DAGCombiner*)DC)->AddToWorkList(N);
416 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
417 ((DAGCombiner*)DC)->removeFromWorkList(N);
420 SDValue TargetLowering::DAGCombinerInfo::
421 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
422 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
425 SDValue TargetLowering::DAGCombinerInfo::
426 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
427 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
431 SDValue TargetLowering::DAGCombinerInfo::
432 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
433 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
436 void TargetLowering::DAGCombinerInfo::
437 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
438 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
441 //===----------------------------------------------------------------------===//
443 //===----------------------------------------------------------------------===//
445 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
446 /// specified expression for the same cost as the expression itself, or 2 if we
447 /// can compute the negated form more cheaply than the expression itself.
448 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
449 const TargetLowering &TLI,
450 const TargetOptions *Options,
451 unsigned Depth = 0) {
452 // fneg is removable even if it has multiple uses.
453 if (Op.getOpcode() == ISD::FNEG) return 2;
455 // Don't allow anything with multiple uses.
456 if (!Op.hasOneUse()) return 0;
458 // Don't recurse exponentially.
459 if (Depth > 6) return 0;
461 switch (Op.getOpcode()) {
462 default: return false;
463 case ISD::ConstantFP:
464 // Don't invert constant FP values after legalize. The negated constant
465 // isn't necessarily legal.
466 return LegalOperations ? 0 : 1;
468 // FIXME: determine better conditions for this xform.
469 if (!Options->UnsafeFPMath) return 0;
471 // After operation legalization, it might not be legal to create new FSUBs.
472 if (LegalOperations &&
473 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
476 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
477 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
480 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
481 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
484 // We can't turn -(A-B) into B-A when we honor signed zeros.
485 if (!Options->UnsafeFPMath) return 0;
487 // fold (fneg (fsub A, B)) -> (fsub B, A)
492 if (Options->HonorSignDependentRoundingFPMath()) return 0;
494 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
495 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
499 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
505 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
510 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
511 /// returns the newly negated expression.
512 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
513 bool LegalOperations, unsigned Depth = 0) {
514 // fneg is removable even if it has multiple uses.
515 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
517 // Don't allow anything with multiple uses.
518 assert(Op.hasOneUse() && "Unknown reuse!");
520 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
521 switch (Op.getOpcode()) {
522 default: llvm_unreachable("Unknown code");
523 case ISD::ConstantFP: {
524 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
526 return DAG.getConstantFP(V, Op.getValueType());
529 // FIXME: determine better conditions for this xform.
530 assert(DAG.getTarget().Options.UnsafeFPMath);
532 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
533 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
534 DAG.getTargetLoweringInfo(),
535 &DAG.getTarget().Options, Depth+1))
536 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
537 GetNegatedExpression(Op.getOperand(0), DAG,
538 LegalOperations, Depth+1),
540 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
541 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
542 GetNegatedExpression(Op.getOperand(1), DAG,
543 LegalOperations, Depth+1),
546 // We can't turn -(A-B) into B-A when we honor signed zeros.
547 assert(DAG.getTarget().Options.UnsafeFPMath);
549 // fold (fneg (fsub 0, B)) -> B
550 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
551 if (N0CFP->getValueAPF().isZero())
552 return Op.getOperand(1);
554 // fold (fneg (fsub A, B)) -> (fsub B, A)
555 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
556 Op.getOperand(1), Op.getOperand(0));
560 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
562 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
563 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
564 DAG.getTargetLoweringInfo(),
565 &DAG.getTarget().Options, Depth+1))
566 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
567 GetNegatedExpression(Op.getOperand(0), DAG,
568 LegalOperations, Depth+1),
571 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
572 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
574 GetNegatedExpression(Op.getOperand(1), DAG,
575 LegalOperations, Depth+1));
579 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
580 GetNegatedExpression(Op.getOperand(0), DAG,
581 LegalOperations, Depth+1));
583 return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
584 GetNegatedExpression(Op.getOperand(0), DAG,
585 LegalOperations, Depth+1),
590 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
591 // that selects between the target values used for true and false, making it
592 // equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to
593 // the appropriate nodes based on the type of node we are checking. This
594 // simplifies life a bit for the callers.
595 bool DAGCombiner::isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
597 if (N.getOpcode() == ISD::SETCC) {
598 LHS = N.getOperand(0);
599 RHS = N.getOperand(1);
600 CC = N.getOperand(2);
604 if (N.getOpcode() != ISD::SELECT_CC ||
605 !TLI.isConstTrueVal(N.getOperand(2).getNode()) ||
606 !TLI.isConstFalseVal(N.getOperand(3).getNode()))
609 LHS = N.getOperand(0);
610 RHS = N.getOperand(1);
611 CC = N.getOperand(4);
615 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
616 // one use. If this is true, it allows the users to invert the operation for
617 // free when it is profitable to do so.
618 bool DAGCombiner::isOneUseSetCC(SDValue N) const {
620 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
625 /// isConstantSplatVector - Returns true if N is a BUILD_VECTOR node whose
626 /// elements are all the same constant or undefined.
627 static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
628 BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
633 unsigned SplatBitSize;
635 EVT EltVT = N->getValueType(0).getVectorElementType();
636 return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
638 EltVT.getSizeInBits() >= SplatBitSize);
641 // \brief Returns the SDNode if it is a constant BuildVector or constant.
642 static SDNode *isConstantBuildVectorOrConstantInt(SDValue N) {
643 if (isa<ConstantSDNode>(N))
645 BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N);
646 if(BV && BV->isConstant())
651 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
653 static ConstantSDNode *isConstOrConstSplat(SDValue N) {
654 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
657 if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
658 BitVector UndefElements;
659 ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
661 // BuildVectors can truncate their operands. Ignore that case here.
662 // FIXME: We blindly ignore splats which include undef which is overly
664 if (CN && UndefElements.none() &&
665 CN->getValueType(0) == N.getValueType().getScalarType())
672 SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
673 SDValue N0, SDValue N1) {
674 EVT VT = N0.getValueType();
675 if (N0.getOpcode() == Opc) {
676 if (SDNode *L = isConstantBuildVectorOrConstantInt(N0.getOperand(1))) {
677 if (SDNode *R = isConstantBuildVectorOrConstantInt(N1)) {
678 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
679 SDValue OpNode = DAG.FoldConstantArithmetic(Opc, VT, L, R);
680 if (!OpNode.getNode())
682 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
684 if (N0.hasOneUse()) {
685 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one
687 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1);
688 if (!OpNode.getNode())
690 AddToWorkList(OpNode.getNode());
691 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
696 if (N1.getOpcode() == Opc) {
697 if (SDNode *R = isConstantBuildVectorOrConstantInt(N1.getOperand(1))) {
698 if (SDNode *L = isConstantBuildVectorOrConstantInt(N0)) {
699 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
700 SDValue OpNode = DAG.FoldConstantArithmetic(Opc, VT, R, L);
701 if (!OpNode.getNode())
703 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
705 if (N1.hasOneUse()) {
706 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one
708 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N1.getOperand(0), N0);
709 if (!OpNode.getNode())
711 AddToWorkList(OpNode.getNode());
712 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
720 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
722 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
724 DEBUG(dbgs() << "\nReplacing.1 ";
726 dbgs() << "\nWith: ";
727 To[0].getNode()->dump(&DAG);
728 dbgs() << " and " << NumTo-1 << " other values\n";
729 for (unsigned i = 0, e = NumTo; i != e; ++i)
730 assert((!To[i].getNode() ||
731 N->getValueType(i) == To[i].getValueType()) &&
732 "Cannot combine value to value of different type!"));
733 WorkListRemover DeadNodes(*this);
734 DAG.ReplaceAllUsesWith(N, To);
736 // Push the new nodes and any users onto the worklist
737 for (unsigned i = 0, e = NumTo; i != e; ++i) {
738 if (To[i].getNode()) {
739 AddToWorkList(To[i].getNode());
740 AddUsersToWorkList(To[i].getNode());
745 // Finally, if the node is now dead, remove it from the graph. The node
746 // may not be dead if the replacement process recursively simplified to
747 // something else needing this node.
748 if (N->use_empty()) {
749 // Nodes can be reintroduced into the worklist. Make sure we do not
750 // process a node that has been replaced.
751 removeFromWorkList(N);
753 // Finally, since the node is now dead, remove it from the graph.
756 return SDValue(N, 0);
760 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
761 // Replace all uses. If any nodes become isomorphic to other nodes and
762 // are deleted, make sure to remove them from our worklist.
763 WorkListRemover DeadNodes(*this);
764 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
766 // Push the new node and any (possibly new) users onto the worklist.
767 AddToWorkList(TLO.New.getNode());
768 AddUsersToWorkList(TLO.New.getNode());
770 // Finally, if the node is now dead, remove it from the graph. The node
771 // may not be dead if the replacement process recursively simplified to
772 // something else needing this node.
773 if (TLO.Old.getNode()->use_empty()) {
774 removeFromWorkList(TLO.Old.getNode());
776 // If the operands of this node are only used by the node, they will now
777 // be dead. Make sure to visit them first to delete dead nodes early.
778 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
779 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
780 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
782 DAG.DeleteNode(TLO.Old.getNode());
786 /// SimplifyDemandedBits - Check the specified integer node value to see if
787 /// it can be simplified or if things it uses can be simplified by bit
788 /// propagation. If so, return true.
789 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
790 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
791 APInt KnownZero, KnownOne;
792 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
796 AddToWorkList(Op.getNode());
798 // Replace the old value with the new one.
800 DEBUG(dbgs() << "\nReplacing.2 ";
801 TLO.Old.getNode()->dump(&DAG);
802 dbgs() << "\nWith: ";
803 TLO.New.getNode()->dump(&DAG);
806 CommitTargetLoweringOpt(TLO);
810 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
812 EVT VT = Load->getValueType(0);
813 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
815 DEBUG(dbgs() << "\nReplacing.9 ";
817 dbgs() << "\nWith: ";
818 Trunc.getNode()->dump(&DAG);
820 WorkListRemover DeadNodes(*this);
821 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
822 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
823 removeFromWorkList(Load);
824 DAG.DeleteNode(Load);
825 AddToWorkList(Trunc.getNode());
828 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
831 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
832 EVT MemVT = LD->getMemoryVT();
833 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
834 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
836 : LD->getExtensionType();
838 return DAG.getExtLoad(ExtType, dl, PVT,
839 LD->getChain(), LD->getBasePtr(),
840 MemVT, LD->getMemOperand());
843 unsigned Opc = Op.getOpcode();
846 case ISD::AssertSext:
847 return DAG.getNode(ISD::AssertSext, dl, PVT,
848 SExtPromoteOperand(Op.getOperand(0), PVT),
850 case ISD::AssertZext:
851 return DAG.getNode(ISD::AssertZext, dl, PVT,
852 ZExtPromoteOperand(Op.getOperand(0), PVT),
854 case ISD::Constant: {
856 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
857 return DAG.getNode(ExtOpc, dl, PVT, Op);
861 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
863 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
866 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
867 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
869 EVT OldVT = Op.getValueType();
871 bool Replace = false;
872 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
873 if (!NewOp.getNode())
875 AddToWorkList(NewOp.getNode());
878 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
879 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
880 DAG.getValueType(OldVT));
883 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
884 EVT OldVT = Op.getValueType();
886 bool Replace = false;
887 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
888 if (!NewOp.getNode())
890 AddToWorkList(NewOp.getNode());
893 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
894 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
897 /// PromoteIntBinOp - Promote the specified integer binary operation if the
898 /// target indicates it is beneficial. e.g. On x86, it's usually better to
899 /// promote i16 operations to i32 since i16 instructions are longer.
900 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
901 if (!LegalOperations)
904 EVT VT = Op.getValueType();
905 if (VT.isVector() || !VT.isInteger())
908 // If operation type is 'undesirable', e.g. i16 on x86, consider
910 unsigned Opc = Op.getOpcode();
911 if (TLI.isTypeDesirableForOp(Opc, VT))
915 // Consult target whether it is a good idea to promote this operation and
916 // what's the right type to promote it to.
917 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
918 assert(PVT != VT && "Don't know what type to promote to!");
920 bool Replace0 = false;
921 SDValue N0 = Op.getOperand(0);
922 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
926 bool Replace1 = false;
927 SDValue N1 = Op.getOperand(1);
932 NN1 = PromoteOperand(N1, PVT, Replace1);
937 AddToWorkList(NN0.getNode());
939 AddToWorkList(NN1.getNode());
942 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
944 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
946 DEBUG(dbgs() << "\nPromoting ";
947 Op.getNode()->dump(&DAG));
949 return DAG.getNode(ISD::TRUNCATE, dl, VT,
950 DAG.getNode(Opc, dl, PVT, NN0, NN1));
955 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
956 /// target indicates it is beneficial. e.g. On x86, it's usually better to
957 /// promote i16 operations to i32 since i16 instructions are longer.
958 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
959 if (!LegalOperations)
962 EVT VT = Op.getValueType();
963 if (VT.isVector() || !VT.isInteger())
966 // If operation type is 'undesirable', e.g. i16 on x86, consider
968 unsigned Opc = Op.getOpcode();
969 if (TLI.isTypeDesirableForOp(Opc, VT))
973 // Consult target whether it is a good idea to promote this operation and
974 // what's the right type to promote it to.
975 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
976 assert(PVT != VT && "Don't know what type to promote to!");
978 bool Replace = false;
979 SDValue N0 = Op.getOperand(0);
981 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
982 else if (Opc == ISD::SRL)
983 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
985 N0 = PromoteOperand(N0, PVT, Replace);
989 AddToWorkList(N0.getNode());
991 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
993 DEBUG(dbgs() << "\nPromoting ";
994 Op.getNode()->dump(&DAG));
996 return DAG.getNode(ISD::TRUNCATE, dl, VT,
997 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
1002 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
1003 if (!LegalOperations)
1006 EVT VT = Op.getValueType();
1007 if (VT.isVector() || !VT.isInteger())
1010 // If operation type is 'undesirable', e.g. i16 on x86, consider
1012 unsigned Opc = Op.getOpcode();
1013 if (TLI.isTypeDesirableForOp(Opc, VT))
1017 // Consult target whether it is a good idea to promote this operation and
1018 // what's the right type to promote it to.
1019 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1020 assert(PVT != VT && "Don't know what type to promote to!");
1021 // fold (aext (aext x)) -> (aext x)
1022 // fold (aext (zext x)) -> (zext x)
1023 // fold (aext (sext x)) -> (sext x)
1024 DEBUG(dbgs() << "\nPromoting ";
1025 Op.getNode()->dump(&DAG));
1026 return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
1031 bool DAGCombiner::PromoteLoad(SDValue Op) {
1032 if (!LegalOperations)
1035 EVT VT = Op.getValueType();
1036 if (VT.isVector() || !VT.isInteger())
1039 // If operation type is 'undesirable', e.g. i16 on x86, consider
1041 unsigned Opc = Op.getOpcode();
1042 if (TLI.isTypeDesirableForOp(Opc, VT))
1046 // Consult target whether it is a good idea to promote this operation and
1047 // what's the right type to promote it to.
1048 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
1049 assert(PVT != VT && "Don't know what type to promote to!");
1052 SDNode *N = Op.getNode();
1053 LoadSDNode *LD = cast<LoadSDNode>(N);
1054 EVT MemVT = LD->getMemoryVT();
1055 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
1056 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
1058 : LD->getExtensionType();
1059 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
1060 LD->getChain(), LD->getBasePtr(),
1061 MemVT, LD->getMemOperand());
1062 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
1064 DEBUG(dbgs() << "\nPromoting ";
1067 Result.getNode()->dump(&DAG);
1069 WorkListRemover DeadNodes(*this);
1070 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
1071 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
1072 removeFromWorkList(N);
1074 AddToWorkList(Result.getNode());
1081 //===----------------------------------------------------------------------===//
1082 // Main DAG Combiner implementation
1083 //===----------------------------------------------------------------------===//
1085 void DAGCombiner::Run(CombineLevel AtLevel) {
1086 // set the instance variables, so that the various visit routines may use it.
1088 LegalOperations = Level >= AfterLegalizeVectorOps;
1089 LegalTypes = Level >= AfterLegalizeTypes;
1091 // Add all the dag nodes to the worklist.
1092 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
1093 E = DAG.allnodes_end(); I != E; ++I)
1096 // Create a dummy node (which is not added to allnodes), that adds a reference
1097 // to the root node, preventing it from being deleted, and tracking any
1098 // changes of the root.
1099 HandleSDNode Dummy(DAG.getRoot());
1101 // The root of the dag may dangle to deleted nodes until the dag combiner is
1102 // done. Set it to null to avoid confusion.
1103 DAG.setRoot(SDValue());
1105 // while the worklist isn't empty, find a node and
1106 // try and combine it.
1107 while (!WorkListContents.empty()) {
1109 // The WorkListOrder holds the SDNodes in order, but it may contain
1111 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1112 // worklist *should* contain, and check the node we want to visit is should
1113 // actually be visited.
1115 N = WorkListOrder.pop_back_val();
1116 } while (!WorkListContents.erase(N));
1118 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1119 // N is deleted from the DAG, since they too may now be dead or may have a
1120 // reduced number of uses, allowing other xforms.
1121 if (N->use_empty() && N != &Dummy) {
1122 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1123 AddToWorkList(N->getOperand(i).getNode());
1129 SDValue RV = combine(N);
1136 // If we get back the same node we passed in, rather than a new node or
1137 // zero, we know that the node must have defined multiple values and
1138 // CombineTo was used. Since CombineTo takes care of the worklist
1139 // mechanics for us, we have no work to do in this case.
1140 if (RV.getNode() == N)
1143 assert(N->getOpcode() != ISD::DELETED_NODE &&
1144 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1145 "Node was deleted but visit returned new node!");
1147 DEBUG(dbgs() << "\nReplacing.3 ";
1149 dbgs() << "\nWith: ";
1150 RV.getNode()->dump(&DAG);
1153 // Transfer debug value.
1154 DAG.TransferDbgValues(SDValue(N, 0), RV);
1155 WorkListRemover DeadNodes(*this);
1156 if (N->getNumValues() == RV.getNode()->getNumValues())
1157 DAG.ReplaceAllUsesWith(N, RV.getNode());
1159 assert(N->getValueType(0) == RV.getValueType() &&
1160 N->getNumValues() == 1 && "Type mismatch");
1162 DAG.ReplaceAllUsesWith(N, &OpV);
1165 // Push the new node and any users onto the worklist
1166 AddToWorkList(RV.getNode());
1167 AddUsersToWorkList(RV.getNode());
1169 // Add any uses of the old node to the worklist in case this node is the
1170 // last one that uses them. They may become dead after this node is
1172 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1173 AddToWorkList(N->getOperand(i).getNode());
1175 // Finally, if the node is now dead, remove it from the graph. The node
1176 // may not be dead if the replacement process recursively simplified to
1177 // something else needing this node.
1178 if (N->use_empty()) {
1179 // Nodes can be reintroduced into the worklist. Make sure we do not
1180 // process a node that has been replaced.
1181 removeFromWorkList(N);
1183 // Finally, since the node is now dead, remove it from the graph.
1188 // If the root changed (e.g. it was a dead load, update the root).
1189 DAG.setRoot(Dummy.getValue());
1190 DAG.RemoveDeadNodes();
1193 SDValue DAGCombiner::visit(SDNode *N) {
1194 switch (N->getOpcode()) {
1196 case ISD::TokenFactor: return visitTokenFactor(N);
1197 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1198 case ISD::ADD: return visitADD(N);
1199 case ISD::SUB: return visitSUB(N);
1200 case ISD::ADDC: return visitADDC(N);
1201 case ISD::SUBC: return visitSUBC(N);
1202 case ISD::ADDE: return visitADDE(N);
1203 case ISD::SUBE: return visitSUBE(N);
1204 case ISD::MUL: return visitMUL(N);
1205 case ISD::SDIV: return visitSDIV(N);
1206 case ISD::UDIV: return visitUDIV(N);
1207 case ISD::SREM: return visitSREM(N);
1208 case ISD::UREM: return visitUREM(N);
1209 case ISD::MULHU: return visitMULHU(N);
1210 case ISD::MULHS: return visitMULHS(N);
1211 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1212 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1213 case ISD::SMULO: return visitSMULO(N);
1214 case ISD::UMULO: return visitUMULO(N);
1215 case ISD::SDIVREM: return visitSDIVREM(N);
1216 case ISD::UDIVREM: return visitUDIVREM(N);
1217 case ISD::AND: return visitAND(N);
1218 case ISD::OR: return visitOR(N);
1219 case ISD::XOR: return visitXOR(N);
1220 case ISD::SHL: return visitSHL(N);
1221 case ISD::SRA: return visitSRA(N);
1222 case ISD::SRL: return visitSRL(N);
1224 case ISD::ROTL: return visitRotate(N);
1225 case ISD::CTLZ: return visitCTLZ(N);
1226 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1227 case ISD::CTTZ: return visitCTTZ(N);
1228 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1229 case ISD::CTPOP: return visitCTPOP(N);
1230 case ISD::SELECT: return visitSELECT(N);
1231 case ISD::VSELECT: return visitVSELECT(N);
1232 case ISD::SELECT_CC: return visitSELECT_CC(N);
1233 case ISD::SETCC: return visitSETCC(N);
1234 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1235 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1236 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1237 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1238 case ISD::TRUNCATE: return visitTRUNCATE(N);
1239 case ISD::BITCAST: return visitBITCAST(N);
1240 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1241 case ISD::FADD: return visitFADD(N);
1242 case ISD::FSUB: return visitFSUB(N);
1243 case ISD::FMUL: return visitFMUL(N);
1244 case ISD::FMA: return visitFMA(N);
1245 case ISD::FDIV: return visitFDIV(N);
1246 case ISD::FREM: return visitFREM(N);
1247 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1248 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1249 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1250 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1251 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1252 case ISD::FP_ROUND: return visitFP_ROUND(N);
1253 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1254 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1255 case ISD::FNEG: return visitFNEG(N);
1256 case ISD::FABS: return visitFABS(N);
1257 case ISD::FFLOOR: return visitFFLOOR(N);
1258 case ISD::FCEIL: return visitFCEIL(N);
1259 case ISD::FTRUNC: return visitFTRUNC(N);
1260 case ISD::BRCOND: return visitBRCOND(N);
1261 case ISD::BR_CC: return visitBR_CC(N);
1262 case ISD::LOAD: return visitLOAD(N);
1263 case ISD::STORE: return visitSTORE(N);
1264 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1265 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1266 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1267 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1268 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1269 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1270 case ISD::INSERT_SUBVECTOR: return visitINSERT_SUBVECTOR(N);
1275 SDValue DAGCombiner::combine(SDNode *N) {
1276 SDValue RV = visit(N);
1278 // If nothing happened, try a target-specific DAG combine.
1279 if (!RV.getNode()) {
1280 assert(N->getOpcode() != ISD::DELETED_NODE &&
1281 "Node was deleted but visit returned NULL!");
1283 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1284 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1286 // Expose the DAG combiner to the target combiner impls.
1287 TargetLowering::DAGCombinerInfo
1288 DagCombineInfo(DAG, Level, false, this);
1290 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1294 // If nothing happened still, try promoting the operation.
1295 if (!RV.getNode()) {
1296 switch (N->getOpcode()) {
1304 RV = PromoteIntBinOp(SDValue(N, 0));
1309 RV = PromoteIntShiftOp(SDValue(N, 0));
1311 case ISD::SIGN_EXTEND:
1312 case ISD::ZERO_EXTEND:
1313 case ISD::ANY_EXTEND:
1314 RV = PromoteExtend(SDValue(N, 0));
1317 if (PromoteLoad(SDValue(N, 0)))
1323 // If N is a commutative binary node, try commuting it to enable more
1325 if (!RV.getNode() && SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1326 N->getNumValues() == 1) {
1327 SDValue N0 = N->getOperand(0);
1328 SDValue N1 = N->getOperand(1);
1330 // Constant operands are canonicalized to RHS.
1331 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1332 SDValue Ops[] = {N1, N0};
1334 if (const BinaryWithFlagsSDNode *BinNode =
1335 dyn_cast<BinaryWithFlagsSDNode>(N)) {
1336 CSENode = DAG.getNodeIfExists(
1337 N->getOpcode(), N->getVTList(), Ops, BinNode->hasNoUnsignedWrap(),
1338 BinNode->hasNoSignedWrap(), BinNode->isExact());
1340 CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops);
1343 return SDValue(CSENode, 0);
1350 /// getInputChainForNode - Given a node, return its input chain if it has one,
1351 /// otherwise return a null sd operand.
1352 static SDValue getInputChainForNode(SDNode *N) {
1353 if (unsigned NumOps = N->getNumOperands()) {
1354 if (N->getOperand(0).getValueType() == MVT::Other)
1355 return N->getOperand(0);
1356 if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1357 return N->getOperand(NumOps-1);
1358 for (unsigned i = 1; i < NumOps-1; ++i)
1359 if (N->getOperand(i).getValueType() == MVT::Other)
1360 return N->getOperand(i);
1365 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1366 // If N has two operands, where one has an input chain equal to the other,
1367 // the 'other' chain is redundant.
1368 if (N->getNumOperands() == 2) {
1369 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1370 return N->getOperand(0);
1371 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1372 return N->getOperand(1);
1375 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1376 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1377 SmallPtrSet<SDNode*, 16> SeenOps;
1378 bool Changed = false; // If we should replace this token factor.
1380 // Start out with this token factor.
1383 // Iterate through token factors. The TFs grows when new token factors are
1385 for (unsigned i = 0; i < TFs.size(); ++i) {
1386 SDNode *TF = TFs[i];
1388 // Check each of the operands.
1389 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1390 SDValue Op = TF->getOperand(i);
1392 switch (Op.getOpcode()) {
1393 case ISD::EntryToken:
1394 // Entry tokens don't need to be added to the list. They are
1399 case ISD::TokenFactor:
1400 if (Op.hasOneUse() &&
1401 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1402 // Queue up for processing.
1403 TFs.push_back(Op.getNode());
1404 // Clean up in case the token factor is removed.
1405 AddToWorkList(Op.getNode());
1412 // Only add if it isn't already in the list.
1413 if (SeenOps.insert(Op.getNode()))
1424 // If we've change things around then replace token factor.
1427 // The entry token is the only possible outcome.
1428 Result = DAG.getEntryNode();
1430 // New and improved token factor.
1431 Result = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Ops);
1434 // Don't add users to work list.
1435 return CombineTo(N, Result, false);
1441 /// MERGE_VALUES can always be eliminated.
1442 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1443 WorkListRemover DeadNodes(*this);
1444 // Replacing results may cause a different MERGE_VALUES to suddenly
1445 // be CSE'd with N, and carry its uses with it. Iterate until no
1446 // uses remain, to ensure that the node can be safely deleted.
1447 // First add the users of this node to the work list so that they
1448 // can be tried again once they have new operands.
1449 AddUsersToWorkList(N);
1451 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1452 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1453 } while (!N->use_empty());
1454 removeFromWorkList(N);
1456 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1460 SDValue combineShlAddConstant(SDLoc DL, SDValue N0, SDValue N1,
1461 SelectionDAG &DAG) {
1462 EVT VT = N0.getValueType();
1463 SDValue N00 = N0.getOperand(0);
1464 SDValue N01 = N0.getOperand(1);
1465 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1467 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1468 isa<ConstantSDNode>(N00.getOperand(1))) {
1469 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1470 N0 = DAG.getNode(ISD::ADD, SDLoc(N0), VT,
1471 DAG.getNode(ISD::SHL, SDLoc(N00), VT,
1472 N00.getOperand(0), N01),
1473 DAG.getNode(ISD::SHL, SDLoc(N01), VT,
1474 N00.getOperand(1), N01));
1475 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1481 SDValue DAGCombiner::visitADD(SDNode *N) {
1482 SDValue N0 = N->getOperand(0);
1483 SDValue N1 = N->getOperand(1);
1484 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1485 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1486 EVT VT = N0.getValueType();
1489 if (VT.isVector()) {
1490 SDValue FoldedVOp = SimplifyVBinOp(N);
1491 if (FoldedVOp.getNode()) return FoldedVOp;
1493 // fold (add x, 0) -> x, vector edition
1494 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1496 if (ISD::isBuildVectorAllZeros(N0.getNode()))
1500 // fold (add x, undef) -> undef
1501 if (N0.getOpcode() == ISD::UNDEF)
1503 if (N1.getOpcode() == ISD::UNDEF)
1505 // fold (add c1, c2) -> c1+c2
1507 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1508 // canonicalize constant to RHS
1510 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N1, N0);
1511 // fold (add x, 0) -> x
1512 if (N1C && N1C->isNullValue())
1514 // fold (add Sym, c) -> Sym+c
1515 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1516 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1517 GA->getOpcode() == ISD::GlobalAddress)
1518 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1520 (uint64_t)N1C->getSExtValue());
1521 // fold ((c1-A)+c2) -> (c1+c2)-A
1522 if (N1C && N0.getOpcode() == ISD::SUB)
1523 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1524 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1525 DAG.getConstant(N1C->getAPIntValue()+
1526 N0C->getAPIntValue(), VT),
1529 SDValue RADD = ReassociateOps(ISD::ADD, SDLoc(N), N0, N1);
1532 // fold ((0-A) + B) -> B-A
1533 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1534 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1535 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1, N0.getOperand(1));
1536 // fold (A + (0-B)) -> A-B
1537 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1538 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1539 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1.getOperand(1));
1540 // fold (A+(B-A)) -> B
1541 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1542 return N1.getOperand(0);
1543 // fold ((B-A)+A) -> B
1544 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1545 return N0.getOperand(0);
1546 // fold (A+(B-(A+C))) to (B-C)
1547 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1548 N0 == N1.getOperand(1).getOperand(0))
1549 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1550 N1.getOperand(1).getOperand(1));
1551 // fold (A+(B-(C+A))) to (B-C)
1552 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1553 N0 == N1.getOperand(1).getOperand(1))
1554 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1555 N1.getOperand(1).getOperand(0));
1556 // fold (A+((B-A)+or-C)) to (B+or-C)
1557 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1558 N1.getOperand(0).getOpcode() == ISD::SUB &&
1559 N0 == N1.getOperand(0).getOperand(1))
1560 return DAG.getNode(N1.getOpcode(), SDLoc(N), VT,
1561 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1563 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1564 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1565 SDValue N00 = N0.getOperand(0);
1566 SDValue N01 = N0.getOperand(1);
1567 SDValue N10 = N1.getOperand(0);
1568 SDValue N11 = N1.getOperand(1);
1570 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1571 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1572 DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
1573 DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
1576 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1577 return SDValue(N, 0);
1579 // fold (a+b) -> (a|b) iff a and b share no bits.
1580 if (VT.isInteger() && !VT.isVector()) {
1581 APInt LHSZero, LHSOne;
1582 APInt RHSZero, RHSOne;
1583 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1585 if (LHSZero.getBoolValue()) {
1586 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1588 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1589 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1590 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero){
1591 if (!LegalOperations || TLI.isOperationLegal(ISD::OR, VT))
1592 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
1597 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1598 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1599 SDValue Result = combineShlAddConstant(SDLoc(N), N0, N1, DAG);
1600 if (Result.getNode()) return Result;
1602 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1603 SDValue Result = combineShlAddConstant(SDLoc(N), N1, N0, DAG);
1604 if (Result.getNode()) return Result;
1607 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1608 if (N1.getOpcode() == ISD::SHL &&
1609 N1.getOperand(0).getOpcode() == ISD::SUB)
1610 if (ConstantSDNode *C =
1611 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1612 if (C->getAPIntValue() == 0)
1613 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
1614 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1615 N1.getOperand(0).getOperand(1),
1617 if (N0.getOpcode() == ISD::SHL &&
1618 N0.getOperand(0).getOpcode() == ISD::SUB)
1619 if (ConstantSDNode *C =
1620 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1621 if (C->getAPIntValue() == 0)
1622 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
1623 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1624 N0.getOperand(0).getOperand(1),
1627 if (N1.getOpcode() == ISD::AND) {
1628 SDValue AndOp0 = N1.getOperand(0);
1629 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1630 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1631 unsigned DestBits = VT.getScalarType().getSizeInBits();
1633 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1634 // and similar xforms where the inner op is either ~0 or 0.
1635 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1637 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1641 // add (sext i1), X -> sub X, (zext i1)
1642 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1643 N0.getOperand(0).getValueType() == MVT::i1 &&
1644 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1646 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1647 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1653 SDValue DAGCombiner::visitADDC(SDNode *N) {
1654 SDValue N0 = N->getOperand(0);
1655 SDValue N1 = N->getOperand(1);
1656 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1657 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1658 EVT VT = N0.getValueType();
1660 // If the flag result is dead, turn this into an ADD.
1661 if (!N->hasAnyUseOfValue(1))
1662 return CombineTo(N, DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N1),
1663 DAG.getNode(ISD::CARRY_FALSE,
1664 SDLoc(N), MVT::Glue));
1666 // canonicalize constant to RHS.
1668 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N1, N0);
1670 // fold (addc x, 0) -> x + no carry out
1671 if (N1C && N1C->isNullValue())
1672 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1673 SDLoc(N), MVT::Glue));
1675 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1676 APInt LHSZero, LHSOne;
1677 APInt RHSZero, RHSOne;
1678 DAG.computeKnownBits(N0, LHSZero, LHSOne);
1680 if (LHSZero.getBoolValue()) {
1681 DAG.computeKnownBits(N1, RHSZero, RHSOne);
1683 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1684 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1685 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1686 return CombineTo(N, DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1),
1687 DAG.getNode(ISD::CARRY_FALSE,
1688 SDLoc(N), MVT::Glue));
1694 SDValue DAGCombiner::visitADDE(SDNode *N) {
1695 SDValue N0 = N->getOperand(0);
1696 SDValue N1 = N->getOperand(1);
1697 SDValue CarryIn = N->getOperand(2);
1698 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1699 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1701 // canonicalize constant to RHS
1703 return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
1706 // fold (adde x, y, false) -> (addc x, y)
1707 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1708 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);
1713 // Since it may not be valid to emit a fold to zero for vector initializers
1714 // check if we can before folding.
1715 static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
1717 bool LegalOperations, bool LegalTypes) {
1719 return DAG.getConstant(0, VT);
1720 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
1721 return DAG.getConstant(0, VT);
1725 SDValue DAGCombiner::visitSUB(SDNode *N) {
1726 SDValue N0 = N->getOperand(0);
1727 SDValue N1 = N->getOperand(1);
1728 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1729 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1730 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? nullptr :
1731 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1732 EVT VT = N0.getValueType();
1735 if (VT.isVector()) {
1736 SDValue FoldedVOp = SimplifyVBinOp(N);
1737 if (FoldedVOp.getNode()) return FoldedVOp;
1739 // fold (sub x, 0) -> x, vector edition
1740 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1744 // fold (sub x, x) -> 0
1745 // FIXME: Refactor this and xor and other similar operations together.
1747 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
1748 // fold (sub c1, c2) -> c1-c2
1750 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1751 // fold (sub x, c) -> (add x, -c)
1753 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N0,
1754 DAG.getConstant(-N1C->getAPIntValue(), VT));
1755 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1756 if (N0C && N0C->isAllOnesValue())
1757 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
1758 // fold A-(A-B) -> B
1759 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1760 return N1.getOperand(1);
1761 // fold (A+B)-A -> B
1762 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1763 return N0.getOperand(1);
1764 // fold (A+B)-B -> A
1765 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1766 return N0.getOperand(0);
1767 // fold C2-(A+C1) -> (C2-C1)-A
1768 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1769 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1771 return DAG.getNode(ISD::SUB, SDLoc(N), VT, NewC,
1774 // fold ((A+(B+or-C))-B) -> A+or-C
1775 if (N0.getOpcode() == ISD::ADD &&
1776 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1777 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1778 N0.getOperand(1).getOperand(0) == N1)
1779 return DAG.getNode(N0.getOperand(1).getOpcode(), SDLoc(N), VT,
1780 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1781 // fold ((A+(C+B))-B) -> A+C
1782 if (N0.getOpcode() == ISD::ADD &&
1783 N0.getOperand(1).getOpcode() == ISD::ADD &&
1784 N0.getOperand(1).getOperand(1) == N1)
1785 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1786 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1787 // fold ((A-(B-C))-C) -> A-B
1788 if (N0.getOpcode() == ISD::SUB &&
1789 N0.getOperand(1).getOpcode() == ISD::SUB &&
1790 N0.getOperand(1).getOperand(1) == N1)
1791 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1792 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1794 // If either operand of a sub is undef, the result is undef
1795 if (N0.getOpcode() == ISD::UNDEF)
1797 if (N1.getOpcode() == ISD::UNDEF)
1800 // If the relocation model supports it, consider symbol offsets.
1801 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1802 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1803 // fold (sub Sym, c) -> Sym-c
1804 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1805 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1807 (uint64_t)N1C->getSExtValue());
1808 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1809 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1810 if (GA->getGlobal() == GB->getGlobal())
1811 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1818 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1819 SDValue N0 = N->getOperand(0);
1820 SDValue N1 = N->getOperand(1);
1821 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1822 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1823 EVT VT = N0.getValueType();
1825 // If the flag result is dead, turn this into an SUB.
1826 if (!N->hasAnyUseOfValue(1))
1827 return CombineTo(N, DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1),
1828 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1831 // fold (subc x, x) -> 0 + no borrow
1833 return CombineTo(N, DAG.getConstant(0, VT),
1834 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1837 // fold (subc x, 0) -> x + no borrow
1838 if (N1C && N1C->isNullValue())
1839 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1842 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1843 if (N0C && N0C->isAllOnesValue())
1844 return CombineTo(N, DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0),
1845 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1851 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1852 SDValue N0 = N->getOperand(0);
1853 SDValue N1 = N->getOperand(1);
1854 SDValue CarryIn = N->getOperand(2);
1856 // fold (sube x, y, false) -> (subc x, y)
1857 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1858 return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);
1863 SDValue DAGCombiner::visitMUL(SDNode *N) {
1864 SDValue N0 = N->getOperand(0);
1865 SDValue N1 = N->getOperand(1);
1866 EVT VT = N0.getValueType();
1868 // fold (mul x, undef) -> 0
1869 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1870 return DAG.getConstant(0, VT);
1872 bool N0IsConst = false;
1873 bool N1IsConst = false;
1874 APInt ConstValue0, ConstValue1;
1876 if (VT.isVector()) {
1877 SDValue FoldedVOp = SimplifyVBinOp(N);
1878 if (FoldedVOp.getNode()) return FoldedVOp;
1880 N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
1881 N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
1883 N0IsConst = dyn_cast<ConstantSDNode>(N0) != nullptr;
1884 ConstValue0 = N0IsConst ? (dyn_cast<ConstantSDNode>(N0))->getAPIntValue()
1886 N1IsConst = dyn_cast<ConstantSDNode>(N1) != nullptr;
1887 ConstValue1 = N1IsConst ? (dyn_cast<ConstantSDNode>(N1))->getAPIntValue()
1891 // fold (mul c1, c2) -> c1*c2
1892 if (N0IsConst && N1IsConst)
1893 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0.getNode(), N1.getNode());
1895 // canonicalize constant to RHS
1896 if (N0IsConst && !N1IsConst)
1897 return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
1898 // fold (mul x, 0) -> 0
1899 if (N1IsConst && ConstValue1 == 0)
1901 // We require a splat of the entire scalar bit width for non-contiguous
1904 ConstValue1.getBitWidth() == VT.getScalarType().getSizeInBits();
1905 // fold (mul x, 1) -> x
1906 if (N1IsConst && ConstValue1 == 1 && IsFullSplat)
1908 // fold (mul x, -1) -> 0-x
1909 if (N1IsConst && ConstValue1.isAllOnesValue())
1910 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1911 DAG.getConstant(0, VT), N0);
1912 // fold (mul x, (1 << c)) -> x << c
1913 if (N1IsConst && ConstValue1.isPowerOf2() && IsFullSplat)
1914 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1915 DAG.getConstant(ConstValue1.logBase2(),
1916 getShiftAmountTy(N0.getValueType())));
1917 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1918 if (N1IsConst && (-ConstValue1).isPowerOf2() && IsFullSplat) {
1919 unsigned Log2Val = (-ConstValue1).logBase2();
1920 // FIXME: If the input is something that is easily negated (e.g. a
1921 // single-use add), we should put the negate there.
1922 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1923 DAG.getConstant(0, VT),
1924 DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1925 DAG.getConstant(Log2Val,
1926 getShiftAmountTy(N0.getValueType()))));
1930 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1931 if (N1IsConst && N0.getOpcode() == ISD::SHL &&
1932 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1933 isa<ConstantSDNode>(N0.getOperand(1)))) {
1934 SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
1935 N1, N0.getOperand(1));
1936 AddToWorkList(C3.getNode());
1937 return DAG.getNode(ISD::MUL, SDLoc(N), VT,
1938 N0.getOperand(0), C3);
1941 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1944 SDValue Sh(nullptr,0), Y(nullptr,0);
1945 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1946 if (N0.getOpcode() == ISD::SHL &&
1947 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1948 isa<ConstantSDNode>(N0.getOperand(1))) &&
1949 N0.getNode()->hasOneUse()) {
1951 } else if (N1.getOpcode() == ISD::SHL &&
1952 isa<ConstantSDNode>(N1.getOperand(1)) &&
1953 N1.getNode()->hasOneUse()) {
1958 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
1959 Sh.getOperand(0), Y);
1960 return DAG.getNode(ISD::SHL, SDLoc(N), VT,
1961 Mul, Sh.getOperand(1));
1965 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1966 if (N1IsConst && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1967 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1968 isa<ConstantSDNode>(N0.getOperand(1))))
1969 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1970 DAG.getNode(ISD::MUL, SDLoc(N0), VT,
1971 N0.getOperand(0), N1),
1972 DAG.getNode(ISD::MUL, SDLoc(N1), VT,
1973 N0.getOperand(1), N1));
1976 SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1);
1983 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1984 SDValue N0 = N->getOperand(0);
1985 SDValue N1 = N->getOperand(1);
1986 ConstantSDNode *N0C = isConstOrConstSplat(N0);
1987 ConstantSDNode *N1C = isConstOrConstSplat(N1);
1988 EVT VT = N->getValueType(0);
1991 if (VT.isVector()) {
1992 SDValue FoldedVOp = SimplifyVBinOp(N);
1993 if (FoldedVOp.getNode()) return FoldedVOp;
1996 // fold (sdiv c1, c2) -> c1/c2
1997 if (N0C && N1C && !N1C->isNullValue())
1998 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1999 // fold (sdiv X, 1) -> X
2000 if (N1C && N1C->getAPIntValue() == 1LL)
2002 // fold (sdiv X, -1) -> 0-X
2003 if (N1C && N1C->isAllOnesValue())
2004 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
2005 DAG.getConstant(0, VT), N0);
2006 // If we know the sign bits of both operands are zero, strength reduce to a
2007 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
2008 if (!VT.isVector()) {
2009 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2010 return DAG.getNode(ISD::UDIV, SDLoc(N), N1.getValueType(),
2014 // fold (sdiv X, pow2) -> simple ops after legalize
2015 if (N1C && !N1C->isNullValue() && (N1C->getAPIntValue().isPowerOf2() ||
2016 (-N1C->getAPIntValue()).isPowerOf2())) {
2017 // If dividing by powers of two is cheap, then don't perform the following
2019 if (TLI.isPow2DivCheap())
2022 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
2024 // Splat the sign bit into the register
2026 DAG.getNode(ISD::SRA, SDLoc(N), VT, N0,
2027 DAG.getConstant(VT.getScalarSizeInBits() - 1,
2028 getShiftAmountTy(N0.getValueType())));
2029 AddToWorkList(SGN.getNode());
2031 // Add (N0 < 0) ? abs2 - 1 : 0;
2033 DAG.getNode(ISD::SRL, SDLoc(N), VT, SGN,
2034 DAG.getConstant(VT.getScalarSizeInBits() - lg2,
2035 getShiftAmountTy(SGN.getValueType())));
2036 SDValue ADD = DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, SRL);
2037 AddToWorkList(SRL.getNode());
2038 AddToWorkList(ADD.getNode()); // Divide by pow2
2039 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), VT, ADD,
2040 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
2042 // If we're dividing by a positive value, we're done. Otherwise, we must
2043 // negate the result.
2044 if (N1C->getAPIntValue().isNonNegative())
2047 AddToWorkList(SRA.getNode());
2048 return DAG.getNode(ISD::SUB, SDLoc(N), VT, DAG.getConstant(0, VT), SRA);
2051 // if integer divide is expensive and we satisfy the requirements, emit an
2052 // alternate sequence.
2053 if (N1C && !TLI.isIntDivCheap()) {
2054 SDValue Op = BuildSDIV(N);
2055 if (Op.getNode()) return Op;
2059 if (N0.getOpcode() == ISD::UNDEF)
2060 return DAG.getConstant(0, VT);
2061 // X / undef -> undef
2062 if (N1.getOpcode() == ISD::UNDEF)
2068 SDValue DAGCombiner::visitUDIV(SDNode *N) {
2069 SDValue N0 = N->getOperand(0);
2070 SDValue N1 = N->getOperand(1);
2071 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2072 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2073 EVT VT = N->getValueType(0);
2076 if (VT.isVector()) {
2077 SDValue FoldedVOp = SimplifyVBinOp(N);
2078 if (FoldedVOp.getNode()) return FoldedVOp;
2081 // fold (udiv c1, c2) -> c1/c2
2082 if (N0C && N1C && !N1C->isNullValue())
2083 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
2084 // fold (udiv x, (1 << c)) -> x >>u c
2085 if (N1C && N1C->getAPIntValue().isPowerOf2())
2086 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0,
2087 DAG.getConstant(N1C->getAPIntValue().logBase2(),
2088 getShiftAmountTy(N0.getValueType())));
2089 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
2090 if (N1.getOpcode() == ISD::SHL) {
2091 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2092 if (SHC->getAPIntValue().isPowerOf2()) {
2093 EVT ADDVT = N1.getOperand(1).getValueType();
2094 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N), ADDVT,
2096 DAG.getConstant(SHC->getAPIntValue()
2099 AddToWorkList(Add.getNode());
2100 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, Add);
2104 // fold (udiv x, c) -> alternate
2105 if (N1C && !TLI.isIntDivCheap()) {
2106 SDValue Op = BuildUDIV(N);
2107 if (Op.getNode()) return Op;
2111 if (N0.getOpcode() == ISD::UNDEF)
2112 return DAG.getConstant(0, VT);
2113 // X / undef -> undef
2114 if (N1.getOpcode() == ISD::UNDEF)
2120 SDValue DAGCombiner::visitSREM(SDNode *N) {
2121 SDValue N0 = N->getOperand(0);
2122 SDValue N1 = N->getOperand(1);
2123 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2124 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2125 EVT VT = N->getValueType(0);
2127 // fold (srem c1, c2) -> c1%c2
2128 if (N0C && N1C && !N1C->isNullValue())
2129 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
2130 // If we know the sign bits of both operands are zero, strength reduce to a
2131 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
2132 if (!VT.isVector()) {
2133 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2134 return DAG.getNode(ISD::UREM, SDLoc(N), VT, N0, N1);
2137 // If X/C can be simplified by the division-by-constant logic, lower
2138 // X%C to the equivalent of X-X/C*C.
2139 if (N1C && !N1C->isNullValue()) {
2140 SDValue Div = DAG.getNode(ISD::SDIV, SDLoc(N), VT, N0, N1);
2141 AddToWorkList(Div.getNode());
2142 SDValue OptimizedDiv = combine(Div.getNode());
2143 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2144 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2146 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2147 AddToWorkList(Mul.getNode());
2153 if (N0.getOpcode() == ISD::UNDEF)
2154 return DAG.getConstant(0, VT);
2155 // X % undef -> undef
2156 if (N1.getOpcode() == ISD::UNDEF)
2162 SDValue DAGCombiner::visitUREM(SDNode *N) {
2163 SDValue N0 = N->getOperand(0);
2164 SDValue N1 = N->getOperand(1);
2165 ConstantSDNode *N0C = isConstOrConstSplat(N0);
2166 ConstantSDNode *N1C = isConstOrConstSplat(N1);
2167 EVT VT = N->getValueType(0);
2169 // fold (urem c1, c2) -> c1%c2
2170 if (N0C && N1C && !N1C->isNullValue())
2171 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2172 // fold (urem x, pow2) -> (and x, pow2-1)
2173 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2174 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0,
2175 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2176 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2177 if (N1.getOpcode() == ISD::SHL) {
2178 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2179 if (SHC->getAPIntValue().isPowerOf2()) {
2181 DAG.getNode(ISD::ADD, SDLoc(N), VT, N1,
2182 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2184 AddToWorkList(Add.getNode());
2185 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, Add);
2190 // If X/C can be simplified by the division-by-constant logic, lower
2191 // X%C to the equivalent of X-X/C*C.
2192 if (N1C && !N1C->isNullValue()) {
2193 SDValue Div = DAG.getNode(ISD::UDIV, SDLoc(N), VT, N0, N1);
2194 AddToWorkList(Div.getNode());
2195 SDValue OptimizedDiv = combine(Div.getNode());
2196 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2197 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2199 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2200 AddToWorkList(Mul.getNode());
2206 if (N0.getOpcode() == ISD::UNDEF)
2207 return DAG.getConstant(0, VT);
2208 // X % undef -> undef
2209 if (N1.getOpcode() == ISD::UNDEF)
2215 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2216 SDValue N0 = N->getOperand(0);
2217 SDValue N1 = N->getOperand(1);
2218 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2219 EVT VT = N->getValueType(0);
2222 // fold (mulhs x, 0) -> 0
2223 if (N1C && N1C->isNullValue())
2225 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2226 if (N1C && N1C->getAPIntValue() == 1)
2227 return DAG.getNode(ISD::SRA, SDLoc(N), N0.getValueType(), N0,
2228 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2229 getShiftAmountTy(N0.getValueType())));
2230 // fold (mulhs x, undef) -> 0
2231 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2232 return DAG.getConstant(0, VT);
2234 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2236 if (VT.isSimple() && !VT.isVector()) {
2237 MVT Simple = VT.getSimpleVT();
2238 unsigned SimpleSize = Simple.getSizeInBits();
2239 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2240 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2241 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2242 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2243 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2244 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2245 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2246 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2253 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2254 SDValue N0 = N->getOperand(0);
2255 SDValue N1 = N->getOperand(1);
2256 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2257 EVT VT = N->getValueType(0);
2260 // fold (mulhu x, 0) -> 0
2261 if (N1C && N1C->isNullValue())
2263 // fold (mulhu x, 1) -> 0
2264 if (N1C && N1C->getAPIntValue() == 1)
2265 return DAG.getConstant(0, N0.getValueType());
2266 // fold (mulhu x, undef) -> 0
2267 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2268 return DAG.getConstant(0, VT);
2270 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2272 if (VT.isSimple() && !VT.isVector()) {
2273 MVT Simple = VT.getSimpleVT();
2274 unsigned SimpleSize = Simple.getSizeInBits();
2275 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2276 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2277 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2278 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2279 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2280 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2281 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2282 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2289 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2290 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2291 /// that are being performed. Return true if a simplification was made.
2293 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2295 // If the high half is not needed, just compute the low half.
2296 bool HiExists = N->hasAnyUseOfValue(1);
2298 (!LegalOperations ||
2299 TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) {
2300 SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2301 ArrayRef<SDUse>(N->op_begin(), N->op_end()));
2302 return CombineTo(N, Res, Res);
2305 // If the low half is not needed, just compute the high half.
2306 bool LoExists = N->hasAnyUseOfValue(0);
2308 (!LegalOperations ||
2309 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2310 SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2311 ArrayRef<SDUse>(N->op_begin(), N->op_end()));
2312 return CombineTo(N, Res, Res);
2315 // If both halves are used, return as it is.
2316 if (LoExists && HiExists)
2319 // If the two computed results can be simplified separately, separate them.
2321 SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2322 ArrayRef<SDUse>(N->op_begin(), N->op_end()));
2323 AddToWorkList(Lo.getNode());
2324 SDValue LoOpt = combine(Lo.getNode());
2325 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2326 (!LegalOperations ||
2327 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2328 return CombineTo(N, LoOpt, LoOpt);
2332 SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2333 ArrayRef<SDUse>(N->op_begin(), N->op_end()));
2334 AddToWorkList(Hi.getNode());
2335 SDValue HiOpt = combine(Hi.getNode());
2336 if (HiOpt.getNode() && HiOpt != Hi &&
2337 (!LegalOperations ||
2338 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2339 return CombineTo(N, HiOpt, HiOpt);
2345 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2346 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2347 if (Res.getNode()) return Res;
2349 EVT VT = N->getValueType(0);
2352 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2354 if (VT.isSimple() && !VT.isVector()) {
2355 MVT Simple = VT.getSimpleVT();
2356 unsigned SimpleSize = Simple.getSizeInBits();
2357 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2358 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2359 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2360 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2361 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2362 // Compute the high part as N1.
2363 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2364 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2365 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2366 // Compute the low part as N0.
2367 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2368 return CombineTo(N, Lo, Hi);
2375 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2376 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2377 if (Res.getNode()) return Res;
2379 EVT VT = N->getValueType(0);
2382 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2384 if (VT.isSimple() && !VT.isVector()) {
2385 MVT Simple = VT.getSimpleVT();
2386 unsigned SimpleSize = Simple.getSizeInBits();
2387 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2388 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2389 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2390 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2391 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2392 // Compute the high part as N1.
2393 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2394 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2395 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2396 // Compute the low part as N0.
2397 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2398 return CombineTo(N, Lo, Hi);
2405 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2406 // (smulo x, 2) -> (saddo x, x)
2407 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2408 if (C2->getAPIntValue() == 2)
2409 return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
2410 N->getOperand(0), N->getOperand(0));
2415 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2416 // (umulo x, 2) -> (uaddo x, x)
2417 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2418 if (C2->getAPIntValue() == 2)
2419 return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
2420 N->getOperand(0), N->getOperand(0));
2425 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2426 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2427 if (Res.getNode()) return Res;
2432 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2433 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2434 if (Res.getNode()) return Res;
2439 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2440 /// two operands of the same opcode, try to simplify it.
2441 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2442 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2443 EVT VT = N0.getValueType();
2444 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2446 // Bail early if none of these transforms apply.
2447 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2449 // For each of OP in AND/OR/XOR:
2450 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2451 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2452 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2453 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2455 // do not sink logical op inside of a vector extend, since it may combine
2457 EVT Op0VT = N0.getOperand(0).getValueType();
2458 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2459 N0.getOpcode() == ISD::SIGN_EXTEND ||
2460 // Avoid infinite looping with PromoteIntBinOp.
2461 (N0.getOpcode() == ISD::ANY_EXTEND &&
2462 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2463 (N0.getOpcode() == ISD::TRUNCATE &&
2464 (!TLI.isZExtFree(VT, Op0VT) ||
2465 !TLI.isTruncateFree(Op0VT, VT)) &&
2466 TLI.isTypeLegal(Op0VT))) &&
2468 Op0VT == N1.getOperand(0).getValueType() &&
2469 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2470 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2471 N0.getOperand(0).getValueType(),
2472 N0.getOperand(0), N1.getOperand(0));
2473 AddToWorkList(ORNode.getNode());
2474 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
2477 // For each of OP in SHL/SRL/SRA/AND...
2478 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2479 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2480 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2481 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2482 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2483 N0.getOperand(1) == N1.getOperand(1)) {
2484 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2485 N0.getOperand(0).getValueType(),
2486 N0.getOperand(0), N1.getOperand(0));
2487 AddToWorkList(ORNode.getNode());
2488 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
2489 ORNode, N0.getOperand(1));
2492 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2493 // Only perform this optimization after type legalization and before
2494 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2495 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2496 // we don't want to undo this promotion.
2497 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2499 if ((N0.getOpcode() == ISD::BITCAST ||
2500 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2501 Level == AfterLegalizeTypes) {
2502 SDValue In0 = N0.getOperand(0);
2503 SDValue In1 = N1.getOperand(0);
2504 EVT In0Ty = In0.getValueType();
2505 EVT In1Ty = In1.getValueType();
2507 // If both incoming values are integers, and the original types are the
2509 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2510 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2511 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2512 AddToWorkList(Op.getNode());
2517 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2518 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2519 // If both shuffles use the same mask, and both shuffle within a single
2520 // vector, then it is worthwhile to move the swizzle after the operation.
2521 // The type-legalizer generates this pattern when loading illegal
2522 // vector types from memory. In many cases this allows additional shuffle
2524 // There are other cases where moving the shuffle after the xor/and/or
2525 // is profitable even if shuffles don't perform a swizzle.
2526 // If both shuffles use the same mask, and both shuffles have the same first
2527 // or second operand, then it might still be profitable to move the shuffle
2528 // after the xor/and/or operation.
2529 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG) {
2530 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2531 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2533 assert(N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() &&
2534 "Inputs to shuffles are not the same type");
2536 // Check that both shuffles use the same mask. The masks are known to be of
2537 // the same length because the result vector type is the same.
2538 // Check also that shuffles have only one use to avoid introducing extra
2540 if (SVN0->hasOneUse() && SVN1->hasOneUse() &&
2541 SVN0->getMask().equals(SVN1->getMask())) {
2542 SDValue ShOp = N0->getOperand(1);
2544 // Don't try to fold this node if it requires introducing a
2545 // build vector of all zeros that might be illegal at this stage.
2546 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2548 ShOp = DAG.getConstant(0, VT);
2553 // (AND (shuf (A, C), shuf (B, C)) -> shuf (AND (A, B), C)
2554 // (OR (shuf (A, C), shuf (B, C)) -> shuf (OR (A, B), C)
2555 // (XOR (shuf (A, C), shuf (B, C)) -> shuf (XOR (A, B), V_0)
2556 if (N0.getOperand(1) == N1.getOperand(1) && ShOp.getNode()) {
2557 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2558 N0->getOperand(0), N1->getOperand(0));
2559 AddToWorkList(NewNode.getNode());
2560 return DAG.getVectorShuffle(VT, SDLoc(N), NewNode, ShOp,
2561 &SVN0->getMask()[0]);
2564 // Don't try to fold this node if it requires introducing a
2565 // build vector of all zeros that might be illegal at this stage.
2566 ShOp = N0->getOperand(0);
2567 if (N->getOpcode() == ISD::XOR && ShOp.getOpcode() != ISD::UNDEF) {
2569 ShOp = DAG.getConstant(0, VT);
2574 // (AND (shuf (C, A), shuf (C, B)) -> shuf (C, AND (A, B))
2575 // (OR (shuf (C, A), shuf (C, B)) -> shuf (C, OR (A, B))
2576 // (XOR (shuf (C, A), shuf (C, B)) -> shuf (V_0, XOR (A, B))
2577 if (N0->getOperand(0) == N1->getOperand(0) && ShOp.getNode()) {
2578 SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2579 N0->getOperand(1), N1->getOperand(1));
2580 AddToWorkList(NewNode.getNode());
2581 return DAG.getVectorShuffle(VT, SDLoc(N), ShOp, NewNode,
2582 &SVN0->getMask()[0]);
2590 SDValue DAGCombiner::visitAND(SDNode *N) {
2591 SDValue N0 = N->getOperand(0);
2592 SDValue N1 = N->getOperand(1);
2593 SDValue LL, LR, RL, RR, CC0, CC1;
2594 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2595 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2596 EVT VT = N1.getValueType();
2597 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2600 if (VT.isVector()) {
2601 SDValue FoldedVOp = SimplifyVBinOp(N);
2602 if (FoldedVOp.getNode()) return FoldedVOp;
2604 // fold (and x, 0) -> 0, vector edition
2605 if (ISD::isBuildVectorAllZeros(N0.getNode()))
2607 if (ISD::isBuildVectorAllZeros(N1.getNode()))
2610 // fold (and x, -1) -> x, vector edition
2611 if (ISD::isBuildVectorAllOnes(N0.getNode()))
2613 if (ISD::isBuildVectorAllOnes(N1.getNode()))
2617 // fold (and x, undef) -> 0
2618 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2619 return DAG.getConstant(0, VT);
2620 // fold (and c1, c2) -> c1&c2
2622 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2623 // canonicalize constant to RHS
2625 return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
2626 // fold (and x, -1) -> x
2627 if (N1C && N1C->isAllOnesValue())
2629 // if (and x, c) is known to be zero, return 0
2630 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2631 APInt::getAllOnesValue(BitWidth)))
2632 return DAG.getConstant(0, VT);
2634 SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1);
2637 // fold (and (or x, C), D) -> D if (C & D) == D
2638 if (N1C && N0.getOpcode() == ISD::OR)
2639 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2640 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2642 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2643 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2644 SDValue N0Op0 = N0.getOperand(0);
2645 APInt Mask = ~N1C->getAPIntValue();
2646 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2647 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2648 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
2649 N0.getValueType(), N0Op0);
2651 // Replace uses of the AND with uses of the Zero extend node.
2654 // We actually want to replace all uses of the any_extend with the
2655 // zero_extend, to avoid duplicating things. This will later cause this
2656 // AND to be folded.
2657 CombineTo(N0.getNode(), Zext);
2658 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2661 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2662 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2663 // already be zero by virtue of the width of the base type of the load.
2665 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2667 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2668 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2669 N0.getOpcode() == ISD::LOAD) {
2670 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2671 N0 : N0.getOperand(0) );
2673 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2674 // This can be a pure constant or a vector splat, in which case we treat the
2675 // vector as a scalar and use the splat value.
2676 APInt Constant = APInt::getNullValue(1);
2677 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2678 Constant = C->getAPIntValue();
2679 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2680 APInt SplatValue, SplatUndef;
2681 unsigned SplatBitSize;
2683 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2684 SplatBitSize, HasAnyUndefs);
2686 // Undef bits can contribute to a possible optimisation if set, so
2688 SplatValue |= SplatUndef;
2690 // The splat value may be something like "0x00FFFFFF", which means 0 for
2691 // the first vector value and FF for the rest, repeating. We need a mask
2692 // that will apply equally to all members of the vector, so AND all the
2693 // lanes of the constant together.
2694 EVT VT = Vector->getValueType(0);
2695 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2697 // If the splat value has been compressed to a bitlength lower
2698 // than the size of the vector lane, we need to re-expand it to
2700 if (BitWidth > SplatBitSize)
2701 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2702 SplatBitSize < BitWidth;
2703 SplatBitSize = SplatBitSize * 2)
2704 SplatValue |= SplatValue.shl(SplatBitSize);
2706 Constant = APInt::getAllOnesValue(BitWidth);
2707 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2708 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2712 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2713 // actually legal and isn't going to get expanded, else this is a false
2715 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2716 Load->getMemoryVT());
2718 // Resize the constant to the same size as the original memory access before
2719 // extension. If it is still the AllOnesValue then this AND is completely
2722 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2725 switch (Load->getExtensionType()) {
2726 default: B = false; break;
2727 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2729 case ISD::NON_EXTLOAD: B = true; break;
2732 if (B && Constant.isAllOnesValue()) {
2733 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2734 // preserve semantics once we get rid of the AND.
2735 SDValue NewLoad(Load, 0);
2736 if (Load->getExtensionType() == ISD::EXTLOAD) {
2737 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2738 Load->getValueType(0), SDLoc(Load),
2739 Load->getChain(), Load->getBasePtr(),
2740 Load->getOffset(), Load->getMemoryVT(),
2741 Load->getMemOperand());
2742 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2743 if (Load->getNumValues() == 3) {
2744 // PRE/POST_INC loads have 3 values.
2745 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2746 NewLoad.getValue(2) };
2747 CombineTo(Load, To, 3, true);
2749 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2753 // Fold the AND away, taking care not to fold to the old load node if we
2755 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2757 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2760 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2761 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2762 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2763 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2765 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2766 LL.getValueType().isInteger()) {
2767 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2768 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2769 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2770 LR.getValueType(), LL, RL);
2771 AddToWorkList(ORNode.getNode());
2772 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2774 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2775 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2776 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(N0),
2777 LR.getValueType(), LL, RL);
2778 AddToWorkList(ANDNode.getNode());
2779 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
2781 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2782 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2783 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2784 LR.getValueType(), LL, RL);
2785 AddToWorkList(ORNode.getNode());
2786 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2789 // Simplify (and (setne X, 0), (setne X, -1)) -> (setuge (add X, 1), 2)
2790 if (LL == RL && isa<ConstantSDNode>(LR) && isa<ConstantSDNode>(RR) &&
2791 Op0 == Op1 && LL.getValueType().isInteger() &&
2792 Op0 == ISD::SETNE && ((cast<ConstantSDNode>(LR)->isNullValue() &&
2793 cast<ConstantSDNode>(RR)->isAllOnesValue()) ||
2794 (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
2795 cast<ConstantSDNode>(RR)->isNullValue()))) {
2796 SDValue ADDNode = DAG.getNode(ISD::ADD, SDLoc(N0), LL.getValueType(),
2797 LL, DAG.getConstant(1, LL.getValueType()));
2798 AddToWorkList(ADDNode.getNode());
2799 return DAG.getSetCC(SDLoc(N), VT, ADDNode,
2800 DAG.getConstant(2, LL.getValueType()), ISD::SETUGE);
2802 // canonicalize equivalent to ll == rl
2803 if (LL == RR && LR == RL) {
2804 Op1 = ISD::getSetCCSwappedOperands(Op1);
2807 if (LL == RL && LR == RR) {
2808 bool isInteger = LL.getValueType().isInteger();
2809 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2810 if (Result != ISD::SETCC_INVALID &&
2811 (!LegalOperations ||
2812 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
2813 TLI.isOperationLegal(ISD::SETCC,
2814 getSetCCResultType(N0.getSimpleValueType())))))
2815 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
2820 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2821 if (N0.getOpcode() == N1.getOpcode()) {
2822 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2823 if (Tmp.getNode()) return Tmp;
2826 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2827 // fold (and (sra)) -> (and (srl)) when possible.
2828 if (!VT.isVector() &&
2829 SimplifyDemandedBits(SDValue(N, 0)))
2830 return SDValue(N, 0);
2832 // fold (zext_inreg (extload x)) -> (zextload x)
2833 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2834 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2835 EVT MemVT = LN0->getMemoryVT();
2836 // If we zero all the possible extended bits, then we can turn this into
2837 // a zextload if we are running before legalize or the operation is legal.
2838 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2839 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2840 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2841 ((!LegalOperations && !LN0->isVolatile()) ||
2842 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2843 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2844 LN0->getChain(), LN0->getBasePtr(),
2845 MemVT, LN0->getMemOperand());
2847 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2848 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2851 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2852 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2854 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2855 EVT MemVT = LN0->getMemoryVT();
2856 // If we zero all the possible extended bits, then we can turn this into
2857 // a zextload if we are running before legalize or the operation is legal.
2858 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2859 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2860 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2861 ((!LegalOperations && !LN0->isVolatile()) ||
2862 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2863 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2864 LN0->getChain(), LN0->getBasePtr(),
2865 MemVT, LN0->getMemOperand());
2867 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2868 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2872 // fold (and (load x), 255) -> (zextload x, i8)
2873 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2874 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2875 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2876 (N0.getOpcode() == ISD::ANY_EXTEND &&
2877 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2878 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2879 LoadSDNode *LN0 = HasAnyExt
2880 ? cast<LoadSDNode>(N0.getOperand(0))
2881 : cast<LoadSDNode>(N0);
2882 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2883 LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
2884 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2885 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2886 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2887 EVT LoadedVT = LN0->getMemoryVT();
2889 if (ExtVT == LoadedVT &&
2890 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2891 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2894 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2895 LN0->getChain(), LN0->getBasePtr(), ExtVT,
2896 LN0->getMemOperand());
2898 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2899 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2902 // Do not change the width of a volatile load.
2903 // Do not generate loads of non-round integer types since these can
2904 // be expensive (and would be wrong if the type is not byte sized).
2905 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2906 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2907 EVT PtrType = LN0->getOperand(1).getValueType();
2909 unsigned Alignment = LN0->getAlignment();
2910 SDValue NewPtr = LN0->getBasePtr();
2912 // For big endian targets, we need to add an offset to the pointer
2913 // to load the correct bytes. For little endian systems, we merely
2914 // need to read fewer bytes from the same pointer.
2915 if (TLI.isBigEndian()) {
2916 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2917 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2918 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2919 NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0), PtrType,
2920 NewPtr, DAG.getConstant(PtrOff, PtrType));
2921 Alignment = MinAlign(Alignment, PtrOff);
2924 AddToWorkList(NewPtr.getNode());
2926 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2928 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2929 LN0->getChain(), NewPtr,
2930 LN0->getPointerInfo(),
2931 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2932 Alignment, LN0->getTBAAInfo());
2934 CombineTo(LN0, Load, Load.getValue(1));
2935 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2941 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2942 VT.getSizeInBits() <= 64) {
2943 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2944 APInt ADDC = ADDI->getAPIntValue();
2945 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2946 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2947 // immediate for an add, but it is legal if its top c2 bits are set,
2948 // transform the ADD so the immediate doesn't need to be materialized
2950 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2951 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2952 SRLI->getZExtValue());
2953 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2955 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2957 DAG.getNode(ISD::ADD, SDLoc(N0), VT,
2958 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2959 CombineTo(N0.getNode(), NewAdd);
2960 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2968 // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
2969 if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
2970 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
2971 N0.getOperand(1), false);
2972 if (BSwap.getNode())
2979 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2981 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2982 bool DemandHighBits) {
2983 if (!LegalOperations)
2986 EVT VT = N->getValueType(0);
2987 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2989 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2992 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2993 bool LookPassAnd0 = false;
2994 bool LookPassAnd1 = false;
2995 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2997 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2999 if (N0.getOpcode() == ISD::AND) {
3000 if (!N0.getNode()->hasOneUse())
3002 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3003 if (!N01C || N01C->getZExtValue() != 0xFF00)
3005 N0 = N0.getOperand(0);
3006 LookPassAnd0 = true;
3009 if (N1.getOpcode() == ISD::AND) {
3010 if (!N1.getNode()->hasOneUse())
3012 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3013 if (!N11C || N11C->getZExtValue() != 0xFF)
3015 N1 = N1.getOperand(0);
3016 LookPassAnd1 = true;
3019 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
3021 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
3023 if (!N0.getNode()->hasOneUse() ||
3024 !N1.getNode()->hasOneUse())
3027 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3028 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
3031 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
3034 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
3035 SDValue N00 = N0->getOperand(0);
3036 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
3037 if (!N00.getNode()->hasOneUse())
3039 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
3040 if (!N001C || N001C->getZExtValue() != 0xFF)
3042 N00 = N00.getOperand(0);
3043 LookPassAnd0 = true;
3046 SDValue N10 = N1->getOperand(0);
3047 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
3048 if (!N10.getNode()->hasOneUse())
3050 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
3051 if (!N101C || N101C->getZExtValue() != 0xFF00)
3053 N10 = N10.getOperand(0);
3054 LookPassAnd1 = true;
3060 // Make sure everything beyond the low halfword gets set to zero since the SRL
3061 // 16 will clear the top bits.
3062 unsigned OpSizeInBits = VT.getSizeInBits();
3063 if (DemandHighBits && OpSizeInBits > 16) {
3064 // If the left-shift isn't masked out then the only way this is a bswap is
3065 // if all bits beyond the low 8 are 0. In that case the entire pattern
3066 // reduces to a left shift anyway: leave it for other parts of the combiner.
3070 // However, if the right shift isn't masked out then it might be because
3071 // it's not needed. See if we can spot that too.
3072 if (!LookPassAnd1 &&
3073 !DAG.MaskedValueIsZero(
3074 N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
3078 SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
3079 if (OpSizeInBits > 16)
3080 Res = DAG.getNode(ISD::SRL, SDLoc(N), VT, Res,
3081 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
3085 /// isBSwapHWordElement - Return true if the specified node is an element
3086 /// that makes up a 32-bit packed halfword byteswap. i.e.
3087 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
3088 static bool isBSwapHWordElement(SDValue N, SmallVectorImpl<SDNode *> &Parts) {
3089 if (!N.getNode()->hasOneUse())
3092 unsigned Opc = N.getOpcode();
3093 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
3096 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3101 switch (N1C->getZExtValue()) {
3104 case 0xFF: Num = 0; break;
3105 case 0xFF00: Num = 1; break;
3106 case 0xFF0000: Num = 2; break;
3107 case 0xFF000000: Num = 3; break;
3110 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
3111 SDValue N0 = N.getOperand(0);
3112 if (Opc == ISD::AND) {
3113 if (Num == 0 || Num == 2) {
3115 // (x >> 8) & 0xff0000
3116 if (N0.getOpcode() != ISD::SRL)
3118 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3119 if (!C || C->getZExtValue() != 8)
3122 // (x << 8) & 0xff00
3123 // (x << 8) & 0xff000000
3124 if (N0.getOpcode() != ISD::SHL)
3126 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3127 if (!C || C->getZExtValue() != 8)
3130 } else if (Opc == ISD::SHL) {
3132 // (x & 0xff0000) << 8
3133 if (Num != 0 && Num != 2)
3135 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3136 if (!C || C->getZExtValue() != 8)
3138 } else { // Opc == ISD::SRL
3139 // (x & 0xff00) >> 8
3140 // (x & 0xff000000) >> 8
3141 if (Num != 1 && Num != 3)
3143 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3144 if (!C || C->getZExtValue() != 8)
3151 Parts[Num] = N0.getOperand(0).getNode();
3155 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
3156 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
3157 /// => (rotl (bswap x), 16)
3158 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
3159 if (!LegalOperations)
3162 EVT VT = N->getValueType(0);
3165 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3168 SmallVector<SDNode*,4> Parts(4, (SDNode*)nullptr);
3170 // (or (or (and), (and)), (or (and), (and)))
3171 // (or (or (or (and), (and)), (and)), (and))
3172 if (N0.getOpcode() != ISD::OR)
3174 SDValue N00 = N0.getOperand(0);
3175 SDValue N01 = N0.getOperand(1);
3177 if (N1.getOpcode() == ISD::OR &&
3178 N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
3179 // (or (or (and), (and)), (or (and), (and)))
3180 SDValue N000 = N00.getOperand(0);
3181 if (!isBSwapHWordElement(N000, Parts))
3184 SDValue N001 = N00.getOperand(1);
3185 if (!isBSwapHWordElement(N001, Parts))
3187 SDValue N010 = N01.getOperand(0);
3188 if (!isBSwapHWordElement(N010, Parts))
3190 SDValue N011 = N01.getOperand(1);
3191 if (!isBSwapHWordElement(N011, Parts))
3194 // (or (or (or (and), (and)), (and)), (and))
3195 if (!isBSwapHWordElement(N1, Parts))
3197 if (!isBSwapHWordElement(N01, Parts))
3199 if (N00.getOpcode() != ISD::OR)
3201 SDValue N000 = N00.getOperand(0);
3202 if (!isBSwapHWordElement(N000, Parts))
3204 SDValue N001 = N00.getOperand(1);
3205 if (!isBSwapHWordElement(N001, Parts))
3209 // Make sure the parts are all coming from the same node.
3210 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3213 SDValue BSwap = DAG.getNode(ISD::BSWAP, SDLoc(N), VT,
3214 SDValue(Parts[0],0));
3216 // Result of the bswap should be rotated by 16. If it's not legal, then
3217 // do (x << 16) | (x >> 16).
3218 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3219 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3220 return DAG.getNode(ISD::ROTL, SDLoc(N), VT, BSwap, ShAmt);
3221 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3222 return DAG.getNode(ISD::ROTR, SDLoc(N), VT, BSwap, ShAmt);
3223 return DAG.getNode(ISD::OR, SDLoc(N), VT,
3224 DAG.getNode(ISD::SHL, SDLoc(N), VT, BSwap, ShAmt),
3225 DAG.getNode(ISD::SRL, SDLoc(N), VT, BSwap, ShAmt));
3228 SDValue DAGCombiner::visitOR(SDNode *N) {
3229 SDValue N0 = N->getOperand(0);
3230 SDValue N1 = N->getOperand(1);
3231 SDValue LL, LR, RL, RR, CC0, CC1;
3232 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3233 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3234 EVT VT = N1.getValueType();
3237 if (VT.isVector()) {
3238 SDValue FoldedVOp = SimplifyVBinOp(N);
3239 if (FoldedVOp.getNode()) return FoldedVOp;
3241 // fold (or x, 0) -> x, vector edition
3242 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3244 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3247 // fold (or x, -1) -> -1, vector edition
3248 if (ISD::isBuildVectorAllOnes(N0.getNode()))
3250 if (ISD::isBuildVectorAllOnes(N1.getNode()))
3253 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf A, B, Mask1)
3254 // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf B, A, Mask2)
3255 // Do this only if the resulting shuffle is legal.
3256 if (isa<ShuffleVectorSDNode>(N0) &&
3257 isa<ShuffleVectorSDNode>(N1) &&
3258 N0->getOperand(1) == N1->getOperand(1) &&
3259 ISD::isBuildVectorAllZeros(N0.getOperand(1).getNode())) {
3260 bool CanFold = true;
3261 unsigned NumElts = VT.getVectorNumElements();
3262 const ShuffleVectorSDNode *SV0 = cast<ShuffleVectorSDNode>(N0);
3263 const ShuffleVectorSDNode *SV1 = cast<ShuffleVectorSDNode>(N1);
3264 // We construct two shuffle masks:
3265 // - Mask1 is a shuffle mask for a shuffle with N0 as the first operand
3266 // and N1 as the second operand.
3267 // - Mask2 is a shuffle mask for a shuffle with N1 as the first operand
3268 // and N0 as the second operand.
3269 // We do this because OR is commutable and therefore there might be
3270 // two ways to fold this node into a shuffle.
3271 SmallVector<int,4> Mask1;
3272 SmallVector<int,4> Mask2;
3274 for (unsigned i = 0; i != NumElts && CanFold; ++i) {
3275 int M0 = SV0->getMaskElt(i);
3276 int M1 = SV1->getMaskElt(i);
3278 // Both shuffle indexes are undef. Propagate Undef.
3279 if (M0 < 0 && M1 < 0) {
3280 Mask1.push_back(M0);
3281 Mask2.push_back(M0);
3285 if (M0 < 0 || M1 < 0 ||
3286 (M0 < (int)NumElts && M1 < (int)NumElts) ||
3287 (M0 >= (int)NumElts && M1 >= (int)NumElts)) {
3292 Mask1.push_back(M0 < (int)NumElts ? M0 : M1 + NumElts);
3293 Mask2.push_back(M1 < (int)NumElts ? M1 : M0 + NumElts);
3297 // Fold this sequence only if the resulting shuffle is 'legal'.
3298 if (TLI.isShuffleMaskLegal(Mask1, VT))
3299 return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(0),
3300 N1->getOperand(0), &Mask1[0]);
3301 if (TLI.isShuffleMaskLegal(Mask2, VT))
3302 return DAG.getVectorShuffle(VT, SDLoc(N), N1->getOperand(0),
3303 N0->getOperand(0), &Mask2[0]);
3308 // fold (or x, undef) -> -1
3309 if (!LegalOperations &&
3310 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3311 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3312 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3314 // fold (or c1, c2) -> c1|c2
3316 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3317 // canonicalize constant to RHS
3319 return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
3320 // fold (or x, 0) -> x
3321 if (N1C && N1C->isNullValue())
3323 // fold (or x, -1) -> -1
3324 if (N1C && N1C->isAllOnesValue())
3326 // fold (or x, c) -> c iff (x & ~c) == 0
3327 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3330 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3331 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3332 if (BSwap.getNode())
3334 BSwap = MatchBSwapHWordLow(N, N0, N1);
3335 if (BSwap.getNode())
3339 SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1);
3342 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3343 // iff (c1 & c2) == 0.
3344 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3345 isa<ConstantSDNode>(N0.getOperand(1))) {
3346 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3347 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0) {
3348 SDValue COR = DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1);
3351 return DAG.getNode(ISD::AND, SDLoc(N), VT,
3352 DAG.getNode(ISD::OR, SDLoc(N0), VT,
3353 N0.getOperand(0), N1), COR);
3356 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3357 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3358 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3359 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3361 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3362 LL.getValueType().isInteger()) {
3363 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3364 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3365 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3366 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3367 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(LR),
3368 LR.getValueType(), LL, RL);
3369 AddToWorkList(ORNode.getNode());
3370 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
3372 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3373 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3374 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3375 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3376 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(LR),
3377 LR.getValueType(), LL, RL);
3378 AddToWorkList(ANDNode.getNode());
3379 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
3382 // canonicalize equivalent to ll == rl
3383 if (LL == RR && LR == RL) {
3384 Op1 = ISD::getSetCCSwappedOperands(Op1);
3387 if (LL == RL && LR == RR) {
3388 bool isInteger = LL.getValueType().isInteger();
3389 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3390 if (Result != ISD::SETCC_INVALID &&
3391 (!LegalOperations ||
3392 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
3393 TLI.isOperationLegal(ISD::SETCC,
3394 getSetCCResultType(N0.getValueType())))))
3395 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
3400 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3401 if (N0.getOpcode() == N1.getOpcode()) {
3402 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3403 if (Tmp.getNode()) return Tmp;
3406 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3407 if (N0.getOpcode() == ISD::AND &&
3408 N1.getOpcode() == ISD::AND &&
3409 N0.getOperand(1).getOpcode() == ISD::Constant &&
3410 N1.getOperand(1).getOpcode() == ISD::Constant &&
3411 // Don't increase # computations.
3412 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3413 // We can only do this xform if we know that bits from X that are set in C2
3414 // but not in C1 are already zero. Likewise for Y.
3415 const APInt &LHSMask =
3416 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3417 const APInt &RHSMask =
3418 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3420 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3421 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3422 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3423 N0.getOperand(0), N1.getOperand(0));
3424 return DAG.getNode(ISD::AND, SDLoc(N), VT, X,
3425 DAG.getConstant(LHSMask | RHSMask, VT));
3429 // See if this is some rotate idiom.
3430 if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
3431 return SDValue(Rot, 0);
3433 // Simplify the operands using demanded-bits information.
3434 if (!VT.isVector() &&
3435 SimplifyDemandedBits(SDValue(N, 0)))
3436 return SDValue(N, 0);
3441 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3442 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3443 if (Op.getOpcode() == ISD::AND) {
3444 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3445 Mask = Op.getOperand(1);
3446 Op = Op.getOperand(0);
3452 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3460 // Return true if we can prove that, whenever Neg and Pos are both in the
3461 // range [0, OpSize), Neg == (Pos == 0 ? 0 : OpSize - Pos). This means that
3462 // for two opposing shifts shift1 and shift2 and a value X with OpBits bits:
3464 // (or (shift1 X, Neg), (shift2 X, Pos))
3466 // reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate
3467 // in direction shift1 by Neg. The range [0, OpSize) means that we only need
3468 // to consider shift amounts with defined behavior.
3469 static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned OpSize) {
3470 // If OpSize is a power of 2 then:
3472 // (a) (Pos == 0 ? 0 : OpSize - Pos) == (OpSize - Pos) & (OpSize - 1)
3473 // (b) Neg == Neg & (OpSize - 1) whenever Neg is in [0, OpSize).
3475 // So if OpSize is a power of 2 and Neg is (and Neg', OpSize-1), we check
3476 // for the stronger condition:
3478 // Neg & (OpSize - 1) == (OpSize - Pos) & (OpSize - 1) [A]
3480 // for all Neg and Pos. Since Neg & (OpSize - 1) == Neg' & (OpSize - 1)
3481 // we can just replace Neg with Neg' for the rest of the function.
3483 // In other cases we check for the even stronger condition:
3485 // Neg == OpSize - Pos [B]
3487 // for all Neg and Pos. Note that the (or ...) then invokes undefined
3488 // behavior if Pos == 0 (and consequently Neg == OpSize).
3490 // We could actually use [A] whenever OpSize is a power of 2, but the
3491 // only extra cases that it would match are those uninteresting ones
3492 // where Neg and Pos are never in range at the same time. E.g. for
3493 // OpSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
3494 // as well as (sub 32, Pos), but:
3496 // (or (shift1 X, (sub 64, Pos)), (shift2 X, Pos))
3498 // always invokes undefined behavior for 32-bit X.
3500 // Below, Mask == OpSize - 1 when using [A] and is all-ones otherwise.
3501 unsigned MaskLoBits = 0;
3502 if (Neg.getOpcode() == ISD::AND &&
3503 isPowerOf2_64(OpSize) &&
3504 Neg.getOperand(1).getOpcode() == ISD::Constant &&
3505 cast<ConstantSDNode>(Neg.getOperand(1))->getAPIntValue() == OpSize - 1) {
3506 Neg = Neg.getOperand(0);
3507 MaskLoBits = Log2_64(OpSize);
3510 // Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
3511 if (Neg.getOpcode() != ISD::SUB)
3513 ConstantSDNode *NegC = dyn_cast<ConstantSDNode>(Neg.getOperand(0));
3516 SDValue NegOp1 = Neg.getOperand(1);
3518 // On the RHS of [A], if Pos is Pos' & (OpSize - 1), just replace Pos with
3519 // Pos'. The truncation is redundant for the purpose of the equality.
3521 Pos.getOpcode() == ISD::AND &&
3522 Pos.getOperand(1).getOpcode() == ISD::Constant &&
3523 cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() == OpSize - 1)
3524 Pos = Pos.getOperand(0);
3526 // The condition we need is now:
3528 // (NegC - NegOp1) & Mask == (OpSize - Pos) & Mask
3530 // If NegOp1 == Pos then we need:
3532 // OpSize & Mask == NegC & Mask
3534 // (because "x & Mask" is a truncation and distributes through subtraction).
3537 Width = NegC->getAPIntValue();
3538 // Check for cases where Pos has the form (add NegOp1, PosC) for some PosC.
3539 // Then the condition we want to prove becomes:
3541 // (NegC - NegOp1) & Mask == (OpSize - (NegOp1 + PosC)) & Mask
3543 // which, again because "x & Mask" is a truncation, becomes:
3545 // NegC & Mask == (OpSize - PosC) & Mask
3546 // OpSize & Mask == (NegC + PosC) & Mask
3547 else if (Pos.getOpcode() == ISD::ADD &&
3548 Pos.getOperand(0) == NegOp1 &&
3549 Pos.getOperand(1).getOpcode() == ISD::Constant)
3550 Width = (cast<ConstantSDNode>(Pos.getOperand(1))->getAPIntValue() +
3551 NegC->getAPIntValue());
3555 // Now we just need to check that OpSize & Mask == Width & Mask.
3557 // Opsize & Mask is 0 since Mask is Opsize - 1.
3558 return Width.getLoBits(MaskLoBits) == 0;
3559 return Width == OpSize;
3562 // A subroutine of MatchRotate used once we have found an OR of two opposite
3563 // shifts of Shifted. If Neg == <operand size> - Pos then the OR reduces
3564 // to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
3565 // former being preferred if supported. InnerPos and InnerNeg are Pos and
3566 // Neg with outer conversions stripped away.
3567 SDNode *DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
3568 SDValue Neg, SDValue InnerPos,
3569 SDValue InnerNeg, unsigned PosOpcode,
3570 unsigned NegOpcode, SDLoc DL) {
3571 // fold (or (shl x, (*ext y)),
3572 // (srl x, (*ext (sub 32, y)))) ->
3573 // (rotl x, y) or (rotr x, (sub 32, y))
3575 // fold (or (shl x, (*ext (sub 32, y))),
3576 // (srl x, (*ext y))) ->
3577 // (rotr x, y) or (rotl x, (sub 32, y))
3578 EVT VT = Shifted.getValueType();
3579 if (matchRotateSub(InnerPos, InnerNeg, VT.getSizeInBits())) {
3580 bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
3581 return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
3582 HasPos ? Pos : Neg).getNode();
3588 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3589 // idioms for rotate, and if the target supports rotation instructions, generate
3591 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL) {
3592 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3593 EVT VT = LHS.getValueType();
3594 if (!TLI.isTypeLegal(VT)) return nullptr;
3596 // The target must have at least one rotate flavor.
3597 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3598 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3599 if (!HasROTL && !HasROTR) return nullptr;
3601 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3602 SDValue LHSShift; // The shift.
3603 SDValue LHSMask; // AND value if any.
3604 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3605 return nullptr; // Not part of a rotate.
3607 SDValue RHSShift; // The shift.
3608 SDValue RHSMask; // AND value if any.
3609 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3610 return nullptr; // Not part of a rotate.
3612 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3613 return nullptr; // Not shifting the same value.
3615 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3616 return nullptr; // Shifts must disagree.
3618 // Canonicalize shl to left side in a shl/srl pair.
3619 if (RHSShift.getOpcode() == ISD::SHL) {
3620 std::swap(LHS, RHS);
3621 std::swap(LHSShift, RHSShift);
3622 std::swap(LHSMask , RHSMask );
3625 unsigned OpSizeInBits = VT.getSizeInBits();
3626 SDValue LHSShiftArg = LHSShift.getOperand(0);
3627 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3628 SDValue RHSShiftArg = RHSShift.getOperand(0);
3629 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3631 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3632 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3633 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3634 RHSShiftAmt.getOpcode() == ISD::Constant) {
3635 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3636 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3637 if ((LShVal + RShVal) != OpSizeInBits)
3640 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3641 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3643 // If there is an AND of either shifted operand, apply it to the result.
3644 if (LHSMask.getNode() || RHSMask.getNode()) {
3645 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3647 if (LHSMask.getNode()) {
3648 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3649 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3651 if (RHSMask.getNode()) {
3652 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3653 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3656 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3659 return Rot.getNode();
3662 // If there is a mask here, and we have a variable shift, we can't be sure
3663 // that we're masking out the right stuff.
3664 if (LHSMask.getNode() || RHSMask.getNode())
3667 // If the shift amount is sign/zext/any-extended just peel it off.
3668 SDValue LExtOp0 = LHSShiftAmt;
3669 SDValue RExtOp0 = RHSShiftAmt;
3670 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3671 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3672 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3673 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3674 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3675 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3676 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3677 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3678 LExtOp0 = LHSShiftAmt.getOperand(0);
3679 RExtOp0 = RHSShiftAmt.getOperand(0);
3682 SDNode *TryL = MatchRotatePosNeg(LHSShiftArg, LHSShiftAmt, RHSShiftAmt,
3683 LExtOp0, RExtOp0, ISD::ROTL, ISD::ROTR, DL);
3687 SDNode *TryR = MatchRotatePosNeg(RHSShiftArg, RHSShiftAmt, LHSShiftAmt,
3688 RExtOp0, LExtOp0, ISD::ROTR, ISD::ROTL, DL);
3695 SDValue DAGCombiner::visitXOR(SDNode *N) {
3696 SDValue N0 = N->getOperand(0);
3697 SDValue N1 = N->getOperand(1);
3698 SDValue LHS, RHS, CC;
3699 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3700 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3701 EVT VT = N0.getValueType();
3704 if (VT.isVector()) {
3705 SDValue FoldedVOp = SimplifyVBinOp(N);
3706 if (FoldedVOp.getNode()) return FoldedVOp;
3708 // fold (xor x, 0) -> x, vector edition
3709 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3711 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3715 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3716 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3717 return DAG.getConstant(0, VT);
3718 // fold (xor x, undef) -> undef
3719 if (N0.getOpcode() == ISD::UNDEF)
3721 if (N1.getOpcode() == ISD::UNDEF)
3723 // fold (xor c1, c2) -> c1^c2
3725 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3726 // canonicalize constant to RHS
3728 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
3729 // fold (xor x, 0) -> x
3730 if (N1C && N1C->isNullValue())
3733 SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1);
3737 // fold !(x cc y) -> (x !cc y)
3738 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3739 bool isInt = LHS.getValueType().isInteger();
3740 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3743 if (!LegalOperations ||
3744 TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
3745 switch (N0.getOpcode()) {
3747 llvm_unreachable("Unhandled SetCC Equivalent!");
3749 return DAG.getSetCC(SDLoc(N), VT, LHS, RHS, NotCC);
3750 case ISD::SELECT_CC:
3751 return DAG.getSelectCC(SDLoc(N), LHS, RHS, N0.getOperand(2),
3752 N0.getOperand(3), NotCC);
3757 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3758 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3759 N0.getNode()->hasOneUse() &&
3760 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3761 SDValue V = N0.getOperand(0);
3762 V = DAG.getNode(ISD::XOR, SDLoc(N0), V.getValueType(), V,
3763 DAG.getConstant(1, V.getValueType()));
3764 AddToWorkList(V.getNode());
3765 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
3768 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3769 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3770 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3771 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3772 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3773 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3774 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3775 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3776 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3777 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3780 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3781 if (N1C && N1C->isAllOnesValue() &&
3782 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3783 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3784 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3785 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3786 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3787 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3788 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3789 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3792 // fold (xor (and x, y), y) -> (and (not x), y)
3793 if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3794 N0->getOperand(1) == N1) {
3795 SDValue X = N0->getOperand(0);
3796 SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
3797 AddToWorkList(NotX.getNode());
3798 return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
3800 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3801 if (N1C && N0.getOpcode() == ISD::XOR) {
3802 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3803 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3805 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(1),
3806 DAG.getConstant(N1C->getAPIntValue() ^
3807 N00C->getAPIntValue(), VT));
3809 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(0),
3810 DAG.getConstant(N1C->getAPIntValue() ^
3811 N01C->getAPIntValue(), VT));
3813 // fold (xor x, x) -> 0
3815 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
3817 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3818 if (N0.getOpcode() == N1.getOpcode()) {
3819 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3820 if (Tmp.getNode()) return Tmp;
3823 // Simplify the expression using non-local knowledge.
3824 if (!VT.isVector() &&
3825 SimplifyDemandedBits(SDValue(N, 0)))
3826 return SDValue(N, 0);
3831 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3832 /// the shift amount is a constant.
3833 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, ConstantSDNode *Amt) {
3834 // We can't and shouldn't fold opaque constants.
3835 if (Amt->isOpaque())
3838 SDNode *LHS = N->getOperand(0).getNode();
3839 if (!LHS->hasOneUse()) return SDValue();
3841 // We want to pull some binops through shifts, so that we have (and (shift))
3842 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3843 // thing happens with address calculations, so it's important to canonicalize
3845 bool HighBitSet = false; // Can we transform this if the high bit is set?
3847 switch (LHS->getOpcode()) {
3848 default: return SDValue();
3851 HighBitSet = false; // We can only transform sra if the high bit is clear.
3854 HighBitSet = true; // We can only transform sra if the high bit is set.
3857 if (N->getOpcode() != ISD::SHL)
3858 return SDValue(); // only shl(add) not sr[al](add).
3859 HighBitSet = false; // We can only transform sra if the high bit is clear.
3863 // We require the RHS of the binop to be a constant and not opaque as well.
3864 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3865 if (!BinOpCst || BinOpCst->isOpaque()) return SDValue();
3867 // FIXME: disable this unless the input to the binop is a shift by a constant.
3868 // If it is not a shift, it pessimizes some common cases like:
3870 // void foo(int *X, int i) { X[i & 1235] = 1; }
3871 // int bar(int *X, int i) { return X[i & 255]; }
3872 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3873 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3874 BinOpLHSVal->getOpcode() != ISD::SRA &&
3875 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3876 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3879 EVT VT = N->getValueType(0);
3881 // If this is a signed shift right, and the high bit is modified by the
3882 // logical operation, do not perform the transformation. The highBitSet
3883 // boolean indicates the value of the high bit of the constant which would
3884 // cause it to be modified for this operation.
3885 if (N->getOpcode() == ISD::SRA) {
3886 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3887 if (BinOpRHSSignSet != HighBitSet)
3891 if (!TLI.isDesirableToCommuteWithShift(LHS))
3894 // Fold the constants, shifting the binop RHS by the shift amount.
3895 SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
3897 LHS->getOperand(1), N->getOperand(1));
3898 assert(isa<ConstantSDNode>(NewRHS) && "Folding was not successful!");
3900 // Create the new shift.
3901 SDValue NewShift = DAG.getNode(N->getOpcode(),
3902 SDLoc(LHS->getOperand(0)),
3903 VT, LHS->getOperand(0), N->getOperand(1));
3905 // Create the new binop.
3906 return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
3909 SDValue DAGCombiner::distributeTruncateThroughAnd(SDNode *N) {
3910 assert(N->getOpcode() == ISD::TRUNCATE);
3911 assert(N->getOperand(0).getOpcode() == ISD::AND);
3913 // (truncate:TruncVT (and N00, N01C)) -> (and (truncate:TruncVT N00), TruncC)
3914 if (N->hasOneUse() && N->getOperand(0).hasOneUse()) {
3915 SDValue N01 = N->getOperand(0).getOperand(1);
3917 if (ConstantSDNode *N01C = isConstOrConstSplat(N01)) {
3918 EVT TruncVT = N->getValueType(0);
3919 SDValue N00 = N->getOperand(0).getOperand(0);
3920 APInt TruncC = N01C->getAPIntValue();
3921 TruncC = TruncC.trunc(TruncVT.getScalarSizeInBits());
3923 return DAG.getNode(ISD::AND, SDLoc(N), TruncVT,
3924 DAG.getNode(ISD::TRUNCATE, SDLoc(N), TruncVT, N00),
3925 DAG.getConstant(TruncC, TruncVT));
3932 SDValue DAGCombiner::visitRotate(SDNode *N) {
3933 // fold (rot* x, (trunc (and y, c))) -> (rot* x, (and (trunc y), (trunc c))).
3934 if (N->getOperand(1).getOpcode() == ISD::TRUNCATE &&
3935 N->getOperand(1).getOperand(0).getOpcode() == ISD::AND) {
3936 SDValue NewOp1 = distributeTruncateThroughAnd(N->getOperand(1).getNode());
3937 if (NewOp1.getNode())
3938 return DAG.getNode(N->getOpcode(), SDLoc(N), N->getValueType(0),
3939 N->getOperand(0), NewOp1);
3944 SDValue DAGCombiner::visitSHL(SDNode *N) {
3945 SDValue N0 = N->getOperand(0);
3946 SDValue N1 = N->getOperand(1);
3947 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3948 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3949 EVT VT = N0.getValueType();
3950 unsigned OpSizeInBits = VT.getScalarSizeInBits();
3953 if (VT.isVector()) {
3954 SDValue FoldedVOp = SimplifyVBinOp(N);
3955 if (FoldedVOp.getNode()) return FoldedVOp;
3957 BuildVectorSDNode *N1CV = dyn_cast<BuildVectorSDNode>(N1);
3958 // If setcc produces all-one true value then:
3959 // (shl (and (setcc) N01CV) N1CV) -> (and (setcc) N01CV<<N1CV)
3960 if (N1CV && N1CV->isConstant()) {
3961 if (N0.getOpcode() == ISD::AND &&
3962 TLI.getBooleanContents(true) ==
3963 TargetLowering::ZeroOrNegativeOneBooleanContent) {
3964 SDValue N00 = N0->getOperand(0);
3965 SDValue N01 = N0->getOperand(1);
3966 BuildVectorSDNode *N01CV = dyn_cast<BuildVectorSDNode>(N01);
3968 if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC) {
3969 SDValue C = DAG.FoldConstantArithmetic(ISD::SHL, VT, N01CV, N1CV);
3971 return DAG.getNode(ISD::AND, SDLoc(N), VT, N00, C);
3974 N1C = isConstOrConstSplat(N1);
3979 // fold (shl c1, c2) -> c1<<c2
3981 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3982 // fold (shl 0, x) -> 0
3983 if (N0C && N0C->isNullValue())
3985 // fold (shl x, c >= size(x)) -> undef
3986 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3987 return DAG.getUNDEF(VT);
3988 // fold (shl x, 0) -> x
3989 if (N1C && N1C->isNullValue())
3991 // fold (shl undef, x) -> 0
3992 if (N0.getOpcode() == ISD::UNDEF)
3993 return DAG.getConstant(0, VT);
3994 // if (shl x, c) is known to be zero, return 0
3995 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3996 APInt::getAllOnesValue(OpSizeInBits)))
3997 return DAG.getConstant(0, VT);
3998 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3999 if (N1.getOpcode() == ISD::TRUNCATE &&
4000 N1.getOperand(0).getOpcode() == ISD::AND) {
4001 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4002 if (NewOp1.getNode())
4003 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0, NewOp1);
4006 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4007 return SDValue(N, 0);
4009 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
4010 if (N1C && N0.getOpcode() == ISD::SHL) {
4011 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4012 uint64_t c1 = N0C1->getZExtValue();
4013 uint64_t c2 = N1C->getZExtValue();
4014 if (c1 + c2 >= OpSizeInBits)
4015 return DAG.getConstant(0, VT);
4016 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
4017 DAG.getConstant(c1 + c2, N1.getValueType()));
4021 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
4022 // For this to be valid, the second form must not preserve any of the bits
4023 // that are shifted out by the inner shift in the first form. This means
4024 // the outer shift size must be >= the number of bits added by the ext.
4025 // As a corollary, we don't care what kind of ext it is.
4026 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
4027 N0.getOpcode() == ISD::ANY_EXTEND ||
4028 N0.getOpcode() == ISD::SIGN_EXTEND) &&
4029 N0.getOperand(0).getOpcode() == ISD::SHL) {
4030 SDValue N0Op0 = N0.getOperand(0);
4031 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4032 uint64_t c1 = N0Op0C1->getZExtValue();
4033 uint64_t c2 = N1C->getZExtValue();
4034 EVT InnerShiftVT = N0Op0.getValueType();
4035 uint64_t InnerShiftSize = InnerShiftVT.getScalarSizeInBits();
4036 if (c2 >= OpSizeInBits - InnerShiftSize) {
4037 if (c1 + c2 >= OpSizeInBits)
4038 return DAG.getConstant(0, VT);
4039 return DAG.getNode(ISD::SHL, SDLoc(N0), VT,
4040 DAG.getNode(N0.getOpcode(), SDLoc(N0), VT,
4041 N0Op0->getOperand(0)),
4042 DAG.getConstant(c1 + c2, N1.getValueType()));
4047 // fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C))
4048 // Only fold this if the inner zext has no other uses to avoid increasing
4049 // the total number of instructions.
4050 if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() &&
4051 N0.getOperand(0).getOpcode() == ISD::SRL) {
4052 SDValue N0Op0 = N0.getOperand(0);
4053 if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
4054 uint64_t c1 = N0Op0C1->getZExtValue();
4055 if (c1 < VT.getScalarSizeInBits()) {
4056 uint64_t c2 = N1C->getZExtValue();
4058 SDValue NewOp0 = N0.getOperand(0);
4059 EVT CountVT = NewOp0.getOperand(1).getValueType();
4060 SDValue NewSHL = DAG.getNode(ISD::SHL, SDLoc(N), NewOp0.getValueType(),
4061 NewOp0, DAG.getConstant(c2, CountVT));
4062 AddToWorkList(NewSHL.getNode());
4063 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL);
4069 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
4070 // (and (srl x, (sub c1, c2), MASK)
4071 // Only fold this if the inner shift has no other uses -- if it does, folding
4072 // this will increase the total number of instructions.
4073 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
4074 if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
4075 uint64_t c1 = N0C1->getZExtValue();
4076 if (c1 < OpSizeInBits) {
4077 uint64_t c2 = N1C->getZExtValue();
4078 APInt Mask = APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - c1);
4081 Mask = Mask.shl(c2 - c1);
4082 Shift = DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
4083 DAG.getConstant(c2 - c1, N1.getValueType()));
4085 Mask = Mask.lshr(c1 - c2);
4086 Shift = DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
4087 DAG.getConstant(c1 - c2, N1.getValueType()));
4089 return DAG.getNode(ISD::AND, SDLoc(N0), VT, Shift,
4090 DAG.getConstant(Mask, VT));
4094 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
4095 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
4096 unsigned BitSize = VT.getScalarSizeInBits();
4097 SDValue HiBitsMask =
4098 DAG.getConstant(APInt::getHighBitsSet(BitSize,
4099 BitSize - N1C->getZExtValue()), VT);
4100 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
4105 SDValue NewSHL = visitShiftByConstant(N, N1C);
4106 if (NewSHL.getNode())
4113 SDValue DAGCombiner::visitSRA(SDNode *N) {
4114 SDValue N0 = N->getOperand(0);
4115 SDValue N1 = N->getOperand(1);
4116 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4117 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4118 EVT VT = N0.getValueType();
4119 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4122 if (VT.isVector()) {
4123 SDValue FoldedVOp = SimplifyVBinOp(N);
4124 if (FoldedVOp.getNode()) return FoldedVOp;
4126 N1C = isConstOrConstSplat(N1);
4129 // fold (sra c1, c2) -> (sra c1, c2)
4131 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
4132 // fold (sra 0, x) -> 0
4133 if (N0C && N0C->isNullValue())
4135 // fold (sra -1, x) -> -1
4136 if (N0C && N0C->isAllOnesValue())
4138 // fold (sra x, (setge c, size(x))) -> undef
4139 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4140 return DAG.getUNDEF(VT);
4141 // fold (sra x, 0) -> x
4142 if (N1C && N1C->isNullValue())
4144 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
4146 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
4147 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
4148 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
4150 ExtVT = EVT::getVectorVT(*DAG.getContext(),
4151 ExtVT, VT.getVectorNumElements());
4152 if ((!LegalOperations ||
4153 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
4154 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
4155 N0.getOperand(0), DAG.getValueType(ExtVT));
4158 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
4159 if (N1C && N0.getOpcode() == ISD::SRA) {
4160 if (ConstantSDNode *C1 = isConstOrConstSplat(N0.getOperand(1))) {
4161 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
4162 if (Sum >= OpSizeInBits)
4163 Sum = OpSizeInBits - 1;
4164 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0.getOperand(0),
4165 DAG.getConstant(Sum, N1.getValueType()));
4169 // fold (sra (shl X, m), (sub result_size, n))
4170 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
4171 // result_size - n != m.
4172 // If truncate is free for the target sext(shl) is likely to result in better
4174 if (N0.getOpcode() == ISD::SHL && N1C) {
4175 // Get the two constanst of the shifts, CN0 = m, CN = n.
4176 const ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1));
4178 LLVMContext &Ctx = *DAG.getContext();
4179 // Determine what the truncate's result bitsize and type would be.
4180 EVT TruncVT = EVT::getIntegerVT(Ctx, OpSizeInBits - N1C->getZExtValue());
4183 TruncVT = EVT::getVectorVT(Ctx, TruncVT, VT.getVectorNumElements());
4185 // Determine the residual right-shift amount.
4186 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
4188 // If the shift is not a no-op (in which case this should be just a sign
4189 // extend already), the truncated to type is legal, sign_extend is legal
4190 // on that type, and the truncate to that type is both legal and free,
4191 // perform the transform.
4192 if ((ShiftAmt > 0) &&
4193 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
4194 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
4195 TLI.isTruncateFree(VT, TruncVT)) {
4197 SDValue Amt = DAG.getConstant(ShiftAmt,
4198 getShiftAmountTy(N0.getOperand(0).getValueType()));
4199 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0), VT,
4200 N0.getOperand(0), Amt);
4201 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), TruncVT,
4203 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N),
4204 N->getValueType(0), Trunc);
4209 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
4210 if (N1.getOpcode() == ISD::TRUNCATE &&
4211 N1.getOperand(0).getOpcode() == ISD::AND) {
4212 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4213 if (NewOp1.getNode())
4214 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0, NewOp1);
4217 // fold (sra (trunc (srl x, c1)), c2) -> (trunc (sra x, c1 + c2))
4218 // if c1 is equal to the number of bits the trunc removes
4219 if (N0.getOpcode() == ISD::TRUNCATE &&
4220 (N0.getOperand(0).getOpcode() == ISD::SRL ||
4221 N0.getOperand(0).getOpcode() == ISD::SRA) &&
4222 N0.getOperand(0).hasOneUse() &&
4223 N0.getOperand(0).getOperand(1).hasOneUse() &&
4225 SDValue N0Op0 = N0.getOperand(0);
4226 if (ConstantSDNode *LargeShift = isConstOrConstSplat(N0Op0.getOperand(1))) {
4227 unsigned LargeShiftVal = LargeShift->getZExtValue();
4228 EVT LargeVT = N0Op0.getValueType();
4230 if (LargeVT.getScalarSizeInBits() - OpSizeInBits == LargeShiftVal) {
4232 DAG.getConstant(LargeShiftVal + N1C->getZExtValue(),
4233 getShiftAmountTy(N0Op0.getOperand(0).getValueType()));
4234 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), LargeVT,
4235 N0Op0.getOperand(0), Amt);
4236 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, SRA);
4241 // Simplify, based on bits shifted out of the LHS.
4242 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4243 return SDValue(N, 0);
4246 // If the sign bit is known to be zero, switch this to a SRL.
4247 if (DAG.SignBitIsZero(N0))
4248 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);
4251 SDValue NewSRA = visitShiftByConstant(N, N1C);
4252 if (NewSRA.getNode())
4259 SDValue DAGCombiner::visitSRL(SDNode *N) {
4260 SDValue N0 = N->getOperand(0);
4261 SDValue N1 = N->getOperand(1);
4262 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4263 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4264 EVT VT = N0.getValueType();
4265 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
4268 if (VT.isVector()) {
4269 SDValue FoldedVOp = SimplifyVBinOp(N);
4270 if (FoldedVOp.getNode()) return FoldedVOp;
4272 N1C = isConstOrConstSplat(N1);
4275 // fold (srl c1, c2) -> c1 >>u c2
4277 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
4278 // fold (srl 0, x) -> 0
4279 if (N0C && N0C->isNullValue())
4281 // fold (srl x, c >= size(x)) -> undef
4282 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
4283 return DAG.getUNDEF(VT);
4284 // fold (srl x, 0) -> x
4285 if (N1C && N1C->isNullValue())
4287 // if (srl x, c) is known to be zero, return 0
4288 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
4289 APInt::getAllOnesValue(OpSizeInBits)))
4290 return DAG.getConstant(0, VT);
4292 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
4293 if (N1C && N0.getOpcode() == ISD::SRL) {
4294 if (ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1))) {
4295 uint64_t c1 = N01C->getZExtValue();
4296 uint64_t c2 = N1C->getZExtValue();
4297 if (c1 + c2 >= OpSizeInBits)
4298 return DAG.getConstant(0, VT);
4299 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
4300 DAG.getConstant(c1 + c2, N1.getValueType()));
4304 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
4305 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
4306 N0.getOperand(0).getOpcode() == ISD::SRL &&
4307 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
4309 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
4310 uint64_t c2 = N1C->getZExtValue();
4311 EVT InnerShiftVT = N0.getOperand(0).getValueType();
4312 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
4313 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
4314 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
4315 if (c1 + OpSizeInBits == InnerShiftSize) {
4316 if (c1 + c2 >= InnerShiftSize)
4317 return DAG.getConstant(0, VT);
4318 return DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT,
4319 DAG.getNode(ISD::SRL, SDLoc(N0), InnerShiftVT,
4320 N0.getOperand(0)->getOperand(0),
4321 DAG.getConstant(c1 + c2, ShiftCountVT)));
4325 // fold (srl (shl x, c), c) -> (and x, cst2)
4326 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1) {
4327 unsigned BitSize = N0.getScalarValueSizeInBits();
4328 if (BitSize <= 64) {
4329 uint64_t ShAmt = N1C->getZExtValue() + 64 - BitSize;
4330 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
4331 DAG.getConstant(~0ULL >> ShAmt, VT));
4335 // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
4336 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
4337 // Shifting in all undef bits?
4338 EVT SmallVT = N0.getOperand(0).getValueType();
4339 unsigned BitSize = SmallVT.getScalarSizeInBits();
4340 if (N1C->getZExtValue() >= BitSize)
4341 return DAG.getUNDEF(VT);
4343 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
4344 uint64_t ShiftAmt = N1C->getZExtValue();
4345 SDValue SmallShift = DAG.getNode(ISD::SRL, SDLoc(N0), SmallVT,
4347 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
4348 AddToWorkList(SmallShift.getNode());
4349 APInt Mask = APInt::getAllOnesValue(OpSizeInBits).lshr(ShiftAmt);
4350 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4351 DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, SmallShift),
4352 DAG.getConstant(Mask, VT));
4356 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
4357 // bit, which is unmodified by sra.
4358 if (N1C && N1C->getZExtValue() + 1 == OpSizeInBits) {
4359 if (N0.getOpcode() == ISD::SRA)
4360 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
4363 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
4364 if (N1C && N0.getOpcode() == ISD::CTLZ &&
4365 N1C->getAPIntValue() == Log2_32(OpSizeInBits)) {
4366 APInt KnownZero, KnownOne;
4367 DAG.computeKnownBits(N0.getOperand(0), KnownZero, KnownOne);
4369 // If any of the input bits are KnownOne, then the input couldn't be all
4370 // zeros, thus the result of the srl will always be zero.
4371 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
4373 // If all of the bits input the to ctlz node are known to be zero, then
4374 // the result of the ctlz is "32" and the result of the shift is one.
4375 APInt UnknownBits = ~KnownZero;
4376 if (UnknownBits == 0) return DAG.getConstant(1, VT);
4378 // Otherwise, check to see if there is exactly one bit input to the ctlz.
4379 if ((UnknownBits & (UnknownBits - 1)) == 0) {
4380 // Okay, we know that only that the single bit specified by UnknownBits
4381 // could be set on input to the CTLZ node. If this bit is set, the SRL
4382 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
4383 // to an SRL/XOR pair, which is likely to simplify more.
4384 unsigned ShAmt = UnknownBits.countTrailingZeros();
4385 SDValue Op = N0.getOperand(0);
4388 Op = DAG.getNode(ISD::SRL, SDLoc(N0), VT, Op,
4389 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
4390 AddToWorkList(Op.getNode());
4393 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
4394 Op, DAG.getConstant(1, VT));
4398 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
4399 if (N1.getOpcode() == ISD::TRUNCATE &&
4400 N1.getOperand(0).getOpcode() == ISD::AND) {
4401 SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode());
4402 if (NewOp1.getNode())
4403 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, NewOp1);
4406 // fold operands of srl based on knowledge that the low bits are not
4408 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4409 return SDValue(N, 0);
4412 SDValue NewSRL = visitShiftByConstant(N, N1C);
4413 if (NewSRL.getNode())
4417 // Attempt to convert a srl of a load into a narrower zero-extending load.
4418 SDValue NarrowLoad = ReduceLoadWidth(N);
4419 if (NarrowLoad.getNode())
4422 // Here is a common situation. We want to optimize:
4425 // %b = and i32 %a, 2
4426 // %c = srl i32 %b, 1
4427 // brcond i32 %c ...
4433 // %c = setcc eq %b, 0
4436 // However when after the source operand of SRL is optimized into AND, the SRL
4437 // itself may not be optimized further. Look for it and add the BRCOND into
4439 if (N->hasOneUse()) {
4440 SDNode *Use = *N->use_begin();
4441 if (Use->getOpcode() == ISD::BRCOND)
4443 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
4444 // Also look pass the truncate.
4445 Use = *Use->use_begin();
4446 if (Use->getOpcode() == ISD::BRCOND)
4454 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
4455 SDValue N0 = N->getOperand(0);
4456 EVT VT = N->getValueType(0);
4458 // fold (ctlz c1) -> c2
4459 if (isa<ConstantSDNode>(N0))
4460 return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);
4464 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
4465 SDValue N0 = N->getOperand(0);
4466 EVT VT = N->getValueType(0);
4468 // fold (ctlz_zero_undef c1) -> c2
4469 if (isa<ConstantSDNode>(N0))
4470 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4474 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4475 SDValue N0 = N->getOperand(0);
4476 EVT VT = N->getValueType(0);
4478 // fold (cttz c1) -> c2
4479 if (isa<ConstantSDNode>(N0))
4480 return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);
4484 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4485 SDValue N0 = N->getOperand(0);
4486 EVT VT = N->getValueType(0);
4488 // fold (cttz_zero_undef c1) -> c2
4489 if (isa<ConstantSDNode>(N0))
4490 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4494 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4495 SDValue N0 = N->getOperand(0);
4496 EVT VT = N->getValueType(0);
4498 // fold (ctpop c1) -> c2
4499 if (isa<ConstantSDNode>(N0))
4500 return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
4504 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4505 SDValue N0 = N->getOperand(0);
4506 SDValue N1 = N->getOperand(1);
4507 SDValue N2 = N->getOperand(2);
4508 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4509 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4510 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4511 EVT VT = N->getValueType(0);
4512 EVT VT0 = N0.getValueType();
4514 // fold (select C, X, X) -> X
4517 // fold (select true, X, Y) -> X
4518 if (N0C && !N0C->isNullValue())
4520 // fold (select false, X, Y) -> Y
4521 if (N0C && N0C->isNullValue())
4523 // fold (select C, 1, X) -> (or C, X)
4524 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4525 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4526 // fold (select C, 0, 1) -> (xor C, 1)
4527 if (VT.isInteger() &&
4530 TLI.getBooleanContents(false) ==
4531 TargetLowering::ZeroOrOneBooleanContent)) &&
4532 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4535 return DAG.getNode(ISD::XOR, SDLoc(N), VT0,
4536 N0, DAG.getConstant(1, VT0));
4537 XORNode = DAG.getNode(ISD::XOR, SDLoc(N0), VT0,
4538 N0, DAG.getConstant(1, VT0));
4539 AddToWorkList(XORNode.getNode());
4541 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, XORNode);
4542 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, XORNode);
4544 // fold (select C, 0, X) -> (and (not C), X)
4545 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4546 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4547 AddToWorkList(NOTNode.getNode());
4548 return DAG.getNode(ISD::AND, SDLoc(N), VT, NOTNode, N2);
4550 // fold (select C, X, 1) -> (or (not C), X)
4551 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4552 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4553 AddToWorkList(NOTNode.getNode());
4554 return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
4556 // fold (select C, X, 0) -> (and C, X)
4557 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4558 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4559 // fold (select X, X, Y) -> (or X, Y)
4560 // fold (select X, 1, Y) -> (or X, Y)
4561 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4562 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4563 // fold (select X, Y, X) -> (and X, Y)
4564 // fold (select X, Y, 0) -> (and X, Y)
4565 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4566 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4568 // If we can fold this based on the true/false value, do so.
4569 if (SimplifySelectOps(N, N1, N2))
4570 return SDValue(N, 0); // Don't revisit N.
4572 // fold selects based on a setcc into other things, such as min/max/abs
4573 if (N0.getOpcode() == ISD::SETCC) {
4574 if ((!LegalOperations &&
4575 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT)) ||
4576 TLI.isOperationLegal(ISD::SELECT_CC, VT))
4577 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
4578 N0.getOperand(0), N0.getOperand(1),
4579 N1, N2, N0.getOperand(2));
4580 return SimplifySelect(SDLoc(N), N0, N1, N2);
4587 std::pair<SDValue, SDValue> SplitVSETCC(const SDNode *N, SelectionDAG &DAG) {
4590 std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
4592 // Split the inputs.
4593 SDValue Lo, Hi, LL, LH, RL, RH;
4594 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 0);
4595 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 1);
4597 Lo = DAG.getNode(N->getOpcode(), DL, LoVT, LL, RL, N->getOperand(2));
4598 Hi = DAG.getNode(N->getOpcode(), DL, HiVT, LH, RH, N->getOperand(2));
4600 return std::make_pair(Lo, Hi);
4603 // This function assumes all the vselect's arguments are CONCAT_VECTOR
4604 // nodes and that the condition is a BV of ConstantSDNodes (or undefs).
4605 static SDValue ConvertSelectToConcatVector(SDNode *N, SelectionDAG &DAG) {
4607 SDValue Cond = N->getOperand(0);
4608 SDValue LHS = N->getOperand(1);
4609 SDValue RHS = N->getOperand(2);
4610 MVT VT = N->getSimpleValueType(0);
4611 int NumElems = VT.getVectorNumElements();
4612 assert(LHS.getOpcode() == ISD::CONCAT_VECTORS &&
4613 RHS.getOpcode() == ISD::CONCAT_VECTORS &&
4614 Cond.getOpcode() == ISD::BUILD_VECTOR);
4616 // We're sure we have an even number of elements due to the
4617 // concat_vectors we have as arguments to vselect.
4618 // Skip BV elements until we find one that's not an UNDEF
4619 // After we find an UNDEF element, keep looping until we get to half the
4620 // length of the BV and see if all the non-undef nodes are the same.
4621 ConstantSDNode *BottomHalf = nullptr;
4622 for (int i = 0; i < NumElems / 2; ++i) {
4623 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
4626 if (BottomHalf == nullptr)
4627 BottomHalf = cast<ConstantSDNode>(Cond.getOperand(i));
4628 else if (Cond->getOperand(i).getNode() != BottomHalf)
4632 // Do the same for the second half of the BuildVector
4633 ConstantSDNode *TopHalf = nullptr;
4634 for (int i = NumElems / 2; i < NumElems; ++i) {
4635 if (Cond->getOperand(i)->getOpcode() == ISD::UNDEF)
4638 if (TopHalf == nullptr)
4639 TopHalf = cast<ConstantSDNode>(Cond.getOperand(i));
4640 else if (Cond->getOperand(i).getNode() != TopHalf)
4644 assert(TopHalf && BottomHalf &&
4645 "One half of the selector was all UNDEFs and the other was all the "
4646 "same value. This should have been addressed before this function.");
4648 ISD::CONCAT_VECTORS, dl, VT,
4649 BottomHalf->isNullValue() ? RHS->getOperand(0) : LHS->getOperand(0),
4650 TopHalf->isNullValue() ? RHS->getOperand(1) : LHS->getOperand(1));
4653 SDValue DAGCombiner::visitVSELECT(SDNode *N) {
4654 SDValue N0 = N->getOperand(0);
4655 SDValue N1 = N->getOperand(1);
4656 SDValue N2 = N->getOperand(2);
4659 // Canonicalize integer abs.
4660 // vselect (setg[te] X, 0), X, -X ->
4661 // vselect (setgt X, -1), X, -X ->
4662 // vselect (setl[te] X, 0), -X, X ->
4663 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
4664 if (N0.getOpcode() == ISD::SETCC) {
4665 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4666 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
4668 bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());
4670 if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
4671 (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
4672 N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
4673 isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
4674 else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
4675 N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
4676 isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
4679 EVT VT = LHS.getValueType();
4680 SDValue Shift = DAG.getNode(
4681 ISD::SRA, DL, VT, LHS,
4682 DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, VT));
4683 SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
4684 AddToWorkList(Shift.getNode());
4685 AddToWorkList(Add.getNode());
4686 return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
4690 // If the VSELECT result requires splitting and the mask is provided by a
4691 // SETCC, then split both nodes and its operands before legalization. This
4692 // prevents the type legalizer from unrolling SETCC into scalar comparisons
4693 // and enables future optimizations (e.g. min/max pattern matching on X86).
4694 if (N0.getOpcode() == ISD::SETCC) {
4695 EVT VT = N->getValueType(0);
4697 // Check if any splitting is required.
4698 if (TLI.getTypeAction(*DAG.getContext(), VT) !=
4699 TargetLowering::TypeSplitVector)
4702 SDValue Lo, Hi, CCLo, CCHi, LL, LH, RL, RH;
4703 std::tie(CCLo, CCHi) = SplitVSETCC(N0.getNode(), DAG);
4704 std::tie(LL, LH) = DAG.SplitVectorOperand(N, 1);
4705 std::tie(RL, RH) = DAG.SplitVectorOperand(N, 2);
4707 Lo = DAG.getNode(N->getOpcode(), DL, LL.getValueType(), CCLo, LL, RL);
4708 Hi = DAG.getNode(N->getOpcode(), DL, LH.getValueType(), CCHi, LH, RH);
4710 // Add the new VSELECT nodes to the work list in case they need to be split
4712 AddToWorkList(Lo.getNode());
4713 AddToWorkList(Hi.getNode());
4715 return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
4718 // Fold (vselect (build_vector all_ones), N1, N2) -> N1
4719 if (ISD::isBuildVectorAllOnes(N0.getNode()))
4721 // Fold (vselect (build_vector all_zeros), N1, N2) -> N2
4722 if (ISD::isBuildVectorAllZeros(N0.getNode()))
4725 // The ConvertSelectToConcatVector function is assuming both the above
4726 // checks for (vselect (build_vector all{ones,zeros) ...) have been made
4728 if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
4729 N2.getOpcode() == ISD::CONCAT_VECTORS &&
4730 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
4731 SDValue CV = ConvertSelectToConcatVector(N, DAG);
4739 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4740 SDValue N0 = N->getOperand(0);
4741 SDValue N1 = N->getOperand(1);
4742 SDValue N2 = N->getOperand(2);
4743 SDValue N3 = N->getOperand(3);
4744 SDValue N4 = N->getOperand(4);
4745 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4747 // fold select_cc lhs, rhs, x, x, cc -> x
4751 // Determine if the condition we're dealing with is constant
4752 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
4753 N0, N1, CC, SDLoc(N), false);
4754 if (SCC.getNode()) {
4755 AddToWorkList(SCC.getNode());
4757 if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
4758 if (!SCCC->isNullValue())
4759 return N2; // cond always true -> true val
4761 return N3; // cond always false -> false val
4764 // Fold to a simpler select_cc
4765 if (SCC.getOpcode() == ISD::SETCC)
4766 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
4767 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4771 // If we can fold this based on the true/false value, do so.
4772 if (SimplifySelectOps(N, N2, N3))
4773 return SDValue(N, 0); // Don't revisit N.
4775 // fold select_cc into other things, such as min/max/abs
4776 return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
4779 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4780 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4781 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4785 // tryToFoldExtendOfConstant - Try to fold a sext/zext/aext
4786 // dag node into a ConstantSDNode or a build_vector of constants.
4787 // This function is called by the DAGCombiner when visiting sext/zext/aext
4788 // dag nodes (see for example method DAGCombiner::visitSIGN_EXTEND).
4789 // Vector extends are not folded if operations are legal; this is to
4790 // avoid introducing illegal build_vector dag nodes.
4791 static SDNode *tryToFoldExtendOfConstant(SDNode *N, const TargetLowering &TLI,
4792 SelectionDAG &DAG, bool LegalTypes,
4793 bool LegalOperations) {
4794 unsigned Opcode = N->getOpcode();
4795 SDValue N0 = N->getOperand(0);
4796 EVT VT = N->getValueType(0);
4798 assert((Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND ||
4799 Opcode == ISD::ANY_EXTEND) && "Expected EXTEND dag node in input!");
4801 // fold (sext c1) -> c1
4802 // fold (zext c1) -> c1
4803 // fold (aext c1) -> c1
4804 if (isa<ConstantSDNode>(N0))
4805 return DAG.getNode(Opcode, SDLoc(N), VT, N0).getNode();
4807 // fold (sext (build_vector AllConstants) -> (build_vector AllConstants)
4808 // fold (zext (build_vector AllConstants) -> (build_vector AllConstants)
4809 // fold (aext (build_vector AllConstants) -> (build_vector AllConstants)
4810 EVT SVT = VT.getScalarType();
4811 if (!(VT.isVector() &&
4812 (!LegalTypes || (!LegalOperations && TLI.isTypeLegal(SVT))) &&
4813 ISD::isBuildVectorOfConstantSDNodes(N0.getNode())))
4816 // We can fold this node into a build_vector.
4817 unsigned VTBits = SVT.getSizeInBits();
4818 unsigned EVTBits = N0->getValueType(0).getScalarType().getSizeInBits();
4819 unsigned ShAmt = VTBits - EVTBits;
4820 SmallVector<SDValue, 8> Elts;
4821 unsigned NumElts = N0->getNumOperands();
4824 for (unsigned i=0; i != NumElts; ++i) {
4825 SDValue Op = N0->getOperand(i);
4826 if (Op->getOpcode() == ISD::UNDEF) {
4827 Elts.push_back(DAG.getUNDEF(SVT));
4831 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
4832 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
4833 if (Opcode == ISD::SIGN_EXTEND)
4834 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
4837 Elts.push_back(DAG.getConstant(C.shl(ShAmt).lshr(ShAmt).getZExtValue(),
4841 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Elts).getNode();
4844 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4845 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4846 // transformation. Returns true if extension are possible and the above
4847 // mentioned transformation is profitable.
4848 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4850 SmallVectorImpl<SDNode *> &ExtendNodes,
4851 const TargetLowering &TLI) {
4852 bool HasCopyToRegUses = false;
4853 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4854 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4855 UE = N0.getNode()->use_end();
4860 if (UI.getUse().getResNo() != N0.getResNo())
4862 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4863 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4864 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4865 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4866 // Sign bits will be lost after a zext.
4869 for (unsigned i = 0; i != 2; ++i) {
4870 SDValue UseOp = User->getOperand(i);
4873 if (!isa<ConstantSDNode>(UseOp))
4878 ExtendNodes.push_back(User);
4881 // If truncates aren't free and there are users we can't
4882 // extend, it isn't worthwhile.
4885 // Remember if this value is live-out.
4886 if (User->getOpcode() == ISD::CopyToReg)
4887 HasCopyToRegUses = true;
4890 if (HasCopyToRegUses) {
4891 bool BothLiveOut = false;
4892 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4894 SDUse &Use = UI.getUse();
4895 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4901 // Both unextended and extended values are live out. There had better be
4902 // a good reason for the transformation.
4903 return ExtendNodes.size();
4908 void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
4909 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
4910 ISD::NodeType ExtType) {
4911 // Extend SetCC uses if necessary.
4912 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4913 SDNode *SetCC = SetCCs[i];
4914 SmallVector<SDValue, 4> Ops;
4916 for (unsigned j = 0; j != 2; ++j) {
4917 SDValue SOp = SetCC->getOperand(j);
4919 Ops.push_back(ExtLoad);
4921 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4924 Ops.push_back(SetCC->getOperand(2));
4925 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0), Ops));
4929 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4930 SDValue N0 = N->getOperand(0);
4931 EVT VT = N->getValueType(0);
4933 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
4935 return SDValue(Res, 0);
4937 // fold (sext (sext x)) -> (sext x)
4938 // fold (sext (aext x)) -> (sext x)
4939 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4940 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT,
4943 if (N0.getOpcode() == ISD::TRUNCATE) {
4944 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4945 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4946 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4947 if (NarrowLoad.getNode()) {
4948 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4949 if (NarrowLoad.getNode() != N0.getNode()) {
4950 CombineTo(N0.getNode(), NarrowLoad);
4951 // CombineTo deleted the truncate, if needed, but not what's under it.
4954 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4957 // See if the value being truncated is already sign extended. If so, just
4958 // eliminate the trunc/sext pair.
4959 SDValue Op = N0.getOperand(0);
4960 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4961 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4962 unsigned DestBits = VT.getScalarType().getSizeInBits();
4963 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4965 if (OpBits == DestBits) {
4966 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4967 // bits, it is already ready.
4968 if (NumSignBits > DestBits-MidBits)
4970 } else if (OpBits < DestBits) {
4971 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4972 // bits, just sext from i32.
4973 if (NumSignBits > OpBits-MidBits)
4974 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, Op);
4976 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4977 // bits, just truncate to i32.
4978 if (NumSignBits > OpBits-MidBits)
4979 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4982 // fold (sext (truncate x)) -> (sextinreg x).
4983 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4984 N0.getValueType())) {
4985 if (OpBits < DestBits)
4986 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
4987 else if (OpBits > DestBits)
4988 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
4989 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, Op,
4990 DAG.getValueType(N0.getValueType()));
4994 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4995 // None of the supported targets knows how to perform load and sign extend
4996 // on vectors in one instruction. We only perform this transformation on
4998 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4999 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5000 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5001 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
5002 bool DoXform = true;
5003 SmallVector<SDNode*, 4> SetCCs;
5004 if (!N0.hasOneUse())
5005 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
5007 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5008 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5010 LN0->getBasePtr(), N0.getValueType(),
5011 LN0->getMemOperand());
5012 CombineTo(N, ExtLoad);
5013 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5014 N0.getValueType(), ExtLoad);
5015 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5016 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5018 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5022 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
5023 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
5024 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
5025 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
5026 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5027 EVT MemVT = LN0->getMemoryVT();
5028 if ((!LegalOperations && !LN0->isVolatile()) ||
5029 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
5030 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5032 LN0->getBasePtr(), MemVT,
5033 LN0->getMemOperand());
5034 CombineTo(N, ExtLoad);
5035 CombineTo(N0.getNode(),
5036 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5037 N0.getValueType(), ExtLoad),
5038 ExtLoad.getValue(1));
5039 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5043 // fold (sext (and/or/xor (load x), cst)) ->
5044 // (and/or/xor (sextload x), (sext cst))
5045 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
5046 N0.getOpcode() == ISD::XOR) &&
5047 isa<LoadSDNode>(N0.getOperand(0)) &&
5048 N0.getOperand(1).getOpcode() == ISD::Constant &&
5049 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
5050 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
5051 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
5052 if (LN0->getExtensionType() != ISD::ZEXTLOAD && LN0->isUnindexed()) {
5053 bool DoXform = true;
5054 SmallVector<SDNode*, 4> SetCCs;
5055 if (!N0.hasOneUse())
5056 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
5059 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
5060 LN0->getChain(), LN0->getBasePtr(),
5062 LN0->getMemOperand());
5063 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5064 Mask = Mask.sext(VT.getSizeInBits());
5065 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
5066 ExtLoad, DAG.getConstant(Mask, VT));
5067 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
5068 SDLoc(N0.getOperand(0)),
5069 N0.getOperand(0).getValueType(), ExtLoad);
5071 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
5072 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5074 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5079 if (N0.getOpcode() == ISD::SETCC) {
5080 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
5081 // Only do this before legalize for now.
5082 if (VT.isVector() && !LegalOperations &&
5083 TLI.getBooleanContents(true) ==
5084 TargetLowering::ZeroOrNegativeOneBooleanContent) {
5085 EVT N0VT = N0.getOperand(0).getValueType();
5086 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
5087 // of the same size as the compared operands. Only optimize sext(setcc())
5088 // if this is the case.
5089 EVT SVT = getSetCCResultType(N0VT);
5091 // We know that the # elements of the results is the same as the
5092 // # elements of the compare (and the # elements of the compare result
5093 // for that matter). Check to see that they are the same size. If so,
5094 // we know that the element size of the sext'd result matches the
5095 // element size of the compare operands.
5096 if (VT.getSizeInBits() == SVT.getSizeInBits())
5097 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5099 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5101 // If the desired elements are smaller or larger than the source
5102 // elements we can use a matching integer vector type and then
5103 // truncate/sign extend
5104 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
5105 if (SVT == MatchingVectorType) {
5106 SDValue VsetCC = DAG.getSetCC(SDLoc(N), MatchingVectorType,
5107 N0.getOperand(0), N0.getOperand(1),
5108 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5109 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
5113 // sext(setcc x, y, cc) -> (select (setcc x, y, cc), -1, 0)
5114 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
5116 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
5118 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
5119 NegOne, DAG.getConstant(0, VT),
5120 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5121 if (SCC.getNode()) return SCC;
5123 if (!VT.isVector()) {
5124 EVT SetCCVT = getSetCCResultType(N0.getOperand(0).getValueType());
5125 if (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, SetCCVT)) {
5127 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
5128 SDValue SetCC = DAG.getSetCC(DL,
5130 N0.getOperand(0), N0.getOperand(1), CC);
5131 EVT SelectVT = getSetCCResultType(VT);
5132 return DAG.getSelect(DL, VT,
5133 DAG.getSExtOrTrunc(SetCC, DL, SelectVT),
5134 NegOne, DAG.getConstant(0, VT));
5140 // fold (sext x) -> (zext x) if the sign bit is known zero.
5141 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
5142 DAG.SignBitIsZero(N0))
5143 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
5148 // isTruncateOf - If N is a truncate of some other value, return true, record
5149 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
5150 // This function computes KnownZero to avoid a duplicated call to
5151 // computeKnownBits in the caller.
5152 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
5155 if (N->getOpcode() == ISD::TRUNCATE) {
5156 Op = N->getOperand(0);
5157 DAG.computeKnownBits(Op, KnownZero, KnownOne);
5161 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
5162 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
5165 SDValue Op0 = N->getOperand(0);
5166 SDValue Op1 = N->getOperand(1);
5167 assert(Op0.getValueType() == Op1.getValueType());
5169 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
5170 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
5171 if (COp0 && COp0->isNullValue())
5173 else if (COp1 && COp1->isNullValue())
5178 DAG.computeKnownBits(Op, KnownZero, KnownOne);
5180 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
5186 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
5187 SDValue N0 = N->getOperand(0);
5188 EVT VT = N->getValueType(0);
5190 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
5192 return SDValue(Res, 0);
5194 // fold (zext (zext x)) -> (zext x)
5195 // fold (zext (aext x)) -> (zext x)
5196 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
5197 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
5200 // fold (zext (truncate x)) -> (zext x) or
5201 // (zext (truncate x)) -> (truncate x)
5202 // This is valid when the truncated bits of x are already zero.
5203 // FIXME: We should extend this to work for vectors too.
5206 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
5207 APInt TruncatedBits =
5208 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
5209 APInt(Op.getValueSizeInBits(), 0) :
5210 APInt::getBitsSet(Op.getValueSizeInBits(),
5211 N0.getValueSizeInBits(),
5212 std::min(Op.getValueSizeInBits(),
5213 VT.getSizeInBits()));
5214 if (TruncatedBits == (KnownZero & TruncatedBits)) {
5215 if (VT.bitsGT(Op.getValueType()))
5216 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, Op);
5217 if (VT.bitsLT(Op.getValueType()))
5218 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
5224 // fold (zext (truncate (load x))) -> (zext (smaller load x))
5225 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
5226 if (N0.getOpcode() == ISD::TRUNCATE) {
5227 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
5228 if (NarrowLoad.getNode()) {
5229 SDNode* oye = N0.getNode()->getOperand(0).getNode();
5230 if (NarrowLoad.getNode() != N0.getNode()) {
5231 CombineTo(N0.getNode(), NarrowLoad);
5232 // CombineTo deleted the truncate, if needed, but not what's under it.
5235 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5239 // fold (zext (truncate x)) -> (and x, mask)
5240 if (N0.getOpcode() == ISD::TRUNCATE &&
5241 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
5243 // fold (zext (truncate (load x))) -> (zext (smaller load x))
5244 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
5245 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
5246 if (NarrowLoad.getNode()) {
5247 SDNode* oye = N0.getNode()->getOperand(0).getNode();
5248 if (NarrowLoad.getNode() != N0.getNode()) {
5249 CombineTo(N0.getNode(), NarrowLoad);
5250 // CombineTo deleted the truncate, if needed, but not what's under it.
5253 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5256 SDValue Op = N0.getOperand(0);
5257 if (Op.getValueType().bitsLT(VT)) {
5258 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Op);
5259 AddToWorkList(Op.getNode());
5260 } else if (Op.getValueType().bitsGT(VT)) {
5261 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
5262 AddToWorkList(Op.getNode());
5264 return DAG.getZeroExtendInReg(Op, SDLoc(N),
5265 N0.getValueType().getScalarType());
5268 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
5269 // if either of the casts is not free.
5270 if (N0.getOpcode() == ISD::AND &&
5271 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
5272 N0.getOperand(1).getOpcode() == ISD::Constant &&
5273 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
5274 N0.getValueType()) ||
5275 !TLI.isZExtFree(N0.getValueType(), VT))) {
5276 SDValue X = N0.getOperand(0).getOperand(0);
5277 if (X.getValueType().bitsLT(VT)) {
5278 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(X), VT, X);
5279 } else if (X.getValueType().bitsGT(VT)) {
5280 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
5282 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5283 Mask = Mask.zext(VT.getSizeInBits());
5284 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5285 X, DAG.getConstant(Mask, VT));
5288 // fold (zext (load x)) -> (zext (truncate (zextload x)))
5289 // None of the supported targets knows how to perform load and vector_zext
5290 // on vectors in one instruction. We only perform this transformation on
5292 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
5293 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5294 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5295 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
5296 bool DoXform = true;
5297 SmallVector<SDNode*, 4> SetCCs;
5298 if (!N0.hasOneUse())
5299 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
5301 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5302 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
5304 LN0->getBasePtr(), N0.getValueType(),
5305 LN0->getMemOperand());
5306 CombineTo(N, ExtLoad);
5307 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5308 N0.getValueType(), ExtLoad);
5309 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5311 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5313 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5317 // fold (zext (and/or/xor (load x), cst)) ->
5318 // (and/or/xor (zextload x), (zext cst))
5319 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
5320 N0.getOpcode() == ISD::XOR) &&
5321 isa<LoadSDNode>(N0.getOperand(0)) &&
5322 N0.getOperand(1).getOpcode() == ISD::Constant &&
5323 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
5324 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
5325 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
5326 if (LN0->getExtensionType() != ISD::SEXTLOAD && LN0->isUnindexed()) {
5327 bool DoXform = true;
5328 SmallVector<SDNode*, 4> SetCCs;
5329 if (!N0.hasOneUse())
5330 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
5333 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
5334 LN0->getChain(), LN0->getBasePtr(),
5336 LN0->getMemOperand());
5337 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5338 Mask = Mask.zext(VT.getSizeInBits());
5339 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
5340 ExtLoad, DAG.getConstant(Mask, VT));
5341 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
5342 SDLoc(N0.getOperand(0)),
5343 N0.getOperand(0).getValueType(), ExtLoad);
5345 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
5346 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5348 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5353 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
5354 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
5355 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
5356 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
5357 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5358 EVT MemVT = LN0->getMemoryVT();
5359 if ((!LegalOperations && !LN0->isVolatile()) ||
5360 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
5361 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
5363 LN0->getBasePtr(), MemVT,
5364 LN0->getMemOperand());
5365 CombineTo(N, ExtLoad);
5366 CombineTo(N0.getNode(),
5367 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
5369 ExtLoad.getValue(1));
5370 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5374 if (N0.getOpcode() == ISD::SETCC) {
5375 if (!LegalOperations && VT.isVector() &&
5376 N0.getValueType().getVectorElementType() == MVT::i1) {
5377 EVT N0VT = N0.getOperand(0).getValueType();
5378 if (getSetCCResultType(N0VT) == N0.getValueType())
5381 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
5382 // Only do this before legalize for now.
5383 EVT EltVT = VT.getVectorElementType();
5384 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
5385 DAG.getConstant(1, EltVT));
5386 if (VT.getSizeInBits() == N0VT.getSizeInBits())
5387 // We know that the # elements of the results is the same as the
5388 // # elements of the compare (and the # elements of the compare result
5389 // for that matter). Check to see that they are the same size. If so,
5390 // we know that the element size of the sext'd result matches the
5391 // element size of the compare operands.
5392 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5393 DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5395 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
5396 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT,
5399 // If the desired elements are smaller or larger than the source
5400 // elements we can use a matching integer vector type and then
5401 // truncate/sign extend
5402 EVT MatchingElementType =
5403 EVT::getIntegerVT(*DAG.getContext(),
5404 N0VT.getScalarType().getSizeInBits());
5405 EVT MatchingVectorType =
5406 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
5407 N0VT.getVectorNumElements());
5409 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
5411 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5412 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5413 DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT),
5414 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, OneOps));
5417 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
5419 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
5420 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
5421 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5422 if (SCC.getNode()) return SCC;
5425 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
5426 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
5427 isa<ConstantSDNode>(N0.getOperand(1)) &&
5428 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
5430 SDValue ShAmt = N0.getOperand(1);
5431 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
5432 if (N0.getOpcode() == ISD::SHL) {
5433 SDValue InnerZExt = N0.getOperand(0);
5434 // If the original shl may be shifting out bits, do not perform this
5436 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
5437 InnerZExt.getOperand(0).getValueType().getSizeInBits();
5438 if (ShAmtVal > KnownZeroBits)
5444 // Ensure that the shift amount is wide enough for the shifted value.
5445 if (VT.getSizeInBits() >= 256)
5446 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
5448 return DAG.getNode(N0.getOpcode(), DL, VT,
5449 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
5456 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
5457 SDValue N0 = N->getOperand(0);
5458 EVT VT = N->getValueType(0);
5460 if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
5462 return SDValue(Res, 0);
5464 // fold (aext (aext x)) -> (aext x)
5465 // fold (aext (zext x)) -> (zext x)
5466 // fold (aext (sext x)) -> (sext x)
5467 if (N0.getOpcode() == ISD::ANY_EXTEND ||
5468 N0.getOpcode() == ISD::ZERO_EXTEND ||
5469 N0.getOpcode() == ISD::SIGN_EXTEND)
5470 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
5472 // fold (aext (truncate (load x))) -> (aext (smaller load x))
5473 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
5474 if (N0.getOpcode() == ISD::TRUNCATE) {
5475 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
5476 if (NarrowLoad.getNode()) {
5477 SDNode* oye = N0.getNode()->getOperand(0).getNode();
5478 if (NarrowLoad.getNode() != N0.getNode()) {
5479 CombineTo(N0.getNode(), NarrowLoad);
5480 // CombineTo deleted the truncate, if needed, but not what's under it.
5483 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5487 // fold (aext (truncate x))
5488 if (N0.getOpcode() == ISD::TRUNCATE) {
5489 SDValue TruncOp = N0.getOperand(0);
5490 if (TruncOp.getValueType() == VT)
5491 return TruncOp; // x iff x size == zext size.
5492 if (TruncOp.getValueType().bitsGT(VT))
5493 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, TruncOp);
5494 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, TruncOp);
5497 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
5498 // if the trunc is not free.
5499 if (N0.getOpcode() == ISD::AND &&
5500 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
5501 N0.getOperand(1).getOpcode() == ISD::Constant &&
5502 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
5503 N0.getValueType())) {
5504 SDValue X = N0.getOperand(0).getOperand(0);
5505 if (X.getValueType().bitsLT(VT)) {
5506 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, X);
5507 } else if (X.getValueType().bitsGT(VT)) {
5508 X = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, X);
5510 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5511 Mask = Mask.zext(VT.getSizeInBits());
5512 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5513 X, DAG.getConstant(Mask, VT));
5516 // fold (aext (load x)) -> (aext (truncate (extload x)))
5517 // None of the supported targets knows how to perform load and any_ext
5518 // on vectors in one instruction. We only perform this transformation on
5520 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
5521 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5522 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5523 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
5524 bool DoXform = true;
5525 SmallVector<SDNode*, 4> SetCCs;
5526 if (!N0.hasOneUse())
5527 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
5529 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5530 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
5532 LN0->getBasePtr(), N0.getValueType(),
5533 LN0->getMemOperand());
5534 CombineTo(N, ExtLoad);
5535 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5536 N0.getValueType(), ExtLoad);
5537 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5538 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5540 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5544 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
5545 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
5546 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
5547 if (N0.getOpcode() == ISD::LOAD &&
5548 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5550 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5551 ISD::LoadExtType ExtType = LN0->getExtensionType();
5552 EVT MemVT = LN0->getMemoryVT();
5553 if (!LegalOperations || TLI.isLoadExtLegal(ExtType, MemVT)) {
5554 SDValue ExtLoad = DAG.getExtLoad(ExtType, SDLoc(N),
5555 VT, LN0->getChain(), LN0->getBasePtr(),
5556 MemVT, LN0->getMemOperand());
5557 CombineTo(N, ExtLoad);
5558 CombineTo(N0.getNode(),
5559 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5560 N0.getValueType(), ExtLoad),
5561 ExtLoad.getValue(1));
5562 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5566 if (N0.getOpcode() == ISD::SETCC) {
5568 // aext(setcc) -> vsetcc
5569 // aext(setcc) -> truncate(vsetcc)
5570 // aext(setcc) -> aext(vsetcc)
5571 // Only do this before legalize for now.
5572 if (VT.isVector() && !LegalOperations) {
5573 EVT N0VT = N0.getOperand(0).getValueType();
5574 // We know that the # elements of the results is the same as the
5575 // # elements of the compare (and the # elements of the compare result
5576 // for that matter). Check to see that they are the same size. If so,
5577 // we know that the element size of the sext'd result matches the
5578 // element size of the compare operands.
5579 if (VT.getSizeInBits() == N0VT.getSizeInBits())
5580 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5582 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5583 // If the desired elements are smaller or larger than the source
5584 // elements we can use a matching integer vector type and then
5585 // truncate/any extend
5587 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
5589 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
5591 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5592 return DAG.getAnyExtOrTrunc(VsetCC, SDLoc(N), VT);
5596 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
5598 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
5599 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
5600 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5608 /// GetDemandedBits - See if the specified operand can be simplified with the
5609 /// knowledge that only the bits specified by Mask are used. If so, return the
5610 /// simpler operand, otherwise return a null SDValue.
5611 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
5612 switch (V.getOpcode()) {
5614 case ISD::Constant: {
5615 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
5616 assert(CV && "Const value should be ConstSDNode.");
5617 const APInt &CVal = CV->getAPIntValue();
5618 APInt NewVal = CVal & Mask;
5620 return DAG.getConstant(NewVal, V.getValueType());
5625 // If the LHS or RHS don't contribute bits to the or, drop them.
5626 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
5627 return V.getOperand(1);
5628 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
5629 return V.getOperand(0);
5632 // Only look at single-use SRLs.
5633 if (!V.getNode()->hasOneUse())
5635 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
5636 // See if we can recursively simplify the LHS.
5637 unsigned Amt = RHSC->getZExtValue();
5639 // Watch out for shift count overflow though.
5640 if (Amt >= Mask.getBitWidth()) break;
5641 APInt NewMask = Mask << Amt;
5642 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
5643 if (SimplifyLHS.getNode())
5644 return DAG.getNode(ISD::SRL, SDLoc(V), V.getValueType(),
5645 SimplifyLHS, V.getOperand(1));
5651 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
5652 /// bits and then truncated to a narrower type and where N is a multiple
5653 /// of number of bits of the narrower type, transform it to a narrower load
5654 /// from address + N / num of bits of new type. If the result is to be
5655 /// extended, also fold the extension to form a extending load.
5656 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
5657 unsigned Opc = N->getOpcode();
5659 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
5660 SDValue N0 = N->getOperand(0);
5661 EVT VT = N->getValueType(0);
5664 // This transformation isn't valid for vector loads.
5668 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
5670 if (Opc == ISD::SIGN_EXTEND_INREG) {
5671 ExtType = ISD::SEXTLOAD;
5672 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
5673 } else if (Opc == ISD::SRL) {
5674 // Another special-case: SRL is basically zero-extending a narrower value.
5675 ExtType = ISD::ZEXTLOAD;
5677 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
5678 if (!N01) return SDValue();
5679 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
5680 VT.getSizeInBits() - N01->getZExtValue());
5682 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5685 unsigned EVTBits = ExtVT.getSizeInBits();
5687 // Do not generate loads of non-round integer types since these can
5688 // be expensive (and would be wrong if the type is not byte sized).
5689 if (!ExtVT.isRound())
5693 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5694 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5695 ShAmt = N01->getZExtValue();
5696 // Is the shift amount a multiple of size of VT?
5697 if ((ShAmt & (EVTBits-1)) == 0) {
5698 N0 = N0.getOperand(0);
5699 // Is the load width a multiple of size of VT?
5700 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5704 // At this point, we must have a load or else we can't do the transform.
5705 if (!isa<LoadSDNode>(N0)) return SDValue();
5707 // Because a SRL must be assumed to *need* to zero-extend the high bits
5708 // (as opposed to anyext the high bits), we can't combine the zextload
5709 // lowering of SRL and an sextload.
5710 if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
5713 // If the shift amount is larger than the input type then we're not
5714 // accessing any of the loaded bytes. If the load was a zextload/extload
5715 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5716 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5721 // If the load is shifted left (and the result isn't shifted back right),
5722 // we can fold the truncate through the shift.
5723 unsigned ShLeftAmt = 0;
5724 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5725 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5726 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5727 ShLeftAmt = N01->getZExtValue();
5728 N0 = N0.getOperand(0);
5732 // If we haven't found a load, we can't narrow it. Don't transform one with
5733 // multiple uses, this would require adding a new load.
5734 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse())
5737 // Don't change the width of a volatile load.
5738 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5739 if (LN0->isVolatile())
5742 // Verify that we are actually reducing a load width here.
5743 if (LN0->getMemoryVT().getSizeInBits() < EVTBits)
5746 // For the transform to be legal, the load must produce only two values
5747 // (the value loaded and the chain). Don't transform a pre-increment
5748 // load, for example, which produces an extra value. Otherwise the
5749 // transformation is not equivalent, and the downstream logic to replace
5750 // uses gets things wrong.
5751 if (LN0->getNumValues() > 2)
5754 // If the load that we're shrinking is an extload and we're not just
5755 // discarding the extension we can't simply shrink the load. Bail.
5756 // TODO: It would be possible to merge the extensions in some cases.
5757 if (LN0->getExtensionType() != ISD::NON_EXTLOAD &&
5758 LN0->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
5761 EVT PtrType = N0.getOperand(1).getValueType();
5763 if (PtrType == MVT::Untyped || PtrType.isExtended())
5764 // It's not possible to generate a constant of extended or untyped type.
5767 // For big endian targets, we need to adjust the offset to the pointer to
5768 // load the correct bytes.
5769 if (TLI.isBigEndian()) {
5770 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5771 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5772 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5775 uint64_t PtrOff = ShAmt / 8;
5776 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5777 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0),
5778 PtrType, LN0->getBasePtr(),
5779 DAG.getConstant(PtrOff, PtrType));
5780 AddToWorkList(NewPtr.getNode());
5783 if (ExtType == ISD::NON_EXTLOAD)
5784 Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
5785 LN0->getPointerInfo().getWithOffset(PtrOff),
5786 LN0->isVolatile(), LN0->isNonTemporal(),
5787 LN0->isInvariant(), NewAlign, LN0->getTBAAInfo());
5789 Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
5790 LN0->getPointerInfo().getWithOffset(PtrOff),
5791 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5792 NewAlign, LN0->getTBAAInfo());
5794 // Replace the old load's chain with the new load's chain.
5795 WorkListRemover DeadNodes(*this);
5796 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5798 // Shift the result left, if we've swallowed a left shift.
5799 SDValue Result = Load;
5800 if (ShLeftAmt != 0) {
5801 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5802 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5804 // If the shift amount is as large as the result size (but, presumably,
5805 // no larger than the source) then the useful bits of the result are
5806 // zero; we can't simply return the shortened shift, because the result
5807 // of that operation is undefined.
5808 if (ShLeftAmt >= VT.getSizeInBits())
5809 Result = DAG.getConstant(0, VT);
5811 Result = DAG.getNode(ISD::SHL, SDLoc(N0), VT,
5812 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5815 // Return the new loaded value.
5819 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5820 SDValue N0 = N->getOperand(0);
5821 SDValue N1 = N->getOperand(1);
5822 EVT VT = N->getValueType(0);
5823 EVT EVT = cast<VTSDNode>(N1)->getVT();
5824 unsigned VTBits = VT.getScalarType().getSizeInBits();
5825 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5827 // fold (sext_in_reg c1) -> c1
5828 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5829 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);
5831 // If the input is already sign extended, just drop the extension.
5832 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5835 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5836 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5837 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
5838 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5839 N0.getOperand(0), N1);
5841 // fold (sext_in_reg (sext x)) -> (sext x)
5842 // fold (sext_in_reg (aext x)) -> (sext x)
5843 // if x is small enough.
5844 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5845 SDValue N00 = N0.getOperand(0);
5846 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5847 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5848 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
5851 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5852 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5853 return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT);
5855 // fold operands of sext_in_reg based on knowledge that the top bits are not
5857 if (SimplifyDemandedBits(SDValue(N, 0)))
5858 return SDValue(N, 0);
5860 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5861 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5862 SDValue NarrowLoad = ReduceLoadWidth(N);
5863 if (NarrowLoad.getNode())
5866 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5867 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5868 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5869 if (N0.getOpcode() == ISD::SRL) {
5870 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5871 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5872 // We can turn this into an SRA iff the input to the SRL is already sign
5874 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5875 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5876 return DAG.getNode(ISD::SRA, SDLoc(N), VT,
5877 N0.getOperand(0), N0.getOperand(1));
5881 // fold (sext_inreg (extload x)) -> (sextload x)
5882 if (ISD::isEXTLoad(N0.getNode()) &&
5883 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5884 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5885 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5886 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5887 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5888 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5890 LN0->getBasePtr(), EVT,
5891 LN0->getMemOperand());
5892 CombineTo(N, ExtLoad);
5893 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5894 AddToWorkList(ExtLoad.getNode());
5895 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5897 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5898 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5900 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5901 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5902 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5903 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5904 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5906 LN0->getBasePtr(), EVT,
5907 LN0->getMemOperand());
5908 CombineTo(N, ExtLoad);
5909 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5910 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5913 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5914 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5915 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5916 N0.getOperand(1), false);
5917 if (BSwap.getNode())
5918 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5922 // Fold a sext_inreg of a build_vector of ConstantSDNodes or undefs
5923 // into a build_vector.
5924 if (ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
5925 SmallVector<SDValue, 8> Elts;
5926 unsigned NumElts = N0->getNumOperands();
5927 unsigned ShAmt = VTBits - EVTBits;
5929 for (unsigned i = 0; i != NumElts; ++i) {
5930 SDValue Op = N0->getOperand(i);
5931 if (Op->getOpcode() == ISD::UNDEF) {
5936 ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
5937 const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
5938 Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
5939 Op.getValueType()));
5942 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Elts);
5948 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5949 SDValue N0 = N->getOperand(0);
5950 EVT VT = N->getValueType(0);
5951 bool isLE = TLI.isLittleEndian();
5954 if (N0.getValueType() == N->getValueType(0))
5956 // fold (truncate c1) -> c1
5957 if (isa<ConstantSDNode>(N0))
5958 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
5959 // fold (truncate (truncate x)) -> (truncate x)
5960 if (N0.getOpcode() == ISD::TRUNCATE)
5961 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5962 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5963 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5964 N0.getOpcode() == ISD::SIGN_EXTEND ||
5965 N0.getOpcode() == ISD::ANY_EXTEND) {
5966 if (N0.getOperand(0).getValueType().bitsLT(VT))
5967 // if the source is smaller than the dest, we still need an extend
5968 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
5970 if (N0.getOperand(0).getValueType().bitsGT(VT))
5971 // if the source is larger than the dest, than we just need the truncate
5972 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5973 // if the source and dest are the same type, we can drop both the extend
5974 // and the truncate.
5975 return N0.getOperand(0);
5978 // Fold extract-and-trunc into a narrow extract. For example:
5979 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5980 // i32 y = TRUNCATE(i64 x)
5982 // v16i8 b = BITCAST (v2i64 val)
5983 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5985 // Note: We only run this optimization after type legalization (which often
5986 // creates this pattern) and before operation legalization after which
5987 // we need to be more careful about the vector instructions that we generate.
5988 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5989 LegalTypes && !LegalOperations && N0->hasOneUse() && VT != MVT::i1) {
5991 EVT VecTy = N0.getOperand(0).getValueType();
5992 EVT ExTy = N0.getValueType();
5993 EVT TrTy = N->getValueType(0);
5995 unsigned NumElem = VecTy.getVectorNumElements();
5996 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5998 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5999 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
6001 SDValue EltNo = N0->getOperand(1);
6002 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
6003 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
6004 EVT IndexTy = TLI.getVectorIdxTy();
6005 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
6007 SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
6008 NVT, N0.getOperand(0));
6010 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
6012 DAG.getConstant(Index, IndexTy));
6016 // trunc (select c, a, b) -> select c, (trunc a), (trunc b)
6017 if (N0.getOpcode() == ISD::SELECT) {
6018 EVT SrcVT = N0.getValueType();
6019 if ((!LegalOperations || TLI.isOperationLegal(ISD::SELECT, SrcVT)) &&
6020 TLI.isTruncateFree(SrcVT, VT)) {
6022 SDValue TruncOp0 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
6023 SDValue TruncOp1 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(2));
6024 EVT SetCCVT = getSetCCResultType(VT);
6025 SDValue Cond = DAG.getSExtOrTrunc(N0.getOperand(0), SL, SetCCVT);
6026 return DAG.getNode(ISD::SELECT, SDLoc(N), VT, Cond, TruncOp0, TruncOp1);
6030 // Fold a series of buildvector, bitcast, and truncate if possible.
6032 // (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
6033 // (2xi32 (buildvector x, y)).
6034 if (Level == AfterLegalizeVectorOps && VT.isVector() &&
6035 N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
6036 N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
6037 N0.getOperand(0).hasOneUse()) {
6039 SDValue BuildVect = N0.getOperand(0);
6040 EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
6041 EVT TruncVecEltTy = VT.getVectorElementType();
6043 // Check that the element types match.
6044 if (BuildVectEltTy == TruncVecEltTy) {
6045 // Now we only need to compute the offset of the truncated elements.
6046 unsigned BuildVecNumElts = BuildVect.getNumOperands();
6047 unsigned TruncVecNumElts = VT.getVectorNumElements();
6048 unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;
6050 assert((BuildVecNumElts % TruncVecNumElts) == 0 &&
6051 "Invalid number of elements");
6053 SmallVector<SDValue, 8> Opnds;
6054 for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
6055 Opnds.push_back(BuildVect.getOperand(i));
6057 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
6061 // See if we can simplify the input to this truncate through knowledge that
6062 // only the low bits are being used.
6063 // For example "trunc (or (shl x, 8), y)" // -> trunc y
6064 // Currently we only perform this optimization on scalars because vectors
6065 // may have different active low bits.
6066 if (!VT.isVector()) {
6068 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
6069 VT.getSizeInBits()));
6070 if (Shorter.getNode())
6071 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
6073 // fold (truncate (load x)) -> (smaller load x)
6074 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
6075 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
6076 SDValue Reduced = ReduceLoadWidth(N);
6077 if (Reduced.getNode())
6079 // Handle the case where the load remains an extending load even
6080 // after truncation.
6081 if (N0.hasOneUse() && ISD::isUNINDEXEDLoad(N0.getNode())) {
6082 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6083 if (!LN0->isVolatile() &&
6084 LN0->getMemoryVT().getStoreSizeInBits() < VT.getSizeInBits()) {
6085 SDValue NewLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(LN0),
6086 VT, LN0->getChain(), LN0->getBasePtr(),
6088 LN0->getMemOperand());
6089 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLoad.getValue(1));
6094 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
6095 // where ... are all 'undef'.
6096 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
6097 SmallVector<EVT, 8> VTs;
6100 unsigned NumDefs = 0;
6102 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
6103 SDValue X = N0.getOperand(i);
6104 if (X.getOpcode() != ISD::UNDEF) {
6109 // Stop if more than one members are non-undef.
6112 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
6113 VT.getVectorElementType(),
6114 X.getValueType().getVectorNumElements()));
6118 return DAG.getUNDEF(VT);
6121 assert(V.getNode() && "The single defined operand is empty!");
6122 SmallVector<SDValue, 8> Opnds;
6123 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
6125 Opnds.push_back(DAG.getUNDEF(VTs[i]));
6128 SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
6129 AddToWorkList(NV.getNode());
6130 Opnds.push_back(NV);
6132 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Opnds);
6136 // Simplify the operands using demanded-bits information.
6137 if (!VT.isVector() &&
6138 SimplifyDemandedBits(SDValue(N, 0)))
6139 return SDValue(N, 0);
6144 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
6145 SDValue Elt = N->getOperand(i);
6146 if (Elt.getOpcode() != ISD::MERGE_VALUES)
6147 return Elt.getNode();
6148 return Elt.getOperand(Elt.getResNo()).getNode();
6151 /// CombineConsecutiveLoads - build_pair (load, load) -> load
6152 /// if load locations are consecutive.
6153 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
6154 assert(N->getOpcode() == ISD::BUILD_PAIR);
6156 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
6157 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
6158 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
6159 LD1->getAddressSpace() != LD2->getAddressSpace())
6161 EVT LD1VT = LD1->getValueType(0);
6163 if (ISD::isNON_EXTLoad(LD2) &&
6165 // If both are volatile this would reduce the number of volatile loads.
6166 // If one is volatile it might be ok, but play conservative and bail out.
6167 !LD1->isVolatile() &&
6168 !LD2->isVolatile() &&
6169 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
6170 unsigned Align = LD1->getAlignment();
6171 unsigned NewAlign = TLI.getDataLayout()->
6172 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
6174 if (NewAlign <= Align &&
6175 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
6176 return DAG.getLoad(VT, SDLoc(N), LD1->getChain(),
6177 LD1->getBasePtr(), LD1->getPointerInfo(),
6178 false, false, false, Align);
6184 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
6185 SDValue N0 = N->getOperand(0);
6186 EVT VT = N->getValueType(0);
6188 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
6189 // Only do this before legalize, since afterward the target may be depending
6190 // on the bitconvert.
6191 // First check to see if this is all constant.
6193 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
6195 bool isSimple = cast<BuildVectorSDNode>(N0)->isConstant();
6197 EVT DestEltVT = N->getValueType(0).getVectorElementType();
6198 assert(!DestEltVT.isVector() &&
6199 "Element type of vector ValueType must not be vector!");
6201 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
6204 // If the input is a constant, let getNode fold it.
6205 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
6206 SDValue Res = DAG.getNode(ISD::BITCAST, SDLoc(N), VT, N0);
6207 if (Res.getNode() != N) {
6208 if (!LegalOperations ||
6209 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
6212 // Folding it resulted in an illegal node, and it's too late to
6213 // do that. Clean up the old node and forego the transformation.
6214 // Ideally this won't happen very often, because instcombine
6215 // and the earlier dagcombine runs (where illegal nodes are
6216 // permitted) should have folded most of them already.
6217 DAG.DeleteNode(Res.getNode());
6221 // (conv (conv x, t1), t2) -> (conv x, t2)
6222 if (N0.getOpcode() == ISD::BITCAST)
6223 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT,
6226 // fold (conv (load x)) -> (load (conv*)x)
6227 // If the resultant load doesn't need a higher alignment than the original!
6228 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
6229 // Do not change the width of a volatile load.
6230 !cast<LoadSDNode>(N0)->isVolatile() &&
6231 // Do not remove the cast if the types differ in endian layout.
6232 TLI.hasBigEndianPartOrdering(N0.getValueType()) ==
6233 TLI.hasBigEndianPartOrdering(VT) &&
6234 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)) &&
6235 TLI.isLoadBitCastBeneficial(N0.getValueType(), VT)) {
6236 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6237 unsigned Align = TLI.getDataLayout()->
6238 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
6239 unsigned OrigAlign = LN0->getAlignment();
6241 if (Align <= OrigAlign) {
6242 SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
6243 LN0->getBasePtr(), LN0->getPointerInfo(),
6244 LN0->isVolatile(), LN0->isNonTemporal(),
6245 LN0->isInvariant(), OrigAlign,
6246 LN0->getTBAAInfo());
6248 CombineTo(N0.getNode(),
6249 DAG.getNode(ISD::BITCAST, SDLoc(N0),
6250 N0.getValueType(), Load),
6256 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
6257 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
6258 // This often reduces constant pool loads.
6259 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
6260 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
6261 N0.getNode()->hasOneUse() && VT.isInteger() &&
6262 !VT.isVector() && !N0.getValueType().isVector()) {
6263 SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
6265 AddToWorkList(NewConv.getNode());
6267 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
6268 if (N0.getOpcode() == ISD::FNEG)
6269 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
6270 NewConv, DAG.getConstant(SignBit, VT));
6271 assert(N0.getOpcode() == ISD::FABS);
6272 return DAG.getNode(ISD::AND, SDLoc(N), VT,
6273 NewConv, DAG.getConstant(~SignBit, VT));
6276 // fold (bitconvert (fcopysign cst, x)) ->
6277 // (or (and (bitconvert x), sign), (and cst, (not sign)))
6278 // Note that we don't handle (copysign x, cst) because this can always be
6279 // folded to an fneg or fabs.
6280 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
6281 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
6282 VT.isInteger() && !VT.isVector()) {
6283 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
6284 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
6285 if (isTypeLegal(IntXVT)) {
6286 SDValue X = DAG.getNode(ISD::BITCAST, SDLoc(N0),
6287 IntXVT, N0.getOperand(1));
6288 AddToWorkList(X.getNode());
6290 // If X has a different width than the result/lhs, sext it or truncate it.
6291 unsigned VTWidth = VT.getSizeInBits();
6292 if (OrigXWidth < VTWidth) {
6293 X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
6294 AddToWorkList(X.getNode());
6295 } else if (OrigXWidth > VTWidth) {
6296 // To get the sign bit in the right place, we have to shift it right
6297 // before truncating.
6298 X = DAG.getNode(ISD::SRL, SDLoc(X),
6299 X.getValueType(), X,
6300 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
6301 AddToWorkList(X.getNode());
6302 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
6303 AddToWorkList(X.getNode());
6306 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
6307 X = DAG.getNode(ISD::AND, SDLoc(X), VT,
6308 X, DAG.getConstant(SignBit, VT));
6309 AddToWorkList(X.getNode());
6311 SDValue Cst = DAG.getNode(ISD::BITCAST, SDLoc(N0),
6312 VT, N0.getOperand(0));
6313 Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
6314 Cst, DAG.getConstant(~SignBit, VT));
6315 AddToWorkList(Cst.getNode());
6317 return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
6321 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
6322 if (N0.getOpcode() == ISD::BUILD_PAIR) {
6323 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
6324 if (CombineLD.getNode())
6331 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
6332 EVT VT = N->getValueType(0);
6333 return CombineConsecutiveLoads(N, VT);
6336 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
6337 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
6338 /// destination element value type.
6339 SDValue DAGCombiner::
6340 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
6341 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
6343 // If this is already the right type, we're done.
6344 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
6346 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
6347 unsigned DstBitSize = DstEltVT.getSizeInBits();
6349 // If this is a conversion of N elements of one type to N elements of another
6350 // type, convert each element. This handles FP<->INT cases.
6351 if (SrcBitSize == DstBitSize) {
6352 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
6353 BV->getValueType(0).getVectorNumElements());
6355 // Due to the FP element handling below calling this routine recursively,
6356 // we can end up with a scalar-to-vector node here.
6357 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
6358 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
6359 DAG.getNode(ISD::BITCAST, SDLoc(BV),
6360 DstEltVT, BV->getOperand(0)));
6362 SmallVector<SDValue, 8> Ops;
6363 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
6364 SDValue Op = BV->getOperand(i);
6365 // If the vector element type is not legal, the BUILD_VECTOR operands
6366 // are promoted and implicitly truncated. Make that explicit here.
6367 if (Op.getValueType() != SrcEltVT)
6368 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
6369 Ops.push_back(DAG.getNode(ISD::BITCAST, SDLoc(BV),
6371 AddToWorkList(Ops.back().getNode());
6373 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT, Ops);
6376 // Otherwise, we're growing or shrinking the elements. To avoid having to
6377 // handle annoying details of growing/shrinking FP values, we convert them to
6379 if (SrcEltVT.isFloatingPoint()) {
6380 // Convert the input float vector to a int vector where the elements are the
6382 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
6383 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
6384 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
6388 // Now we know the input is an integer vector. If the output is a FP type,
6389 // convert to integer first, then to FP of the right size.
6390 if (DstEltVT.isFloatingPoint()) {
6391 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
6392 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
6393 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
6395 // Next, convert to FP elements of the same size.
6396 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
6399 // Okay, we know the src/dst types are both integers of differing types.
6400 // Handling growing first.
6401 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
6402 if (SrcBitSize < DstBitSize) {
6403 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
6405 SmallVector<SDValue, 8> Ops;
6406 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
6407 i += NumInputsPerOutput) {
6408 bool isLE = TLI.isLittleEndian();
6409 APInt NewBits = APInt(DstBitSize, 0);
6410 bool EltIsUndef = true;
6411 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
6412 // Shift the previously computed bits over.
6413 NewBits <<= SrcBitSize;
6414 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
6415 if (Op.getOpcode() == ISD::UNDEF) continue;
6418 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
6419 zextOrTrunc(SrcBitSize).zext(DstBitSize);
6423 Ops.push_back(DAG.getUNDEF(DstEltVT));
6425 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
6428 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
6429 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT, Ops);
6432 // Finally, this must be the case where we are shrinking elements: each input
6433 // turns into multiple outputs.
6434 bool isS2V = ISD::isScalarToVector(BV);
6435 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
6436 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
6437 NumOutputsPerInput*BV->getNumOperands());
6438 SmallVector<SDValue, 8> Ops;
6440 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
6441 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
6442 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
6443 Ops.push_back(DAG.getUNDEF(DstEltVT));
6447 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
6448 getAPIntValue().zextOrTrunc(SrcBitSize);
6450 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
6451 APInt ThisVal = OpVal.trunc(DstBitSize);
6452 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
6453 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
6454 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
6455 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
6457 OpVal = OpVal.lshr(DstBitSize);
6460 // For big endian targets, swap the order of the pieces of each element.
6461 if (TLI.isBigEndian())
6462 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
6465 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT, Ops);
6468 SDValue DAGCombiner::visitFADD(SDNode *N) {
6469 SDValue N0 = N->getOperand(0);
6470 SDValue N1 = N->getOperand(1);
6471 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6472 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6473 EVT VT = N->getValueType(0);
6476 if (VT.isVector()) {
6477 SDValue FoldedVOp = SimplifyVBinOp(N);
6478 if (FoldedVOp.getNode()) return FoldedVOp;
6481 // fold (fadd c1, c2) -> c1 + c2
6483 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N1);
6484 // canonicalize constant to RHS
6485 if (N0CFP && !N1CFP)
6486 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N0);
6487 // fold (fadd A, 0) -> A
6488 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6489 N1CFP->getValueAPF().isZero())
6491 // fold (fadd A, (fneg B)) -> (fsub A, B)
6492 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
6493 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
6494 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0,
6495 GetNegatedExpression(N1, DAG, LegalOperations));
6496 // fold (fadd (fneg A), B) -> (fsub B, A)
6497 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
6498 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
6499 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N1,
6500 GetNegatedExpression(N0, DAG, LegalOperations));
6502 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
6503 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6504 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
6505 isa<ConstantFPSDNode>(N0.getOperand(1)))
6506 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0.getOperand(0),
6507 DAG.getNode(ISD::FADD, SDLoc(N), VT,
6508 N0.getOperand(1), N1));
6510 // No FP constant should be created after legalization as Instruction
6511 // Selection pass has hard time in dealing with FP constant.
6513 // We don't need test this condition for transformation like following, as
6514 // the DAG being transformed implies it is legal to take FP constant as
6517 // (fadd (fmul c, x), x) -> (fmul c+1, x)
6519 bool AllowNewFpConst = (Level < AfterLegalizeDAG);
6521 // If allow, fold (fadd (fneg x), x) -> 0.0
6522 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
6523 N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
6524 return DAG.getConstantFP(0.0, VT);
6526 // If allow, fold (fadd x, (fneg x)) -> 0.0
6527 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
6528 N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
6529 return DAG.getConstantFP(0.0, VT);
6531 // In unsafe math mode, we can fold chains of FADD's of the same value
6532 // into multiplications. This transform is not safe in general because
6533 // we are reducing the number of rounding steps.
6534 if (DAG.getTarget().Options.UnsafeFPMath &&
6535 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
6537 if (N0.getOpcode() == ISD::FMUL) {
6538 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
6539 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6541 // (fadd (fmul c, x), x) -> (fmul x, c+1)
6542 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
6543 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6545 DAG.getConstantFP(1.0, VT));
6546 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6550 // (fadd (fmul x, c), x) -> (fmul x, c+1)
6551 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
6552 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6554 DAG.getConstantFP(1.0, VT));
6555 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6559 // (fadd (fmul c, x), (fadd x, x)) -> (fmul x, c+2)
6560 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
6561 N1.getOperand(0) == N1.getOperand(1) &&
6562 N0.getOperand(1) == N1.getOperand(0)) {
6563 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6565 DAG.getConstantFP(2.0, VT));
6566 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6567 N0.getOperand(1), NewCFP);
6570 // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
6571 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
6572 N1.getOperand(0) == N1.getOperand(1) &&
6573 N0.getOperand(0) == N1.getOperand(0)) {
6574 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6576 DAG.getConstantFP(2.0, VT));
6577 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6578 N0.getOperand(0), NewCFP);
6582 if (N1.getOpcode() == ISD::FMUL) {
6583 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6584 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
6586 // (fadd x, (fmul c, x)) -> (fmul x, c+1)
6587 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
6588 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6590 DAG.getConstantFP(1.0, VT));
6591 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6595 // (fadd x, (fmul x, c)) -> (fmul x, c+1)
6596 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
6597 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6599 DAG.getConstantFP(1.0, VT));
6600 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6605 // (fadd (fadd x, x), (fmul c, x)) -> (fmul x, c+2)
6606 if (CFP10 && !CFP11 && N0.getOpcode() == ISD::FADD &&
6607 N0.getOperand(0) == N0.getOperand(1) &&
6608 N1.getOperand(1) == N0.getOperand(0)) {
6609 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6611 DAG.getConstantFP(2.0, VT));
6612 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6613 N1.getOperand(1), NewCFP);
6616 // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
6617 if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
6618 N0.getOperand(0) == N0.getOperand(1) &&
6619 N1.getOperand(0) == N0.getOperand(0)) {
6620 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6622 DAG.getConstantFP(2.0, VT));
6623 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6624 N1.getOperand(0), NewCFP);
6628 if (N0.getOpcode() == ISD::FADD && AllowNewFpConst) {
6629 ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
6630 // (fadd (fadd x, x), x) -> (fmul x, 3.0)
6631 if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
6632 (N0.getOperand(0) == N1))
6633 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6634 N1, DAG.getConstantFP(3.0, VT));
6637 if (N1.getOpcode() == ISD::FADD && AllowNewFpConst) {
6638 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6639 // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
6640 if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
6641 N1.getOperand(0) == N0)
6642 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6643 N0, DAG.getConstantFP(3.0, VT));
6646 // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
6647 if (AllowNewFpConst &&
6648 N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
6649 N0.getOperand(0) == N0.getOperand(1) &&
6650 N1.getOperand(0) == N1.getOperand(1) &&
6651 N0.getOperand(0) == N1.getOperand(0))
6652 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6654 DAG.getConstantFP(4.0, VT));
6657 // FADD -> FMA combines:
6658 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6659 DAG.getTarget().Options.UnsafeFPMath) &&
6660 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6661 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6663 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
6664 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6665 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6666 N0.getOperand(0), N0.getOperand(1), N1);
6668 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
6669 // Note: Commutes FADD operands.
6670 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6671 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6672 N1.getOperand(0), N1.getOperand(1), N0);
6678 SDValue DAGCombiner::visitFSUB(SDNode *N) {
6679 SDValue N0 = N->getOperand(0);
6680 SDValue N1 = N->getOperand(1);
6681 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6682 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6683 EVT VT = N->getValueType(0);
6687 if (VT.isVector()) {
6688 SDValue FoldedVOp = SimplifyVBinOp(N);
6689 if (FoldedVOp.getNode()) return FoldedVOp;
6692 // fold (fsub c1, c2) -> c1-c2
6694 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0, N1);
6695 // fold (fsub A, 0) -> A
6696 if (DAG.getTarget().Options.UnsafeFPMath &&
6697 N1CFP && N1CFP->getValueAPF().isZero())
6699 // fold (fsub 0, B) -> -B
6700 if (DAG.getTarget().Options.UnsafeFPMath &&
6701 N0CFP && N0CFP->getValueAPF().isZero()) {
6702 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6703 return GetNegatedExpression(N1, DAG, LegalOperations);
6704 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6705 return DAG.getNode(ISD::FNEG, dl, VT, N1);
6707 // fold (fsub A, (fneg B)) -> (fadd A, B)
6708 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6709 return DAG.getNode(ISD::FADD, dl, VT, N0,
6710 GetNegatedExpression(N1, DAG, LegalOperations));
6712 // If 'unsafe math' is enabled, fold
6713 // (fsub x, x) -> 0.0 &
6714 // (fsub x, (fadd x, y)) -> (fneg y) &
6715 // (fsub x, (fadd y, x)) -> (fneg y)
6716 if (DAG.getTarget().Options.UnsafeFPMath) {
6718 return DAG.getConstantFP(0.0f, VT);
6720 if (N1.getOpcode() == ISD::FADD) {
6721 SDValue N10 = N1->getOperand(0);
6722 SDValue N11 = N1->getOperand(1);
6724 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
6725 &DAG.getTarget().Options))
6726 return GetNegatedExpression(N11, DAG, LegalOperations);
6728 if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
6729 &DAG.getTarget().Options))
6730 return GetNegatedExpression(N10, DAG, LegalOperations);
6734 // FSUB -> FMA combines:
6735 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6736 DAG.getTarget().Options.UnsafeFPMath) &&
6737 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6738 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6740 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
6741 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6742 return DAG.getNode(ISD::FMA, dl, VT,
6743 N0.getOperand(0), N0.getOperand(1),
6744 DAG.getNode(ISD::FNEG, dl, VT, N1));
6746 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
6747 // Note: Commutes FSUB operands.
6748 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6749 return DAG.getNode(ISD::FMA, dl, VT,
6750 DAG.getNode(ISD::FNEG, dl, VT,
6752 N1.getOperand(1), N0);
6754 // fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
6755 if (N0.getOpcode() == ISD::FNEG &&
6756 N0.getOperand(0).getOpcode() == ISD::FMUL &&
6757 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
6758 SDValue N00 = N0.getOperand(0).getOperand(0);
6759 SDValue N01 = N0.getOperand(0).getOperand(1);
6760 return DAG.getNode(ISD::FMA, dl, VT,
6761 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
6762 DAG.getNode(ISD::FNEG, dl, VT, N1));
6769 SDValue DAGCombiner::visitFMUL(SDNode *N) {
6770 SDValue N0 = N->getOperand(0);
6771 SDValue N1 = N->getOperand(1);
6772 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6773 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6774 EVT VT = N->getValueType(0);
6775 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6778 if (VT.isVector()) {
6779 SDValue FoldedVOp = SimplifyVBinOp(N);
6780 if (FoldedVOp.getNode()) return FoldedVOp;
6783 // fold (fmul c1, c2) -> c1*c2
6785 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0, N1);
6786 // canonicalize constant to RHS
6787 if (N0CFP && !N1CFP)
6788 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1, N0);
6789 // fold (fmul A, 0) -> 0
6790 if (DAG.getTarget().Options.UnsafeFPMath &&
6791 N1CFP && N1CFP->getValueAPF().isZero())
6793 // fold (fmul A, 0) -> 0, vector edition.
6794 if (DAG.getTarget().Options.UnsafeFPMath &&
6795 ISD::isBuildVectorAllZeros(N1.getNode()))
6797 // fold (fmul A, 1.0) -> A
6798 if (N1CFP && N1CFP->isExactlyValue(1.0))
6800 // fold (fmul X, 2.0) -> (fadd X, X)
6801 if (N1CFP && N1CFP->isExactlyValue(+2.0))
6802 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N0);
6803 // fold (fmul X, -1.0) -> (fneg X)
6804 if (N1CFP && N1CFP->isExactlyValue(-1.0))
6805 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6806 return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
6808 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
6809 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6810 &DAG.getTarget().Options)) {
6811 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6812 &DAG.getTarget().Options)) {
6813 // Both can be negated for free, check to see if at least one is cheaper
6815 if (LHSNeg == 2 || RHSNeg == 2)
6816 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6817 GetNegatedExpression(N0, DAG, LegalOperations),
6818 GetNegatedExpression(N1, DAG, LegalOperations));
6822 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
6823 if (DAG.getTarget().Options.UnsafeFPMath &&
6824 N1CFP && N0.getOpcode() == ISD::FMUL &&
6825 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
6826 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
6827 DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6828 N0.getOperand(1), N1));
6833 SDValue DAGCombiner::visitFMA(SDNode *N) {
6834 SDValue N0 = N->getOperand(0);
6835 SDValue N1 = N->getOperand(1);
6836 SDValue N2 = N->getOperand(2);
6837 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6838 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6839 EVT VT = N->getValueType(0);
6842 if (DAG.getTarget().Options.UnsafeFPMath) {
6843 if (N0CFP && N0CFP->isZero())
6845 if (N1CFP && N1CFP->isZero())
6848 if (N0CFP && N0CFP->isExactlyValue(1.0))
6849 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
6850 if (N1CFP && N1CFP->isExactlyValue(1.0))
6851 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);
6853 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6854 if (N0CFP && !N1CFP)
6855 return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
6857 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6858 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6859 N2.getOpcode() == ISD::FMUL &&
6860 N0 == N2.getOperand(0) &&
6861 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6862 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6863 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6867 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6868 if (DAG.getTarget().Options.UnsafeFPMath &&
6869 N0.getOpcode() == ISD::FMUL && N1CFP &&
6870 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6871 return DAG.getNode(ISD::FMA, dl, VT,
6873 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6877 // (fma x, 1, y) -> (fadd x, y)
6878 // (fma x, -1, y) -> (fadd (fneg x), y)
6880 if (N1CFP->isExactlyValue(1.0))
6881 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6883 if (N1CFP->isExactlyValue(-1.0) &&
6884 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6885 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6886 AddToWorkList(RHSNeg.getNode());
6887 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6891 // (fma x, c, x) -> (fmul x, (c+1))
6892 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2)
6893 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6894 DAG.getNode(ISD::FADD, dl, VT,
6895 N1, DAG.getConstantFP(1.0, VT)));
6897 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6898 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6899 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
6900 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6901 DAG.getNode(ISD::FADD, dl, VT,
6902 N1, DAG.getConstantFP(-1.0, VT)));
6908 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6909 SDValue N0 = N->getOperand(0);
6910 SDValue N1 = N->getOperand(1);
6911 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6912 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6913 EVT VT = N->getValueType(0);
6914 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6917 if (VT.isVector()) {
6918 SDValue FoldedVOp = SimplifyVBinOp(N);
6919 if (FoldedVOp.getNode()) return FoldedVOp;
6922 // fold (fdiv c1, c2) -> c1/c2
6924 return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
6926 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6927 if (N1CFP && DAG.getTarget().Options.UnsafeFPMath) {
6928 // Compute the reciprocal 1.0 / c2.
6929 APFloat N1APF = N1CFP->getValueAPF();
6930 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6931 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6932 // Only do the transform if the reciprocal is a legal fp immediate that
6933 // isn't too nasty (eg NaN, denormal, ...).
6934 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6935 (!LegalOperations ||
6936 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6937 // backend)... we should handle this gracefully after Legalize.
6938 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6939 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6940 TLI.isFPImmLegal(Recip, VT)))
6941 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0,
6942 DAG.getConstantFP(Recip, VT));
6945 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6946 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6947 &DAG.getTarget().Options)) {
6948 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6949 &DAG.getTarget().Options)) {
6950 // Both can be negated for free, check to see if at least one is cheaper
6952 if (LHSNeg == 2 || RHSNeg == 2)
6953 return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
6954 GetNegatedExpression(N0, DAG, LegalOperations),
6955 GetNegatedExpression(N1, DAG, LegalOperations));
6962 SDValue DAGCombiner::visitFREM(SDNode *N) {
6963 SDValue N0 = N->getOperand(0);
6964 SDValue N1 = N->getOperand(1);
6965 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6966 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6967 EVT VT = N->getValueType(0);
6969 // fold (frem c1, c2) -> fmod(c1,c2)
6971 return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1);
6976 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6977 SDValue N0 = N->getOperand(0);
6978 SDValue N1 = N->getOperand(1);
6979 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6980 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6981 EVT VT = N->getValueType(0);
6983 if (N0CFP && N1CFP) // Constant fold
6984 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);
6987 const APFloat& V = N1CFP->getValueAPF();
6988 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6989 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6990 if (!V.isNegative()) {
6991 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6992 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6994 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6995 return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
6996 DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
7000 // copysign(fabs(x), y) -> copysign(x, y)
7001 // copysign(fneg(x), y) -> copysign(x, y)
7002 // copysign(copysign(x,z), y) -> copysign(x, y)
7003 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
7004 N0.getOpcode() == ISD::FCOPYSIGN)
7005 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
7006 N0.getOperand(0), N1);
7008 // copysign(x, abs(y)) -> abs(x)
7009 if (N1.getOpcode() == ISD::FABS)
7010 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
7012 // copysign(x, copysign(y,z)) -> copysign(x, z)
7013 if (N1.getOpcode() == ISD::FCOPYSIGN)
7014 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
7015 N0, N1.getOperand(1));
7017 // copysign(x, fp_extend(y)) -> copysign(x, y)
7018 // copysign(x, fp_round(y)) -> copysign(x, y)
7019 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
7020 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
7021 N0, N1.getOperand(0));
7026 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
7027 SDValue N0 = N->getOperand(0);
7028 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
7029 EVT VT = N->getValueType(0);
7030 EVT OpVT = N0.getValueType();
7032 // fold (sint_to_fp c1) -> c1fp
7034 // ...but only if the target supports immediate floating-point values
7035 (!LegalOperations ||
7036 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
7037 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
7039 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
7040 // but UINT_TO_FP is legal on this target, try to convert.
7041 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
7042 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
7043 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
7044 if (DAG.SignBitIsZero(N0))
7045 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
7048 // The next optimizations are desirable only if SELECT_CC can be lowered.
7049 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
7050 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
7051 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
7053 (!LegalOperations ||
7054 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
7056 { N0.getOperand(0), N0.getOperand(1),
7057 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
7059 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops);
7062 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
7063 // (select_cc x, y, 1.0, 0.0,, cc)
7064 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
7065 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
7066 (!LegalOperations ||
7067 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
7069 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
7070 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
7071 N0.getOperand(0).getOperand(2) };
7072 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops);
7079 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
7080 SDValue N0 = N->getOperand(0);
7081 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
7082 EVT VT = N->getValueType(0);
7083 EVT OpVT = N0.getValueType();
7085 // fold (uint_to_fp c1) -> c1fp
7087 // ...but only if the target supports immediate floating-point values
7088 (!LegalOperations ||
7089 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
7090 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
7092 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
7093 // but SINT_TO_FP is legal on this target, try to convert.
7094 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
7095 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
7096 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
7097 if (DAG.SignBitIsZero(N0))
7098 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
7101 // The next optimizations are desirable only if SELECT_CC can be lowered.
7102 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
7103 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
7105 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
7106 (!LegalOperations ||
7107 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
7109 { N0.getOperand(0), N0.getOperand(1),
7110 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
7112 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops);
7119 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
7120 SDValue N0 = N->getOperand(0);
7121 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7122 EVT VT = N->getValueType(0);
7124 // fold (fp_to_sint c1fp) -> c1
7126 return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
7131 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
7132 SDValue N0 = N->getOperand(0);
7133 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7134 EVT VT = N->getValueType(0);
7136 // fold (fp_to_uint c1fp) -> c1
7138 return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);
7143 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
7144 SDValue N0 = N->getOperand(0);
7145 SDValue N1 = N->getOperand(1);
7146 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7147 EVT VT = N->getValueType(0);
7149 // fold (fp_round c1fp) -> c1fp
7151 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);
7153 // fold (fp_round (fp_extend x)) -> x
7154 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
7155 return N0.getOperand(0);
7157 // fold (fp_round (fp_round x)) -> (fp_round x)
7158 if (N0.getOpcode() == ISD::FP_ROUND) {
7159 // This is a value preserving truncation if both round's are.
7160 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
7161 N0.getNode()->getConstantOperandVal(1) == 1;
7162 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0.getOperand(0),
7163 DAG.getIntPtrConstant(IsTrunc));
7166 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
7167 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
7168 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
7169 N0.getOperand(0), N1);
7170 AddToWorkList(Tmp.getNode());
7171 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
7172 Tmp, N0.getOperand(1));
7178 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
7179 SDValue N0 = N->getOperand(0);
7180 EVT VT = N->getValueType(0);
7181 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
7182 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7184 // fold (fp_round_inreg c1fp) -> c1fp
7185 if (N0CFP && isTypeLegal(EVT)) {
7186 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
7187 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, Round);
7193 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
7194 SDValue N0 = N->getOperand(0);
7195 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7196 EVT VT = N->getValueType(0);
7198 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
7199 if (N->hasOneUse() &&
7200 N->use_begin()->getOpcode() == ISD::FP_ROUND)
7203 // fold (fp_extend c1fp) -> c1fp
7205 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);
7207 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
7209 if (N0.getOpcode() == ISD::FP_ROUND
7210 && N0.getNode()->getConstantOperandVal(1) == 1) {
7211 SDValue In = N0.getOperand(0);
7212 if (In.getValueType() == VT) return In;
7213 if (VT.bitsLT(In.getValueType()))
7214 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
7215 In, N0.getOperand(1));
7216 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
7219 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
7220 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7221 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
7222 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
7223 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
7224 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
7226 LN0->getBasePtr(), N0.getValueType(),
7227 LN0->getMemOperand());
7228 CombineTo(N, ExtLoad);
7229 CombineTo(N0.getNode(),
7230 DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
7231 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
7232 ExtLoad.getValue(1));
7233 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7239 SDValue DAGCombiner::visitFNEG(SDNode *N) {
7240 SDValue N0 = N->getOperand(0);
7241 EVT VT = N->getValueType(0);
7243 if (VT.isVector()) {
7244 SDValue FoldedVOp = SimplifyVUnaryOp(N);
7245 if (FoldedVOp.getNode()) return FoldedVOp;
7248 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
7249 &DAG.getTarget().Options))
7250 return GetNegatedExpression(N0, DAG, LegalOperations);
7252 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
7253 // constant pool values.
7254 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
7256 N0.getNode()->hasOneUse() &&
7257 N0.getOperand(0).getValueType().isInteger()) {
7258 SDValue Int = N0.getOperand(0);
7259 EVT IntVT = Int.getValueType();
7260 if (IntVT.isInteger() && !IntVT.isVector()) {
7261 Int = DAG.getNode(ISD::XOR, SDLoc(N0), IntVT, Int,
7262 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
7263 AddToWorkList(Int.getNode());
7264 return DAG.getNode(ISD::BITCAST, SDLoc(N),
7269 // (fneg (fmul c, x)) -> (fmul -c, x)
7270 if (N0.getOpcode() == ISD::FMUL) {
7271 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
7273 APFloat CVal = CFP1->getValueAPF();
7275 if (Level >= AfterLegalizeDAG &&
7276 (TLI.isFPImmLegal(CVal, N->getValueType(0)) ||
7277 TLI.isOperationLegal(ISD::ConstantFP, N->getValueType(0))))
7279 ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
7280 DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0.getOperand(1)));
7287 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
7288 SDValue N0 = N->getOperand(0);
7289 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7290 EVT VT = N->getValueType(0);
7292 // fold (fceil c1) -> fceil(c1)
7294 return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
7299 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
7300 SDValue N0 = N->getOperand(0);
7301 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7302 EVT VT = N->getValueType(0);
7304 // fold (ftrunc c1) -> ftrunc(c1)
7306 return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
7311 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
7312 SDValue N0 = N->getOperand(0);
7313 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7314 EVT VT = N->getValueType(0);
7316 // fold (ffloor c1) -> ffloor(c1)
7318 return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
7323 SDValue DAGCombiner::visitFABS(SDNode *N) {
7324 SDValue N0 = N->getOperand(0);
7325 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
7326 EVT VT = N->getValueType(0);
7328 if (VT.isVector()) {
7329 SDValue FoldedVOp = SimplifyVUnaryOp(N);
7330 if (FoldedVOp.getNode()) return FoldedVOp;
7333 // fold (fabs c1) -> fabs(c1)
7335 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
7336 // fold (fabs (fabs x)) -> (fabs x)
7337 if (N0.getOpcode() == ISD::FABS)
7338 return N->getOperand(0);
7339 // fold (fabs (fneg x)) -> (fabs x)
7340 // fold (fabs (fcopysign x, y)) -> (fabs x)
7341 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
7342 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));
7344 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
7345 // constant pool values.
7346 if (!TLI.isFAbsFree(VT) &&
7347 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
7348 N0.getOperand(0).getValueType().isInteger() &&
7349 !N0.getOperand(0).getValueType().isVector()) {
7350 SDValue Int = N0.getOperand(0);
7351 EVT IntVT = Int.getValueType();
7352 if (IntVT.isInteger() && !IntVT.isVector()) {
7353 Int = DAG.getNode(ISD::AND, SDLoc(N0), IntVT, Int,
7354 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
7355 AddToWorkList(Int.getNode());
7356 return DAG.getNode(ISD::BITCAST, SDLoc(N),
7357 N->getValueType(0), Int);
7364 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
7365 SDValue Chain = N->getOperand(0);
7366 SDValue N1 = N->getOperand(1);
7367 SDValue N2 = N->getOperand(2);
7369 // If N is a constant we could fold this into a fallthrough or unconditional
7370 // branch. However that doesn't happen very often in normal code, because
7371 // Instcombine/SimplifyCFG should have handled the available opportunities.
7372 // If we did this folding here, it would be necessary to update the
7373 // MachineBasicBlock CFG, which is awkward.
7375 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
7377 if (N1.getOpcode() == ISD::SETCC &&
7378 TLI.isOperationLegalOrCustom(ISD::BR_CC,
7379 N1.getOperand(0).getValueType())) {
7380 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
7381 Chain, N1.getOperand(2),
7382 N1.getOperand(0), N1.getOperand(1), N2);
7385 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
7386 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
7387 (N1.getOperand(0).hasOneUse() &&
7388 N1.getOperand(0).getOpcode() == ISD::SRL))) {
7389 SDNode *Trunc = nullptr;
7390 if (N1.getOpcode() == ISD::TRUNCATE) {
7391 // Look pass the truncate.
7392 Trunc = N1.getNode();
7393 N1 = N1.getOperand(0);
7396 // Match this pattern so that we can generate simpler code:
7399 // %b = and i32 %a, 2
7400 // %c = srl i32 %b, 1
7401 // brcond i32 %c ...
7406 // %b = and i32 %a, 2
7407 // %c = setcc eq %b, 0
7410 // This applies only when the AND constant value has one bit set and the
7411 // SRL constant is equal to the log2 of the AND constant. The back-end is
7412 // smart enough to convert the result into a TEST/JMP sequence.
7413 SDValue Op0 = N1.getOperand(0);
7414 SDValue Op1 = N1.getOperand(1);
7416 if (Op0.getOpcode() == ISD::AND &&
7417 Op1.getOpcode() == ISD::Constant) {
7418 SDValue AndOp1 = Op0.getOperand(1);
7420 if (AndOp1.getOpcode() == ISD::Constant) {
7421 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
7423 if (AndConst.isPowerOf2() &&
7424 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
7426 DAG.getSetCC(SDLoc(N),
7427 getSetCCResultType(Op0.getValueType()),
7428 Op0, DAG.getConstant(0, Op0.getValueType()),
7431 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, SDLoc(N),
7432 MVT::Other, Chain, SetCC, N2);
7433 // Don't add the new BRCond into the worklist or else SimplifySelectCC
7434 // will convert it back to (X & C1) >> C2.
7435 CombineTo(N, NewBRCond, false);
7436 // Truncate is dead.
7438 removeFromWorkList(Trunc);
7439 DAG.DeleteNode(Trunc);
7441 // Replace the uses of SRL with SETCC
7442 WorkListRemover DeadNodes(*this);
7443 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
7444 removeFromWorkList(N1.getNode());
7445 DAG.DeleteNode(N1.getNode());
7446 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7452 // Restore N1 if the above transformation doesn't match.
7453 N1 = N->getOperand(1);
7456 // Transform br(xor(x, y)) -> br(x != y)
7457 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
7458 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
7459 SDNode *TheXor = N1.getNode();
7460 SDValue Op0 = TheXor->getOperand(0);
7461 SDValue Op1 = TheXor->getOperand(1);
7462 if (Op0.getOpcode() == Op1.getOpcode()) {
7463 // Avoid missing important xor optimizations.
7464 SDValue Tmp = visitXOR(TheXor);
7465 if (Tmp.getNode()) {
7466 if (Tmp.getNode() != TheXor) {
7467 DEBUG(dbgs() << "\nReplacing.8 ";
7469 dbgs() << "\nWith: ";
7470 Tmp.getNode()->dump(&DAG);
7472 WorkListRemover DeadNodes(*this);
7473 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
7474 removeFromWorkList(TheXor);
7475 DAG.DeleteNode(TheXor);
7476 return DAG.getNode(ISD::BRCOND, SDLoc(N),
7477 MVT::Other, Chain, Tmp, N2);
7480 // visitXOR has changed XOR's operands or replaced the XOR completely,
7482 return SDValue(N, 0);
7486 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
7488 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
7489 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
7490 Op0.getOpcode() == ISD::XOR) {
7491 TheXor = Op0.getNode();
7495 EVT SetCCVT = N1.getValueType();
7497 SetCCVT = getSetCCResultType(SetCCVT);
7498 SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
7501 Equal ? ISD::SETEQ : ISD::SETNE);
7502 // Replace the uses of XOR with SETCC
7503 WorkListRemover DeadNodes(*this);
7504 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
7505 removeFromWorkList(N1.getNode());
7506 DAG.DeleteNode(N1.getNode());
7507 return DAG.getNode(ISD::BRCOND, SDLoc(N),
7508 MVT::Other, Chain, SetCC, N2);
7515 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
7517 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
7518 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
7519 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
7521 // If N is a constant we could fold this into a fallthrough or unconditional
7522 // branch. However that doesn't happen very often in normal code, because
7523 // Instcombine/SimplifyCFG should have handled the available opportunities.
7524 // If we did this folding here, it would be necessary to update the
7525 // MachineBasicBlock CFG, which is awkward.
7527 // Use SimplifySetCC to simplify SETCC's.
7528 SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
7529 CondLHS, CondRHS, CC->get(), SDLoc(N),
7531 if (Simp.getNode()) AddToWorkList(Simp.getNode());
7533 // fold to a simpler setcc
7534 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
7535 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
7536 N->getOperand(0), Simp.getOperand(2),
7537 Simp.getOperand(0), Simp.getOperand(1),
7543 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
7544 /// uses N as its base pointer and that N may be folded in the load / store
7545 /// addressing mode.
7546 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
7548 const TargetLowering &TLI) {
7550 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
7551 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
7553 VT = Use->getValueType(0);
7554 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
7555 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
7557 VT = ST->getValue().getValueType();
7561 TargetLowering::AddrMode AM;
7562 if (N->getOpcode() == ISD::ADD) {
7563 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
7566 AM.BaseOffs = Offset->getSExtValue();
7570 } else if (N->getOpcode() == ISD::SUB) {
7571 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
7574 AM.BaseOffs = -Offset->getSExtValue();
7581 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
7584 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
7585 /// pre-indexed load / store when the base pointer is an add or subtract
7586 /// and it has other uses besides the load / store. After the
7587 /// transformation, the new indexed load / store has effectively folded
7588 /// the add / subtract in and all of its other uses are redirected to the
7589 /// new load / store.
7590 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
7591 if (Level < AfterLegalizeDAG)
7597 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7598 if (LD->isIndexed())
7600 VT = LD->getMemoryVT();
7601 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
7602 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
7604 Ptr = LD->getBasePtr();
7605 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7606 if (ST->isIndexed())
7608 VT = ST->getMemoryVT();
7609 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
7610 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
7612 Ptr = ST->getBasePtr();
7618 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
7619 // out. There is no reason to make this a preinc/predec.
7620 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
7621 Ptr.getNode()->hasOneUse())
7624 // Ask the target to do addressing mode selection.
7627 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7628 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
7631 // Backends without true r+i pre-indexed forms may need to pass a
7632 // constant base with a variable offset so that constant coercion
7633 // will work with the patterns in canonical form.
7634 bool Swapped = false;
7635 if (isa<ConstantSDNode>(BasePtr)) {
7636 std::swap(BasePtr, Offset);
7640 // Don't create a indexed load / store with zero offset.
7641 if (isa<ConstantSDNode>(Offset) &&
7642 cast<ConstantSDNode>(Offset)->isNullValue())
7645 // Try turning it into a pre-indexed load / store except when:
7646 // 1) The new base ptr is a frame index.
7647 // 2) If N is a store and the new base ptr is either the same as or is a
7648 // predecessor of the value being stored.
7649 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
7650 // that would create a cycle.
7651 // 4) All uses are load / store ops that use it as old base ptr.
7653 // Check #1. Preinc'ing a frame index would require copying the stack pointer
7654 // (plus the implicit offset) to a register to preinc anyway.
7655 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7660 SDValue Val = cast<StoreSDNode>(N)->getValue();
7661 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
7665 // If the offset is a constant, there may be other adds of constants that
7666 // can be folded with this one. We should do this to avoid having to keep
7667 // a copy of the original base pointer.
7668 SmallVector<SDNode *, 16> OtherUses;
7669 if (isa<ConstantSDNode>(Offset))
7670 for (SDNode *Use : BasePtr.getNode()->uses()) {
7671 if (Use == Ptr.getNode())
7674 if (Use->isPredecessorOf(N))
7677 if (Use->getOpcode() != ISD::ADD && Use->getOpcode() != ISD::SUB) {
7682 SDValue Op0 = Use->getOperand(0), Op1 = Use->getOperand(1);
7683 if (Op1.getNode() == BasePtr.getNode())
7684 std::swap(Op0, Op1);
7685 assert(Op0.getNode() == BasePtr.getNode() &&
7686 "Use of ADD/SUB but not an operand");
7688 if (!isa<ConstantSDNode>(Op1)) {
7693 // FIXME: In some cases, we can be smarter about this.
7694 if (Op1.getValueType() != Offset.getValueType()) {
7699 OtherUses.push_back(Use);
7703 std::swap(BasePtr, Offset);
7705 // Now check for #3 and #4.
7706 bool RealUse = false;
7708 // Caches for hasPredecessorHelper
7709 SmallPtrSet<const SDNode *, 32> Visited;
7710 SmallVector<const SDNode *, 16> Worklist;
7712 for (SDNode *Use : Ptr.getNode()->uses()) {
7715 if (N->hasPredecessorHelper(Use, Visited, Worklist))
7718 // If Ptr may be folded in addressing mode of other use, then it's
7719 // not profitable to do this transformation.
7720 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
7729 Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7730 BasePtr, Offset, AM);
7732 Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7733 BasePtr, Offset, AM);
7736 DEBUG(dbgs() << "\nReplacing.4 ";
7738 dbgs() << "\nWith: ";
7739 Result.getNode()->dump(&DAG);
7741 WorkListRemover DeadNodes(*this);
7743 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7744 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7746 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7749 // Finally, since the node is now dead, remove it from the graph.
7753 std::swap(BasePtr, Offset);
7755 // Replace other uses of BasePtr that can be updated to use Ptr
7756 for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
7757 unsigned OffsetIdx = 1;
7758 if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
7760 assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==
7761 BasePtr.getNode() && "Expected BasePtr operand");
7763 // We need to replace ptr0 in the following expression:
7764 // x0 * offset0 + y0 * ptr0 = t0
7766 // x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
7768 // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
7769 // indexed load/store and the expresion that needs to be re-written.
7771 // Therefore, we have:
7772 // t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1
7774 ConstantSDNode *CN =
7775 cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
7777 APInt Offset0 = CN->getAPIntValue();
7778 APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();
7780 X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
7781 Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
7782 X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
7783 Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;
7785 unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;
7787 APInt CNV = Offset0;
7788 if (X0 < 0) CNV = -CNV;
7789 if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
7790 else CNV = CNV - Offset1;
7792 // We can now generate the new expression.
7793 SDValue NewOp1 = DAG.getConstant(CNV, CN->getValueType(0));
7794 SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);
7796 SDValue NewUse = DAG.getNode(Opcode,
7797 SDLoc(OtherUses[i]),
7798 OtherUses[i]->getValueType(0), NewOp1, NewOp2);
7799 DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
7800 removeFromWorkList(OtherUses[i]);
7801 DAG.DeleteNode(OtherUses[i]);
7804 // Replace the uses of Ptr with uses of the updated base value.
7805 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
7806 removeFromWorkList(Ptr.getNode());
7807 DAG.DeleteNode(Ptr.getNode());
7812 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
7813 /// add / sub of the base pointer node into a post-indexed load / store.
7814 /// The transformation folded the add / subtract into the new indexed
7815 /// load / store effectively and all of its uses are redirected to the
7816 /// new load / store.
7817 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
7818 if (Level < AfterLegalizeDAG)
7824 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7825 if (LD->isIndexed())
7827 VT = LD->getMemoryVT();
7828 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
7829 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
7831 Ptr = LD->getBasePtr();
7832 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7833 if (ST->isIndexed())
7835 VT = ST->getMemoryVT();
7836 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
7837 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
7839 Ptr = ST->getBasePtr();
7845 if (Ptr.getNode()->hasOneUse())
7848 for (SDNode *Op : Ptr.getNode()->uses()) {
7850 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
7855 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7856 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
7857 // Don't create a indexed load / store with zero offset.
7858 if (isa<ConstantSDNode>(Offset) &&
7859 cast<ConstantSDNode>(Offset)->isNullValue())
7862 // Try turning it into a post-indexed load / store except when
7863 // 1) All uses are load / store ops that use it as base ptr (and
7864 // it may be folded as addressing mmode).
7865 // 2) Op must be independent of N, i.e. Op is neither a predecessor
7866 // nor a successor of N. Otherwise, if Op is folded that would
7869 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7873 bool TryNext = false;
7874 for (SDNode *Use : BasePtr.getNode()->uses()) {
7875 if (Use == Ptr.getNode())
7878 // If all the uses are load / store addresses, then don't do the
7880 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
7881 bool RealUse = false;
7882 for (SDNode *UseUse : Use->uses()) {
7883 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
7898 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
7899 SDValue Result = isLoad
7900 ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7901 BasePtr, Offset, AM)
7902 : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7903 BasePtr, Offset, AM);
7906 DEBUG(dbgs() << "\nReplacing.5 ";
7908 dbgs() << "\nWith: ";
7909 Result.getNode()->dump(&DAG);
7911 WorkListRemover DeadNodes(*this);
7913 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7914 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7916 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7919 // Finally, since the node is now dead, remove it from the graph.
7922 // Replace the uses of Use with uses of the updated base value.
7923 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
7924 Result.getValue(isLoad ? 1 : 0));
7925 removeFromWorkList(Op);
7935 SDValue DAGCombiner::visitLOAD(SDNode *N) {
7936 LoadSDNode *LD = cast<LoadSDNode>(N);
7937 SDValue Chain = LD->getChain();
7938 SDValue Ptr = LD->getBasePtr();
7940 // If load is not volatile and there are no uses of the loaded value (and
7941 // the updated indexed value in case of indexed loads), change uses of the
7942 // chain value into uses of the chain input (i.e. delete the dead load).
7943 if (!LD->isVolatile()) {
7944 if (N->getValueType(1) == MVT::Other) {
7946 if (!N->hasAnyUseOfValue(0)) {
7947 // It's not safe to use the two value CombineTo variant here. e.g.
7948 // v1, chain2 = load chain1, loc
7949 // v2, chain3 = load chain2, loc
7951 // Now we replace use of chain2 with chain1. This makes the second load
7952 // isomorphic to the one we are deleting, and thus makes this load live.
7953 DEBUG(dbgs() << "\nReplacing.6 ";
7955 dbgs() << "\nWith chain: ";
7956 Chain.getNode()->dump(&DAG);
7958 WorkListRemover DeadNodes(*this);
7959 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7961 if (N->use_empty()) {
7962 removeFromWorkList(N);
7966 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7970 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7971 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7972 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7973 DEBUG(dbgs() << "\nReplacing.7 ";
7975 dbgs() << "\nWith: ";
7976 Undef.getNode()->dump(&DAG);
7977 dbgs() << " and 2 other values\n");
7978 WorkListRemover DeadNodes(*this);
7979 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7980 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7981 DAG.getUNDEF(N->getValueType(1)));
7982 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7983 removeFromWorkList(N);
7985 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7990 // If this load is directly stored, replace the load value with the stored
7992 // TODO: Handle store large -> read small portion.
7993 // TODO: Handle TRUNCSTORE/LOADEXT
7994 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7995 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7996 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7997 if (PrevST->getBasePtr() == Ptr &&
7998 PrevST->getValue().getValueType() == N->getValueType(0))
7999 return CombineTo(N, Chain.getOperand(1), Chain);
8003 // Try to infer better alignment information than the load already has.
8004 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
8005 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
8006 if (Align > LD->getMemOperand()->getBaseAlignment()) {
8008 DAG.getExtLoad(LD->getExtensionType(), SDLoc(N),
8009 LD->getValueType(0),
8010 Chain, Ptr, LD->getPointerInfo(),
8012 LD->isVolatile(), LD->isNonTemporal(), Align,
8014 return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
8019 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
8020 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
8022 if (CombinerAAOnlyFunc.getNumOccurrences() &&
8023 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
8026 if (UseAA && LD->isUnindexed()) {
8027 // Walk up chain skipping non-aliasing memory nodes.
8028 SDValue BetterChain = FindBetterChain(N, Chain);
8030 // If there is a better chain.
8031 if (Chain != BetterChain) {
8034 // Replace the chain to void dependency.
8035 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
8036 ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
8037 BetterChain, Ptr, LD->getMemOperand());
8039 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
8040 LD->getValueType(0),
8041 BetterChain, Ptr, LD->getMemoryVT(),
8042 LD->getMemOperand());
8045 // Create token factor to keep old chain connected.
8046 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
8047 MVT::Other, Chain, ReplLoad.getValue(1));
8049 // Make sure the new and old chains are cleaned up.
8050 AddToWorkList(Token.getNode());
8052 // Replace uses with load result and token factor. Don't add users
8054 return CombineTo(N, ReplLoad.getValue(0), Token, false);
8058 // Try transforming N to an indexed load.
8059 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
8060 return SDValue(N, 0);
8062 // Try to slice up N to more direct loads if the slices are mapped to
8063 // different register banks or pairing can take place.
8065 return SDValue(N, 0);
8071 /// \brief Helper structure used to slice a load in smaller loads.
8072 /// Basically a slice is obtained from the following sequence:
8073 /// Origin = load Ty1, Base
8074 /// Shift = srl Ty1 Origin, CstTy Amount
8075 /// Inst = trunc Shift to Ty2
8077 /// Then, it will be rewriten into:
8078 /// Slice = load SliceTy, Base + SliceOffset
8079 /// [Inst = zext Slice to Ty2], only if SliceTy <> Ty2
8081 /// SliceTy is deduced from the number of bits that are actually used to
8083 struct LoadedSlice {
8084 /// \brief Helper structure used to compute the cost of a slice.
8086 /// Are we optimizing for code size.
8091 unsigned CrossRegisterBanksCopies;
8095 Cost(bool ForCodeSize = false)
8096 : ForCodeSize(ForCodeSize), Loads(0), Truncates(0),
8097 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {}
8099 /// \brief Get the cost of one isolated slice.
8100 Cost(const LoadedSlice &LS, bool ForCodeSize = false)
8101 : ForCodeSize(ForCodeSize), Loads(1), Truncates(0),
8102 CrossRegisterBanksCopies(0), ZExts(0), Shift(0) {
8103 EVT TruncType = LS.Inst->getValueType(0);
8104 EVT LoadedType = LS.getLoadedType();
8105 if (TruncType != LoadedType &&
8106 !LS.DAG->getTargetLoweringInfo().isZExtFree(LoadedType, TruncType))
8110 /// \brief Account for slicing gain in the current cost.
8111 /// Slicing provide a few gains like removing a shift or a
8112 /// truncate. This method allows to grow the cost of the original
8113 /// load with the gain from this slice.
8114 void addSliceGain(const LoadedSlice &LS) {
8115 // Each slice saves a truncate.
8116 const TargetLowering &TLI = LS.DAG->getTargetLoweringInfo();
8117 if (!TLI.isTruncateFree(LS.Inst->getValueType(0),
8118 LS.Inst->getOperand(0).getValueType()))
8120 // If there is a shift amount, this slice gets rid of it.
8123 // If this slice can merge a cross register bank copy, account for it.
8124 if (LS.canMergeExpensiveCrossRegisterBankCopy())
8125 ++CrossRegisterBanksCopies;
8128 Cost &operator+=(const Cost &RHS) {
8130 Truncates += RHS.Truncates;
8131 CrossRegisterBanksCopies += RHS.CrossRegisterBanksCopies;
8137 bool operator==(const Cost &RHS) const {
8138 return Loads == RHS.Loads && Truncates == RHS.Truncates &&
8139 CrossRegisterBanksCopies == RHS.CrossRegisterBanksCopies &&
8140 ZExts == RHS.ZExts && Shift == RHS.Shift;
8143 bool operator!=(const Cost &RHS) const { return !(*this == RHS); }
8145 bool operator<(const Cost &RHS) const {
8146 // Assume cross register banks copies are as expensive as loads.
8147 // FIXME: Do we want some more target hooks?
8148 unsigned ExpensiveOpsLHS = Loads + CrossRegisterBanksCopies;
8149 unsigned ExpensiveOpsRHS = RHS.Loads + RHS.CrossRegisterBanksCopies;
8150 // Unless we are optimizing for code size, consider the
8151 // expensive operation first.
8152 if (!ForCodeSize && ExpensiveOpsLHS != ExpensiveOpsRHS)
8153 return ExpensiveOpsLHS < ExpensiveOpsRHS;
8154 return (Truncates + ZExts + Shift + ExpensiveOpsLHS) <
8155 (RHS.Truncates + RHS.ZExts + RHS.Shift + ExpensiveOpsRHS);
8158 bool operator>(const Cost &RHS) const { return RHS < *this; }
8160 bool operator<=(const Cost &RHS) const { return !(RHS < *this); }
8162 bool operator>=(const Cost &RHS) const { return !(*this < RHS); }
8164 // The last instruction that represent the slice. This should be a
8165 // truncate instruction.
8167 // The original load instruction.
8169 // The right shift amount in bits from the original load.
8171 // The DAG from which Origin came from.
8172 // This is used to get some contextual information about legal types, etc.
8175 LoadedSlice(SDNode *Inst = nullptr, LoadSDNode *Origin = nullptr,
8176 unsigned Shift = 0, SelectionDAG *DAG = nullptr)
8177 : Inst(Inst), Origin(Origin), Shift(Shift), DAG(DAG) {}
8179 LoadedSlice(const LoadedSlice &LS)
8180 : Inst(LS.Inst), Origin(LS.Origin), Shift(LS.Shift), DAG(LS.DAG) {}
8182 /// \brief Get the bits used in a chunk of bits \p BitWidth large.
8183 /// \return Result is \p BitWidth and has used bits set to 1 and
8184 /// not used bits set to 0.
8185 APInt getUsedBits() const {
8186 // Reproduce the trunc(lshr) sequence:
8187 // - Start from the truncated value.
8188 // - Zero extend to the desired bit width.
8190 assert(Origin && "No original load to compare against.");
8191 unsigned BitWidth = Origin->getValueSizeInBits(0);
8192 assert(Inst && "This slice is not bound to an instruction");
8193 assert(Inst->getValueSizeInBits(0) <= BitWidth &&
8194 "Extracted slice is bigger than the whole type!");
8195 APInt UsedBits(Inst->getValueSizeInBits(0), 0);
8196 UsedBits.setAllBits();
8197 UsedBits = UsedBits.zext(BitWidth);
8202 /// \brief Get the size of the slice to be loaded in bytes.
8203 unsigned getLoadedSize() const {
8204 unsigned SliceSize = getUsedBits().countPopulation();
8205 assert(!(SliceSize & 0x7) && "Size is not a multiple of a byte.");
8206 return SliceSize / 8;
8209 /// \brief Get the type that will be loaded for this slice.
8210 /// Note: This may not be the final type for the slice.
8211 EVT getLoadedType() const {
8212 assert(DAG && "Missing context");
8213 LLVMContext &Ctxt = *DAG->getContext();
8214 return EVT::getIntegerVT(Ctxt, getLoadedSize() * 8);
8217 /// \brief Get the alignment of the load used for this slice.
8218 unsigned getAlignment() const {
8219 unsigned Alignment = Origin->getAlignment();
8220 unsigned Offset = getOffsetFromBase();
8222 Alignment = MinAlign(Alignment, Alignment + Offset);
8226 /// \brief Check if this slice can be rewritten with legal operations.
8227 bool isLegal() const {
8228 // An invalid slice is not legal.
8229 if (!Origin || !Inst || !DAG)
8232 // Offsets are for indexed load only, we do not handle that.
8233 if (Origin->getOffset().getOpcode() != ISD::UNDEF)
8236 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
8238 // Check that the type is legal.
8239 EVT SliceType = getLoadedType();
8240 if (!TLI.isTypeLegal(SliceType))
8243 // Check that the load is legal for this type.
8244 if (!TLI.isOperationLegal(ISD::LOAD, SliceType))
8247 // Check that the offset can be computed.
8248 // 1. Check its type.
8249 EVT PtrType = Origin->getBasePtr().getValueType();
8250 if (PtrType == MVT::Untyped || PtrType.isExtended())
8253 // 2. Check that it fits in the immediate.
8254 if (!TLI.isLegalAddImmediate(getOffsetFromBase()))
8257 // 3. Check that the computation is legal.
8258 if (!TLI.isOperationLegal(ISD::ADD, PtrType))
8261 // Check that the zext is legal if it needs one.
8262 EVT TruncateType = Inst->getValueType(0);
8263 if (TruncateType != SliceType &&
8264 !TLI.isOperationLegal(ISD::ZERO_EXTEND, TruncateType))
8270 /// \brief Get the offset in bytes of this slice in the original chunk of
8272 /// \pre DAG != nullptr.
8273 uint64_t getOffsetFromBase() const {
8274 assert(DAG && "Missing context.");
8276 DAG->getTargetLoweringInfo().getDataLayout()->isBigEndian();
8277 assert(!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported.");
8278 uint64_t Offset = Shift / 8;
8279 unsigned TySizeInBytes = Origin->getValueSizeInBits(0) / 8;
8280 assert(!(Origin->getValueSizeInBits(0) & 0x7) &&
8281 "The size of the original loaded type is not a multiple of a"
8283 // If Offset is bigger than TySizeInBytes, it means we are loading all
8284 // zeros. This should have been optimized before in the process.
8285 assert(TySizeInBytes > Offset &&
8286 "Invalid shift amount for given loaded size");
8288 Offset = TySizeInBytes - Offset - getLoadedSize();
8292 /// \brief Generate the sequence of instructions to load the slice
8293 /// represented by this object and redirect the uses of this slice to
8294 /// this new sequence of instructions.
8295 /// \pre this->Inst && this->Origin are valid Instructions and this
8296 /// object passed the legal check: LoadedSlice::isLegal returned true.
8297 /// \return The last instruction of the sequence used to load the slice.
8298 SDValue loadSlice() const {
8299 assert(Inst && Origin && "Unable to replace a non-existing slice.");
8300 const SDValue &OldBaseAddr = Origin->getBasePtr();
8301 SDValue BaseAddr = OldBaseAddr;
8302 // Get the offset in that chunk of bytes w.r.t. the endianess.
8303 int64_t Offset = static_cast<int64_t>(getOffsetFromBase());
8304 assert(Offset >= 0 && "Offset too big to fit in int64_t!");
8306 // BaseAddr = BaseAddr + Offset.
8307 EVT ArithType = BaseAddr.getValueType();
8308 BaseAddr = DAG->getNode(ISD::ADD, SDLoc(Origin), ArithType, BaseAddr,
8309 DAG->getConstant(Offset, ArithType));
8312 // Create the type of the loaded slice according to its size.
8313 EVT SliceType = getLoadedType();
8315 // Create the load for the slice.
8316 SDValue LastInst = DAG->getLoad(
8317 SliceType, SDLoc(Origin), Origin->getChain(), BaseAddr,
8318 Origin->getPointerInfo().getWithOffset(Offset), Origin->isVolatile(),
8319 Origin->isNonTemporal(), Origin->isInvariant(), getAlignment());
8320 // If the final type is not the same as the loaded type, this means that
8321 // we have to pad with zero. Create a zero extend for that.
8322 EVT FinalType = Inst->getValueType(0);
8323 if (SliceType != FinalType)
8325 DAG->getNode(ISD::ZERO_EXTEND, SDLoc(LastInst), FinalType, LastInst);
8329 /// \brief Check if this slice can be merged with an expensive cross register
8330 /// bank copy. E.g.,
8332 /// f = bitcast i32 i to float
8333 bool canMergeExpensiveCrossRegisterBankCopy() const {
8334 if (!Inst || !Inst->hasOneUse())
8336 SDNode *Use = *Inst->use_begin();
8337 if (Use->getOpcode() != ISD::BITCAST)
8339 assert(DAG && "Missing context");
8340 const TargetLowering &TLI = DAG->getTargetLoweringInfo();
8341 EVT ResVT = Use->getValueType(0);
8342 const TargetRegisterClass *ResRC = TLI.getRegClassFor(ResVT.getSimpleVT());
8343 const TargetRegisterClass *ArgRC =
8344 TLI.getRegClassFor(Use->getOperand(0).getValueType().getSimpleVT());
8345 if (ArgRC == ResRC || !TLI.isOperationLegal(ISD::LOAD, ResVT))
8348 // At this point, we know that we perform a cross-register-bank copy.
8349 // Check if it is expensive.
8350 const TargetRegisterInfo *TRI = TLI.getTargetMachine().getRegisterInfo();
8351 // Assume bitcasts are cheap, unless both register classes do not
8352 // explicitly share a common sub class.
8353 if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
8356 // Check if it will be merged with the load.
8357 // 1. Check the alignment constraint.
8358 unsigned RequiredAlignment = TLI.getDataLayout()->getABITypeAlignment(
8359 ResVT.getTypeForEVT(*DAG->getContext()));
8361 if (RequiredAlignment > getAlignment())
8364 // 2. Check that the load is a legal operation for that type.
8365 if (!TLI.isOperationLegal(ISD::LOAD, ResVT))
8368 // 3. Check that we do not have a zext in the way.
8369 if (Inst->getValueType(0) != getLoadedType())
8377 /// \brief Check that all bits set in \p UsedBits form a dense region, i.e.,
8378 /// \p UsedBits looks like 0..0 1..1 0..0.
8379 static bool areUsedBitsDense(const APInt &UsedBits) {
8380 // If all the bits are one, this is dense!
8381 if (UsedBits.isAllOnesValue())
8384 // Get rid of the unused bits on the right.
8385 APInt NarrowedUsedBits = UsedBits.lshr(UsedBits.countTrailingZeros());
8386 // Get rid of the unused bits on the left.
8387 if (NarrowedUsedBits.countLeadingZeros())
8388 NarrowedUsedBits = NarrowedUsedBits.trunc(NarrowedUsedBits.getActiveBits());
8389 // Check that the chunk of bits is completely used.
8390 return NarrowedUsedBits.isAllOnesValue();
8393 /// \brief Check whether or not \p First and \p Second are next to each other
8394 /// in memory. This means that there is no hole between the bits loaded
8395 /// by \p First and the bits loaded by \p Second.
8396 static bool areSlicesNextToEachOther(const LoadedSlice &First,
8397 const LoadedSlice &Second) {
8398 assert(First.Origin == Second.Origin && First.Origin &&
8399 "Unable to match different memory origins.");
8400 APInt UsedBits = First.getUsedBits();
8401 assert((UsedBits & Second.getUsedBits()) == 0 &&
8402 "Slices are not supposed to overlap.");
8403 UsedBits |= Second.getUsedBits();
8404 return areUsedBitsDense(UsedBits);
8407 /// \brief Adjust the \p GlobalLSCost according to the target
8408 /// paring capabilities and the layout of the slices.
8409 /// \pre \p GlobalLSCost should account for at least as many loads as
8410 /// there is in the slices in \p LoadedSlices.
8411 static void adjustCostForPairing(SmallVectorImpl<LoadedSlice> &LoadedSlices,
8412 LoadedSlice::Cost &GlobalLSCost) {
8413 unsigned NumberOfSlices = LoadedSlices.size();
8414 // If there is less than 2 elements, no pairing is possible.
8415 if (NumberOfSlices < 2)
8418 // Sort the slices so that elements that are likely to be next to each
8419 // other in memory are next to each other in the list.
8420 std::sort(LoadedSlices.begin(), LoadedSlices.end(),
8421 [](const LoadedSlice &LHS, const LoadedSlice &RHS) {
8422 assert(LHS.Origin == RHS.Origin && "Different bases not implemented.");
8423 return LHS.getOffsetFromBase() < RHS.getOffsetFromBase();
8425 const TargetLowering &TLI = LoadedSlices[0].DAG->getTargetLoweringInfo();
8426 // First (resp. Second) is the first (resp. Second) potentially candidate
8427 // to be placed in a paired load.
8428 const LoadedSlice *First = nullptr;
8429 const LoadedSlice *Second = nullptr;
8430 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice,
8431 // Set the beginning of the pair.
8434 Second = &LoadedSlices[CurrSlice];
8436 // If First is NULL, it means we start a new pair.
8437 // Get to the next slice.
8441 EVT LoadedType = First->getLoadedType();
8443 // If the types of the slices are different, we cannot pair them.
8444 if (LoadedType != Second->getLoadedType())
8447 // Check if the target supplies paired loads for this type.
8448 unsigned RequiredAlignment = 0;
8449 if (!TLI.hasPairedLoad(LoadedType, RequiredAlignment)) {
8450 // move to the next pair, this type is hopeless.
8454 // Check if we meet the alignment requirement.
8455 if (RequiredAlignment > First->getAlignment())
8458 // Check that both loads are next to each other in memory.
8459 if (!areSlicesNextToEachOther(*First, *Second))
8462 assert(GlobalLSCost.Loads > 0 && "We save more loads than we created!");
8463 --GlobalLSCost.Loads;
8464 // Move to the next pair.
8469 /// \brief Check the profitability of all involved LoadedSlice.
8470 /// Currently, it is considered profitable if there is exactly two
8471 /// involved slices (1) which are (2) next to each other in memory, and
8472 /// whose cost (\see LoadedSlice::Cost) is smaller than the original load (3).
8474 /// Note: The order of the elements in \p LoadedSlices may be modified, but not
8475 /// the elements themselves.
8477 /// FIXME: When the cost model will be mature enough, we can relax
8478 /// constraints (1) and (2).
8479 static bool isSlicingProfitable(SmallVectorImpl<LoadedSlice> &LoadedSlices,
8480 const APInt &UsedBits, bool ForCodeSize) {
8481 unsigned NumberOfSlices = LoadedSlices.size();
8482 if (StressLoadSlicing)
8483 return NumberOfSlices > 1;
8486 if (NumberOfSlices != 2)
8490 if (!areUsedBitsDense(UsedBits))
8494 LoadedSlice::Cost OrigCost(ForCodeSize), GlobalSlicingCost(ForCodeSize);
8495 // The original code has one big load.
8497 for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice) {
8498 const LoadedSlice &LS = LoadedSlices[CurrSlice];
8499 // Accumulate the cost of all the slices.
8500 LoadedSlice::Cost SliceCost(LS, ForCodeSize);
8501 GlobalSlicingCost += SliceCost;
8503 // Account as cost in the original configuration the gain obtained
8504 // with the current slices.
8505 OrigCost.addSliceGain(LS);
8508 // If the target supports paired load, adjust the cost accordingly.
8509 adjustCostForPairing(LoadedSlices, GlobalSlicingCost);
8510 return OrigCost > GlobalSlicingCost;
8513 /// \brief If the given load, \p LI, is used only by trunc or trunc(lshr)
8514 /// operations, split it in the various pieces being extracted.
8516 /// This sort of thing is introduced by SROA.
8517 /// This slicing takes care not to insert overlapping loads.
8518 /// \pre LI is a simple load (i.e., not an atomic or volatile load).
8519 bool DAGCombiner::SliceUpLoad(SDNode *N) {
8520 if (Level < AfterLegalizeDAG)
8523 LoadSDNode *LD = cast<LoadSDNode>(N);
8524 if (LD->isVolatile() || !ISD::isNormalLoad(LD) ||
8525 !LD->getValueType(0).isInteger())
8528 // Keep track of already used bits to detect overlapping values.
8529 // In that case, we will just abort the transformation.
8530 APInt UsedBits(LD->getValueSizeInBits(0), 0);
8532 SmallVector<LoadedSlice, 4> LoadedSlices;
8534 // Check if this load is used as several smaller chunks of bits.
8535 // Basically, look for uses in trunc or trunc(lshr) and record a new chain
8536 // of computation for each trunc.
8537 for (SDNode::use_iterator UI = LD->use_begin(), UIEnd = LD->use_end();
8538 UI != UIEnd; ++UI) {
8539 // Skip the uses of the chain.
8540 if (UI.getUse().getResNo() != 0)
8546 // Check if this is a trunc(lshr).
8547 if (User->getOpcode() == ISD::SRL && User->hasOneUse() &&
8548 isa<ConstantSDNode>(User->getOperand(1))) {
8549 Shift = cast<ConstantSDNode>(User->getOperand(1))->getZExtValue();
8550 User = *User->use_begin();
8553 // At this point, User is a Truncate, iff we encountered, trunc or
8555 if (User->getOpcode() != ISD::TRUNCATE)
8558 // The width of the type must be a power of 2 and greater than 8-bits.
8559 // Otherwise the load cannot be represented in LLVM IR.
8560 // Moreover, if we shifted with a non-8-bits multiple, the slice
8561 // will be across several bytes. We do not support that.
8562 unsigned Width = User->getValueSizeInBits(0);
8563 if (Width < 8 || !isPowerOf2_32(Width) || (Shift & 0x7))
8566 // Build the slice for this chain of computations.
8567 LoadedSlice LS(User, LD, Shift, &DAG);
8568 APInt CurrentUsedBits = LS.getUsedBits();
8570 // Check if this slice overlaps with another.
8571 if ((CurrentUsedBits & UsedBits) != 0)
8573 // Update the bits used globally.
8574 UsedBits |= CurrentUsedBits;
8576 // Check if the new slice would be legal.
8580 // Record the slice.
8581 LoadedSlices.push_back(LS);
8584 // Abort slicing if it does not seem to be profitable.
8585 if (!isSlicingProfitable(LoadedSlices, UsedBits, ForCodeSize))
8590 // Rewrite each chain to use an independent load.
8591 // By construction, each chain can be represented by a unique load.
8593 // Prepare the argument for the new token factor for all the slices.
8594 SmallVector<SDValue, 8> ArgChains;
8595 for (SmallVectorImpl<LoadedSlice>::const_iterator
8596 LSIt = LoadedSlices.begin(),
8597 LSItEnd = LoadedSlices.end();
8598 LSIt != LSItEnd; ++LSIt) {
8599 SDValue SliceInst = LSIt->loadSlice();
8600 CombineTo(LSIt->Inst, SliceInst, true);
8601 if (SliceInst.getNode()->getOpcode() != ISD::LOAD)
8602 SliceInst = SliceInst.getOperand(0);
8603 assert(SliceInst->getOpcode() == ISD::LOAD &&
8604 "It takes more than a zext to get to the loaded slice!!");
8605 ArgChains.push_back(SliceInst.getValue(1));
8608 SDValue Chain = DAG.getNode(ISD::TokenFactor, SDLoc(LD), MVT::Other,
8610 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
8614 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
8615 /// load is having specific bytes cleared out. If so, return the byte size
8616 /// being masked out and the shift amount.
8617 static std::pair<unsigned, unsigned>
8618 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
8619 std::pair<unsigned, unsigned> Result(0, 0);
8621 // Check for the structure we're looking for.
8622 if (V->getOpcode() != ISD::AND ||
8623 !isa<ConstantSDNode>(V->getOperand(1)) ||
8624 !ISD::isNormalLoad(V->getOperand(0).getNode()))
8627 // Check the chain and pointer.
8628 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
8629 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
8631 // The store should be chained directly to the load or be an operand of a
8633 if (LD == Chain.getNode())
8635 else if (Chain->getOpcode() != ISD::TokenFactor)
8636 return Result; // Fail.
8639 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
8640 if (Chain->getOperand(i).getNode() == LD) {
8644 if (!isOk) return Result;
8647 // This only handles simple types.
8648 if (V.getValueType() != MVT::i16 &&
8649 V.getValueType() != MVT::i32 &&
8650 V.getValueType() != MVT::i64)
8653 // Check the constant mask. Invert it so that the bits being masked out are
8654 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
8655 // follow the sign bit for uniformity.
8656 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
8657 unsigned NotMaskLZ = countLeadingZeros(NotMask);
8658 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
8659 unsigned NotMaskTZ = countTrailingZeros(NotMask);
8660 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
8661 if (NotMaskLZ == 64) return Result; // All zero mask.
8663 // See if we have a continuous run of bits. If so, we have 0*1+0*
8664 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
8667 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
8668 if (V.getValueType() != MVT::i64 && NotMaskLZ)
8669 NotMaskLZ -= 64-V.getValueSizeInBits();
8671 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
8672 switch (MaskedBytes) {
8676 default: return Result; // All one mask, or 5-byte mask.
8679 // Verify that the first bit starts at a multiple of mask so that the access
8680 // is aligned the same as the access width.
8681 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
8683 Result.first = MaskedBytes;
8684 Result.second = NotMaskTZ/8;
8689 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
8690 /// provides a value as specified by MaskInfo. If so, replace the specified
8691 /// store with a narrower store of truncated IVal.
8693 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
8694 SDValue IVal, StoreSDNode *St,
8696 unsigned NumBytes = MaskInfo.first;
8697 unsigned ByteShift = MaskInfo.second;
8698 SelectionDAG &DAG = DC->getDAG();
8700 // Check to see if IVal is all zeros in the part being masked in by the 'or'
8701 // that uses this. If not, this is not a replacement.
8702 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
8703 ByteShift*8, (ByteShift+NumBytes)*8);
8704 if (!DAG.MaskedValueIsZero(IVal, Mask)) return nullptr;
8706 // Check that it is legal on the target to do this. It is legal if the new
8707 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
8709 MVT VT = MVT::getIntegerVT(NumBytes*8);
8710 if (!DC->isTypeLegal(VT))
8713 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
8714 // shifted by ByteShift and truncated down to NumBytes.
8716 IVal = DAG.getNode(ISD::SRL, SDLoc(IVal), IVal.getValueType(), IVal,
8717 DAG.getConstant(ByteShift*8,
8718 DC->getShiftAmountTy(IVal.getValueType())));
8720 // Figure out the offset for the store and the alignment of the access.
8722 unsigned NewAlign = St->getAlignment();
8724 if (DAG.getTargetLoweringInfo().isLittleEndian())
8725 StOffset = ByteShift;
8727 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
8729 SDValue Ptr = St->getBasePtr();
8731 Ptr = DAG.getNode(ISD::ADD, SDLoc(IVal), Ptr.getValueType(),
8732 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
8733 NewAlign = MinAlign(NewAlign, StOffset);
8736 // Truncate down to the new size.
8737 IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);
8740 return DAG.getStore(St->getChain(), SDLoc(St), IVal, Ptr,
8741 St->getPointerInfo().getWithOffset(StOffset),
8742 false, false, NewAlign).getNode();
8746 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
8747 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
8748 /// of the loaded bits, try narrowing the load and store if it would end up
8749 /// being a win for performance or code size.
8750 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
8751 StoreSDNode *ST = cast<StoreSDNode>(N);
8752 if (ST->isVolatile())
8755 SDValue Chain = ST->getChain();
8756 SDValue Value = ST->getValue();
8757 SDValue Ptr = ST->getBasePtr();
8758 EVT VT = Value.getValueType();
8760 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
8763 unsigned Opc = Value.getOpcode();
8765 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
8766 // is a byte mask indicating a consecutive number of bytes, check to see if
8767 // Y is known to provide just those bytes. If so, we try to replace the
8768 // load + replace + store sequence with a single (narrower) store, which makes
8770 if (Opc == ISD::OR) {
8771 std::pair<unsigned, unsigned> MaskedLoad;
8772 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
8773 if (MaskedLoad.first)
8774 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
8775 Value.getOperand(1), ST,this))
8776 return SDValue(NewST, 0);
8778 // Or is commutative, so try swapping X and Y.
8779 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
8780 if (MaskedLoad.first)
8781 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
8782 Value.getOperand(0), ST,this))
8783 return SDValue(NewST, 0);
8786 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
8787 Value.getOperand(1).getOpcode() != ISD::Constant)
8790 SDValue N0 = Value.getOperand(0);
8791 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
8792 Chain == SDValue(N0.getNode(), 1)) {
8793 LoadSDNode *LD = cast<LoadSDNode>(N0);
8794 if (LD->getBasePtr() != Ptr ||
8795 LD->getPointerInfo().getAddrSpace() !=
8796 ST->getPointerInfo().getAddrSpace())
8799 // Find the type to narrow it the load / op / store to.
8800 SDValue N1 = Value.getOperand(1);
8801 unsigned BitWidth = N1.getValueSizeInBits();
8802 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
8803 if (Opc == ISD::AND)
8804 Imm ^= APInt::getAllOnesValue(BitWidth);
8805 if (Imm == 0 || Imm.isAllOnesValue())
8807 unsigned ShAmt = Imm.countTrailingZeros();
8808 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
8809 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
8810 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
8811 while (NewBW < BitWidth &&
8812 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
8813 TLI.isNarrowingProfitable(VT, NewVT))) {
8814 NewBW = NextPowerOf2(NewBW);
8815 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
8817 if (NewBW >= BitWidth)
8820 // If the lsb changed does not start at the type bitwidth boundary,
8821 // start at the previous one.
8823 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
8824 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
8825 std::min(BitWidth, ShAmt + NewBW));
8826 if ((Imm & Mask) == Imm) {
8827 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
8828 if (Opc == ISD::AND)
8829 NewImm ^= APInt::getAllOnesValue(NewBW);
8830 uint64_t PtrOff = ShAmt / 8;
8831 // For big endian targets, we need to adjust the offset to the pointer to
8832 // load the correct bytes.
8833 if (TLI.isBigEndian())
8834 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
8836 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
8837 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
8838 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
8841 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
8842 Ptr.getValueType(), Ptr,
8843 DAG.getConstant(PtrOff, Ptr.getValueType()));
8844 SDValue NewLD = DAG.getLoad(NewVT, SDLoc(N0),
8845 LD->getChain(), NewPtr,
8846 LD->getPointerInfo().getWithOffset(PtrOff),
8847 LD->isVolatile(), LD->isNonTemporal(),
8848 LD->isInvariant(), NewAlign,
8850 SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
8851 DAG.getConstant(NewImm, NewVT));
8852 SDValue NewST = DAG.getStore(Chain, SDLoc(N),
8854 ST->getPointerInfo().getWithOffset(PtrOff),
8855 false, false, NewAlign);
8857 AddToWorkList(NewPtr.getNode());
8858 AddToWorkList(NewLD.getNode());
8859 AddToWorkList(NewVal.getNode());
8860 WorkListRemover DeadNodes(*this);
8861 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
8870 /// TransformFPLoadStorePair - For a given floating point load / store pair,
8871 /// if the load value isn't used by any other operations, then consider
8872 /// transforming the pair to integer load / store operations if the target
8873 /// deems the transformation profitable.
8874 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
8875 StoreSDNode *ST = cast<StoreSDNode>(N);
8876 SDValue Chain = ST->getChain();
8877 SDValue Value = ST->getValue();
8878 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
8879 Value.hasOneUse() &&
8880 Chain == SDValue(Value.getNode(), 1)) {
8881 LoadSDNode *LD = cast<LoadSDNode>(Value);
8882 EVT VT = LD->getMemoryVT();
8883 if (!VT.isFloatingPoint() ||
8884 VT != ST->getMemoryVT() ||
8885 LD->isNonTemporal() ||
8886 ST->isNonTemporal() ||
8887 LD->getPointerInfo().getAddrSpace() != 0 ||
8888 ST->getPointerInfo().getAddrSpace() != 0)
8891 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
8892 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
8893 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
8894 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
8895 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
8898 unsigned LDAlign = LD->getAlignment();
8899 unsigned STAlign = ST->getAlignment();
8900 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
8901 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
8902 if (LDAlign < ABIAlign || STAlign < ABIAlign)
8905 SDValue NewLD = DAG.getLoad(IntVT, SDLoc(Value),
8906 LD->getChain(), LD->getBasePtr(),
8907 LD->getPointerInfo(),
8908 false, false, false, LDAlign);
8910 SDValue NewST = DAG.getStore(NewLD.getValue(1), SDLoc(N),
8911 NewLD, ST->getBasePtr(),
8912 ST->getPointerInfo(),
8913 false, false, STAlign);
8915 AddToWorkList(NewLD.getNode());
8916 AddToWorkList(NewST.getNode());
8917 WorkListRemover DeadNodes(*this);
8918 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
8926 /// Helper struct to parse and store a memory address as base + index + offset.
8927 /// We ignore sign extensions when it is safe to do so.
8928 /// The following two expressions are not equivalent. To differentiate we need
8929 /// to store whether there was a sign extension involved in the index
8931 /// (load (i64 add (i64 copyfromreg %c)
8932 /// (i64 signextend (add (i8 load %index)
8936 /// (load (i64 add (i64 copyfromreg %c)
8937 /// (i64 signextend (i32 add (i32 signextend (i8 load %index))
8939 struct BaseIndexOffset {
8943 bool IsIndexSignExt;
8945 BaseIndexOffset() : Offset(0), IsIndexSignExt(false) {}
8947 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
8948 bool IsIndexSignExt) :
8949 Base(Base), Index(Index), Offset(Offset), IsIndexSignExt(IsIndexSignExt) {}
8951 bool equalBaseIndex(const BaseIndexOffset &Other) {
8952 return Other.Base == Base && Other.Index == Index &&
8953 Other.IsIndexSignExt == IsIndexSignExt;
8956 /// Parses tree in Ptr for base, index, offset addresses.
8957 static BaseIndexOffset match(SDValue Ptr) {
8958 bool IsIndexSignExt = false;
8960 // We only can pattern match BASE + INDEX + OFFSET. If Ptr is not an ADD
8961 // instruction, then it could be just the BASE or everything else we don't
8962 // know how to handle. Just use Ptr as BASE and give up.
8963 if (Ptr->getOpcode() != ISD::ADD)
8964 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
8966 // We know that we have at least an ADD instruction. Try to pattern match
8967 // the simple case of BASE + OFFSET.
8968 if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
8969 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
8970 return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
8974 // Inside a loop the current BASE pointer is calculated using an ADD and a
8975 // MUL instruction. In this case Ptr is the actual BASE pointer.
8976 // (i64 add (i64 %array_ptr)
8977 // (i64 mul (i64 %induction_var)
8978 // (i64 %element_size)))
8979 if (Ptr->getOperand(1)->getOpcode() == ISD::MUL)
8980 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
8982 // Look at Base + Index + Offset cases.
8983 SDValue Base = Ptr->getOperand(0);
8984 SDValue IndexOffset = Ptr->getOperand(1);
8986 // Skip signextends.
8987 if (IndexOffset->getOpcode() == ISD::SIGN_EXTEND) {
8988 IndexOffset = IndexOffset->getOperand(0);
8989 IsIndexSignExt = true;
8992 // Either the case of Base + Index (no offset) or something else.
8993 if (IndexOffset->getOpcode() != ISD::ADD)
8994 return BaseIndexOffset(Base, IndexOffset, 0, IsIndexSignExt);
8996 // Now we have the case of Base + Index + offset.
8997 SDValue Index = IndexOffset->getOperand(0);
8998 SDValue Offset = IndexOffset->getOperand(1);
9000 if (!isa<ConstantSDNode>(Offset))
9001 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
9003 // Ignore signextends.
9004 if (Index->getOpcode() == ISD::SIGN_EXTEND) {
9005 Index = Index->getOperand(0);
9006 IsIndexSignExt = true;
9007 } else IsIndexSignExt = false;
9009 int64_t Off = cast<ConstantSDNode>(Offset)->getSExtValue();
9010 return BaseIndexOffset(Base, Index, Off, IsIndexSignExt);
9014 /// Holds a pointer to an LSBaseSDNode as well as information on where it
9015 /// is located in a sequence of memory operations connected by a chain.
9017 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
9018 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
9019 // Ptr to the mem node.
9020 LSBaseSDNode *MemNode;
9021 // Offset from the base ptr.
9022 int64_t OffsetFromBase;
9023 // What is the sequence number of this mem node.
9024 // Lowest mem operand in the DAG starts at zero.
9025 unsigned SequenceNum;
9028 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
9029 EVT MemVT = St->getMemoryVT();
9030 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
9031 bool NoVectors = DAG.getMachineFunction().getFunction()->getAttributes().
9032 hasAttribute(AttributeSet::FunctionIndex, Attribute::NoImplicitFloat);
9034 // Don't merge vectors into wider inputs.
9035 if (MemVT.isVector() || !MemVT.isSimple())
9038 // Perform an early exit check. Do not bother looking at stored values that
9039 // are not constants or loads.
9040 SDValue StoredVal = St->getValue();
9041 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
9042 if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
9046 // Only look at ends of store sequences.
9047 SDValue Chain = SDValue(St, 1);
9048 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
9051 // This holds the base pointer, index, and the offset in bytes from the base
9053 BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
9055 // We must have a base and an offset.
9056 if (!BasePtr.Base.getNode())
9059 // Do not handle stores to undef base pointers.
9060 if (BasePtr.Base.getOpcode() == ISD::UNDEF)
9063 // Save the LoadSDNodes that we find in the chain.
9064 // We need to make sure that these nodes do not interfere with
9065 // any of the store nodes.
9066 SmallVector<LSBaseSDNode*, 8> AliasLoadNodes;
9068 // Save the StoreSDNodes that we find in the chain.
9069 SmallVector<MemOpLink, 8> StoreNodes;
9071 // Walk up the chain and look for nodes with offsets from the same
9072 // base pointer. Stop when reaching an instruction with a different kind
9073 // or instruction which has a different base pointer.
9075 StoreSDNode *Index = St;
9077 // If the chain has more than one use, then we can't reorder the mem ops.
9078 if (Index != St && !SDValue(Index, 1)->hasOneUse())
9081 // Find the base pointer and offset for this memory node.
9082 BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
9084 // Check that the base pointer is the same as the original one.
9085 if (!Ptr.equalBaseIndex(BasePtr))
9088 // Check that the alignment is the same.
9089 if (Index->getAlignment() != St->getAlignment())
9092 // The memory operands must not be volatile.
9093 if (Index->isVolatile() || Index->isIndexed())
9097 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
9098 if (St->isTruncatingStore())
9101 // The stored memory type must be the same.
9102 if (Index->getMemoryVT() != MemVT)
9105 // We do not allow unaligned stores because we want to prevent overriding
9107 if (Index->getAlignment()*8 != MemVT.getSizeInBits())
9110 // We found a potential memory operand to merge.
9111 StoreNodes.push_back(MemOpLink(Index, Ptr.Offset, Seq++));
9113 // Find the next memory operand in the chain. If the next operand in the
9114 // chain is a store then move up and continue the scan with the next
9115 // memory operand. If the next operand is a load save it and use alias
9116 // information to check if it interferes with anything.
9117 SDNode *NextInChain = Index->getChain().getNode();
9119 if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
9120 // We found a store node. Use it for the next iteration.
9123 } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
9124 if (Ldn->isVolatile()) {
9129 // Save the load node for later. Continue the scan.
9130 AliasLoadNodes.push_back(Ldn);
9131 NextInChain = Ldn->getChain().getNode();
9140 // Check if there is anything to merge.
9141 if (StoreNodes.size() < 2)
9144 // Sort the memory operands according to their distance from the base pointer.
9145 std::sort(StoreNodes.begin(), StoreNodes.end(),
9146 [](MemOpLink LHS, MemOpLink RHS) {
9147 return LHS.OffsetFromBase < RHS.OffsetFromBase ||
9148 (LHS.OffsetFromBase == RHS.OffsetFromBase &&
9149 LHS.SequenceNum > RHS.SequenceNum);
9152 // Scan the memory operations on the chain and find the first non-consecutive
9153 // store memory address.
9154 unsigned LastConsecutiveStore = 0;
9155 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
9156 for (unsigned i = 0, e = StoreNodes.size(); i < e; ++i) {
9158 // Check that the addresses are consecutive starting from the second
9159 // element in the list of stores.
9161 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
9162 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
9167 // Check if this store interferes with any of the loads that we found.
9168 for (unsigned ld = 0, lde = AliasLoadNodes.size(); ld < lde; ++ld)
9169 if (isAlias(AliasLoadNodes[ld], StoreNodes[i].MemNode)) {
9173 // We found a load that alias with this store. Stop the sequence.
9177 // Mark this node as useful.
9178 LastConsecutiveStore = i;
9181 // The node with the lowest store address.
9182 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
9184 // Store the constants into memory as one consecutive store.
9186 unsigned LastLegalType = 0;
9187 unsigned LastLegalVectorType = 0;
9188 bool NonZero = false;
9189 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
9190 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
9191 SDValue StoredVal = St->getValue();
9193 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
9194 NonZero |= !C->isNullValue();
9195 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
9196 NonZero |= !C->getConstantFPValue()->isNullValue();
9202 // Find a legal type for the constant store.
9203 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
9204 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
9205 if (TLI.isTypeLegal(StoreTy))
9206 LastLegalType = i+1;
9207 // Or check whether a truncstore is legal.
9208 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
9209 TargetLowering::TypePromoteInteger) {
9210 EVT LegalizedStoredValueTy =
9211 TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
9212 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy))
9213 LastLegalType = i+1;
9216 // Find a legal type for the vector store.
9217 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
9218 if (TLI.isTypeLegal(Ty))
9219 LastLegalVectorType = i + 1;
9222 // We only use vectors if the constant is known to be zero and the
9223 // function is not marked with the noimplicitfloat attribute.
9224 if (NonZero || NoVectors)
9225 LastLegalVectorType = 0;
9227 // Check if we found a legal integer type to store.
9228 if (LastLegalType == 0 && LastLegalVectorType == 0)
9231 bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
9232 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
9234 // Make sure we have something to merge.
9238 unsigned EarliestNodeUsed = 0;
9239 for (unsigned i=0; i < NumElem; ++i) {
9240 // Find a chain for the new wide-store operand. Notice that some
9241 // of the store nodes that we found may not be selected for inclusion
9242 // in the wide store. The chain we use needs to be the chain of the
9243 // earliest store node which is *used* and replaced by the wide store.
9244 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
9245 EarliestNodeUsed = i;
9248 // The earliest Node in the DAG.
9249 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
9250 SDLoc DL(StoreNodes[0].MemNode);
9254 // Find a legal type for the vector store.
9255 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
9256 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
9257 StoredVal = DAG.getConstant(0, Ty);
9259 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
9260 APInt StoreInt(StoreBW, 0);
9262 // Construct a single integer constant which is made of the smaller
9264 bool IsLE = TLI.isLittleEndian();
9265 for (unsigned i = 0; i < NumElem ; ++i) {
9266 unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
9267 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
9268 SDValue Val = St->getValue();
9269 StoreInt<<=ElementSizeBytes*8;
9270 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
9271 StoreInt|=C->getAPIntValue().zext(StoreBW);
9272 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
9273 StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
9275 assert(false && "Invalid constant element type");
9279 // Create the new Load and Store operations.
9280 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
9281 StoredVal = DAG.getConstant(StoreInt, StoreTy);
9284 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, StoredVal,
9285 FirstInChain->getBasePtr(),
9286 FirstInChain->getPointerInfo(),
9288 FirstInChain->getAlignment());
9290 // Replace the first store with the new store
9291 CombineTo(EarliestOp, NewStore);
9292 // Erase all other stores.
9293 for (unsigned i = 0; i < NumElem ; ++i) {
9294 if (StoreNodes[i].MemNode == EarliestOp)
9296 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
9297 // ReplaceAllUsesWith will replace all uses that existed when it was
9298 // called, but graph optimizations may cause new ones to appear. For
9299 // example, the case in pr14333 looks like
9301 // St's chain -> St -> another store -> X
9303 // And the only difference from St to the other store is the chain.
9304 // When we change it's chain to be St's chain they become identical,
9305 // get CSEed and the net result is that X is now a use of St.
9306 // Since we know that St is redundant, just iterate.
9307 while (!St->use_empty())
9308 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
9309 removeFromWorkList(St);
9316 // Below we handle the case of multiple consecutive stores that
9317 // come from multiple consecutive loads. We merge them into a single
9318 // wide load and a single wide store.
9320 // Look for load nodes which are used by the stored values.
9321 SmallVector<MemOpLink, 8> LoadNodes;
9323 // Find acceptable loads. Loads need to have the same chain (token factor),
9324 // must not be zext, volatile, indexed, and they must be consecutive.
9325 BaseIndexOffset LdBasePtr;
9326 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
9327 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
9328 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
9331 // Loads must only have one use.
9332 if (!Ld->hasNUsesOfValue(1, 0))
9335 // Check that the alignment is the same as the stores.
9336 if (Ld->getAlignment() != St->getAlignment())
9339 // The memory operands must not be volatile.
9340 if (Ld->isVolatile() || Ld->isIndexed())
9343 // We do not accept ext loads.
9344 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
9347 // The stored memory type must be the same.
9348 if (Ld->getMemoryVT() != MemVT)
9351 BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
9352 // If this is not the first ptr that we check.
9353 if (LdBasePtr.Base.getNode()) {
9354 // The base ptr must be the same.
9355 if (!LdPtr.equalBaseIndex(LdBasePtr))
9358 // Check that all other base pointers are the same as this one.
9362 // We found a potential memory operand to merge.
9363 LoadNodes.push_back(MemOpLink(Ld, LdPtr.Offset, 0));
9366 if (LoadNodes.size() < 2)
9369 // Scan the memory operations on the chain and find the first non-consecutive
9370 // load memory address. These variables hold the index in the store node
9372 unsigned LastConsecutiveLoad = 0;
9373 // This variable refers to the size and not index in the array.
9374 unsigned LastLegalVectorType = 0;
9375 unsigned LastLegalIntegerType = 0;
9376 StartAddress = LoadNodes[0].OffsetFromBase;
9377 SDValue FirstChain = LoadNodes[0].MemNode->getChain();
9378 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
9379 // All loads much share the same chain.
9380 if (LoadNodes[i].MemNode->getChain() != FirstChain)
9383 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
9384 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
9386 LastConsecutiveLoad = i;
9388 // Find a legal type for the vector store.
9389 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
9390 if (TLI.isTypeLegal(StoreTy))
9391 LastLegalVectorType = i + 1;
9393 // Find a legal type for the integer store.
9394 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
9395 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
9396 if (TLI.isTypeLegal(StoreTy))
9397 LastLegalIntegerType = i + 1;
9398 // Or check whether a truncstore and extload is legal.
9399 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
9400 TargetLowering::TypePromoteInteger) {
9401 EVT LegalizedStoredValueTy =
9402 TLI.getTypeToTransformTo(*DAG.getContext(), StoreTy);
9403 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
9404 TLI.isLoadExtLegal(ISD::ZEXTLOAD, StoreTy) &&
9405 TLI.isLoadExtLegal(ISD::SEXTLOAD, StoreTy) &&
9406 TLI.isLoadExtLegal(ISD::EXTLOAD, StoreTy))
9407 LastLegalIntegerType = i+1;
9411 // Only use vector types if the vector type is larger than the integer type.
9412 // If they are the same, use integers.
9413 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
9414 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
9416 // We add +1 here because the LastXXX variables refer to location while
9417 // the NumElem refers to array/index size.
9418 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
9419 NumElem = std::min(LastLegalType, NumElem);
9424 // The earliest Node in the DAG.
9425 unsigned EarliestNodeUsed = 0;
9426 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
9427 for (unsigned i=1; i<NumElem; ++i) {
9428 // Find a chain for the new wide-store operand. Notice that some
9429 // of the store nodes that we found may not be selected for inclusion
9430 // in the wide store. The chain we use needs to be the chain of the
9431 // earliest store node which is *used* and replaced by the wide store.
9432 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
9433 EarliestNodeUsed = i;
9436 // Find if it is better to use vectors or integers to load and store
9440 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
9442 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
9443 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
9446 SDLoc LoadDL(LoadNodes[0].MemNode);
9447 SDLoc StoreDL(StoreNodes[0].MemNode);
9449 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
9450 SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
9451 FirstLoad->getChain(),
9452 FirstLoad->getBasePtr(),
9453 FirstLoad->getPointerInfo(),
9454 false, false, false,
9455 FirstLoad->getAlignment());
9457 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
9458 FirstInChain->getBasePtr(),
9459 FirstInChain->getPointerInfo(), false, false,
9460 FirstInChain->getAlignment());
9462 // Replace one of the loads with the new load.
9463 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
9464 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
9465 SDValue(NewLoad.getNode(), 1));
9467 // Remove the rest of the load chains.
9468 for (unsigned i = 1; i < NumElem ; ++i) {
9469 // Replace all chain users of the old load nodes with the chain of the new
9471 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
9472 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
9475 // Replace the first store with the new store.
9476 CombineTo(EarliestOp, NewStore);
9477 // Erase all other stores.
9478 for (unsigned i = 0; i < NumElem ; ++i) {
9479 // Remove all Store nodes.
9480 if (StoreNodes[i].MemNode == EarliestOp)
9482 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
9483 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
9484 removeFromWorkList(St);
9491 SDValue DAGCombiner::visitSTORE(SDNode *N) {
9492 StoreSDNode *ST = cast<StoreSDNode>(N);
9493 SDValue Chain = ST->getChain();
9494 SDValue Value = ST->getValue();
9495 SDValue Ptr = ST->getBasePtr();
9497 // If this is a store of a bit convert, store the input value if the
9498 // resultant store does not need a higher alignment than the original.
9499 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
9500 ST->isUnindexed()) {
9501 unsigned OrigAlign = ST->getAlignment();
9502 EVT SVT = Value.getOperand(0).getValueType();
9503 unsigned Align = TLI.getDataLayout()->
9504 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
9505 if (Align <= OrigAlign &&
9506 ((!LegalOperations && !ST->isVolatile()) ||
9507 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
9508 return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
9509 Ptr, ST->getPointerInfo(), ST->isVolatile(),
9510 ST->isNonTemporal(), OrigAlign,
9514 // Turn 'store undef, Ptr' -> nothing.
9515 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
9518 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
9519 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
9520 // NOTE: If the original store is volatile, this transform must not increase
9521 // the number of stores. For example, on x86-32 an f64 can be stored in one
9522 // processor operation but an i64 (which is not legal) requires two. So the
9523 // transform should not be done in this case.
9524 if (Value.getOpcode() != ISD::TargetConstantFP) {
9526 switch (CFP->getSimpleValueType(0).SimpleTy) {
9527 default: llvm_unreachable("Unknown FP type");
9528 case MVT::f16: // We don't do this for these yet.
9534 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
9535 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
9536 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
9537 bitcastToAPInt().getZExtValue(), MVT::i32);
9538 return DAG.getStore(Chain, SDLoc(N), Tmp,
9539 Ptr, ST->getMemOperand());
9543 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
9544 !ST->isVolatile()) ||
9545 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
9546 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
9547 getZExtValue(), MVT::i64);
9548 return DAG.getStore(Chain, SDLoc(N), Tmp,
9549 Ptr, ST->getMemOperand());
9552 if (!ST->isVolatile() &&
9553 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
9554 // Many FP stores are not made apparent until after legalize, e.g. for
9555 // argument passing. Since this is so common, custom legalize the
9556 // 64-bit integer store into two 32-bit stores.
9557 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
9558 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
9559 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
9560 if (TLI.isBigEndian()) std::swap(Lo, Hi);
9562 unsigned Alignment = ST->getAlignment();
9563 bool isVolatile = ST->isVolatile();
9564 bool isNonTemporal = ST->isNonTemporal();
9565 const MDNode *TBAAInfo = ST->getTBAAInfo();
9567 SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
9568 Ptr, ST->getPointerInfo(),
9569 isVolatile, isNonTemporal,
9570 ST->getAlignment(), TBAAInfo);
9571 Ptr = DAG.getNode(ISD::ADD, SDLoc(N), Ptr.getValueType(), Ptr,
9572 DAG.getConstant(4, Ptr.getValueType()));
9573 Alignment = MinAlign(Alignment, 4U);
9574 SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
9575 Ptr, ST->getPointerInfo().getWithOffset(4),
9576 isVolatile, isNonTemporal,
9577 Alignment, TBAAInfo);
9578 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
9587 // Try to infer better alignment information than the store already has.
9588 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
9589 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
9590 if (Align > ST->getAlignment())
9591 return DAG.getTruncStore(Chain, SDLoc(N), Value,
9592 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
9593 ST->isVolatile(), ST->isNonTemporal(), Align,
9598 // Try transforming a pair floating point load / store ops to integer
9599 // load / store ops.
9600 SDValue NewST = TransformFPLoadStorePair(N);
9601 if (NewST.getNode())
9604 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
9605 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
9607 if (CombinerAAOnlyFunc.getNumOccurrences() &&
9608 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
9611 if (UseAA && ST->isUnindexed()) {
9612 // Walk up chain skipping non-aliasing memory nodes.
9613 SDValue BetterChain = FindBetterChain(N, Chain);
9615 // If there is a better chain.
9616 if (Chain != BetterChain) {
9619 // Replace the chain to avoid dependency.
9620 if (ST->isTruncatingStore()) {
9621 ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
9622 ST->getMemoryVT(), ST->getMemOperand());
9624 ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
9625 ST->getMemOperand());
9628 // Create token to keep both nodes around.
9629 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
9630 MVT::Other, Chain, ReplStore);
9632 // Make sure the new and old chains are cleaned up.
9633 AddToWorkList(Token.getNode());
9635 // Don't add users to work list.
9636 return CombineTo(N, Token, false);
9640 // Try transforming N to an indexed store.
9641 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
9642 return SDValue(N, 0);
9644 // FIXME: is there such a thing as a truncating indexed store?
9645 if (ST->isTruncatingStore() && ST->isUnindexed() &&
9646 Value.getValueType().isInteger()) {
9647 // See if we can simplify the input to this truncstore with knowledge that
9648 // only the low bits are being used. For example:
9649 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
9651 GetDemandedBits(Value,
9652 APInt::getLowBitsSet(
9653 Value.getValueType().getScalarType().getSizeInBits(),
9654 ST->getMemoryVT().getScalarType().getSizeInBits()));
9655 AddToWorkList(Value.getNode());
9656 if (Shorter.getNode())
9657 return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
9658 Ptr, ST->getMemoryVT(), ST->getMemOperand());
9660 // Otherwise, see if we can simplify the operation with
9661 // SimplifyDemandedBits, which only works if the value has a single use.
9662 if (SimplifyDemandedBits(Value,
9663 APInt::getLowBitsSet(
9664 Value.getValueType().getScalarType().getSizeInBits(),
9665 ST->getMemoryVT().getScalarType().getSizeInBits())))
9666 return SDValue(N, 0);
9669 // If this is a load followed by a store to the same location, then the store
9671 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
9672 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
9673 ST->isUnindexed() && !ST->isVolatile() &&
9674 // There can't be any side effects between the load and store, such as
9676 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
9677 // The store is dead, remove it.
9682 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
9683 // truncating store. We can do this even if this is already a truncstore.
9684 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
9685 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
9686 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
9687 ST->getMemoryVT())) {
9688 return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
9689 Ptr, ST->getMemoryVT(), ST->getMemOperand());
9692 // Only perform this optimization before the types are legal, because we
9693 // don't want to perform this optimization on every DAGCombine invocation.
9695 bool EverChanged = false;
9698 // There can be multiple store sequences on the same chain.
9699 // Keep trying to merge store sequences until we are unable to do so
9700 // or until we merge the last store on the chain.
9701 bool Changed = MergeConsecutiveStores(ST);
9702 EverChanged |= Changed;
9703 if (!Changed) break;
9704 } while (ST->getOpcode() != ISD::DELETED_NODE);
9707 return SDValue(N, 0);
9710 return ReduceLoadOpStoreWidth(N);
9713 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
9714 SDValue InVec = N->getOperand(0);
9715 SDValue InVal = N->getOperand(1);
9716 SDValue EltNo = N->getOperand(2);
9719 // If the inserted element is an UNDEF, just use the input vector.
9720 if (InVal.getOpcode() == ISD::UNDEF)
9723 EVT VT = InVec.getValueType();
9725 // If we can't generate a legal BUILD_VECTOR, exit
9726 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
9729 // Check that we know which element is being inserted
9730 if (!isa<ConstantSDNode>(EltNo))
9732 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
9734 // Canonicalize insert_vector_elt dag nodes.
9736 // (insert_vector_elt (insert_vector_elt A, Idx0), Idx1)
9737 // -> (insert_vector_elt (insert_vector_elt A, Idx1), Idx0)
9739 // Do this only if the child insert_vector node has one use; also
9740 // do this only if indices are both constants and Idx1 < Idx0.
9741 if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT && InVec.hasOneUse()
9742 && isa<ConstantSDNode>(InVec.getOperand(2))) {
9744 cast<ConstantSDNode>(InVec.getOperand(2))->getZExtValue();
9745 if (Elt < OtherElt) {
9747 SDValue NewOp = DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(N), VT,
9748 InVec.getOperand(0), InVal, EltNo);
9749 AddToWorkList(NewOp.getNode());
9750 return DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(InVec.getNode()),
9751 VT, NewOp, InVec.getOperand(1), InVec.getOperand(2));
9755 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
9756 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
9758 SmallVector<SDValue, 8> Ops;
9759 // Do not combine these two vectors if the output vector will not replace
9760 // the input vector.
9761 if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
9762 Ops.append(InVec.getNode()->op_begin(),
9763 InVec.getNode()->op_end());
9764 } else if (InVec.getOpcode() == ISD::UNDEF) {
9765 unsigned NElts = VT.getVectorNumElements();
9766 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
9771 // Insert the element
9772 if (Elt < Ops.size()) {
9773 // All the operands of BUILD_VECTOR must have the same type;
9774 // we enforce that here.
9775 EVT OpVT = Ops[0].getValueType();
9776 if (InVal.getValueType() != OpVT)
9777 InVal = OpVT.bitsGT(InVal.getValueType()) ?
9778 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
9779 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
9783 // Return the new vector
9784 return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
9787 SDValue DAGCombiner::ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
9788 SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad) {
9789 EVT ResultVT = EVE->getValueType(0);
9790 EVT VecEltVT = InVecVT.getVectorElementType();
9791 unsigned Align = OriginalLoad->getAlignment();
9792 unsigned NewAlign = TLI.getDataLayout()->getABITypeAlignment(
9793 VecEltVT.getTypeForEVT(*DAG.getContext()));
9795 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, VecEltVT))
9800 SDValue NewPtr = OriginalLoad->getBasePtr();
9802 EVT PtrType = NewPtr.getValueType();
9803 MachinePointerInfo MPI;
9804 if (auto *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo)) {
9805 int Elt = ConstEltNo->getZExtValue();
9806 unsigned PtrOff = VecEltVT.getSizeInBits() * Elt / 8;
9807 if (TLI.isBigEndian())
9808 PtrOff = InVecVT.getSizeInBits() / 8 - PtrOff;
9809 Offset = DAG.getConstant(PtrOff, PtrType);
9810 MPI = OriginalLoad->getPointerInfo().getWithOffset(PtrOff);
9812 Offset = DAG.getNode(
9813 ISD::MUL, SDLoc(EVE), EltNo.getValueType(), EltNo,
9814 DAG.getConstant(VecEltVT.getStoreSize(), EltNo.getValueType()));
9815 if (TLI.isBigEndian())
9816 Offset = DAG.getNode(
9817 ISD::SUB, SDLoc(EVE), EltNo.getValueType(),
9818 DAG.getConstant(InVecVT.getStoreSize(), EltNo.getValueType()), Offset);
9819 MPI = OriginalLoad->getPointerInfo();
9821 NewPtr = DAG.getNode(ISD::ADD, SDLoc(EVE), PtrType, NewPtr, Offset);
9823 // The replacement we need to do here is a little tricky: we need to
9824 // replace an extractelement of a load with a load.
9825 // Use ReplaceAllUsesOfValuesWith to do the replacement.
9826 // Note that this replacement assumes that the extractvalue is the only
9827 // use of the load; that's okay because we don't want to perform this
9828 // transformation in other cases anyway.
9831 if (ResultVT.bitsGT(VecEltVT)) {
9832 // If the result type of vextract is wider than the load, then issue an
9833 // extending load instead.
9834 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, VecEltVT)
9837 Load = DAG.getExtLoad(ExtType, SDLoc(EVE), ResultVT, OriginalLoad->getChain(),
9838 NewPtr, MPI, VecEltVT, OriginalLoad->isVolatile(),
9839 OriginalLoad->isNonTemporal(), Align,
9840 OriginalLoad->getTBAAInfo());
9841 Chain = Load.getValue(1);
9844 VecEltVT, SDLoc(EVE), OriginalLoad->getChain(), NewPtr, MPI,
9845 OriginalLoad->isVolatile(), OriginalLoad->isNonTemporal(),
9846 OriginalLoad->isInvariant(), Align, OriginalLoad->getTBAAInfo());
9847 Chain = Load.getValue(1);
9848 if (ResultVT.bitsLT(VecEltVT))
9849 Load = DAG.getNode(ISD::TRUNCATE, SDLoc(EVE), ResultVT, Load);
9851 Load = DAG.getNode(ISD::BITCAST, SDLoc(EVE), ResultVT, Load);
9853 WorkListRemover DeadNodes(*this);
9854 SDValue From[] = { SDValue(EVE, 0), SDValue(OriginalLoad, 1) };
9855 SDValue To[] = { Load, Chain };
9856 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
9857 // Since we're explicitly calling ReplaceAllUses, add the new node to the
9858 // worklist explicitly as well.
9859 AddToWorkList(Load.getNode());
9860 AddUsersToWorkList(Load.getNode()); // Add users too
9861 // Make sure to revisit this node to clean it up; it will usually be dead.
9864 return SDValue(EVE, 0);
9867 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
9868 // (vextract (scalar_to_vector val, 0) -> val
9869 SDValue InVec = N->getOperand(0);
9870 EVT VT = InVec.getValueType();
9871 EVT NVT = N->getValueType(0);
9873 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
9874 // Check if the result type doesn't match the inserted element type. A
9875 // SCALAR_TO_VECTOR may truncate the inserted element and the
9876 // EXTRACT_VECTOR_ELT may widen the extracted vector.
9877 SDValue InOp = InVec.getOperand(0);
9878 if (InOp.getValueType() != NVT) {
9879 assert(InOp.getValueType().isInteger() && NVT.isInteger());
9880 return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
9885 SDValue EltNo = N->getOperand(1);
9886 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
9888 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
9889 // We only perform this optimization before the op legalization phase because
9890 // we may introduce new vector instructions which are not backed by TD
9891 // patterns. For example on AVX, extracting elements from a wide vector
9892 // without using extract_subvector. However, if we can find an underlying
9893 // scalar value, then we can always use that.
9894 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
9896 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
9897 int NumElem = VT.getVectorNumElements();
9898 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
9899 // Find the new index to extract from.
9900 int OrigElt = SVOp->getMaskElt(Elt);
9902 // Extracting an undef index is undef.
9904 return DAG.getUNDEF(NVT);
9906 // Select the right vector half to extract from.
9908 if (OrigElt < NumElem) {
9909 SVInVec = InVec->getOperand(0);
9911 SVInVec = InVec->getOperand(1);
9915 if (SVInVec.getOpcode() == ISD::BUILD_VECTOR) {
9916 SDValue InOp = SVInVec.getOperand(OrigElt);
9917 if (InOp.getValueType() != NVT) {
9918 assert(InOp.getValueType().isInteger() && NVT.isInteger());
9919 InOp = DAG.getSExtOrTrunc(InOp, SDLoc(SVInVec), NVT);
9925 // FIXME: We should handle recursing on other vector shuffles and
9926 // scalar_to_vector here as well.
9928 if (!LegalOperations) {
9929 EVT IndexTy = TLI.getVectorIdxTy();
9930 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT,
9931 SVInVec, DAG.getConstant(OrigElt, IndexTy));
9935 bool BCNumEltsChanged = false;
9936 EVT ExtVT = VT.getVectorElementType();
9939 // If the result of load has to be truncated, then it's not necessarily
9941 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
9944 if (InVec.getOpcode() == ISD::BITCAST) {
9945 // Don't duplicate a load with other uses.
9946 if (!InVec.hasOneUse())
9949 EVT BCVT = InVec.getOperand(0).getValueType();
9950 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
9952 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
9953 BCNumEltsChanged = true;
9954 InVec = InVec.getOperand(0);
9955 ExtVT = BCVT.getVectorElementType();
9958 // (vextract (vN[if]M load $addr), i) -> ([if]M load $addr + i * size)
9959 if (!LegalOperations && !ConstEltNo && InVec.hasOneUse() &&
9960 ISD::isNormalLoad(InVec.getNode())) {
9961 SDValue Index = N->getOperand(1);
9962 if (LoadSDNode *OrigLoad = dyn_cast<LoadSDNode>(InVec))
9963 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, Index,
9967 // Perform only after legalization to ensure build_vector / vector_shuffle
9968 // optimizations have already been done.
9969 if (!LegalOperations) return SDValue();
9971 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
9972 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
9973 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
9976 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
9978 LoadSDNode *LN0 = nullptr;
9979 const ShuffleVectorSDNode *SVN = nullptr;
9980 if (ISD::isNormalLoad(InVec.getNode())) {
9981 LN0 = cast<LoadSDNode>(InVec);
9982 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
9983 InVec.getOperand(0).getValueType() == ExtVT &&
9984 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
9985 // Don't duplicate a load with other uses.
9986 if (!InVec.hasOneUse())
9989 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
9990 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
9991 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
9993 // (load $addr+1*size)
9995 // Don't duplicate a load with other uses.
9996 if (!InVec.hasOneUse())
9999 // If the bit convert changed the number of elements, it is unsafe
10000 // to examine the mask.
10001 if (BCNumEltsChanged)
10004 // Select the input vector, guarding against out of range extract vector.
10005 unsigned NumElems = VT.getVectorNumElements();
10006 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
10007 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
10009 if (InVec.getOpcode() == ISD::BITCAST) {
10010 // Don't duplicate a load with other uses.
10011 if (!InVec.hasOneUse())
10014 InVec = InVec.getOperand(0);
10016 if (ISD::isNormalLoad(InVec.getNode())) {
10017 LN0 = cast<LoadSDNode>(InVec);
10018 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
10019 EltNo = DAG.getConstant(Elt, EltNo.getValueType());
10023 // Make sure we found a non-volatile load and the extractelement is
10025 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
10028 // If Idx was -1 above, Elt is going to be -1, so just return undef.
10030 return DAG.getUNDEF(LVT);
10032 return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, EltNo, LN0);
10038 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
10039 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
10040 // We perform this optimization post type-legalization because
10041 // the type-legalizer often scalarizes integer-promoted vectors.
10042 // Performing this optimization before may create bit-casts which
10043 // will be type-legalized to complex code sequences.
10044 // We perform this optimization only before the operation legalizer because we
10045 // may introduce illegal operations.
10046 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
10049 unsigned NumInScalars = N->getNumOperands();
10051 EVT VT = N->getValueType(0);
10053 // Check to see if this is a BUILD_VECTOR of a bunch of values
10054 // which come from any_extend or zero_extend nodes. If so, we can create
10055 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
10056 // optimizations. We do not handle sign-extend because we can't fill the sign
10058 EVT SourceType = MVT::Other;
10059 bool AllAnyExt = true;
10061 for (unsigned i = 0; i != NumInScalars; ++i) {
10062 SDValue In = N->getOperand(i);
10063 // Ignore undef inputs.
10064 if (In.getOpcode() == ISD::UNDEF) continue;
10066 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
10067 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
10069 // Abort if the element is not an extension.
10070 if (!ZeroExt && !AnyExt) {
10071 SourceType = MVT::Other;
10075 // The input is a ZeroExt or AnyExt. Check the original type.
10076 EVT InTy = In.getOperand(0).getValueType();
10078 // Check that all of the widened source types are the same.
10079 if (SourceType == MVT::Other)
10082 else if (InTy != SourceType) {
10083 // Multiple income types. Abort.
10084 SourceType = MVT::Other;
10088 // Check if all of the extends are ANY_EXTENDs.
10089 AllAnyExt &= AnyExt;
10092 // In order to have valid types, all of the inputs must be extended from the
10093 // same source type and all of the inputs must be any or zero extend.
10094 // Scalar sizes must be a power of two.
10095 EVT OutScalarTy = VT.getScalarType();
10096 bool ValidTypes = SourceType != MVT::Other &&
10097 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
10098 isPowerOf2_32(SourceType.getSizeInBits());
10100 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
10101 // turn into a single shuffle instruction.
10105 bool isLE = TLI.isLittleEndian();
10106 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
10107 assert(ElemRatio > 1 && "Invalid element size ratio");
10108 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
10109 DAG.getConstant(0, SourceType);
10111 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
10112 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
10114 // Populate the new build_vector
10115 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
10116 SDValue Cast = N->getOperand(i);
10117 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
10118 Cast.getOpcode() == ISD::ZERO_EXTEND ||
10119 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
10121 if (Cast.getOpcode() == ISD::UNDEF)
10122 In = DAG.getUNDEF(SourceType);
10124 In = Cast->getOperand(0);
10125 unsigned Index = isLE ? (i * ElemRatio) :
10126 (i * ElemRatio + (ElemRatio - 1));
10128 assert(Index < Ops.size() && "Invalid index");
10132 // The type of the new BUILD_VECTOR node.
10133 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
10134 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
10135 "Invalid vector size");
10136 // Check if the new vector type is legal.
10137 if (!isTypeLegal(VecVT)) return SDValue();
10139 // Make the new BUILD_VECTOR.
10140 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, Ops);
10142 // The new BUILD_VECTOR node has the potential to be further optimized.
10143 AddToWorkList(BV.getNode());
10144 // Bitcast to the desired type.
10145 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
10148 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
10149 EVT VT = N->getValueType(0);
10151 unsigned NumInScalars = N->getNumOperands();
10154 EVT SrcVT = MVT::Other;
10155 unsigned Opcode = ISD::DELETED_NODE;
10156 unsigned NumDefs = 0;
10158 for (unsigned i = 0; i != NumInScalars; ++i) {
10159 SDValue In = N->getOperand(i);
10160 unsigned Opc = In.getOpcode();
10162 if (Opc == ISD::UNDEF)
10165 // If all scalar values are floats and converted from integers.
10166 if (Opcode == ISD::DELETED_NODE &&
10167 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
10174 EVT InVT = In.getOperand(0).getValueType();
10176 // If all scalar values are typed differently, bail out. It's chosen to
10177 // simplify BUILD_VECTOR of integer types.
10178 if (SrcVT == MVT::Other)
10185 // If the vector has just one element defined, it's not worth to fold it into
10186 // a vectorized one.
10190 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
10191 && "Should only handle conversion from integer to float.");
10192 assert(SrcVT != MVT::Other && "Cannot determine source type!");
10194 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
10196 if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
10199 SmallVector<SDValue, 8> Opnds;
10200 for (unsigned i = 0; i != NumInScalars; ++i) {
10201 SDValue In = N->getOperand(i);
10203 if (In.getOpcode() == ISD::UNDEF)
10204 Opnds.push_back(DAG.getUNDEF(SrcVT));
10206 Opnds.push_back(In.getOperand(0));
10208 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT, Opnds);
10209 AddToWorkList(BV.getNode());
10211 return DAG.getNode(Opcode, dl, VT, BV);
10214 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
10215 unsigned NumInScalars = N->getNumOperands();
10217 EVT VT = N->getValueType(0);
10219 // A vector built entirely of undefs is undef.
10220 if (ISD::allOperandsUndef(N))
10221 return DAG.getUNDEF(VT);
10223 SDValue V = reduceBuildVecExtToExtBuildVec(N);
10227 V = reduceBuildVecConvertToConvertBuildVec(N);
10231 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
10232 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
10233 // at most two distinct vectors, turn this into a shuffle node.
10235 // May only combine to shuffle after legalize if shuffle is legal.
10236 if (LegalOperations &&
10237 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
10240 SDValue VecIn1, VecIn2;
10241 for (unsigned i = 0; i != NumInScalars; ++i) {
10242 // Ignore undef inputs.
10243 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
10245 // If this input is something other than a EXTRACT_VECTOR_ELT with a
10246 // constant index, bail out.
10247 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
10248 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
10249 VecIn1 = VecIn2 = SDValue(nullptr, 0);
10253 // We allow up to two distinct input vectors.
10254 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
10255 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
10258 if (!VecIn1.getNode()) {
10259 VecIn1 = ExtractedFromVec;
10260 } else if (!VecIn2.getNode()) {
10261 VecIn2 = ExtractedFromVec;
10263 // Too many inputs.
10264 VecIn1 = VecIn2 = SDValue(nullptr, 0);
10269 // If everything is good, we can make a shuffle operation.
10270 if (VecIn1.getNode()) {
10271 SmallVector<int, 8> Mask;
10272 for (unsigned i = 0; i != NumInScalars; ++i) {
10273 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
10274 Mask.push_back(-1);
10278 // If extracting from the first vector, just use the index directly.
10279 SDValue Extract = N->getOperand(i);
10280 SDValue ExtVal = Extract.getOperand(1);
10281 if (Extract.getOperand(0) == VecIn1) {
10282 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
10283 if (ExtIndex > VT.getVectorNumElements())
10286 Mask.push_back(ExtIndex);
10290 // Otherwise, use InIdx + VecSize
10291 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
10292 Mask.push_back(Idx+NumInScalars);
10295 // We can't generate a shuffle node with mismatched input and output types.
10296 // Attempt to transform a single input vector to the correct type.
10297 if ((VT != VecIn1.getValueType())) {
10298 // We don't support shuffeling between TWO values of different types.
10299 if (VecIn2.getNode())
10302 // We only support widening of vectors which are half the size of the
10303 // output registers. For example XMM->YMM widening on X86 with AVX.
10304 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
10307 // If the input vector type has a different base type to the output
10308 // vector type, bail out.
10309 if (VecIn1.getValueType().getVectorElementType() !=
10310 VT.getVectorElementType())
10313 // Widen the input vector by adding undef values.
10314 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
10315 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
10318 // If VecIn2 is unused then change it to undef.
10319 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
10321 // Check that we were able to transform all incoming values to the same
10323 if (VecIn2.getValueType() != VecIn1.getValueType() ||
10324 VecIn1.getValueType() != VT)
10327 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
10328 if (!isTypeLegal(VT))
10331 // Return the new VECTOR_SHUFFLE node.
10335 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
10341 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
10342 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
10343 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
10344 // inputs come from at most two distinct vectors, turn this into a shuffle
10347 // If we only have one input vector, we don't need to do any concatenation.
10348 if (N->getNumOperands() == 1)
10349 return N->getOperand(0);
10351 // Check if all of the operands are undefs.
10352 EVT VT = N->getValueType(0);
10353 if (ISD::allOperandsUndef(N))
10354 return DAG.getUNDEF(VT);
10356 // Optimize concat_vectors where one of the vectors is undef.
10357 if (N->getNumOperands() == 2 &&
10358 N->getOperand(1)->getOpcode() == ISD::UNDEF) {
10359 SDValue In = N->getOperand(0);
10360 assert(In.getValueType().isVector() && "Must concat vectors");
10362 // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
10363 if (In->getOpcode() == ISD::BITCAST &&
10364 !In->getOperand(0)->getValueType(0).isVector()) {
10365 SDValue Scalar = In->getOperand(0);
10366 EVT SclTy = Scalar->getValueType(0);
10368 if (!SclTy.isFloatingPoint() && !SclTy.isInteger())
10371 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SclTy,
10372 VT.getSizeInBits() / SclTy.getSizeInBits());
10373 if (!TLI.isTypeLegal(NVT) || !TLI.isTypeLegal(Scalar.getValueType()))
10376 SDLoc dl = SDLoc(N);
10377 SDValue Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, NVT, Scalar);
10378 return DAG.getNode(ISD::BITCAST, dl, VT, Res);
10382 // fold (concat_vectors (BUILD_VECTOR A, B, ...), (BUILD_VECTOR C, D, ...))
10383 // -> (BUILD_VECTOR A, B, ..., C, D, ...)
10384 if (N->getNumOperands() == 2 &&
10385 N->getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
10386 N->getOperand(1).getOpcode() == ISD::BUILD_VECTOR) {
10387 EVT VT = N->getValueType(0);
10388 SDValue N0 = N->getOperand(0);
10389 SDValue N1 = N->getOperand(1);
10390 SmallVector<SDValue, 8> Opnds;
10391 unsigned BuildVecNumElts = N0.getNumOperands();
10393 for (unsigned i = 0; i != BuildVecNumElts; ++i)
10394 Opnds.push_back(N0.getOperand(i));
10395 for (unsigned i = 0; i != BuildVecNumElts; ++i)
10396 Opnds.push_back(N1.getOperand(i));
10398 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, Opnds);
10401 // Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
10402 // nodes often generate nop CONCAT_VECTOR nodes.
10403 // Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
10404 // place the incoming vectors at the exact same location.
10405 SDValue SingleSource = SDValue();
10406 unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();
10408 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
10409 SDValue Op = N->getOperand(i);
10411 if (Op.getOpcode() == ISD::UNDEF)
10414 // Check if this is the identity extract:
10415 if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
10418 // Find the single incoming vector for the extract_subvector.
10419 if (SingleSource.getNode()) {
10420 if (Op.getOperand(0) != SingleSource)
10423 SingleSource = Op.getOperand(0);
10425 // Check the source type is the same as the type of the result.
10426 // If not, this concat may extend the vector, so we can not
10427 // optimize it away.
10428 if (SingleSource.getValueType() != N->getValueType(0))
10432 unsigned IdentityIndex = i * PartNumElem;
10433 ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
10434 // The extract index must be constant.
10438 // Check that we are reading from the identity index.
10439 if (CS->getZExtValue() != IdentityIndex)
10443 if (SingleSource.getNode())
10444 return SingleSource;
10449 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
10450 EVT NVT = N->getValueType(0);
10451 SDValue V = N->getOperand(0);
10453 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
10455 // (extract_subvec (concat V1, V2, ...), i)
10458 // Only operand 0 is checked as 'concat' assumes all inputs of the same
10460 if (V->getOperand(0).getValueType() != NVT)
10462 unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
10463 unsigned NumElems = NVT.getVectorNumElements();
10464 assert((Idx % NumElems) == 0 &&
10465 "IDX in concat is not a multiple of the result vector length.");
10466 return V->getOperand(Idx / NumElems);
10470 if (V->getOpcode() == ISD::BITCAST)
10471 V = V.getOperand(0);
10473 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
10475 // Handle only simple case where vector being inserted and vector
10476 // being extracted are of same type, and are half size of larger vectors.
10477 EVT BigVT = V->getOperand(0).getValueType();
10478 EVT SmallVT = V->getOperand(1).getValueType();
10479 if (!NVT.bitsEq(SmallVT) || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
10482 // Only handle cases where both indexes are constants with the same type.
10483 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
10484 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
10486 if (InsIdx && ExtIdx &&
10487 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
10488 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
10490 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
10492 // indices are equal or bit offsets are equal => V1
10493 // otherwise => (extract_subvec V1, ExtIdx)
10494 if (InsIdx->getZExtValue() * SmallVT.getScalarType().getSizeInBits() ==
10495 ExtIdx->getZExtValue() * NVT.getScalarType().getSizeInBits())
10496 return DAG.getNode(ISD::BITCAST, dl, NVT, V->getOperand(1));
10497 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT,
10498 DAG.getNode(ISD::BITCAST, dl,
10499 N->getOperand(0).getValueType(),
10500 V->getOperand(0)), N->getOperand(1));
10507 // Tries to turn a shuffle of two CONCAT_VECTORS into a single concat.
10508 static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
10509 EVT VT = N->getValueType(0);
10510 unsigned NumElts = VT.getVectorNumElements();
10512 SDValue N0 = N->getOperand(0);
10513 SDValue N1 = N->getOperand(1);
10514 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
10516 SmallVector<SDValue, 4> Ops;
10517 EVT ConcatVT = N0.getOperand(0).getValueType();
10518 unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
10519 unsigned NumConcats = NumElts / NumElemsPerConcat;
10521 // Look at every vector that's inserted. We're looking for exact
10522 // subvector-sized copies from a concatenated vector
10523 for (unsigned I = 0; I != NumConcats; ++I) {
10524 // Make sure we're dealing with a copy.
10525 unsigned Begin = I * NumElemsPerConcat;
10526 bool AllUndef = true, NoUndef = true;
10527 for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
10528 if (SVN->getMaskElt(J) >= 0)
10535 if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
10538 for (unsigned J = 1; J != NumElemsPerConcat; ++J)
10539 if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
10542 unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
10543 if (FirstElt < N0.getNumOperands())
10544 Ops.push_back(N0.getOperand(FirstElt));
10546 Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));
10548 } else if (AllUndef) {
10549 Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
10550 } else { // Mixed with general masks and undefs, can't do optimization.
10555 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops);
10558 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
10559 EVT VT = N->getValueType(0);
10560 unsigned NumElts = VT.getVectorNumElements();
10562 SDValue N0 = N->getOperand(0);
10563 SDValue N1 = N->getOperand(1);
10565 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
10567 // Canonicalize shuffle undef, undef -> undef
10568 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
10569 return DAG.getUNDEF(VT);
10571 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
10573 // Canonicalize shuffle v, v -> v, undef
10575 SmallVector<int, 8> NewMask;
10576 for (unsigned i = 0; i != NumElts; ++i) {
10577 int Idx = SVN->getMaskElt(i);
10578 if (Idx >= (int)NumElts) Idx -= NumElts;
10579 NewMask.push_back(Idx);
10581 return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT),
10585 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
10586 if (N0.getOpcode() == ISD::UNDEF) {
10587 SmallVector<int, 8> NewMask;
10588 for (unsigned i = 0; i != NumElts; ++i) {
10589 int Idx = SVN->getMaskElt(i);
10591 if (Idx >= (int)NumElts)
10594 Idx = -1; // remove reference to lhs
10596 NewMask.push_back(Idx);
10598 return DAG.getVectorShuffle(VT, SDLoc(N), N1, DAG.getUNDEF(VT),
10602 // Remove references to rhs if it is undef
10603 if (N1.getOpcode() == ISD::UNDEF) {
10604 bool Changed = false;
10605 SmallVector<int, 8> NewMask;
10606 for (unsigned i = 0; i != NumElts; ++i) {
10607 int Idx = SVN->getMaskElt(i);
10608 if (Idx >= (int)NumElts) {
10612 NewMask.push_back(Idx);
10615 return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, &NewMask[0]);
10618 // If it is a splat, check if the argument vector is another splat or a
10619 // build_vector with all scalar elements the same.
10620 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
10621 SDNode *V = N0.getNode();
10623 // If this is a bit convert that changes the element type of the vector but
10624 // not the number of vector elements, look through it. Be careful not to
10625 // look though conversions that change things like v4f32 to v2f64.
10626 if (V->getOpcode() == ISD::BITCAST) {
10627 SDValue ConvInput = V->getOperand(0);
10628 if (ConvInput.getValueType().isVector() &&
10629 ConvInput.getValueType().getVectorNumElements() == NumElts)
10630 V = ConvInput.getNode();
10633 if (V->getOpcode() == ISD::BUILD_VECTOR) {
10634 assert(V->getNumOperands() == NumElts &&
10635 "BUILD_VECTOR has wrong number of operands");
10637 bool AllSame = true;
10638 for (unsigned i = 0; i != NumElts; ++i) {
10639 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
10640 Base = V->getOperand(i);
10644 // Splat of <u, u, u, u>, return <u, u, u, u>
10645 if (!Base.getNode())
10647 for (unsigned i = 0; i != NumElts; ++i) {
10648 if (V->getOperand(i) != Base) {
10653 // Splat of <x, x, x, x>, return <x, x, x, x>
10659 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
10660 Level < AfterLegalizeVectorOps &&
10661 (N1.getOpcode() == ISD::UNDEF ||
10662 (N1.getOpcode() == ISD::CONCAT_VECTORS &&
10663 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
10664 SDValue V = partitionShuffleOfConcats(N, DAG);
10670 // If this shuffle node is simply a swizzle of another shuffle node,
10671 // and it reverses the swizzle of the previous shuffle then we can
10672 // optimize shuffle(shuffle(x, undef), undef) -> x.
10673 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
10674 N1.getOpcode() == ISD::UNDEF) {
10676 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
10678 // Shuffle nodes can only reverse shuffles with a single non-undef value.
10679 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
10682 // The incoming shuffle must be of the same type as the result of the
10683 // current shuffle.
10684 assert(OtherSV->getOperand(0).getValueType() == VT &&
10685 "Shuffle types don't match");
10687 SmallVector<int, 4> Mask;
10688 // Compute the combined shuffle mask.
10689 for (unsigned i = 0; i != NumElts; ++i) {
10690 int Idx = SVN->getMaskElt(i);
10691 assert(Idx < (int)NumElts && "Index references undef operand");
10692 // Next, this index comes from the first value, which is the incoming
10693 // shuffle. Adopt the incoming index.
10695 Idx = OtherSV->getMaskElt(Idx);
10696 Mask.push_back(Idx);
10699 bool IsIdentityMask = true;
10700 for (unsigned i = 0; i != NumElts && IsIdentityMask; ++i) {
10705 // The combined shuffle must map each index to itself.
10706 IsIdentityMask = (unsigned)Mask[i] == i;
10709 if (IsIdentityMask)
10710 // optimize shuffle(shuffle(x, undef), undef) -> x.
10711 return OtherSV->getOperand(0);
10713 // It may still be beneficial to combine the two shuffles if the
10714 // resulting shuffle is legal.
10715 // shuffle(shuffle(x, undef, M1), undef, M2) -> shuffle(x, undef, M3).
10716 if (TLI.isShuffleMaskLegal(Mask, VT))
10717 return DAG.getVectorShuffle(VT, SDLoc(N), N0->getOperand(0), N1,
10724 SDValue DAGCombiner::visitINSERT_SUBVECTOR(SDNode *N) {
10725 SDValue N0 = N->getOperand(0);
10726 SDValue N2 = N->getOperand(2);
10728 // If the input vector is a concatenation, and the insert replaces
10729 // one of the halves, we can optimize into a single concat_vectors.
10730 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
10731 N0->getNumOperands() == 2 && N2.getOpcode() == ISD::Constant) {
10732 APInt InsIdx = cast<ConstantSDNode>(N2)->getAPIntValue();
10733 EVT VT = N->getValueType(0);
10735 // Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
10736 // (concat_vectors Z, Y)
10738 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
10739 N->getOperand(1), N0.getOperand(1));
10741 // Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
10742 // (concat_vectors X, Z)
10743 if (InsIdx == VT.getVectorNumElements()/2)
10744 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
10745 N0.getOperand(0), N->getOperand(1));
10751 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
10752 /// an AND to a vector_shuffle with the destination vector and a zero vector.
10753 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
10754 /// vector_shuffle V, Zero, <0, 4, 2, 4>
10755 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
10756 EVT VT = N->getValueType(0);
10758 SDValue LHS = N->getOperand(0);
10759 SDValue RHS = N->getOperand(1);
10760 if (N->getOpcode() == ISD::AND) {
10761 if (RHS.getOpcode() == ISD::BITCAST)
10762 RHS = RHS.getOperand(0);
10763 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
10764 SmallVector<int, 8> Indices;
10765 unsigned NumElts = RHS.getNumOperands();
10766 for (unsigned i = 0; i != NumElts; ++i) {
10767 SDValue Elt = RHS.getOperand(i);
10768 if (!isa<ConstantSDNode>(Elt))
10771 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
10772 Indices.push_back(i);
10773 else if (cast<ConstantSDNode>(Elt)->isNullValue())
10774 Indices.push_back(NumElts);
10779 // Let's see if the target supports this vector_shuffle.
10780 EVT RVT = RHS.getValueType();
10781 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
10784 // Return the new VECTOR_SHUFFLE node.
10785 EVT EltVT = RVT.getVectorElementType();
10786 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
10787 DAG.getConstant(0, EltVT));
10788 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), RVT, ZeroOps);
10789 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
10790 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
10791 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
10798 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
10799 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
10800 assert(N->getValueType(0).isVector() &&
10801 "SimplifyVBinOp only works on vectors!");
10803 SDValue LHS = N->getOperand(0);
10804 SDValue RHS = N->getOperand(1);
10805 SDValue Shuffle = XformToShuffleWithZero(N);
10806 if (Shuffle.getNode()) return Shuffle;
10808 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
10810 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
10811 RHS.getOpcode() == ISD::BUILD_VECTOR) {
10812 // Check if both vectors are constants. If not bail out.
10813 if (!(cast<BuildVectorSDNode>(LHS)->isConstant() &&
10814 cast<BuildVectorSDNode>(RHS)->isConstant()))
10817 SmallVector<SDValue, 8> Ops;
10818 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
10819 SDValue LHSOp = LHS.getOperand(i);
10820 SDValue RHSOp = RHS.getOperand(i);
10822 // Can't fold divide by zero.
10823 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
10824 N->getOpcode() == ISD::FDIV) {
10825 if ((RHSOp.getOpcode() == ISD::Constant &&
10826 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
10827 (RHSOp.getOpcode() == ISD::ConstantFP &&
10828 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
10832 EVT VT = LHSOp.getValueType();
10833 EVT RVT = RHSOp.getValueType();
10835 // Integer BUILD_VECTOR operands may have types larger than the element
10836 // size (e.g., when the element type is not legal). Prior to type
10837 // legalization, the types may not match between the two BUILD_VECTORS.
10838 // Truncate one of the operands to make them match.
10839 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
10840 RHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, RHSOp);
10842 LHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), RVT, LHSOp);
10846 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(LHS), VT,
10848 if (FoldOp.getOpcode() != ISD::UNDEF &&
10849 FoldOp.getOpcode() != ISD::Constant &&
10850 FoldOp.getOpcode() != ISD::ConstantFP)
10852 Ops.push_back(FoldOp);
10853 AddToWorkList(FoldOp.getNode());
10856 if (Ops.size() == LHS.getNumOperands())
10857 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), LHS.getValueType(), Ops);
10860 // Type legalization might introduce new shuffles in the DAG.
10861 // Fold (VBinOp (shuffle (A, Undef, Mask)), (shuffle (B, Undef, Mask)))
10862 // -> (shuffle (VBinOp (A, B)), Undef, Mask).
10863 if (LegalTypes && isa<ShuffleVectorSDNode>(LHS) &&
10864 isa<ShuffleVectorSDNode>(RHS) && LHS.hasOneUse() && RHS.hasOneUse() &&
10865 LHS.getOperand(1).getOpcode() == ISD::UNDEF &&
10866 RHS.getOperand(1).getOpcode() == ISD::UNDEF) {
10867 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(LHS);
10868 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(RHS);
10870 if (SVN0->getMask().equals(SVN1->getMask())) {
10871 EVT VT = N->getValueType(0);
10872 SDValue UndefVector = LHS.getOperand(1);
10873 SDValue NewBinOp = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
10874 LHS.getOperand(0), RHS.getOperand(0));
10875 AddUsersToWorkList(N);
10876 return DAG.getVectorShuffle(VT, SDLoc(N), NewBinOp, UndefVector,
10877 &SVN0->getMask()[0]);
10884 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
10885 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
10886 assert(N->getValueType(0).isVector() &&
10887 "SimplifyVUnaryOp only works on vectors!");
10889 SDValue N0 = N->getOperand(0);
10891 if (N0.getOpcode() != ISD::BUILD_VECTOR)
10894 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
10895 SmallVector<SDValue, 8> Ops;
10896 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
10897 SDValue Op = N0.getOperand(i);
10898 if (Op.getOpcode() != ISD::UNDEF &&
10899 Op.getOpcode() != ISD::ConstantFP)
10901 EVT EltVT = Op.getValueType();
10902 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(N0), EltVT, Op);
10903 if (FoldOp.getOpcode() != ISD::UNDEF &&
10904 FoldOp.getOpcode() != ISD::ConstantFP)
10906 Ops.push_back(FoldOp);
10907 AddToWorkList(FoldOp.getNode());
10910 if (Ops.size() != N0.getNumOperands())
10913 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), N0.getValueType(), Ops);
10916 SDValue DAGCombiner::SimplifySelect(SDLoc DL, SDValue N0,
10917 SDValue N1, SDValue N2){
10918 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
10920 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
10921 cast<CondCodeSDNode>(N0.getOperand(2))->get());
10923 // If we got a simplified select_cc node back from SimplifySelectCC, then
10924 // break it down into a new SETCC node, and a new SELECT node, and then return
10925 // the SELECT node, since we were called with a SELECT node.
10926 if (SCC.getNode()) {
10927 // Check to see if we got a select_cc back (to turn into setcc/select).
10928 // Otherwise, just return whatever node we got back, like fabs.
10929 if (SCC.getOpcode() == ISD::SELECT_CC) {
10930 SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
10932 SCC.getOperand(0), SCC.getOperand(1),
10933 SCC.getOperand(4));
10934 AddToWorkList(SETCC.getNode());
10935 return DAG.getSelect(SDLoc(SCC), SCC.getValueType(),
10936 SCC.getOperand(2), SCC.getOperand(3), SETCC);
10944 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
10945 /// are the two values being selected between, see if we can simplify the
10946 /// select. Callers of this should assume that TheSelect is deleted if this
10947 /// returns true. As such, they should return the appropriate thing (e.g. the
10948 /// node) back to the top-level of the DAG combiner loop to avoid it being
10950 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
10953 // Cannot simplify select with vector condition
10954 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
10956 // If this is a select from two identical things, try to pull the operation
10957 // through the select.
10958 if (LHS.getOpcode() != RHS.getOpcode() ||
10959 !LHS.hasOneUse() || !RHS.hasOneUse())
10962 // If this is a load and the token chain is identical, replace the select
10963 // of two loads with a load through a select of the address to load from.
10964 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
10965 // constants have been dropped into the constant pool.
10966 if (LHS.getOpcode() == ISD::LOAD) {
10967 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
10968 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
10970 // Token chains must be identical.
10971 if (LHS.getOperand(0) != RHS.getOperand(0) ||
10972 // Do not let this transformation reduce the number of volatile loads.
10973 LLD->isVolatile() || RLD->isVolatile() ||
10974 // If this is an EXTLOAD, the VT's must match.
10975 LLD->getMemoryVT() != RLD->getMemoryVT() ||
10976 // If this is an EXTLOAD, the kind of extension must match.
10977 (LLD->getExtensionType() != RLD->getExtensionType() &&
10978 // The only exception is if one of the extensions is anyext.
10979 LLD->getExtensionType() != ISD::EXTLOAD &&
10980 RLD->getExtensionType() != ISD::EXTLOAD) ||
10981 // FIXME: this discards src value information. This is
10982 // over-conservative. It would be beneficial to be able to remember
10983 // both potential memory locations. Since we are discarding
10984 // src value info, don't do the transformation if the memory
10985 // locations are not in the default address space.
10986 LLD->getPointerInfo().getAddrSpace() != 0 ||
10987 RLD->getPointerInfo().getAddrSpace() != 0 ||
10988 !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
10989 LLD->getBasePtr().getValueType()))
10992 // Check that the select condition doesn't reach either load. If so,
10993 // folding this will induce a cycle into the DAG. If not, this is safe to
10994 // xform, so create a select of the addresses.
10996 if (TheSelect->getOpcode() == ISD::SELECT) {
10997 SDNode *CondNode = TheSelect->getOperand(0).getNode();
10998 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
10999 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
11001 // The loads must not depend on one another.
11002 if (LLD->isPredecessorOf(RLD) ||
11003 RLD->isPredecessorOf(LLD))
11005 Addr = DAG.getSelect(SDLoc(TheSelect),
11006 LLD->getBasePtr().getValueType(),
11007 TheSelect->getOperand(0), LLD->getBasePtr(),
11008 RLD->getBasePtr());
11009 } else { // Otherwise SELECT_CC
11010 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
11011 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
11013 if ((LLD->hasAnyUseOfValue(1) &&
11014 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
11015 (RLD->hasAnyUseOfValue(1) &&
11016 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
11019 Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
11020 LLD->getBasePtr().getValueType(),
11021 TheSelect->getOperand(0),
11022 TheSelect->getOperand(1),
11023 LLD->getBasePtr(), RLD->getBasePtr(),
11024 TheSelect->getOperand(4));
11028 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
11029 Load = DAG.getLoad(TheSelect->getValueType(0),
11031 // FIXME: Discards pointer and TBAA info.
11032 LLD->getChain(), Addr, MachinePointerInfo(),
11033 LLD->isVolatile(), LLD->isNonTemporal(),
11034 LLD->isInvariant(), LLD->getAlignment());
11036 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
11037 RLD->getExtensionType() : LLD->getExtensionType(),
11039 TheSelect->getValueType(0),
11040 // FIXME: Discards pointer and TBAA info.
11041 LLD->getChain(), Addr, MachinePointerInfo(),
11042 LLD->getMemoryVT(), LLD->isVolatile(),
11043 LLD->isNonTemporal(), LLD->getAlignment());
11046 // Users of the select now use the result of the load.
11047 CombineTo(TheSelect, Load);
11049 // Users of the old loads now use the new load's chain. We know the
11050 // old-load value is dead now.
11051 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
11052 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
11059 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
11060 /// where 'cond' is the comparison specified by CC.
11061 SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
11062 SDValue N2, SDValue N3,
11063 ISD::CondCode CC, bool NotExtCompare) {
11064 // (x ? y : y) -> y.
11065 if (N2 == N3) return N2;
11067 EVT VT = N2.getValueType();
11068 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
11069 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
11070 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
11072 // Determine if the condition we're dealing with is constant
11073 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
11074 N0, N1, CC, DL, false);
11075 if (SCC.getNode()) AddToWorkList(SCC.getNode());
11076 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
11078 // fold select_cc true, x, y -> x
11079 if (SCCC && !SCCC->isNullValue())
11081 // fold select_cc false, x, y -> y
11082 if (SCCC && SCCC->isNullValue())
11085 // Check to see if we can simplify the select into an fabs node
11086 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
11087 // Allow either -0.0 or 0.0
11088 if (CFP->getValueAPF().isZero()) {
11089 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
11090 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
11091 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
11092 N2 == N3.getOperand(0))
11093 return DAG.getNode(ISD::FABS, DL, VT, N0);
11095 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
11096 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
11097 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
11098 N2.getOperand(0) == N3)
11099 return DAG.getNode(ISD::FABS, DL, VT, N3);
11103 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
11104 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
11105 // in it. This is a win when the constant is not otherwise available because
11106 // it replaces two constant pool loads with one. We only do this if the FP
11107 // type is known to be legal, because if it isn't, then we are before legalize
11108 // types an we want the other legalization to happen first (e.g. to avoid
11109 // messing with soft float) and if the ConstantFP is not legal, because if
11110 // it is legal, we may not need to store the FP constant in a constant pool.
11111 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
11112 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
11113 if (TLI.isTypeLegal(N2.getValueType()) &&
11114 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
11115 TargetLowering::Legal &&
11116 !TLI.isFPImmLegal(TV->getValueAPF(), TV->getValueType(0)) &&
11117 !TLI.isFPImmLegal(FV->getValueAPF(), FV->getValueType(0))) &&
11118 // If both constants have multiple uses, then we won't need to do an
11119 // extra load, they are likely around in registers for other users.
11120 (TV->hasOneUse() || FV->hasOneUse())) {
11121 Constant *Elts[] = {
11122 const_cast<ConstantFP*>(FV->getConstantFPValue()),
11123 const_cast<ConstantFP*>(TV->getConstantFPValue())
11125 Type *FPTy = Elts[0]->getType();
11126 const DataLayout &TD = *TLI.getDataLayout();
11128 // Create a ConstantArray of the two constants.
11129 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
11130 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
11131 TD.getPrefTypeAlignment(FPTy));
11132 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
11134 // Get the offsets to the 0 and 1 element of the array so that we can
11135 // select between them.
11136 SDValue Zero = DAG.getIntPtrConstant(0);
11137 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
11138 SDValue One = DAG.getIntPtrConstant(EltSize);
11140 SDValue Cond = DAG.getSetCC(DL,
11141 getSetCCResultType(N0.getValueType()),
11143 AddToWorkList(Cond.getNode());
11144 SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
11146 AddToWorkList(CstOffset.getNode());
11147 CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
11149 AddToWorkList(CPIdx.getNode());
11150 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
11151 MachinePointerInfo::getConstantPool(), false,
11152 false, false, Alignment);
11157 // Check to see if we can perform the "gzip trick", transforming
11158 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
11159 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
11160 (N1C->isNullValue() || // (a < 0) ? b : 0
11161 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
11162 EVT XType = N0.getValueType();
11163 EVT AType = N2.getValueType();
11164 if (XType.bitsGE(AType)) {
11165 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
11166 // single-bit constant.
11167 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
11168 unsigned ShCtV = N2C->getAPIntValue().logBase2();
11169 ShCtV = XType.getSizeInBits()-ShCtV-1;
11170 SDValue ShCt = DAG.getConstant(ShCtV,
11171 getShiftAmountTy(N0.getValueType()));
11172 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0),
11174 AddToWorkList(Shift.getNode());
11176 if (XType.bitsGT(AType)) {
11177 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
11178 AddToWorkList(Shift.getNode());
11181 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
11184 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0),
11186 DAG.getConstant(XType.getSizeInBits()-1,
11187 getShiftAmountTy(N0.getValueType())));
11188 AddToWorkList(Shift.getNode());
11190 if (XType.bitsGT(AType)) {
11191 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
11192 AddToWorkList(Shift.getNode());
11195 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
11199 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
11200 // where y is has a single bit set.
11201 // A plaintext description would be, we can turn the SELECT_CC into an AND
11202 // when the condition can be materialized as an all-ones register. Any
11203 // single bit-test can be materialized as an all-ones register with
11204 // shift-left and shift-right-arith.
11205 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
11206 N0->getValueType(0) == VT &&
11207 N1C && N1C->isNullValue() &&
11208 N2C && N2C->isNullValue()) {
11209 SDValue AndLHS = N0->getOperand(0);
11210 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
11211 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
11212 // Shift the tested bit over the sign bit.
11213 APInt AndMask = ConstAndRHS->getAPIntValue();
11215 DAG.getConstant(AndMask.countLeadingZeros(),
11216 getShiftAmountTy(AndLHS.getValueType()));
11217 SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);
11219 // Now arithmetic right shift it all the way over, so the result is either
11220 // all-ones, or zero.
11222 DAG.getConstant(AndMask.getBitWidth()-1,
11223 getShiftAmountTy(Shl.getValueType()));
11224 SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);
11226 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
11230 // fold select C, 16, 0 -> shl C, 4
11231 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
11232 TLI.getBooleanContents(N0.getValueType().isVector()) ==
11233 TargetLowering::ZeroOrOneBooleanContent) {
11235 // If the caller doesn't want us to simplify this into a zext of a compare,
11237 if (NotExtCompare && N2C->getAPIntValue() == 1)
11240 // Get a SetCC of the condition
11241 // NOTE: Don't create a SETCC if it's not legal on this target.
11242 if (!LegalOperations ||
11243 TLI.isOperationLegal(ISD::SETCC,
11244 LegalTypes ? getSetCCResultType(N0.getValueType()) : MVT::i1)) {
11246 // cast from setcc result type to select result type
11248 SCC = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
11250 if (N2.getValueType().bitsLT(SCC.getValueType()))
11251 Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
11252 N2.getValueType());
11254 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
11255 N2.getValueType(), SCC);
11257 SCC = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
11258 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
11259 N2.getValueType(), SCC);
11262 AddToWorkList(SCC.getNode());
11263 AddToWorkList(Temp.getNode());
11265 if (N2C->getAPIntValue() == 1)
11268 // shl setcc result by log2 n2c
11269 return DAG.getNode(
11270 ISD::SHL, DL, N2.getValueType(), Temp,
11271 DAG.getConstant(N2C->getAPIntValue().logBase2(),
11272 getShiftAmountTy(Temp.getValueType())));
11276 // Check to see if this is the equivalent of setcc
11277 // FIXME: Turn all of these into setcc if setcc if setcc is legal
11278 // otherwise, go ahead with the folds.
11279 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
11280 EVT XType = N0.getValueType();
11281 if (!LegalOperations ||
11282 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(XType))) {
11283 SDValue Res = DAG.getSetCC(DL, getSetCCResultType(XType), N0, N1, CC);
11284 if (Res.getValueType() != VT)
11285 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
11289 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
11290 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
11291 (!LegalOperations ||
11292 TLI.isOperationLegal(ISD::CTLZ, XType))) {
11293 SDValue Ctlz = DAG.getNode(ISD::CTLZ, SDLoc(N0), XType, N0);
11294 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
11295 DAG.getConstant(Log2_32(XType.getSizeInBits()),
11296 getShiftAmountTy(Ctlz.getValueType())));
11298 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
11299 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
11300 SDValue NegN0 = DAG.getNode(ISD::SUB, SDLoc(N0),
11301 XType, DAG.getConstant(0, XType), N0);
11302 SDValue NotN0 = DAG.getNOT(SDLoc(N0), N0, XType);
11303 return DAG.getNode(ISD::SRL, DL, XType,
11304 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
11305 DAG.getConstant(XType.getSizeInBits()-1,
11306 getShiftAmountTy(XType)));
11308 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
11309 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
11310 SDValue Sign = DAG.getNode(ISD::SRL, SDLoc(N0), XType, N0,
11311 DAG.getConstant(XType.getSizeInBits()-1,
11312 getShiftAmountTy(N0.getValueType())));
11313 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
11317 // Check to see if this is an integer abs.
11318 // select_cc setg[te] X, 0, X, -X ->
11319 // select_cc setgt X, -1, X, -X ->
11320 // select_cc setl[te] X, 0, -X, X ->
11321 // select_cc setlt X, 1, -X, X ->
11322 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
11324 ConstantSDNode *SubC = nullptr;
11325 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
11326 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
11327 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
11328 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
11329 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
11330 (N1C->isOne() && CC == ISD::SETLT)) &&
11331 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
11332 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
11334 EVT XType = N0.getValueType();
11335 if (SubC && SubC->isNullValue() && XType.isInteger()) {
11336 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0), XType,
11338 DAG.getConstant(XType.getSizeInBits()-1,
11339 getShiftAmountTy(N0.getValueType())));
11340 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N0),
11342 AddToWorkList(Shift.getNode());
11343 AddToWorkList(Add.getNode());
11344 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
11351 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
11352 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
11353 SDValue N1, ISD::CondCode Cond,
11354 SDLoc DL, bool foldBooleans) {
11355 TargetLowering::DAGCombinerInfo
11356 DagCombineInfo(DAG, Level, false, this);
11357 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
11360 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
11361 /// return a DAG expression to select that will generate the same value by
11362 /// multiplying by a magic number. See:
11363 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
11364 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
11365 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
11369 // Avoid division by zero.
11370 if (!C->getAPIntValue())
11373 std::vector<SDNode*> Built;
11375 TLI.BuildSDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
11377 for (SDNode *N : Built)
11382 /// BuildUDIV - Given an ISD::UDIV node expressing a divide by constant,
11383 /// return a DAG expression to select that will generate the same value by
11384 /// multiplying by a magic number. See:
11385 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
11386 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
11387 ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
11391 // Avoid division by zero.
11392 if (!C->getAPIntValue())
11395 std::vector<SDNode*> Built;
11397 TLI.BuildUDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);
11399 for (SDNode *N : Built)
11404 /// FindBaseOffset - Return true if base is a frame index, which is known not
11405 // to alias with anything but itself. Provides base object and offset as
11407 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
11408 const GlobalValue *&GV, const void *&CV) {
11409 // Assume it is a primitive operation.
11410 Base = Ptr; Offset = 0; GV = nullptr; CV = nullptr;
11412 // If it's an adding a simple constant then integrate the offset.
11413 if (Base.getOpcode() == ISD::ADD) {
11414 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
11415 Base = Base.getOperand(0);
11416 Offset += C->getZExtValue();
11420 // Return the underlying GlobalValue, and update the Offset. Return false
11421 // for GlobalAddressSDNode since the same GlobalAddress may be represented
11422 // by multiple nodes with different offsets.
11423 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
11424 GV = G->getGlobal();
11425 Offset += G->getOffset();
11429 // Return the underlying Constant value, and update the Offset. Return false
11430 // for ConstantSDNodes since the same constant pool entry may be represented
11431 // by multiple nodes with different offsets.
11432 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
11433 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
11434 : (const void *)C->getConstVal();
11435 Offset += C->getOffset();
11438 // If it's any of the following then it can't alias with anything but itself.
11439 return isa<FrameIndexSDNode>(Base);
11442 /// isAlias - Return true if there is any possibility that the two addresses
11444 bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
11445 // If they are the same then they must be aliases.
11446 if (Op0->getBasePtr() == Op1->getBasePtr()) return true;
11448 // If they are both volatile then they cannot be reordered.
11449 if (Op0->isVolatile() && Op1->isVolatile()) return true;
11451 // Gather base node and offset information.
11452 SDValue Base1, Base2;
11453 int64_t Offset1, Offset2;
11454 const GlobalValue *GV1, *GV2;
11455 const void *CV1, *CV2;
11456 bool isFrameIndex1 = FindBaseOffset(Op0->getBasePtr(),
11457 Base1, Offset1, GV1, CV1);
11458 bool isFrameIndex2 = FindBaseOffset(Op1->getBasePtr(),
11459 Base2, Offset2, GV2, CV2);
11461 // If they have a same base address then check to see if they overlap.
11462 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
11463 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
11464 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
11466 // It is possible for different frame indices to alias each other, mostly
11467 // when tail call optimization reuses return address slots for arguments.
11468 // To catch this case, look up the actual index of frame indices to compute
11469 // the real alias relationship.
11470 if (isFrameIndex1 && isFrameIndex2) {
11471 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
11472 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
11473 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
11474 return !((Offset1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= Offset2 ||
11475 (Offset2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= Offset1);
11478 // Otherwise, if we know what the bases are, and they aren't identical, then
11479 // we know they cannot alias.
11480 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
11483 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
11484 // compared to the size and offset of the access, we may be able to prove they
11485 // do not alias. This check is conservative for now to catch cases created by
11486 // splitting vector types.
11487 if ((Op0->getOriginalAlignment() == Op1->getOriginalAlignment()) &&
11488 (Op0->getSrcValueOffset() != Op1->getSrcValueOffset()) &&
11489 (Op0->getMemoryVT().getSizeInBits() >> 3 ==
11490 Op1->getMemoryVT().getSizeInBits() >> 3) &&
11491 (Op0->getOriginalAlignment() > Op0->getMemoryVT().getSizeInBits()) >> 3) {
11492 int64_t OffAlign1 = Op0->getSrcValueOffset() % Op0->getOriginalAlignment();
11493 int64_t OffAlign2 = Op1->getSrcValueOffset() % Op1->getOriginalAlignment();
11495 // There is no overlap between these relatively aligned accesses of similar
11496 // size, return no alias.
11497 if ((OffAlign1 + (Op0->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign2 ||
11498 (OffAlign2 + (Op1->getMemoryVT().getSizeInBits() >> 3)) <= OffAlign1)
11502 bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0 ? CombinerGlobalAA :
11503 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
11505 if (CombinerAAOnlyFunc.getNumOccurrences() &&
11506 CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
11510 Op0->getMemOperand()->getValue() && Op1->getMemOperand()->getValue()) {
11511 // Use alias analysis information.
11512 int64_t MinOffset = std::min(Op0->getSrcValueOffset(),
11513 Op1->getSrcValueOffset());
11514 int64_t Overlap1 = (Op0->getMemoryVT().getSizeInBits() >> 3) +
11515 Op0->getSrcValueOffset() - MinOffset;
11516 int64_t Overlap2 = (Op1->getMemoryVT().getSizeInBits() >> 3) +
11517 Op1->getSrcValueOffset() - MinOffset;
11518 AliasAnalysis::AliasResult AAResult =
11519 AA.alias(AliasAnalysis::Location(Op0->getMemOperand()->getValue(),
11521 UseTBAA ? Op0->getTBAAInfo() : nullptr),
11522 AliasAnalysis::Location(Op1->getMemOperand()->getValue(),
11524 UseTBAA ? Op1->getTBAAInfo() : nullptr));
11525 if (AAResult == AliasAnalysis::NoAlias)
11529 // Otherwise we have to assume they alias.
11533 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
11534 /// looking for aliasing nodes and adding them to the Aliases vector.
11535 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
11536 SmallVectorImpl<SDValue> &Aliases) {
11537 SmallVector<SDValue, 8> Chains; // List of chains to visit.
11538 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
11540 // Get alias information for node.
11541 bool IsLoad = isa<LoadSDNode>(N) && !cast<LSBaseSDNode>(N)->isVolatile();
11544 Chains.push_back(OriginalChain);
11545 unsigned Depth = 0;
11547 // Look at each chain and determine if it is an alias. If so, add it to the
11548 // aliases list. If not, then continue up the chain looking for the next
11550 while (!Chains.empty()) {
11551 SDValue Chain = Chains.back();
11554 // For TokenFactor nodes, look at each operand and only continue up the
11555 // chain until we find two aliases. If we've seen two aliases, assume we'll
11556 // find more and revert to original chain since the xform is unlikely to be
11559 // FIXME: The depth check could be made to return the last non-aliasing
11560 // chain we found before we hit a tokenfactor rather than the original
11562 if (Depth > 6 || Aliases.size() == 2) {
11564 Aliases.push_back(OriginalChain);
11568 // Don't bother if we've been before.
11569 if (!Visited.insert(Chain.getNode()))
11572 switch (Chain.getOpcode()) {
11573 case ISD::EntryToken:
11574 // Entry token is ideal chain operand, but handled in FindBetterChain.
11579 // Get alias information for Chain.
11580 bool IsOpLoad = isa<LoadSDNode>(Chain.getNode()) &&
11581 !cast<LSBaseSDNode>(Chain.getNode())->isVolatile();
11583 // If chain is alias then stop here.
11584 if (!(IsLoad && IsOpLoad) &&
11585 isAlias(cast<LSBaseSDNode>(N), cast<LSBaseSDNode>(Chain.getNode()))) {
11586 Aliases.push_back(Chain);
11588 // Look further up the chain.
11589 Chains.push_back(Chain.getOperand(0));
11595 case ISD::TokenFactor:
11596 // We have to check each of the operands of the token factor for "small"
11597 // token factors, so we queue them up. Adding the operands to the queue
11598 // (stack) in reverse order maintains the original order and increases the
11599 // likelihood that getNode will find a matching token factor (CSE.)
11600 if (Chain.getNumOperands() > 16) {
11601 Aliases.push_back(Chain);
11604 for (unsigned n = Chain.getNumOperands(); n;)
11605 Chains.push_back(Chain.getOperand(--n));
11610 // For all other instructions we will just have to take what we can get.
11611 Aliases.push_back(Chain);
11616 // We need to be careful here to also search for aliases through the
11617 // value operand of a store, etc. Consider the following situation:
11619 // L1 = load Token1, %52
11620 // S1 = store Token1, L1, %51
11621 // L2 = load Token1, %52+8
11622 // S2 = store Token1, L2, %51+8
11623 // Token2 = Token(S1, S2)
11624 // L3 = load Token2, %53
11625 // S3 = store Token2, L3, %52
11626 // L4 = load Token2, %53+8
11627 // S4 = store Token2, L4, %52+8
11628 // If we search for aliases of S3 (which loads address %52), and we look
11629 // only through the chain, then we'll miss the trivial dependence on L1
11630 // (which also loads from %52). We then might change all loads and
11631 // stores to use Token1 as their chain operand, which could result in
11632 // copying %53 into %52 before copying %52 into %51 (which should
11635 // The problem is, however, that searching for such data dependencies
11636 // can become expensive, and the cost is not directly related to the
11637 // chain depth. Instead, we'll rule out such configurations here by
11638 // insisting that we've visited all chain users (except for users
11639 // of the original chain, which is not necessary). When doing this,
11640 // we need to look through nodes we don't care about (otherwise, things
11641 // like register copies will interfere with trivial cases).
11643 SmallVector<const SDNode *, 16> Worklist;
11644 for (SmallPtrSet<SDNode *, 16>::iterator I = Visited.begin(),
11645 IE = Visited.end(); I != IE; ++I)
11646 if (*I != OriginalChain.getNode())
11647 Worklist.push_back(*I);
11649 while (!Worklist.empty()) {
11650 const SDNode *M = Worklist.pop_back_val();
11652 // We have already visited M, and want to make sure we've visited any uses
11653 // of M that we care about. For uses that we've not visisted, and don't
11654 // care about, queue them to the worklist.
11656 for (SDNode::use_iterator UI = M->use_begin(),
11657 UIE = M->use_end(); UI != UIE; ++UI)
11658 if (UI.getUse().getValueType() == MVT::Other && Visited.insert(*UI)) {
11659 if (isa<MemIntrinsicSDNode>(*UI) || isa<MemSDNode>(*UI)) {
11660 // We've not visited this use, and we care about it (it could have an
11661 // ordering dependency with the original node).
11663 Aliases.push_back(OriginalChain);
11667 // We've not visited this use, but we don't care about it. Mark it as
11668 // visited and enqueue it to the worklist.
11669 Worklist.push_back(*UI);
11674 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
11675 /// for a better chain (aliasing node.)
11676 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
11677 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
11679 // Accumulate all the aliases to this node.
11680 GatherAllAliases(N, OldChain, Aliases);
11682 // If no operands then chain to entry token.
11683 if (Aliases.size() == 0)
11684 return DAG.getEntryNode();
11686 // If a single operand then chain to it. We don't need to revisit it.
11687 if (Aliases.size() == 1)
11690 // Construct a custom tailored token factor.
11691 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Aliases);
11694 // SelectionDAG::Combine - This is the entry point for the file.
11696 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
11697 CodeGenOpt::Level OptLevel) {
11698 /// run - This is the main entry point to this class.
11700 DAGCombiner(*this, AA, OptLevel).Run(Level);