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 #define DEBUG_TYPE "dagcombine"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/ADT/SmallPtrSet.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/Analysis/AliasAnalysis.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/DerivedTypes.h"
28 #include "llvm/IR/Function.h"
29 #include "llvm/IR/LLVMContext.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/MathExtras.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/Target/TargetLowering.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
41 STATISTIC(NodesCombined , "Number of dag nodes combined");
42 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
43 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
44 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
45 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
49 CombinerAA("combiner-alias-analysis", cl::Hidden,
50 cl::desc("Turn on alias analysis during testing"));
53 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
54 cl::desc("Include global information in alias analysis"));
56 //------------------------------ DAGCombiner ---------------------------------//
60 const TargetLowering &TLI;
62 CodeGenOpt::Level OptLevel;
66 // Worklist of all of the nodes that need to be simplified.
68 // This has the semantics that when adding to the worklist,
69 // the item added must be next to be processed. It should
70 // also only appear once. The naive approach to this takes
73 // To reduce the insert/remove time to logarithmic, we use
74 // a set and a vector to maintain our worklist.
76 // The set contains the items on the worklist, but does not
77 // maintain the order they should be visited.
79 // The vector maintains the order nodes should be visited, but may
80 // contain duplicate or removed nodes. When choosing a node to
81 // visit, we pop off the order stack until we find an item that is
82 // also in the contents set. All operations are O(log N).
83 SmallPtrSet<SDNode*, 64> WorkListContents;
84 SmallVector<SDNode*, 64> WorkListOrder;
86 // AA - Used for DAG load/store alias analysis.
89 /// AddUsersToWorkList - When an instruction is simplified, add all users of
90 /// the instruction to the work lists because they might get more simplified
93 void AddUsersToWorkList(SDNode *N) {
94 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
99 /// visit - call the node-specific routine that knows how to fold each
100 /// particular type of node.
101 SDValue visit(SDNode *N);
104 /// AddToWorkList - Add to the work list making sure its instance is at the
105 /// back (next to be processed.)
106 void AddToWorkList(SDNode *N) {
107 WorkListContents.insert(N);
108 WorkListOrder.push_back(N);
111 /// removeFromWorkList - remove all instances of N from the worklist.
113 void removeFromWorkList(SDNode *N) {
114 WorkListContents.erase(N);
117 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
120 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
121 return CombineTo(N, &Res, 1, AddTo);
124 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
126 SDValue To[] = { Res0, Res1 };
127 return CombineTo(N, To, 2, AddTo);
130 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
134 /// SimplifyDemandedBits - Check the specified integer node value to see if
135 /// it can be simplified or if things it uses can be simplified by bit
136 /// propagation. If so, return true.
137 bool SimplifyDemandedBits(SDValue Op) {
138 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
139 APInt Demanded = APInt::getAllOnesValue(BitWidth);
140 return SimplifyDemandedBits(Op, Demanded);
143 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
145 bool CombineToPreIndexedLoadStore(SDNode *N);
146 bool CombineToPostIndexedLoadStore(SDNode *N);
148 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
149 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
150 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
151 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
152 SDValue PromoteIntBinOp(SDValue Op);
153 SDValue PromoteIntShiftOp(SDValue Op);
154 SDValue PromoteExtend(SDValue Op);
155 bool PromoteLoad(SDValue Op);
157 void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
158 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
159 ISD::NodeType ExtType);
161 /// combine - call the node-specific routine that knows how to fold each
162 /// particular type of node. If that doesn't do anything, try the
163 /// target-specific DAG combines.
164 SDValue combine(SDNode *N);
166 // Visitation implementation - Implement dag node combining for different
167 // node types. The semantics are as follows:
169 // SDValue.getNode() == 0 - No change was made
170 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
171 // otherwise - N should be replaced by the returned Operand.
173 SDValue visitTokenFactor(SDNode *N);
174 SDValue visitMERGE_VALUES(SDNode *N);
175 SDValue visitADD(SDNode *N);
176 SDValue visitSUB(SDNode *N);
177 SDValue visitADDC(SDNode *N);
178 SDValue visitSUBC(SDNode *N);
179 SDValue visitADDE(SDNode *N);
180 SDValue visitSUBE(SDNode *N);
181 SDValue visitMUL(SDNode *N);
182 SDValue visitSDIV(SDNode *N);
183 SDValue visitUDIV(SDNode *N);
184 SDValue visitSREM(SDNode *N);
185 SDValue visitUREM(SDNode *N);
186 SDValue visitMULHU(SDNode *N);
187 SDValue visitMULHS(SDNode *N);
188 SDValue visitSMUL_LOHI(SDNode *N);
189 SDValue visitUMUL_LOHI(SDNode *N);
190 SDValue visitSMULO(SDNode *N);
191 SDValue visitUMULO(SDNode *N);
192 SDValue visitSDIVREM(SDNode *N);
193 SDValue visitUDIVREM(SDNode *N);
194 SDValue visitAND(SDNode *N);
195 SDValue visitOR(SDNode *N);
196 SDValue visitXOR(SDNode *N);
197 SDValue SimplifyVBinOp(SDNode *N);
198 SDValue SimplifyVUnaryOp(SDNode *N);
199 SDValue visitSHL(SDNode *N);
200 SDValue visitSRA(SDNode *N);
201 SDValue visitSRL(SDNode *N);
202 SDValue visitCTLZ(SDNode *N);
203 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
204 SDValue visitCTTZ(SDNode *N);
205 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
206 SDValue visitCTPOP(SDNode *N);
207 SDValue visitSELECT(SDNode *N);
208 SDValue visitVSELECT(SDNode *N);
209 SDValue visitSELECT_CC(SDNode *N);
210 SDValue visitSETCC(SDNode *N);
211 SDValue visitSIGN_EXTEND(SDNode *N);
212 SDValue visitZERO_EXTEND(SDNode *N);
213 SDValue visitANY_EXTEND(SDNode *N);
214 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
215 SDValue visitTRUNCATE(SDNode *N);
216 SDValue visitBITCAST(SDNode *N);
217 SDValue visitBUILD_PAIR(SDNode *N);
218 SDValue visitFADD(SDNode *N);
219 SDValue visitFSUB(SDNode *N);
220 SDValue visitFMUL(SDNode *N);
221 SDValue visitFMA(SDNode *N);
222 SDValue visitFDIV(SDNode *N);
223 SDValue visitFREM(SDNode *N);
224 SDValue visitFCOPYSIGN(SDNode *N);
225 SDValue visitSINT_TO_FP(SDNode *N);
226 SDValue visitUINT_TO_FP(SDNode *N);
227 SDValue visitFP_TO_SINT(SDNode *N);
228 SDValue visitFP_TO_UINT(SDNode *N);
229 SDValue visitFP_ROUND(SDNode *N);
230 SDValue visitFP_ROUND_INREG(SDNode *N);
231 SDValue visitFP_EXTEND(SDNode *N);
232 SDValue visitFNEG(SDNode *N);
233 SDValue visitFABS(SDNode *N);
234 SDValue visitFCEIL(SDNode *N);
235 SDValue visitFTRUNC(SDNode *N);
236 SDValue visitFFLOOR(SDNode *N);
237 SDValue visitBRCOND(SDNode *N);
238 SDValue visitBR_CC(SDNode *N);
239 SDValue visitLOAD(SDNode *N);
240 SDValue visitSTORE(SDNode *N);
241 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
242 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
243 SDValue visitBUILD_VECTOR(SDNode *N);
244 SDValue visitCONCAT_VECTORS(SDNode *N);
245 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
246 SDValue visitVECTOR_SHUFFLE(SDNode *N);
248 SDValue XformToShuffleWithZero(SDNode *N);
249 SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
251 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
253 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
254 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
255 SDValue SimplifySelect(SDLoc DL, SDValue N0, SDValue N1, SDValue N2);
256 SDValue SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1, SDValue N2,
257 SDValue N3, ISD::CondCode CC,
258 bool NotExtCompare = false);
259 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
260 SDLoc DL, bool foldBooleans = true);
261 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
263 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
264 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
265 SDValue BuildSDIV(SDNode *N);
266 SDValue BuildUDIV(SDNode *N);
267 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
268 bool DemandHighBits = true);
269 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
270 SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
271 SDValue ReduceLoadWidth(SDNode *N);
272 SDValue ReduceLoadOpStoreWidth(SDNode *N);
273 SDValue TransformFPLoadStorePair(SDNode *N);
274 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
275 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
277 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
279 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
280 /// looking for aliasing nodes and adding them to the Aliases vector.
281 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
282 SmallVectorImpl<SDValue> &Aliases);
284 /// isAlias - Return true if there is any possibility that the two addresses
286 bool isAlias(SDValue Ptr1, int64_t Size1,
287 const Value *SrcValue1, int SrcValueOffset1,
288 unsigned SrcValueAlign1,
289 const MDNode *TBAAInfo1,
290 SDValue Ptr2, int64_t Size2,
291 const Value *SrcValue2, int SrcValueOffset2,
292 unsigned SrcValueAlign2,
293 const MDNode *TBAAInfo2) const;
295 /// isAlias - Return true if there is any possibility that the two addresses
297 bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1);
299 /// FindAliasInfo - Extracts the relevant alias information from the memory
300 /// node. Returns true if the operand was a load.
301 bool FindAliasInfo(SDNode *N,
302 SDValue &Ptr, int64_t &Size,
303 const Value *&SrcValue, int &SrcValueOffset,
304 unsigned &SrcValueAlignment,
305 const MDNode *&TBAAInfo) const;
307 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
308 /// looking for a better chain (aliasing node.)
309 SDValue FindBetterChain(SDNode *N, SDValue Chain);
311 /// Merge consecutive store operations into a wide store.
312 /// This optimization uses wide integers or vectors when possible.
313 /// \return True if some memory operations were changed.
314 bool MergeConsecutiveStores(StoreSDNode *N);
317 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
318 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
319 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
321 /// Run - runs the dag combiner on all nodes in the work list
322 void Run(CombineLevel AtLevel);
324 SelectionDAG &getDAG() const { return DAG; }
326 /// getShiftAmountTy - Returns a type large enough to hold any valid
327 /// shift amount - before type legalization these can be huge.
328 EVT getShiftAmountTy(EVT LHSTy) {
329 assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
330 if (LHSTy.isVector())
332 return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy) : TLI.getPointerTy();
335 /// isTypeLegal - This method returns true if we are running before type
336 /// legalization or if the specified VT is legal.
337 bool isTypeLegal(const EVT &VT) {
338 if (!LegalTypes) return true;
339 return TLI.isTypeLegal(VT);
342 /// getSetCCResultType - Convenience wrapper around
343 /// TargetLowering::getSetCCResultType
344 EVT getSetCCResultType(EVT VT) const {
345 return TLI.getSetCCResultType(*DAG.getContext(), VT);
352 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
353 /// nodes from the worklist.
354 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
357 explicit WorkListRemover(DAGCombiner &dc)
358 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
360 virtual void NodeDeleted(SDNode *N, SDNode *E) {
361 DC.removeFromWorkList(N);
366 //===----------------------------------------------------------------------===//
367 // TargetLowering::DAGCombinerInfo implementation
368 //===----------------------------------------------------------------------===//
370 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
371 ((DAGCombiner*)DC)->AddToWorkList(N);
374 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
375 ((DAGCombiner*)DC)->removeFromWorkList(N);
378 SDValue TargetLowering::DAGCombinerInfo::
379 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
380 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
383 SDValue TargetLowering::DAGCombinerInfo::
384 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
385 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
389 SDValue TargetLowering::DAGCombinerInfo::
390 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
391 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
394 void TargetLowering::DAGCombinerInfo::
395 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
396 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
399 //===----------------------------------------------------------------------===//
401 //===----------------------------------------------------------------------===//
403 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
404 /// specified expression for the same cost as the expression itself, or 2 if we
405 /// can compute the negated form more cheaply than the expression itself.
406 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
407 const TargetLowering &TLI,
408 const TargetOptions *Options,
409 unsigned Depth = 0) {
410 // fneg is removable even if it has multiple uses.
411 if (Op.getOpcode() == ISD::FNEG) return 2;
413 // Don't allow anything with multiple uses.
414 if (!Op.hasOneUse()) return 0;
416 // Don't recurse exponentially.
417 if (Depth > 6) return 0;
419 switch (Op.getOpcode()) {
420 default: return false;
421 case ISD::ConstantFP:
422 // Don't invert constant FP values after legalize. The negated constant
423 // isn't necessarily legal.
424 return LegalOperations ? 0 : 1;
426 // FIXME: determine better conditions for this xform.
427 if (!Options->UnsafeFPMath) return 0;
429 // After operation legalization, it might not be legal to create new FSUBs.
430 if (LegalOperations &&
431 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
434 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
435 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
438 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
439 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
442 // We can't turn -(A-B) into B-A when we honor signed zeros.
443 if (!Options->UnsafeFPMath) return 0;
445 // fold (fneg (fsub A, B)) -> (fsub B, A)
450 if (Options->HonorSignDependentRoundingFPMath()) return 0;
452 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
453 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
457 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
463 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
468 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
469 /// returns the newly negated expression.
470 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
471 bool LegalOperations, unsigned Depth = 0) {
472 // fneg is removable even if it has multiple uses.
473 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
475 // Don't allow anything with multiple uses.
476 assert(Op.hasOneUse() && "Unknown reuse!");
478 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
479 switch (Op.getOpcode()) {
480 default: llvm_unreachable("Unknown code");
481 case ISD::ConstantFP: {
482 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
484 return DAG.getConstantFP(V, Op.getValueType());
487 // FIXME: determine better conditions for this xform.
488 assert(DAG.getTarget().Options.UnsafeFPMath);
490 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
491 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
492 DAG.getTargetLoweringInfo(),
493 &DAG.getTarget().Options, Depth+1))
494 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
495 GetNegatedExpression(Op.getOperand(0), DAG,
496 LegalOperations, Depth+1),
498 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
499 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
500 GetNegatedExpression(Op.getOperand(1), DAG,
501 LegalOperations, Depth+1),
504 // We can't turn -(A-B) into B-A when we honor signed zeros.
505 assert(DAG.getTarget().Options.UnsafeFPMath);
507 // fold (fneg (fsub 0, B)) -> B
508 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
509 if (N0CFP->getValueAPF().isZero())
510 return Op.getOperand(1);
512 // fold (fneg (fsub A, B)) -> (fsub B, A)
513 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
514 Op.getOperand(1), Op.getOperand(0));
518 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
520 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
521 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
522 DAG.getTargetLoweringInfo(),
523 &DAG.getTarget().Options, Depth+1))
524 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
525 GetNegatedExpression(Op.getOperand(0), DAG,
526 LegalOperations, Depth+1),
529 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
530 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
532 GetNegatedExpression(Op.getOperand(1), DAG,
533 LegalOperations, Depth+1));
537 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
538 GetNegatedExpression(Op.getOperand(0), DAG,
539 LegalOperations, Depth+1));
541 return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
542 GetNegatedExpression(Op.getOperand(0), DAG,
543 LegalOperations, Depth+1),
549 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
550 // that selects between the values 1 and 0, making it equivalent to a setcc.
551 // Also, set the incoming LHS, RHS, and CC references to the appropriate
552 // nodes based on the type of node we are checking. This simplifies life a
553 // bit for the callers.
554 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
556 if (N.getOpcode() == ISD::SETCC) {
557 LHS = N.getOperand(0);
558 RHS = N.getOperand(1);
559 CC = N.getOperand(2);
562 if (N.getOpcode() == ISD::SELECT_CC &&
563 N.getOperand(2).getOpcode() == ISD::Constant &&
564 N.getOperand(3).getOpcode() == ISD::Constant &&
565 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
566 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
567 LHS = N.getOperand(0);
568 RHS = N.getOperand(1);
569 CC = N.getOperand(4);
575 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
576 // one use. If this is true, it allows the users to invert the operation for
577 // free when it is profitable to do so.
578 static bool isOneUseSetCC(SDValue N) {
580 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
585 SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
586 SDValue N0, SDValue N1) {
587 EVT VT = N0.getValueType();
588 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
589 if (isa<ConstantSDNode>(N1)) {
590 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
592 DAG.FoldConstantArithmetic(Opc, VT,
593 cast<ConstantSDNode>(N0.getOperand(1)),
594 cast<ConstantSDNode>(N1));
595 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
597 if (N0.hasOneUse()) {
598 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
599 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
600 N0.getOperand(0), N1);
601 AddToWorkList(OpNode.getNode());
602 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
606 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
607 if (isa<ConstantSDNode>(N0)) {
608 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
610 DAG.FoldConstantArithmetic(Opc, VT,
611 cast<ConstantSDNode>(N1.getOperand(1)),
612 cast<ConstantSDNode>(N0));
613 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
615 if (N1.hasOneUse()) {
616 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
617 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
618 N1.getOperand(0), N0);
619 AddToWorkList(OpNode.getNode());
620 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
627 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
629 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
631 DEBUG(dbgs() << "\nReplacing.1 ";
633 dbgs() << "\nWith: ";
634 To[0].getNode()->dump(&DAG);
635 dbgs() << " and " << NumTo-1 << " other values\n";
636 for (unsigned i = 0, e = NumTo; i != e; ++i)
637 assert((!To[i].getNode() ||
638 N->getValueType(i) == To[i].getValueType()) &&
639 "Cannot combine value to value of different type!"));
640 WorkListRemover DeadNodes(*this);
641 DAG.ReplaceAllUsesWith(N, To);
643 // Push the new nodes and any users onto the worklist
644 for (unsigned i = 0, e = NumTo; i != e; ++i) {
645 if (To[i].getNode()) {
646 AddToWorkList(To[i].getNode());
647 AddUsersToWorkList(To[i].getNode());
652 // Finally, if the node is now dead, remove it from the graph. The node
653 // may not be dead if the replacement process recursively simplified to
654 // something else needing this node.
655 if (N->use_empty()) {
656 // Nodes can be reintroduced into the worklist. Make sure we do not
657 // process a node that has been replaced.
658 removeFromWorkList(N);
660 // Finally, since the node is now dead, remove it from the graph.
663 return SDValue(N, 0);
667 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
668 // Replace all uses. If any nodes become isomorphic to other nodes and
669 // are deleted, make sure to remove them from our worklist.
670 WorkListRemover DeadNodes(*this);
671 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
673 // Push the new node and any (possibly new) users onto the worklist.
674 AddToWorkList(TLO.New.getNode());
675 AddUsersToWorkList(TLO.New.getNode());
677 // Finally, if the node is now dead, remove it from the graph. The node
678 // may not be dead if the replacement process recursively simplified to
679 // something else needing this node.
680 if (TLO.Old.getNode()->use_empty()) {
681 removeFromWorkList(TLO.Old.getNode());
683 // If the operands of this node are only used by the node, they will now
684 // be dead. Make sure to visit them first to delete dead nodes early.
685 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
686 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
687 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
689 DAG.DeleteNode(TLO.Old.getNode());
693 /// SimplifyDemandedBits - Check the specified integer node value to see if
694 /// it can be simplified or if things it uses can be simplified by bit
695 /// propagation. If so, return true.
696 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
697 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
698 APInt KnownZero, KnownOne;
699 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
703 AddToWorkList(Op.getNode());
705 // Replace the old value with the new one.
707 DEBUG(dbgs() << "\nReplacing.2 ";
708 TLO.Old.getNode()->dump(&DAG);
709 dbgs() << "\nWith: ";
710 TLO.New.getNode()->dump(&DAG);
713 CommitTargetLoweringOpt(TLO);
717 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
719 EVT VT = Load->getValueType(0);
720 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
722 DEBUG(dbgs() << "\nReplacing.9 ";
724 dbgs() << "\nWith: ";
725 Trunc.getNode()->dump(&DAG);
727 WorkListRemover DeadNodes(*this);
728 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
729 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
730 removeFromWorkList(Load);
731 DAG.DeleteNode(Load);
732 AddToWorkList(Trunc.getNode());
735 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
738 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
739 EVT MemVT = LD->getMemoryVT();
740 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
741 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
743 : LD->getExtensionType();
745 return DAG.getExtLoad(ExtType, dl, PVT,
746 LD->getChain(), LD->getBasePtr(),
747 LD->getPointerInfo(),
748 MemVT, LD->isVolatile(),
749 LD->isNonTemporal(), LD->getAlignment());
752 unsigned Opc = Op.getOpcode();
755 case ISD::AssertSext:
756 return DAG.getNode(ISD::AssertSext, dl, PVT,
757 SExtPromoteOperand(Op.getOperand(0), PVT),
759 case ISD::AssertZext:
760 return DAG.getNode(ISD::AssertZext, dl, PVT,
761 ZExtPromoteOperand(Op.getOperand(0), PVT),
763 case ISD::Constant: {
765 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
766 return DAG.getNode(ExtOpc, dl, PVT, Op);
770 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
772 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
775 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
776 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
778 EVT OldVT = Op.getValueType();
780 bool Replace = false;
781 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
782 if (NewOp.getNode() == 0)
784 AddToWorkList(NewOp.getNode());
787 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
788 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
789 DAG.getValueType(OldVT));
792 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
793 EVT OldVT = Op.getValueType();
795 bool Replace = false;
796 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
797 if (NewOp.getNode() == 0)
799 AddToWorkList(NewOp.getNode());
802 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
803 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
806 /// PromoteIntBinOp - Promote the specified integer binary operation if the
807 /// target indicates it is beneficial. e.g. On x86, it's usually better to
808 /// promote i16 operations to i32 since i16 instructions are longer.
809 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
810 if (!LegalOperations)
813 EVT VT = Op.getValueType();
814 if (VT.isVector() || !VT.isInteger())
817 // If operation type is 'undesirable', e.g. i16 on x86, consider
819 unsigned Opc = Op.getOpcode();
820 if (TLI.isTypeDesirableForOp(Opc, VT))
824 // Consult target whether it is a good idea to promote this operation and
825 // what's the right type to promote it to.
826 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
827 assert(PVT != VT && "Don't know what type to promote to!");
829 bool Replace0 = false;
830 SDValue N0 = Op.getOperand(0);
831 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
832 if (NN0.getNode() == 0)
835 bool Replace1 = false;
836 SDValue N1 = Op.getOperand(1);
841 NN1 = PromoteOperand(N1, PVT, Replace1);
842 if (NN1.getNode() == 0)
846 AddToWorkList(NN0.getNode());
848 AddToWorkList(NN1.getNode());
851 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
853 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
855 DEBUG(dbgs() << "\nPromoting ";
856 Op.getNode()->dump(&DAG));
858 return DAG.getNode(ISD::TRUNCATE, dl, VT,
859 DAG.getNode(Opc, dl, PVT, NN0, NN1));
864 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
865 /// target indicates it is beneficial. e.g. On x86, it's usually better to
866 /// promote i16 operations to i32 since i16 instructions are longer.
867 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
868 if (!LegalOperations)
871 EVT VT = Op.getValueType();
872 if (VT.isVector() || !VT.isInteger())
875 // If operation type is 'undesirable', e.g. i16 on x86, consider
877 unsigned Opc = Op.getOpcode();
878 if (TLI.isTypeDesirableForOp(Opc, VT))
882 // Consult target whether it is a good idea to promote this operation and
883 // what's the right type to promote it to.
884 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
885 assert(PVT != VT && "Don't know what type to promote to!");
887 bool Replace = false;
888 SDValue N0 = Op.getOperand(0);
890 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
891 else if (Opc == ISD::SRL)
892 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
894 N0 = PromoteOperand(N0, PVT, Replace);
895 if (N0.getNode() == 0)
898 AddToWorkList(N0.getNode());
900 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
902 DEBUG(dbgs() << "\nPromoting ";
903 Op.getNode()->dump(&DAG));
905 return DAG.getNode(ISD::TRUNCATE, dl, VT,
906 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
911 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
912 if (!LegalOperations)
915 EVT VT = Op.getValueType();
916 if (VT.isVector() || !VT.isInteger())
919 // If operation type is 'undesirable', e.g. i16 on x86, consider
921 unsigned Opc = Op.getOpcode();
922 if (TLI.isTypeDesirableForOp(Opc, VT))
926 // Consult target whether it is a good idea to promote this operation and
927 // what's the right type to promote it to.
928 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
929 assert(PVT != VT && "Don't know what type to promote to!");
930 // fold (aext (aext x)) -> (aext x)
931 // fold (aext (zext x)) -> (zext x)
932 // fold (aext (sext x)) -> (sext x)
933 DEBUG(dbgs() << "\nPromoting ";
934 Op.getNode()->dump(&DAG));
935 return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
940 bool DAGCombiner::PromoteLoad(SDValue Op) {
941 if (!LegalOperations)
944 EVT VT = Op.getValueType();
945 if (VT.isVector() || !VT.isInteger())
948 // If operation type is 'undesirable', e.g. i16 on x86, consider
950 unsigned Opc = Op.getOpcode();
951 if (TLI.isTypeDesirableForOp(Opc, VT))
955 // Consult target whether it is a good idea to promote this operation and
956 // what's the right type to promote it to.
957 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
958 assert(PVT != VT && "Don't know what type to promote to!");
961 SDNode *N = Op.getNode();
962 LoadSDNode *LD = cast<LoadSDNode>(N);
963 EVT MemVT = LD->getMemoryVT();
964 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
965 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
967 : LD->getExtensionType();
968 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
969 LD->getChain(), LD->getBasePtr(),
970 LD->getPointerInfo(),
971 MemVT, LD->isVolatile(),
972 LD->isNonTemporal(), LD->getAlignment());
973 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
975 DEBUG(dbgs() << "\nPromoting ";
978 Result.getNode()->dump(&DAG);
980 WorkListRemover DeadNodes(*this);
981 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
982 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
983 removeFromWorkList(N);
985 AddToWorkList(Result.getNode());
992 //===----------------------------------------------------------------------===//
993 // Main DAG Combiner implementation
994 //===----------------------------------------------------------------------===//
996 void DAGCombiner::Run(CombineLevel AtLevel) {
997 // set the instance variables, so that the various visit routines may use it.
999 LegalOperations = Level >= AfterLegalizeVectorOps;
1000 LegalTypes = Level >= AfterLegalizeTypes;
1002 // Add all the dag nodes to the worklist.
1003 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
1004 E = DAG.allnodes_end(); I != E; ++I)
1007 // Create a dummy node (which is not added to allnodes), that adds a reference
1008 // to the root node, preventing it from being deleted, and tracking any
1009 // changes of the root.
1010 HandleSDNode Dummy(DAG.getRoot());
1012 // The root of the dag may dangle to deleted nodes until the dag combiner is
1013 // done. Set it to null to avoid confusion.
1014 DAG.setRoot(SDValue());
1016 // while the worklist isn't empty, find a node and
1017 // try and combine it.
1018 while (!WorkListContents.empty()) {
1020 // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
1021 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1022 // worklist *should* contain, and check the node we want to visit is should
1023 // actually be visited.
1025 N = WorkListOrder.pop_back_val();
1026 } while (!WorkListContents.erase(N));
1028 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1029 // N is deleted from the DAG, since they too may now be dead or may have a
1030 // reduced number of uses, allowing other xforms.
1031 if (N->use_empty() && N != &Dummy) {
1032 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1033 AddToWorkList(N->getOperand(i).getNode());
1039 SDValue RV = combine(N);
1041 if (RV.getNode() == 0)
1046 // If we get back the same node we passed in, rather than a new node or
1047 // zero, we know that the node must have defined multiple values and
1048 // CombineTo was used. Since CombineTo takes care of the worklist
1049 // mechanics for us, we have no work to do in this case.
1050 if (RV.getNode() == N)
1053 assert(N->getOpcode() != ISD::DELETED_NODE &&
1054 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1055 "Node was deleted but visit returned new node!");
1057 DEBUG(dbgs() << "\nReplacing.3 ";
1059 dbgs() << "\nWith: ";
1060 RV.getNode()->dump(&DAG);
1063 // Transfer debug value.
1064 DAG.TransferDbgValues(SDValue(N, 0), RV);
1065 WorkListRemover DeadNodes(*this);
1066 if (N->getNumValues() == RV.getNode()->getNumValues())
1067 DAG.ReplaceAllUsesWith(N, RV.getNode());
1069 assert(N->getValueType(0) == RV.getValueType() &&
1070 N->getNumValues() == 1 && "Type mismatch");
1072 DAG.ReplaceAllUsesWith(N, &OpV);
1075 // Push the new node and any users onto the worklist
1076 AddToWorkList(RV.getNode());
1077 AddUsersToWorkList(RV.getNode());
1079 // Add any uses of the old node to the worklist in case this node is the
1080 // last one that uses them. They may become dead after this node is
1082 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1083 AddToWorkList(N->getOperand(i).getNode());
1085 // Finally, if the node is now dead, remove it from the graph. The node
1086 // may not be dead if the replacement process recursively simplified to
1087 // something else needing this node.
1088 if (N->use_empty()) {
1089 // Nodes can be reintroduced into the worklist. Make sure we do not
1090 // process a node that has been replaced.
1091 removeFromWorkList(N);
1093 // Finally, since the node is now dead, remove it from the graph.
1098 // If the root changed (e.g. it was a dead load, update the root).
1099 DAG.setRoot(Dummy.getValue());
1100 DAG.RemoveDeadNodes();
1103 SDValue DAGCombiner::visit(SDNode *N) {
1104 switch (N->getOpcode()) {
1106 case ISD::TokenFactor: return visitTokenFactor(N);
1107 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1108 case ISD::ADD: return visitADD(N);
1109 case ISD::SUB: return visitSUB(N);
1110 case ISD::ADDC: return visitADDC(N);
1111 case ISD::SUBC: return visitSUBC(N);
1112 case ISD::ADDE: return visitADDE(N);
1113 case ISD::SUBE: return visitSUBE(N);
1114 case ISD::MUL: return visitMUL(N);
1115 case ISD::SDIV: return visitSDIV(N);
1116 case ISD::UDIV: return visitUDIV(N);
1117 case ISD::SREM: return visitSREM(N);
1118 case ISD::UREM: return visitUREM(N);
1119 case ISD::MULHU: return visitMULHU(N);
1120 case ISD::MULHS: return visitMULHS(N);
1121 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1122 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1123 case ISD::SMULO: return visitSMULO(N);
1124 case ISD::UMULO: return visitUMULO(N);
1125 case ISD::SDIVREM: return visitSDIVREM(N);
1126 case ISD::UDIVREM: return visitUDIVREM(N);
1127 case ISD::AND: return visitAND(N);
1128 case ISD::OR: return visitOR(N);
1129 case ISD::XOR: return visitXOR(N);
1130 case ISD::SHL: return visitSHL(N);
1131 case ISD::SRA: return visitSRA(N);
1132 case ISD::SRL: return visitSRL(N);
1133 case ISD::CTLZ: return visitCTLZ(N);
1134 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1135 case ISD::CTTZ: return visitCTTZ(N);
1136 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1137 case ISD::CTPOP: return visitCTPOP(N);
1138 case ISD::SELECT: return visitSELECT(N);
1139 case ISD::VSELECT: return visitVSELECT(N);
1140 case ISD::SELECT_CC: return visitSELECT_CC(N);
1141 case ISD::SETCC: return visitSETCC(N);
1142 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1143 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1144 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1145 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1146 case ISD::TRUNCATE: return visitTRUNCATE(N);
1147 case ISD::BITCAST: return visitBITCAST(N);
1148 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1149 case ISD::FADD: return visitFADD(N);
1150 case ISD::FSUB: return visitFSUB(N);
1151 case ISD::FMUL: return visitFMUL(N);
1152 case ISD::FMA: return visitFMA(N);
1153 case ISD::FDIV: return visitFDIV(N);
1154 case ISD::FREM: return visitFREM(N);
1155 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1156 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1157 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1158 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1159 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1160 case ISD::FP_ROUND: return visitFP_ROUND(N);
1161 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1162 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1163 case ISD::FNEG: return visitFNEG(N);
1164 case ISD::FABS: return visitFABS(N);
1165 case ISD::FFLOOR: return visitFFLOOR(N);
1166 case ISD::FCEIL: return visitFCEIL(N);
1167 case ISD::FTRUNC: return visitFTRUNC(N);
1168 case ISD::BRCOND: return visitBRCOND(N);
1169 case ISD::BR_CC: return visitBR_CC(N);
1170 case ISD::LOAD: return visitLOAD(N);
1171 case ISD::STORE: return visitSTORE(N);
1172 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1173 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1174 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1175 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1176 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1177 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1182 SDValue DAGCombiner::combine(SDNode *N) {
1183 SDValue RV = visit(N);
1185 // If nothing happened, try a target-specific DAG combine.
1186 if (RV.getNode() == 0) {
1187 assert(N->getOpcode() != ISD::DELETED_NODE &&
1188 "Node was deleted but visit returned NULL!");
1190 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1191 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1193 // Expose the DAG combiner to the target combiner impls.
1194 TargetLowering::DAGCombinerInfo
1195 DagCombineInfo(DAG, Level, false, this);
1197 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1201 // If nothing happened still, try promoting the operation.
1202 if (RV.getNode() == 0) {
1203 switch (N->getOpcode()) {
1211 RV = PromoteIntBinOp(SDValue(N, 0));
1216 RV = PromoteIntShiftOp(SDValue(N, 0));
1218 case ISD::SIGN_EXTEND:
1219 case ISD::ZERO_EXTEND:
1220 case ISD::ANY_EXTEND:
1221 RV = PromoteExtend(SDValue(N, 0));
1224 if (PromoteLoad(SDValue(N, 0)))
1230 // If N is a commutative binary node, try commuting it to enable more
1232 if (RV.getNode() == 0 &&
1233 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1234 N->getNumValues() == 1) {
1235 SDValue N0 = N->getOperand(0);
1236 SDValue N1 = N->getOperand(1);
1238 // Constant operands are canonicalized to RHS.
1239 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1240 SDValue Ops[] = { N1, N0 };
1241 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
1244 return SDValue(CSENode, 0);
1251 /// getInputChainForNode - Given a node, return its input chain if it has one,
1252 /// otherwise return a null sd operand.
1253 static SDValue getInputChainForNode(SDNode *N) {
1254 if (unsigned NumOps = N->getNumOperands()) {
1255 if (N->getOperand(0).getValueType() == MVT::Other)
1256 return N->getOperand(0);
1257 if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1258 return N->getOperand(NumOps-1);
1259 for (unsigned i = 1; i < NumOps-1; ++i)
1260 if (N->getOperand(i).getValueType() == MVT::Other)
1261 return N->getOperand(i);
1266 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1267 // If N has two operands, where one has an input chain equal to the other,
1268 // the 'other' chain is redundant.
1269 if (N->getNumOperands() == 2) {
1270 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1271 return N->getOperand(0);
1272 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1273 return N->getOperand(1);
1276 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1277 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1278 SmallPtrSet<SDNode*, 16> SeenOps;
1279 bool Changed = false; // If we should replace this token factor.
1281 // Start out with this token factor.
1284 // Iterate through token factors. The TFs grows when new token factors are
1286 for (unsigned i = 0; i < TFs.size(); ++i) {
1287 SDNode *TF = TFs[i];
1289 // Check each of the operands.
1290 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1291 SDValue Op = TF->getOperand(i);
1293 switch (Op.getOpcode()) {
1294 case ISD::EntryToken:
1295 // Entry tokens don't need to be added to the list. They are
1300 case ISD::TokenFactor:
1301 if (Op.hasOneUse() &&
1302 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1303 // Queue up for processing.
1304 TFs.push_back(Op.getNode());
1305 // Clean up in case the token factor is removed.
1306 AddToWorkList(Op.getNode());
1313 // Only add if it isn't already in the list.
1314 if (SeenOps.insert(Op.getNode()))
1325 // If we've change things around then replace token factor.
1328 // The entry token is the only possible outcome.
1329 Result = DAG.getEntryNode();
1331 // New and improved token factor.
1332 Result = DAG.getNode(ISD::TokenFactor, SDLoc(N),
1333 MVT::Other, &Ops[0], Ops.size());
1336 // Don't add users to work list.
1337 return CombineTo(N, Result, false);
1343 /// MERGE_VALUES can always be eliminated.
1344 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1345 WorkListRemover DeadNodes(*this);
1346 // Replacing results may cause a different MERGE_VALUES to suddenly
1347 // be CSE'd with N, and carry its uses with it. Iterate until no
1348 // uses remain, to ensure that the node can be safely deleted.
1349 // First add the users of this node to the work list so that they
1350 // can be tried again once they have new operands.
1351 AddUsersToWorkList(N);
1353 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1354 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1355 } while (!N->use_empty());
1356 removeFromWorkList(N);
1358 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1362 SDValue combineShlAddConstant(SDLoc DL, SDValue N0, SDValue N1,
1363 SelectionDAG &DAG) {
1364 EVT VT = N0.getValueType();
1365 SDValue N00 = N0.getOperand(0);
1366 SDValue N01 = N0.getOperand(1);
1367 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1369 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1370 isa<ConstantSDNode>(N00.getOperand(1))) {
1371 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1372 N0 = DAG.getNode(ISD::ADD, SDLoc(N0), VT,
1373 DAG.getNode(ISD::SHL, SDLoc(N00), VT,
1374 N00.getOperand(0), N01),
1375 DAG.getNode(ISD::SHL, SDLoc(N01), VT,
1376 N00.getOperand(1), N01));
1377 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1383 SDValue DAGCombiner::visitADD(SDNode *N) {
1384 SDValue N0 = N->getOperand(0);
1385 SDValue N1 = N->getOperand(1);
1386 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1387 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1388 EVT VT = N0.getValueType();
1391 if (VT.isVector()) {
1392 SDValue FoldedVOp = SimplifyVBinOp(N);
1393 if (FoldedVOp.getNode()) return FoldedVOp;
1395 // fold (add x, 0) -> x, vector edition
1396 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1398 if (ISD::isBuildVectorAllZeros(N0.getNode()))
1402 // fold (add x, undef) -> undef
1403 if (N0.getOpcode() == ISD::UNDEF)
1405 if (N1.getOpcode() == ISD::UNDEF)
1407 // fold (add c1, c2) -> c1+c2
1409 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1410 // canonicalize constant to RHS
1412 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N1, N0);
1413 // fold (add x, 0) -> x
1414 if (N1C && N1C->isNullValue())
1416 // fold (add Sym, c) -> Sym+c
1417 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1418 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1419 GA->getOpcode() == ISD::GlobalAddress)
1420 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1422 (uint64_t)N1C->getSExtValue());
1423 // fold ((c1-A)+c2) -> (c1+c2)-A
1424 if (N1C && N0.getOpcode() == ISD::SUB)
1425 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1426 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1427 DAG.getConstant(N1C->getAPIntValue()+
1428 N0C->getAPIntValue(), VT),
1431 SDValue RADD = ReassociateOps(ISD::ADD, SDLoc(N), N0, N1);
1432 if (RADD.getNode() != 0)
1434 // fold ((0-A) + B) -> B-A
1435 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1436 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1437 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1, N0.getOperand(1));
1438 // fold (A + (0-B)) -> A-B
1439 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1440 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1441 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1.getOperand(1));
1442 // fold (A+(B-A)) -> B
1443 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1444 return N1.getOperand(0);
1445 // fold ((B-A)+A) -> B
1446 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1447 return N0.getOperand(0);
1448 // fold (A+(B-(A+C))) to (B-C)
1449 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1450 N0 == N1.getOperand(1).getOperand(0))
1451 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1452 N1.getOperand(1).getOperand(1));
1453 // fold (A+(B-(C+A))) to (B-C)
1454 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1455 N0 == N1.getOperand(1).getOperand(1))
1456 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1457 N1.getOperand(1).getOperand(0));
1458 // fold (A+((B-A)+or-C)) to (B+or-C)
1459 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1460 N1.getOperand(0).getOpcode() == ISD::SUB &&
1461 N0 == N1.getOperand(0).getOperand(1))
1462 return DAG.getNode(N1.getOpcode(), SDLoc(N), VT,
1463 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1465 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1466 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1467 SDValue N00 = N0.getOperand(0);
1468 SDValue N01 = N0.getOperand(1);
1469 SDValue N10 = N1.getOperand(0);
1470 SDValue N11 = N1.getOperand(1);
1472 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1473 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1474 DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
1475 DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
1478 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1479 return SDValue(N, 0);
1481 // fold (a+b) -> (a|b) iff a and b share no bits.
1482 if (VT.isInteger() && !VT.isVector()) {
1483 APInt LHSZero, LHSOne;
1484 APInt RHSZero, RHSOne;
1485 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1487 if (LHSZero.getBoolValue()) {
1488 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1490 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1491 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1492 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1493 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
1497 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1498 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1499 SDValue Result = combineShlAddConstant(SDLoc(N), N0, N1, DAG);
1500 if (Result.getNode()) return Result;
1502 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1503 SDValue Result = combineShlAddConstant(SDLoc(N), N1, N0, DAG);
1504 if (Result.getNode()) return Result;
1507 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1508 if (N1.getOpcode() == ISD::SHL &&
1509 N1.getOperand(0).getOpcode() == ISD::SUB)
1510 if (ConstantSDNode *C =
1511 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1512 if (C->getAPIntValue() == 0)
1513 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
1514 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1515 N1.getOperand(0).getOperand(1),
1517 if (N0.getOpcode() == ISD::SHL &&
1518 N0.getOperand(0).getOpcode() == ISD::SUB)
1519 if (ConstantSDNode *C =
1520 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1521 if (C->getAPIntValue() == 0)
1522 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
1523 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1524 N0.getOperand(0).getOperand(1),
1527 if (N1.getOpcode() == ISD::AND) {
1528 SDValue AndOp0 = N1.getOperand(0);
1529 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1530 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1531 unsigned DestBits = VT.getScalarType().getSizeInBits();
1533 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1534 // and similar xforms where the inner op is either ~0 or 0.
1535 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1537 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1541 // add (sext i1), X -> sub X, (zext i1)
1542 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1543 N0.getOperand(0).getValueType() == MVT::i1 &&
1544 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1546 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1547 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1553 SDValue DAGCombiner::visitADDC(SDNode *N) {
1554 SDValue N0 = N->getOperand(0);
1555 SDValue N1 = N->getOperand(1);
1556 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1557 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1558 EVT VT = N0.getValueType();
1560 // If the flag result is dead, turn this into an ADD.
1561 if (!N->hasAnyUseOfValue(1))
1562 return CombineTo(N, DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N1),
1563 DAG.getNode(ISD::CARRY_FALSE,
1564 SDLoc(N), MVT::Glue));
1566 // canonicalize constant to RHS.
1568 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N1, N0);
1570 // fold (addc x, 0) -> x + no carry out
1571 if (N1C && N1C->isNullValue())
1572 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1573 SDLoc(N), MVT::Glue));
1575 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1576 APInt LHSZero, LHSOne;
1577 APInt RHSZero, RHSOne;
1578 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1580 if (LHSZero.getBoolValue()) {
1581 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1583 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1584 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1585 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1586 return CombineTo(N, DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1),
1587 DAG.getNode(ISD::CARRY_FALSE,
1588 SDLoc(N), MVT::Glue));
1594 SDValue DAGCombiner::visitADDE(SDNode *N) {
1595 SDValue N0 = N->getOperand(0);
1596 SDValue N1 = N->getOperand(1);
1597 SDValue CarryIn = N->getOperand(2);
1598 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1599 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1601 // canonicalize constant to RHS
1603 return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
1606 // fold (adde x, y, false) -> (addc x, y)
1607 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1608 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);
1613 // Since it may not be valid to emit a fold to zero for vector initializers
1614 // check if we can before folding.
1615 static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
1617 bool LegalOperations, bool LegalTypes) {
1619 return DAG.getConstant(0, VT);
1620 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1621 // Produce a vector of zeros.
1622 EVT ElemTy = VT.getVectorElementType();
1623 if (LegalTypes && TLI.getTypeAction(*DAG.getContext(), ElemTy) ==
1624 TargetLowering::TypePromoteInteger)
1625 ElemTy = TLI.getTypeToTransformTo(*DAG.getContext(), ElemTy);
1626 assert((!LegalTypes || TLI.isTypeLegal(ElemTy)) &&
1627 "Type for zero vector elements is not legal");
1628 SDValue El = DAG.getConstant(0, ElemTy);
1629 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
1630 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
1631 &Ops[0], Ops.size());
1636 SDValue DAGCombiner::visitSUB(SDNode *N) {
1637 SDValue N0 = N->getOperand(0);
1638 SDValue N1 = N->getOperand(1);
1639 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1640 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1641 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? 0 :
1642 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1643 EVT VT = N0.getValueType();
1646 if (VT.isVector()) {
1647 SDValue FoldedVOp = SimplifyVBinOp(N);
1648 if (FoldedVOp.getNode()) return FoldedVOp;
1650 // fold (sub x, 0) -> x, vector edition
1651 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1655 // fold (sub x, x) -> 0
1656 // FIXME: Refactor this and xor and other similar operations together.
1658 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
1659 // fold (sub c1, c2) -> c1-c2
1661 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1662 // fold (sub x, c) -> (add x, -c)
1664 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N0,
1665 DAG.getConstant(-N1C->getAPIntValue(), VT));
1666 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1667 if (N0C && N0C->isAllOnesValue())
1668 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
1669 // fold A-(A-B) -> B
1670 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1671 return N1.getOperand(1);
1672 // fold (A+B)-A -> B
1673 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1674 return N0.getOperand(1);
1675 // fold (A+B)-B -> A
1676 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1677 return N0.getOperand(0);
1678 // fold C2-(A+C1) -> (C2-C1)-A
1679 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1680 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1682 return DAG.getNode(ISD::SUB, SDLoc(N), VT, NewC,
1685 // fold ((A+(B+or-C))-B) -> A+or-C
1686 if (N0.getOpcode() == ISD::ADD &&
1687 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1688 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1689 N0.getOperand(1).getOperand(0) == N1)
1690 return DAG.getNode(N0.getOperand(1).getOpcode(), SDLoc(N), VT,
1691 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1692 // fold ((A+(C+B))-B) -> A+C
1693 if (N0.getOpcode() == ISD::ADD &&
1694 N0.getOperand(1).getOpcode() == ISD::ADD &&
1695 N0.getOperand(1).getOperand(1) == N1)
1696 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1697 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1698 // fold ((A-(B-C))-C) -> A-B
1699 if (N0.getOpcode() == ISD::SUB &&
1700 N0.getOperand(1).getOpcode() == ISD::SUB &&
1701 N0.getOperand(1).getOperand(1) == N1)
1702 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1703 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1705 // If either operand of a sub is undef, the result is undef
1706 if (N0.getOpcode() == ISD::UNDEF)
1708 if (N1.getOpcode() == ISD::UNDEF)
1711 // If the relocation model supports it, consider symbol offsets.
1712 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1713 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1714 // fold (sub Sym, c) -> Sym-c
1715 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1716 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1718 (uint64_t)N1C->getSExtValue());
1719 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1720 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1721 if (GA->getGlobal() == GB->getGlobal())
1722 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1729 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1730 SDValue N0 = N->getOperand(0);
1731 SDValue N1 = N->getOperand(1);
1732 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1733 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1734 EVT VT = N0.getValueType();
1736 // If the flag result is dead, turn this into an SUB.
1737 if (!N->hasAnyUseOfValue(1))
1738 return CombineTo(N, DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1),
1739 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1742 // fold (subc x, x) -> 0 + no borrow
1744 return CombineTo(N, DAG.getConstant(0, VT),
1745 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1748 // fold (subc x, 0) -> x + no borrow
1749 if (N1C && N1C->isNullValue())
1750 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1753 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1754 if (N0C && N0C->isAllOnesValue())
1755 return CombineTo(N, DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0),
1756 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1762 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1763 SDValue N0 = N->getOperand(0);
1764 SDValue N1 = N->getOperand(1);
1765 SDValue CarryIn = N->getOperand(2);
1767 // fold (sube x, y, false) -> (subc x, y)
1768 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1769 return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);
1774 /// isConstantSplatVector - Returns true if N is a BUILD_VECTOR node whose elements are
1775 /// all the same constant or undefined.
1776 static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
1777 BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
1782 unsigned SplatBitSize;
1784 EVT EltVT = N->getValueType(0).getVectorElementType();
1785 return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
1787 EltVT.getSizeInBits() >= SplatBitSize);
1790 SDValue DAGCombiner::visitMUL(SDNode *N) {
1791 SDValue N0 = N->getOperand(0);
1792 SDValue N1 = N->getOperand(1);
1793 EVT VT = N0.getValueType();
1795 // fold (mul x, undef) -> 0
1796 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1797 return DAG.getConstant(0, VT);
1799 bool N0IsConst = false;
1800 bool N1IsConst = false;
1801 APInt ConstValue0, ConstValue1;
1803 if (VT.isVector()) {
1804 SDValue FoldedVOp = SimplifyVBinOp(N);
1805 if (FoldedVOp.getNode()) return FoldedVOp;
1807 N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
1808 N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
1810 N0IsConst = dyn_cast<ConstantSDNode>(N0) != 0;
1811 ConstValue0 = N0IsConst? (dyn_cast<ConstantSDNode>(N0))->getAPIntValue() : APInt();
1812 N1IsConst = dyn_cast<ConstantSDNode>(N1) != 0;
1813 ConstValue1 = N1IsConst? (dyn_cast<ConstantSDNode>(N1))->getAPIntValue() : APInt();
1816 // fold (mul c1, c2) -> c1*c2
1817 if (N0IsConst && N1IsConst)
1818 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0.getNode(), N1.getNode());
1820 // canonicalize constant to RHS
1821 if (N0IsConst && !N1IsConst)
1822 return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
1823 // fold (mul x, 0) -> 0
1824 if (N1IsConst && ConstValue1 == 0)
1826 // fold (mul x, 1) -> x
1827 if (N1IsConst && ConstValue1 == 1)
1829 // fold (mul x, -1) -> 0-x
1830 if (N1IsConst && ConstValue1.isAllOnesValue())
1831 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1832 DAG.getConstant(0, VT), N0);
1833 // fold (mul x, (1 << c)) -> x << c
1834 if (N1IsConst && ConstValue1.isPowerOf2())
1835 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1836 DAG.getConstant(ConstValue1.logBase2(),
1837 getShiftAmountTy(N0.getValueType())));
1838 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1839 if (N1IsConst && (-ConstValue1).isPowerOf2()) {
1840 unsigned Log2Val = (-ConstValue1).logBase2();
1841 // FIXME: If the input is something that is easily negated (e.g. a
1842 // single-use add), we should put the negate there.
1843 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1844 DAG.getConstant(0, VT),
1845 DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1846 DAG.getConstant(Log2Val,
1847 getShiftAmountTy(N0.getValueType()))));
1851 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1852 if (N1IsConst && N0.getOpcode() == ISD::SHL &&
1853 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1854 isa<ConstantSDNode>(N0.getOperand(1)))) {
1855 SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
1856 N1, N0.getOperand(1));
1857 AddToWorkList(C3.getNode());
1858 return DAG.getNode(ISD::MUL, SDLoc(N), VT,
1859 N0.getOperand(0), C3);
1862 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1865 SDValue Sh(0,0), Y(0,0);
1866 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1867 if (N0.getOpcode() == ISD::SHL &&
1868 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1869 isa<ConstantSDNode>(N0.getOperand(1))) &&
1870 N0.getNode()->hasOneUse()) {
1872 } else if (N1.getOpcode() == ISD::SHL &&
1873 isa<ConstantSDNode>(N1.getOperand(1)) &&
1874 N1.getNode()->hasOneUse()) {
1879 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
1880 Sh.getOperand(0), Y);
1881 return DAG.getNode(ISD::SHL, SDLoc(N), VT,
1882 Mul, Sh.getOperand(1));
1886 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1887 if (N1IsConst && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1888 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1889 isa<ConstantSDNode>(N0.getOperand(1))))
1890 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1891 DAG.getNode(ISD::MUL, SDLoc(N0), VT,
1892 N0.getOperand(0), N1),
1893 DAG.getNode(ISD::MUL, SDLoc(N1), VT,
1894 N0.getOperand(1), N1));
1897 SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1);
1898 if (RMUL.getNode() != 0)
1904 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1905 SDValue N0 = N->getOperand(0);
1906 SDValue N1 = N->getOperand(1);
1907 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1908 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1909 EVT VT = N->getValueType(0);
1912 if (VT.isVector()) {
1913 SDValue FoldedVOp = SimplifyVBinOp(N);
1914 if (FoldedVOp.getNode()) return FoldedVOp;
1917 // fold (sdiv c1, c2) -> c1/c2
1918 if (N0C && N1C && !N1C->isNullValue())
1919 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1920 // fold (sdiv X, 1) -> X
1921 if (N1C && N1C->getAPIntValue() == 1LL)
1923 // fold (sdiv X, -1) -> 0-X
1924 if (N1C && N1C->isAllOnesValue())
1925 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1926 DAG.getConstant(0, VT), N0);
1927 // If we know the sign bits of both operands are zero, strength reduce to a
1928 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1929 if (!VT.isVector()) {
1930 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1931 return DAG.getNode(ISD::UDIV, SDLoc(N), N1.getValueType(),
1934 // fold (sdiv X, pow2) -> simple ops after legalize
1935 if (N1C && !N1C->isNullValue() &&
1936 (N1C->getAPIntValue().isPowerOf2() ||
1937 (-N1C->getAPIntValue()).isPowerOf2())) {
1938 // If dividing by powers of two is cheap, then don't perform the following
1940 if (TLI.isPow2DivCheap())
1943 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
1945 // Splat the sign bit into the register
1946 SDValue SGN = DAG.getNode(ISD::SRA, SDLoc(N), VT, N0,
1947 DAG.getConstant(VT.getSizeInBits()-1,
1948 getShiftAmountTy(N0.getValueType())));
1949 AddToWorkList(SGN.getNode());
1951 // Add (N0 < 0) ? abs2 - 1 : 0;
1952 SDValue SRL = DAG.getNode(ISD::SRL, SDLoc(N), VT, SGN,
1953 DAG.getConstant(VT.getSizeInBits() - lg2,
1954 getShiftAmountTy(SGN.getValueType())));
1955 SDValue ADD = DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, SRL);
1956 AddToWorkList(SRL.getNode());
1957 AddToWorkList(ADD.getNode()); // Divide by pow2
1958 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), VT, ADD,
1959 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
1961 // If we're dividing by a positive value, we're done. Otherwise, we must
1962 // negate the result.
1963 if (N1C->getAPIntValue().isNonNegative())
1966 AddToWorkList(SRA.getNode());
1967 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1968 DAG.getConstant(0, VT), SRA);
1971 // if integer divide is expensive and we satisfy the requirements, emit an
1972 // alternate sequence.
1973 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1974 SDValue Op = BuildSDIV(N);
1975 if (Op.getNode()) return Op;
1979 if (N0.getOpcode() == ISD::UNDEF)
1980 return DAG.getConstant(0, VT);
1981 // X / undef -> undef
1982 if (N1.getOpcode() == ISD::UNDEF)
1988 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1989 SDValue N0 = N->getOperand(0);
1990 SDValue N1 = N->getOperand(1);
1991 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1992 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1993 EVT VT = N->getValueType(0);
1996 if (VT.isVector()) {
1997 SDValue FoldedVOp = SimplifyVBinOp(N);
1998 if (FoldedVOp.getNode()) return FoldedVOp;
2001 // fold (udiv c1, c2) -> c1/c2
2002 if (N0C && N1C && !N1C->isNullValue())
2003 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
2004 // fold (udiv x, (1 << c)) -> x >>u c
2005 if (N1C && N1C->getAPIntValue().isPowerOf2())
2006 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0,
2007 DAG.getConstant(N1C->getAPIntValue().logBase2(),
2008 getShiftAmountTy(N0.getValueType())));
2009 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
2010 if (N1.getOpcode() == ISD::SHL) {
2011 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2012 if (SHC->getAPIntValue().isPowerOf2()) {
2013 EVT ADDVT = N1.getOperand(1).getValueType();
2014 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N), ADDVT,
2016 DAG.getConstant(SHC->getAPIntValue()
2019 AddToWorkList(Add.getNode());
2020 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, Add);
2024 // fold (udiv x, c) -> alternate
2025 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
2026 SDValue Op = BuildUDIV(N);
2027 if (Op.getNode()) return Op;
2031 if (N0.getOpcode() == ISD::UNDEF)
2032 return DAG.getConstant(0, VT);
2033 // X / undef -> undef
2034 if (N1.getOpcode() == ISD::UNDEF)
2040 SDValue DAGCombiner::visitSREM(SDNode *N) {
2041 SDValue N0 = N->getOperand(0);
2042 SDValue N1 = N->getOperand(1);
2043 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2044 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2045 EVT VT = N->getValueType(0);
2047 // fold (srem c1, c2) -> c1%c2
2048 if (N0C && N1C && !N1C->isNullValue())
2049 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
2050 // If we know the sign bits of both operands are zero, strength reduce to a
2051 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
2052 if (!VT.isVector()) {
2053 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2054 return DAG.getNode(ISD::UREM, SDLoc(N), VT, N0, N1);
2057 // If X/C can be simplified by the division-by-constant logic, lower
2058 // X%C to the equivalent of X-X/C*C.
2059 if (N1C && !N1C->isNullValue()) {
2060 SDValue Div = DAG.getNode(ISD::SDIV, SDLoc(N), VT, N0, N1);
2061 AddToWorkList(Div.getNode());
2062 SDValue OptimizedDiv = combine(Div.getNode());
2063 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2064 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2066 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2067 AddToWorkList(Mul.getNode());
2073 if (N0.getOpcode() == ISD::UNDEF)
2074 return DAG.getConstant(0, VT);
2075 // X % undef -> undef
2076 if (N1.getOpcode() == ISD::UNDEF)
2082 SDValue DAGCombiner::visitUREM(SDNode *N) {
2083 SDValue N0 = N->getOperand(0);
2084 SDValue N1 = N->getOperand(1);
2085 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2086 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2087 EVT VT = N->getValueType(0);
2089 // fold (urem c1, c2) -> c1%c2
2090 if (N0C && N1C && !N1C->isNullValue())
2091 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2092 // fold (urem x, pow2) -> (and x, pow2-1)
2093 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2094 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0,
2095 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2096 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2097 if (N1.getOpcode() == ISD::SHL) {
2098 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2099 if (SHC->getAPIntValue().isPowerOf2()) {
2101 DAG.getNode(ISD::ADD, SDLoc(N), VT, N1,
2102 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2104 AddToWorkList(Add.getNode());
2105 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, Add);
2110 // If X/C can be simplified by the division-by-constant logic, lower
2111 // X%C to the equivalent of X-X/C*C.
2112 if (N1C && !N1C->isNullValue()) {
2113 SDValue Div = DAG.getNode(ISD::UDIV, SDLoc(N), VT, N0, N1);
2114 AddToWorkList(Div.getNode());
2115 SDValue OptimizedDiv = combine(Div.getNode());
2116 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2117 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2119 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2120 AddToWorkList(Mul.getNode());
2126 if (N0.getOpcode() == ISD::UNDEF)
2127 return DAG.getConstant(0, VT);
2128 // X % undef -> undef
2129 if (N1.getOpcode() == ISD::UNDEF)
2135 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2136 SDValue N0 = N->getOperand(0);
2137 SDValue N1 = N->getOperand(1);
2138 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2139 EVT VT = N->getValueType(0);
2142 // fold (mulhs x, 0) -> 0
2143 if (N1C && N1C->isNullValue())
2145 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2146 if (N1C && N1C->getAPIntValue() == 1)
2147 return DAG.getNode(ISD::SRA, SDLoc(N), N0.getValueType(), N0,
2148 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2149 getShiftAmountTy(N0.getValueType())));
2150 // fold (mulhs x, undef) -> 0
2151 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2152 return DAG.getConstant(0, VT);
2154 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2156 if (VT.isSimple() && !VT.isVector()) {
2157 MVT Simple = VT.getSimpleVT();
2158 unsigned SimpleSize = Simple.getSizeInBits();
2159 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2160 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2161 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2162 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2163 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2164 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2165 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2166 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2173 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2174 SDValue N0 = N->getOperand(0);
2175 SDValue N1 = N->getOperand(1);
2176 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2177 EVT VT = N->getValueType(0);
2180 // fold (mulhu x, 0) -> 0
2181 if (N1C && N1C->isNullValue())
2183 // fold (mulhu x, 1) -> 0
2184 if (N1C && N1C->getAPIntValue() == 1)
2185 return DAG.getConstant(0, N0.getValueType());
2186 // fold (mulhu x, undef) -> 0
2187 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2188 return DAG.getConstant(0, VT);
2190 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2192 if (VT.isSimple() && !VT.isVector()) {
2193 MVT Simple = VT.getSimpleVT();
2194 unsigned SimpleSize = Simple.getSizeInBits();
2195 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2196 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2197 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2198 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2199 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2200 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2201 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2202 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2209 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2210 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2211 /// that are being performed. Return true if a simplification was made.
2213 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2215 // If the high half is not needed, just compute the low half.
2216 bool HiExists = N->hasAnyUseOfValue(1);
2218 (!LegalOperations ||
2219 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
2220 SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2221 N->op_begin(), N->getNumOperands());
2222 return CombineTo(N, Res, Res);
2225 // If the low half is not needed, just compute the high half.
2226 bool LoExists = N->hasAnyUseOfValue(0);
2228 (!LegalOperations ||
2229 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2230 SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2231 N->op_begin(), N->getNumOperands());
2232 return CombineTo(N, Res, Res);
2235 // If both halves are used, return as it is.
2236 if (LoExists && HiExists)
2239 // If the two computed results can be simplified separately, separate them.
2241 SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2242 N->op_begin(), N->getNumOperands());
2243 AddToWorkList(Lo.getNode());
2244 SDValue LoOpt = combine(Lo.getNode());
2245 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2246 (!LegalOperations ||
2247 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2248 return CombineTo(N, LoOpt, LoOpt);
2252 SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2253 N->op_begin(), N->getNumOperands());
2254 AddToWorkList(Hi.getNode());
2255 SDValue HiOpt = combine(Hi.getNode());
2256 if (HiOpt.getNode() && HiOpt != Hi &&
2257 (!LegalOperations ||
2258 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2259 return CombineTo(N, HiOpt, HiOpt);
2265 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2266 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2267 if (Res.getNode()) return Res;
2269 EVT VT = N->getValueType(0);
2272 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2274 if (VT.isSimple() && !VT.isVector()) {
2275 MVT Simple = VT.getSimpleVT();
2276 unsigned SimpleSize = Simple.getSizeInBits();
2277 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2278 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2279 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2280 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2281 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2282 // Compute the high part as N1.
2283 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2284 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2285 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2286 // Compute the low part as N0.
2287 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2288 return CombineTo(N, Lo, Hi);
2295 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2296 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2297 if (Res.getNode()) return Res;
2299 EVT VT = N->getValueType(0);
2302 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2304 if (VT.isSimple() && !VT.isVector()) {
2305 MVT Simple = VT.getSimpleVT();
2306 unsigned SimpleSize = Simple.getSizeInBits();
2307 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2308 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2309 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2310 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2311 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2312 // Compute the high part as N1.
2313 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2314 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2315 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2316 // Compute the low part as N0.
2317 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2318 return CombineTo(N, Lo, Hi);
2325 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2326 // (smulo x, 2) -> (saddo x, x)
2327 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2328 if (C2->getAPIntValue() == 2)
2329 return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
2330 N->getOperand(0), N->getOperand(0));
2335 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2336 // (umulo x, 2) -> (uaddo x, x)
2337 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2338 if (C2->getAPIntValue() == 2)
2339 return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
2340 N->getOperand(0), N->getOperand(0));
2345 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2346 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2347 if (Res.getNode()) return Res;
2352 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2353 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2354 if (Res.getNode()) return Res;
2359 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2360 /// two operands of the same opcode, try to simplify it.
2361 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2362 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2363 EVT VT = N0.getValueType();
2364 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2366 // Bail early if none of these transforms apply.
2367 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2369 // For each of OP in AND/OR/XOR:
2370 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2371 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2372 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2373 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2375 // do not sink logical op inside of a vector extend, since it may combine
2377 EVT Op0VT = N0.getOperand(0).getValueType();
2378 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2379 N0.getOpcode() == ISD::SIGN_EXTEND ||
2380 // Avoid infinite looping with PromoteIntBinOp.
2381 (N0.getOpcode() == ISD::ANY_EXTEND &&
2382 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2383 (N0.getOpcode() == ISD::TRUNCATE &&
2384 (!TLI.isZExtFree(VT, Op0VT) ||
2385 !TLI.isTruncateFree(Op0VT, VT)) &&
2386 TLI.isTypeLegal(Op0VT))) &&
2388 Op0VT == N1.getOperand(0).getValueType() &&
2389 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2390 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2391 N0.getOperand(0).getValueType(),
2392 N0.getOperand(0), N1.getOperand(0));
2393 AddToWorkList(ORNode.getNode());
2394 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
2397 // For each of OP in SHL/SRL/SRA/AND...
2398 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2399 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2400 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2401 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2402 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2403 N0.getOperand(1) == N1.getOperand(1)) {
2404 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2405 N0.getOperand(0).getValueType(),
2406 N0.getOperand(0), N1.getOperand(0));
2407 AddToWorkList(ORNode.getNode());
2408 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
2409 ORNode, N0.getOperand(1));
2412 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2413 // Only perform this optimization after type legalization and before
2414 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2415 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2416 // we don't want to undo this promotion.
2417 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2419 if ((N0.getOpcode() == ISD::BITCAST ||
2420 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2421 Level == AfterLegalizeTypes) {
2422 SDValue In0 = N0.getOperand(0);
2423 SDValue In1 = N1.getOperand(0);
2424 EVT In0Ty = In0.getValueType();
2425 EVT In1Ty = In1.getValueType();
2427 // If both incoming values are integers, and the original types are the
2429 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2430 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2431 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2432 AddToWorkList(Op.getNode());
2437 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2438 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2439 // If both shuffles use the same mask, and both shuffle within a single
2440 // vector, then it is worthwhile to move the swizzle after the operation.
2441 // The type-legalizer generates this pattern when loading illegal
2442 // vector types from memory. In many cases this allows additional shuffle
2444 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
2445 N0.getOperand(1).getOpcode() == ISD::UNDEF &&
2446 N1.getOperand(1).getOpcode() == ISD::UNDEF) {
2447 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2448 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2450 assert(N0.getOperand(0).getValueType() == N1.getOperand(1).getValueType() &&
2451 "Inputs to shuffles are not the same type");
2453 unsigned NumElts = VT.getVectorNumElements();
2455 // Check that both shuffles use the same mask. The masks are known to be of
2456 // the same length because the result vector type is the same.
2457 bool SameMask = true;
2458 for (unsigned i = 0; i != NumElts; ++i) {
2459 int Idx0 = SVN0->getMaskElt(i);
2460 int Idx1 = SVN1->getMaskElt(i);
2468 SDValue Op = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2469 N0.getOperand(0), N1.getOperand(0));
2470 AddToWorkList(Op.getNode());
2471 return DAG.getVectorShuffle(VT, SDLoc(N), Op,
2472 DAG.getUNDEF(VT), &SVN0->getMask()[0]);
2479 SDValue DAGCombiner::visitAND(SDNode *N) {
2480 SDValue N0 = N->getOperand(0);
2481 SDValue N1 = N->getOperand(1);
2482 SDValue LL, LR, RL, RR, CC0, CC1;
2483 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2484 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2485 EVT VT = N1.getValueType();
2486 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2489 if (VT.isVector()) {
2490 SDValue FoldedVOp = SimplifyVBinOp(N);
2491 if (FoldedVOp.getNode()) return FoldedVOp;
2493 // fold (and x, 0) -> 0, vector edition
2494 if (ISD::isBuildVectorAllZeros(N0.getNode()))
2496 if (ISD::isBuildVectorAllZeros(N1.getNode()))
2499 // fold (and x, -1) -> x, vector edition
2500 if (ISD::isBuildVectorAllOnes(N0.getNode()))
2502 if (ISD::isBuildVectorAllOnes(N1.getNode()))
2506 // fold (and x, undef) -> 0
2507 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2508 return DAG.getConstant(0, VT);
2509 // fold (and c1, c2) -> c1&c2
2511 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2512 // canonicalize constant to RHS
2514 return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
2515 // fold (and x, -1) -> x
2516 if (N1C && N1C->isAllOnesValue())
2518 // if (and x, c) is known to be zero, return 0
2519 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2520 APInt::getAllOnesValue(BitWidth)))
2521 return DAG.getConstant(0, VT);
2523 SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1);
2524 if (RAND.getNode() != 0)
2526 // fold (and (or x, C), D) -> D if (C & D) == D
2527 if (N1C && N0.getOpcode() == ISD::OR)
2528 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2529 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2531 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2532 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2533 SDValue N0Op0 = N0.getOperand(0);
2534 APInt Mask = ~N1C->getAPIntValue();
2535 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2536 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2537 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
2538 N0.getValueType(), N0Op0);
2540 // Replace uses of the AND with uses of the Zero extend node.
2543 // We actually want to replace all uses of the any_extend with the
2544 // zero_extend, to avoid duplicating things. This will later cause this
2545 // AND to be folded.
2546 CombineTo(N0.getNode(), Zext);
2547 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2550 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2551 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2552 // already be zero by virtue of the width of the base type of the load.
2554 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2556 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2557 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2558 N0.getOpcode() == ISD::LOAD) {
2559 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2560 N0 : N0.getOperand(0) );
2562 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2563 // This can be a pure constant or a vector splat, in which case we treat the
2564 // vector as a scalar and use the splat value.
2565 APInt Constant = APInt::getNullValue(1);
2566 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2567 Constant = C->getAPIntValue();
2568 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2569 APInt SplatValue, SplatUndef;
2570 unsigned SplatBitSize;
2572 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2573 SplatBitSize, HasAnyUndefs);
2575 // Undef bits can contribute to a possible optimisation if set, so
2577 SplatValue |= SplatUndef;
2579 // The splat value may be something like "0x00FFFFFF", which means 0 for
2580 // the first vector value and FF for the rest, repeating. We need a mask
2581 // that will apply equally to all members of the vector, so AND all the
2582 // lanes of the constant together.
2583 EVT VT = Vector->getValueType(0);
2584 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2586 // If the splat value has been compressed to a bitlength lower
2587 // than the size of the vector lane, we need to re-expand it to
2589 if (BitWidth > SplatBitSize)
2590 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2591 SplatBitSize < BitWidth;
2592 SplatBitSize = SplatBitSize * 2)
2593 SplatValue |= SplatValue.shl(SplatBitSize);
2595 Constant = APInt::getAllOnesValue(BitWidth);
2596 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2597 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2601 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2602 // actually legal and isn't going to get expanded, else this is a false
2604 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2605 Load->getMemoryVT());
2607 // Resize the constant to the same size as the original memory access before
2608 // extension. If it is still the AllOnesValue then this AND is completely
2611 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2614 switch (Load->getExtensionType()) {
2615 default: B = false; break;
2616 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2618 case ISD::NON_EXTLOAD: B = true; break;
2621 if (B && Constant.isAllOnesValue()) {
2622 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2623 // preserve semantics once we get rid of the AND.
2624 SDValue NewLoad(Load, 0);
2625 if (Load->getExtensionType() == ISD::EXTLOAD) {
2626 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2627 Load->getValueType(0), SDLoc(Load),
2628 Load->getChain(), Load->getBasePtr(),
2629 Load->getOffset(), Load->getMemoryVT(),
2630 Load->getMemOperand());
2631 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2632 if (Load->getNumValues() == 3) {
2633 // PRE/POST_INC loads have 3 values.
2634 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2635 NewLoad.getValue(2) };
2636 CombineTo(Load, To, 3, true);
2638 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2642 // Fold the AND away, taking care not to fold to the old load node if we
2644 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2646 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2649 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2650 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2651 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2652 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2654 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2655 LL.getValueType().isInteger()) {
2656 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2657 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2658 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2659 LR.getValueType(), LL, RL);
2660 AddToWorkList(ORNode.getNode());
2661 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2663 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2664 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2665 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(N0),
2666 LR.getValueType(), LL, RL);
2667 AddToWorkList(ANDNode.getNode());
2668 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
2670 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2671 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2672 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2673 LR.getValueType(), LL, RL);
2674 AddToWorkList(ORNode.getNode());
2675 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2678 // canonicalize equivalent to ll == rl
2679 if (LL == RR && LR == RL) {
2680 Op1 = ISD::getSetCCSwappedOperands(Op1);
2683 if (LL == RL && LR == RR) {
2684 bool isInteger = LL.getValueType().isInteger();
2685 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2686 if (Result != ISD::SETCC_INVALID &&
2687 (!LegalOperations ||
2688 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
2689 TLI.isOperationLegal(ISD::SETCC,
2690 getSetCCResultType(N0.getSimpleValueType())))))
2691 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
2696 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2697 if (N0.getOpcode() == N1.getOpcode()) {
2698 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2699 if (Tmp.getNode()) return Tmp;
2702 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2703 // fold (and (sra)) -> (and (srl)) when possible.
2704 if (!VT.isVector() &&
2705 SimplifyDemandedBits(SDValue(N, 0)))
2706 return SDValue(N, 0);
2708 // fold (zext_inreg (extload x)) -> (zextload x)
2709 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2710 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2711 EVT MemVT = LN0->getMemoryVT();
2712 // If we zero all the possible extended bits, then we can turn this into
2713 // a zextload if we are running before legalize or the operation is legal.
2714 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2715 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2716 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2717 ((!LegalOperations && !LN0->isVolatile()) ||
2718 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2719 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2720 LN0->getChain(), LN0->getBasePtr(),
2721 LN0->getPointerInfo(), MemVT,
2722 LN0->isVolatile(), LN0->isNonTemporal(),
2723 LN0->getAlignment());
2725 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2726 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2729 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2730 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2732 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2733 EVT MemVT = LN0->getMemoryVT();
2734 // If we zero all the possible extended bits, then we can turn this into
2735 // a zextload if we are running before legalize or the operation is legal.
2736 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2737 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2738 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2739 ((!LegalOperations && !LN0->isVolatile()) ||
2740 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2741 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2743 LN0->getBasePtr(), LN0->getPointerInfo(),
2745 LN0->isVolatile(), LN0->isNonTemporal(),
2746 LN0->getAlignment());
2748 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2749 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2753 // fold (and (load x), 255) -> (zextload x, i8)
2754 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2755 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2756 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2757 (N0.getOpcode() == ISD::ANY_EXTEND &&
2758 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2759 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2760 LoadSDNode *LN0 = HasAnyExt
2761 ? cast<LoadSDNode>(N0.getOperand(0))
2762 : cast<LoadSDNode>(N0);
2763 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2764 LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
2765 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2766 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2767 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2768 EVT LoadedVT = LN0->getMemoryVT();
2770 if (ExtVT == LoadedVT &&
2771 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2772 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2775 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2776 LN0->getChain(), LN0->getBasePtr(),
2777 LN0->getPointerInfo(),
2778 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2779 LN0->getAlignment());
2781 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2782 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2785 // Do not change the width of a volatile load.
2786 // Do not generate loads of non-round integer types since these can
2787 // be expensive (and would be wrong if the type is not byte sized).
2788 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2789 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2790 EVT PtrType = LN0->getOperand(1).getValueType();
2792 unsigned Alignment = LN0->getAlignment();
2793 SDValue NewPtr = LN0->getBasePtr();
2795 // For big endian targets, we need to add an offset to the pointer
2796 // to load the correct bytes. For little endian systems, we merely
2797 // need to read fewer bytes from the same pointer.
2798 if (TLI.isBigEndian()) {
2799 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2800 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2801 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2802 NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0), PtrType,
2803 NewPtr, DAG.getConstant(PtrOff, PtrType));
2804 Alignment = MinAlign(Alignment, PtrOff);
2807 AddToWorkList(NewPtr.getNode());
2809 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2811 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2812 LN0->getChain(), NewPtr,
2813 LN0->getPointerInfo(),
2814 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2817 CombineTo(LN0, Load, Load.getValue(1));
2818 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2824 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2825 VT.getSizeInBits() <= 64) {
2826 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2827 APInt ADDC = ADDI->getAPIntValue();
2828 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2829 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2830 // immediate for an add, but it is legal if its top c2 bits are set,
2831 // transform the ADD so the immediate doesn't need to be materialized
2833 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2834 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2835 SRLI->getZExtValue());
2836 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2838 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2840 DAG.getNode(ISD::ADD, SDLoc(N0), VT,
2841 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2842 CombineTo(N0.getNode(), NewAdd);
2843 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2854 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2856 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2857 bool DemandHighBits) {
2858 if (!LegalOperations)
2861 EVT VT = N->getValueType(0);
2862 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2864 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2867 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2868 bool LookPassAnd0 = false;
2869 bool LookPassAnd1 = false;
2870 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2872 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2874 if (N0.getOpcode() == ISD::AND) {
2875 if (!N0.getNode()->hasOneUse())
2877 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2878 if (!N01C || N01C->getZExtValue() != 0xFF00)
2880 N0 = N0.getOperand(0);
2881 LookPassAnd0 = true;
2884 if (N1.getOpcode() == ISD::AND) {
2885 if (!N1.getNode()->hasOneUse())
2887 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2888 if (!N11C || N11C->getZExtValue() != 0xFF)
2890 N1 = N1.getOperand(0);
2891 LookPassAnd1 = true;
2894 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
2896 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
2898 if (!N0.getNode()->hasOneUse() ||
2899 !N1.getNode()->hasOneUse())
2902 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2903 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2906 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
2909 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
2910 SDValue N00 = N0->getOperand(0);
2911 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
2912 if (!N00.getNode()->hasOneUse())
2914 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
2915 if (!N001C || N001C->getZExtValue() != 0xFF)
2917 N00 = N00.getOperand(0);
2918 LookPassAnd0 = true;
2921 SDValue N10 = N1->getOperand(0);
2922 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
2923 if (!N10.getNode()->hasOneUse())
2925 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
2926 if (!N101C || N101C->getZExtValue() != 0xFF00)
2928 N10 = N10.getOperand(0);
2929 LookPassAnd1 = true;
2935 // Make sure everything beyond the low halfword is zero since the SRL 16
2936 // will clear the top bits.
2937 unsigned OpSizeInBits = VT.getSizeInBits();
2938 if (DemandHighBits && OpSizeInBits > 16 &&
2939 (!LookPassAnd0 || !LookPassAnd1) &&
2940 !DAG.MaskedValueIsZero(N10, APInt::getHighBitsSet(OpSizeInBits, 16)))
2943 SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
2944 if (OpSizeInBits > 16)
2945 Res = DAG.getNode(ISD::SRL, SDLoc(N), VT, Res,
2946 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
2950 /// isBSwapHWordElement - Return true if the specified node is an element
2951 /// that makes up a 32-bit packed halfword byteswap. i.e.
2952 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2953 static bool isBSwapHWordElement(SDValue N, SmallVectorImpl<SDNode *> &Parts) {
2954 if (!N.getNode()->hasOneUse())
2957 unsigned Opc = N.getOpcode();
2958 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
2961 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2966 switch (N1C->getZExtValue()) {
2969 case 0xFF: Num = 0; break;
2970 case 0xFF00: Num = 1; break;
2971 case 0xFF0000: Num = 2; break;
2972 case 0xFF000000: Num = 3; break;
2975 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
2976 SDValue N0 = N.getOperand(0);
2977 if (Opc == ISD::AND) {
2978 if (Num == 0 || Num == 2) {
2980 // (x >> 8) & 0xff0000
2981 if (N0.getOpcode() != ISD::SRL)
2983 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2984 if (!C || C->getZExtValue() != 8)
2987 // (x << 8) & 0xff00
2988 // (x << 8) & 0xff000000
2989 if (N0.getOpcode() != ISD::SHL)
2991 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2992 if (!C || C->getZExtValue() != 8)
2995 } else if (Opc == ISD::SHL) {
2997 // (x & 0xff0000) << 8
2998 if (Num != 0 && Num != 2)
3000 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3001 if (!C || C->getZExtValue() != 8)
3003 } else { // Opc == ISD::SRL
3004 // (x & 0xff00) >> 8
3005 // (x & 0xff000000) >> 8
3006 if (Num != 1 && Num != 3)
3008 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3009 if (!C || C->getZExtValue() != 8)
3016 Parts[Num] = N0.getOperand(0).getNode();
3020 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
3021 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
3022 /// => (rotl (bswap x), 16)
3023 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
3024 if (!LegalOperations)
3027 EVT VT = N->getValueType(0);
3030 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3033 SmallVector<SDNode*,4> Parts(4, (SDNode*)0);
3035 // (or (or (and), (and)), (or (and), (and)))
3036 // (or (or (or (and), (and)), (and)), (and))
3037 if (N0.getOpcode() != ISD::OR)
3039 SDValue N00 = N0.getOperand(0);
3040 SDValue N01 = N0.getOperand(1);
3042 if (N1.getOpcode() == ISD::OR &&
3043 N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
3044 // (or (or (and), (and)), (or (and), (and)))
3045 SDValue N000 = N00.getOperand(0);
3046 if (!isBSwapHWordElement(N000, Parts))
3049 SDValue N001 = N00.getOperand(1);
3050 if (!isBSwapHWordElement(N001, Parts))
3052 SDValue N010 = N01.getOperand(0);
3053 if (!isBSwapHWordElement(N010, Parts))
3055 SDValue N011 = N01.getOperand(1);
3056 if (!isBSwapHWordElement(N011, Parts))
3059 // (or (or (or (and), (and)), (and)), (and))
3060 if (!isBSwapHWordElement(N1, Parts))
3062 if (!isBSwapHWordElement(N01, Parts))
3064 if (N00.getOpcode() != ISD::OR)
3066 SDValue N000 = N00.getOperand(0);
3067 if (!isBSwapHWordElement(N000, Parts))
3069 SDValue N001 = N00.getOperand(1);
3070 if (!isBSwapHWordElement(N001, Parts))
3074 // Make sure the parts are all coming from the same node.
3075 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3078 SDValue BSwap = DAG.getNode(ISD::BSWAP, SDLoc(N), VT,
3079 SDValue(Parts[0],0));
3081 // Result of the bswap should be rotated by 16. If it's not legal, than
3082 // do (x << 16) | (x >> 16).
3083 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3084 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3085 return DAG.getNode(ISD::ROTL, SDLoc(N), VT, BSwap, ShAmt);
3086 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3087 return DAG.getNode(ISD::ROTR, SDLoc(N), VT, BSwap, ShAmt);
3088 return DAG.getNode(ISD::OR, SDLoc(N), VT,
3089 DAG.getNode(ISD::SHL, SDLoc(N), VT, BSwap, ShAmt),
3090 DAG.getNode(ISD::SRL, SDLoc(N), VT, BSwap, ShAmt));
3093 SDValue DAGCombiner::visitOR(SDNode *N) {
3094 SDValue N0 = N->getOperand(0);
3095 SDValue N1 = N->getOperand(1);
3096 SDValue LL, LR, RL, RR, CC0, CC1;
3097 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3098 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3099 EVT VT = N1.getValueType();
3102 if (VT.isVector()) {
3103 SDValue FoldedVOp = SimplifyVBinOp(N);
3104 if (FoldedVOp.getNode()) return FoldedVOp;
3106 // fold (or x, 0) -> x, vector edition
3107 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3109 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3112 // fold (or x, -1) -> -1, vector edition
3113 if (ISD::isBuildVectorAllOnes(N0.getNode()))
3115 if (ISD::isBuildVectorAllOnes(N1.getNode()))
3119 // fold (or x, undef) -> -1
3120 if (!LegalOperations &&
3121 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3122 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3123 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3125 // fold (or c1, c2) -> c1|c2
3127 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3128 // canonicalize constant to RHS
3130 return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
3131 // fold (or x, 0) -> x
3132 if (N1C && N1C->isNullValue())
3134 // fold (or x, -1) -> -1
3135 if (N1C && N1C->isAllOnesValue())
3137 // fold (or x, c) -> c iff (x & ~c) == 0
3138 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3141 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3142 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3143 if (BSwap.getNode() != 0)
3145 BSwap = MatchBSwapHWordLow(N, N0, N1);
3146 if (BSwap.getNode() != 0)
3150 SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1);
3151 if (ROR.getNode() != 0)
3153 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3154 // iff (c1 & c2) == 0.
3155 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3156 isa<ConstantSDNode>(N0.getOperand(1))) {
3157 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3158 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
3159 return DAG.getNode(ISD::AND, SDLoc(N), VT,
3160 DAG.getNode(ISD::OR, SDLoc(N0), VT,
3161 N0.getOperand(0), N1),
3162 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
3164 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3165 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3166 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3167 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3169 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3170 LL.getValueType().isInteger()) {
3171 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3172 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3173 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3174 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3175 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(LR),
3176 LR.getValueType(), LL, RL);
3177 AddToWorkList(ORNode.getNode());
3178 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
3180 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3181 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3182 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3183 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3184 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(LR),
3185 LR.getValueType(), LL, RL);
3186 AddToWorkList(ANDNode.getNode());
3187 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
3190 // canonicalize equivalent to ll == rl
3191 if (LL == RR && LR == RL) {
3192 Op1 = ISD::getSetCCSwappedOperands(Op1);
3195 if (LL == RL && LR == RR) {
3196 bool isInteger = LL.getValueType().isInteger();
3197 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3198 if (Result != ISD::SETCC_INVALID &&
3199 (!LegalOperations ||
3200 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
3201 TLI.isOperationLegal(ISD::SETCC,
3202 getSetCCResultType(N0.getValueType())))))
3203 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
3208 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3209 if (N0.getOpcode() == N1.getOpcode()) {
3210 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3211 if (Tmp.getNode()) return Tmp;
3214 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3215 if (N0.getOpcode() == ISD::AND &&
3216 N1.getOpcode() == ISD::AND &&
3217 N0.getOperand(1).getOpcode() == ISD::Constant &&
3218 N1.getOperand(1).getOpcode() == ISD::Constant &&
3219 // Don't increase # computations.
3220 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3221 // We can only do this xform if we know that bits from X that are set in C2
3222 // but not in C1 are already zero. Likewise for Y.
3223 const APInt &LHSMask =
3224 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3225 const APInt &RHSMask =
3226 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3228 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3229 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3230 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3231 N0.getOperand(0), N1.getOperand(0));
3232 return DAG.getNode(ISD::AND, SDLoc(N), VT, X,
3233 DAG.getConstant(LHSMask | RHSMask, VT));
3237 // See if this is some rotate idiom.
3238 if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
3239 return SDValue(Rot, 0);
3241 // Simplify the operands using demanded-bits information.
3242 if (!VT.isVector() &&
3243 SimplifyDemandedBits(SDValue(N, 0)))
3244 return SDValue(N, 0);
3249 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3250 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3251 if (Op.getOpcode() == ISD::AND) {
3252 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3253 Mask = Op.getOperand(1);
3254 Op = Op.getOperand(0);
3260 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3268 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3269 // idioms for rotate, and if the target supports rotation instructions, generate
3271 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL) {
3272 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3273 EVT VT = LHS.getValueType();
3274 if (!TLI.isTypeLegal(VT)) return 0;
3276 // The target must have at least one rotate flavor.
3277 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3278 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3279 if (!HasROTL && !HasROTR) return 0;
3281 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3282 SDValue LHSShift; // The shift.
3283 SDValue LHSMask; // AND value if any.
3284 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3285 return 0; // Not part of a rotate.
3287 SDValue RHSShift; // The shift.
3288 SDValue RHSMask; // AND value if any.
3289 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3290 return 0; // Not part of a rotate.
3292 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3293 return 0; // Not shifting the same value.
3295 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3296 return 0; // Shifts must disagree.
3298 // Canonicalize shl to left side in a shl/srl pair.
3299 if (RHSShift.getOpcode() == ISD::SHL) {
3300 std::swap(LHS, RHS);
3301 std::swap(LHSShift, RHSShift);
3302 std::swap(LHSMask , RHSMask );
3305 unsigned OpSizeInBits = VT.getSizeInBits();
3306 SDValue LHSShiftArg = LHSShift.getOperand(0);
3307 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3308 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3310 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3311 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3312 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3313 RHSShiftAmt.getOpcode() == ISD::Constant) {
3314 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3315 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3316 if ((LShVal + RShVal) != OpSizeInBits)
3319 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3320 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3322 // If there is an AND of either shifted operand, apply it to the result.
3323 if (LHSMask.getNode() || RHSMask.getNode()) {
3324 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3326 if (LHSMask.getNode()) {
3327 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3328 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3330 if (RHSMask.getNode()) {
3331 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3332 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3335 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3338 return Rot.getNode();
3341 // If there is a mask here, and we have a variable shift, we can't be sure
3342 // that we're masking out the right stuff.
3343 if (LHSMask.getNode() || RHSMask.getNode())
3346 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
3347 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
3348 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
3349 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
3350 if (ConstantSDNode *SUBC =
3351 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
3352 if (SUBC->getAPIntValue() == OpSizeInBits)
3353 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
3354 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3358 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
3359 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
3360 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
3361 RHSShiftAmt == LHSShiftAmt.getOperand(1))
3362 if (ConstantSDNode *SUBC =
3363 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0)))
3364 if (SUBC->getAPIntValue() == OpSizeInBits)
3365 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
3366 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3368 // Look for sign/zext/any-extended or truncate cases:
3369 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3370 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3371 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3372 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3373 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3374 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3375 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3376 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3377 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
3378 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
3379 if (RExtOp0.getOpcode() == ISD::SUB &&
3380 RExtOp0.getOperand(1) == LExtOp0) {
3381 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3383 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3384 // (rotr x, (sub 32, y))
3385 if (ConstantSDNode *SUBC =
3386 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0)))
3387 if (SUBC->getAPIntValue() == OpSizeInBits)
3388 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3390 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3391 } else if (LExtOp0.getOpcode() == ISD::SUB &&
3392 RExtOp0 == LExtOp0.getOperand(1)) {
3393 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3395 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3396 // (rotl x, (sub 32, y))
3397 if (ConstantSDNode *SUBC =
3398 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0)))
3399 if (SUBC->getAPIntValue() == OpSizeInBits)
3400 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
3402 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3409 SDValue DAGCombiner::visitXOR(SDNode *N) {
3410 SDValue N0 = N->getOperand(0);
3411 SDValue N1 = N->getOperand(1);
3412 SDValue LHS, RHS, CC;
3413 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3414 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3415 EVT VT = N0.getValueType();
3418 if (VT.isVector()) {
3419 SDValue FoldedVOp = SimplifyVBinOp(N);
3420 if (FoldedVOp.getNode()) return FoldedVOp;
3422 // fold (xor x, 0) -> x, vector edition
3423 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3425 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3429 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3430 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3431 return DAG.getConstant(0, VT);
3432 // fold (xor x, undef) -> undef
3433 if (N0.getOpcode() == ISD::UNDEF)
3435 if (N1.getOpcode() == ISD::UNDEF)
3437 // fold (xor c1, c2) -> c1^c2
3439 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3440 // canonicalize constant to RHS
3442 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
3443 // fold (xor x, 0) -> x
3444 if (N1C && N1C->isNullValue())
3447 SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1);
3448 if (RXOR.getNode() != 0)
3451 // fold !(x cc y) -> (x !cc y)
3452 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3453 bool isInt = LHS.getValueType().isInteger();
3454 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3457 if (!LegalOperations ||
3458 TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
3459 switch (N0.getOpcode()) {
3461 llvm_unreachable("Unhandled SetCC Equivalent!");
3463 return DAG.getSetCC(SDLoc(N), VT, LHS, RHS, NotCC);
3464 case ISD::SELECT_CC:
3465 return DAG.getSelectCC(SDLoc(N), LHS, RHS, N0.getOperand(2),
3466 N0.getOperand(3), NotCC);
3471 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3472 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3473 N0.getNode()->hasOneUse() &&
3474 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3475 SDValue V = N0.getOperand(0);
3476 V = DAG.getNode(ISD::XOR, SDLoc(N0), V.getValueType(), V,
3477 DAG.getConstant(1, V.getValueType()));
3478 AddToWorkList(V.getNode());
3479 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
3482 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3483 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3484 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3485 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3486 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3487 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3488 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3489 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3490 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3491 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3494 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3495 if (N1C && N1C->isAllOnesValue() &&
3496 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3497 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3498 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3499 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3500 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3501 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3502 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3503 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3506 // fold (xor (and x, y), y) -> (and (not x), y)
3507 if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3508 N0->getOperand(1) == N1) {
3509 SDValue X = N0->getOperand(0);
3510 SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
3511 AddToWorkList(NotX.getNode());
3512 return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
3514 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3515 if (N1C && N0.getOpcode() == ISD::XOR) {
3516 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3517 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3519 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(1),
3520 DAG.getConstant(N1C->getAPIntValue() ^
3521 N00C->getAPIntValue(), VT));
3523 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(0),
3524 DAG.getConstant(N1C->getAPIntValue() ^
3525 N01C->getAPIntValue(), VT));
3527 // fold (xor x, x) -> 0
3529 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
3531 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3532 if (N0.getOpcode() == N1.getOpcode()) {
3533 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3534 if (Tmp.getNode()) return Tmp;
3537 // Simplify the expression using non-local knowledge.
3538 if (!VT.isVector() &&
3539 SimplifyDemandedBits(SDValue(N, 0)))
3540 return SDValue(N, 0);
3545 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3546 /// the shift amount is a constant.
3547 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
3548 SDNode *LHS = N->getOperand(0).getNode();
3549 if (!LHS->hasOneUse()) return SDValue();
3551 // We want to pull some binops through shifts, so that we have (and (shift))
3552 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3553 // thing happens with address calculations, so it's important to canonicalize
3555 bool HighBitSet = false; // Can we transform this if the high bit is set?
3557 switch (LHS->getOpcode()) {
3558 default: return SDValue();
3561 HighBitSet = false; // We can only transform sra if the high bit is clear.
3564 HighBitSet = true; // We can only transform sra if the high bit is set.
3567 if (N->getOpcode() != ISD::SHL)
3568 return SDValue(); // only shl(add) not sr[al](add).
3569 HighBitSet = false; // We can only transform sra if the high bit is clear.
3573 // We require the RHS of the binop to be a constant as well.
3574 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3575 if (!BinOpCst) return SDValue();
3577 // FIXME: disable this unless the input to the binop is a shift by a constant.
3578 // If it is not a shift, it pessimizes some common cases like:
3580 // void foo(int *X, int i) { X[i & 1235] = 1; }
3581 // int bar(int *X, int i) { return X[i & 255]; }
3582 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3583 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3584 BinOpLHSVal->getOpcode() != ISD::SRA &&
3585 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3586 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3589 EVT VT = N->getValueType(0);
3591 // If this is a signed shift right, and the high bit is modified by the
3592 // logical operation, do not perform the transformation. The highBitSet
3593 // boolean indicates the value of the high bit of the constant which would
3594 // cause it to be modified for this operation.
3595 if (N->getOpcode() == ISD::SRA) {
3596 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3597 if (BinOpRHSSignSet != HighBitSet)
3601 // Fold the constants, shifting the binop RHS by the shift amount.
3602 SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
3604 LHS->getOperand(1), N->getOperand(1));
3606 // Create the new shift.
3607 SDValue NewShift = DAG.getNode(N->getOpcode(),
3608 SDLoc(LHS->getOperand(0)),
3609 VT, LHS->getOperand(0), N->getOperand(1));
3611 // Create the new binop.
3612 return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
3615 SDValue DAGCombiner::visitSHL(SDNode *N) {
3616 SDValue N0 = N->getOperand(0);
3617 SDValue N1 = N->getOperand(1);
3618 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3619 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3620 EVT VT = N0.getValueType();
3621 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3623 // fold (shl c1, c2) -> c1<<c2
3625 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3626 // fold (shl 0, x) -> 0
3627 if (N0C && N0C->isNullValue())
3629 // fold (shl x, c >= size(x)) -> undef
3630 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3631 return DAG.getUNDEF(VT);
3632 // fold (shl x, 0) -> x
3633 if (N1C && N1C->isNullValue())
3635 // fold (shl undef, x) -> 0
3636 if (N0.getOpcode() == ISD::UNDEF)
3637 return DAG.getConstant(0, VT);
3638 // if (shl x, c) is known to be zero, return 0
3639 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3640 APInt::getAllOnesValue(OpSizeInBits)))
3641 return DAG.getConstant(0, VT);
3642 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3643 if (N1.getOpcode() == ISD::TRUNCATE &&
3644 N1.getOperand(0).getOpcode() == ISD::AND &&
3645 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3646 SDValue N101 = N1.getOperand(0).getOperand(1);
3647 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3648 EVT TruncVT = N1.getValueType();
3649 SDValue N100 = N1.getOperand(0).getOperand(0);
3650 APInt TruncC = N101C->getAPIntValue();
3651 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3652 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
3653 DAG.getNode(ISD::AND, SDLoc(N), TruncVT,
3654 DAG.getNode(ISD::TRUNCATE,
3657 DAG.getConstant(TruncC, TruncVT)));
3661 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3662 return SDValue(N, 0);
3664 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
3665 if (N1C && N0.getOpcode() == ISD::SHL &&
3666 N0.getOperand(1).getOpcode() == ISD::Constant) {
3667 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3668 uint64_t c2 = N1C->getZExtValue();
3669 if (c1 + c2 >= OpSizeInBits)
3670 return DAG.getConstant(0, VT);
3671 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
3672 DAG.getConstant(c1 + c2, N1.getValueType()));
3675 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
3676 // For this to be valid, the second form must not preserve any of the bits
3677 // that are shifted out by the inner shift in the first form. This means
3678 // the outer shift size must be >= the number of bits added by the ext.
3679 // As a corollary, we don't care what kind of ext it is.
3680 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
3681 N0.getOpcode() == ISD::ANY_EXTEND ||
3682 N0.getOpcode() == ISD::SIGN_EXTEND) &&
3683 N0.getOperand(0).getOpcode() == ISD::SHL &&
3684 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3686 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3687 uint64_t c2 = N1C->getZExtValue();
3688 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3689 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3690 if (c2 >= OpSizeInBits - InnerShiftSize) {
3691 if (c1 + c2 >= OpSizeInBits)
3692 return DAG.getConstant(0, VT);
3693 return DAG.getNode(ISD::SHL, SDLoc(N0), VT,
3694 DAG.getNode(N0.getOpcode(), SDLoc(N0), VT,
3695 N0.getOperand(0)->getOperand(0)),
3696 DAG.getConstant(c1 + c2, N1.getValueType()));
3700 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
3701 // (and (srl x, (sub c1, c2), MASK)
3702 // Only fold this if the inner shift has no other uses -- if it does, folding
3703 // this will increase the total number of instructions.
3704 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse() &&
3705 N0.getOperand(1).getOpcode() == ISD::Constant) {
3706 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3707 if (c1 < VT.getSizeInBits()) {
3708 uint64_t c2 = N1C->getZExtValue();
3709 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
3710 VT.getSizeInBits() - c1);
3713 Mask = Mask.shl(c2-c1);
3714 Shift = DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
3715 DAG.getConstant(c2-c1, N1.getValueType()));
3717 Mask = Mask.lshr(c1-c2);
3718 Shift = DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
3719 DAG.getConstant(c1-c2, N1.getValueType()));
3721 return DAG.getNode(ISD::AND, SDLoc(N0), VT, Shift,
3722 DAG.getConstant(Mask, VT));
3725 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
3726 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
3727 SDValue HiBitsMask =
3728 DAG.getConstant(APInt::getHighBitsSet(VT.getSizeInBits(),
3729 VT.getSizeInBits() -
3730 N1C->getZExtValue()),
3732 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
3737 SDValue NewSHL = visitShiftByConstant(N, N1C->getZExtValue());
3738 if (NewSHL.getNode())
3745 SDValue DAGCombiner::visitSRA(SDNode *N) {
3746 SDValue N0 = N->getOperand(0);
3747 SDValue N1 = N->getOperand(1);
3748 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3749 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3750 EVT VT = N0.getValueType();
3751 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3753 // fold (sra c1, c2) -> (sra c1, c2)
3755 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
3756 // fold (sra 0, x) -> 0
3757 if (N0C && N0C->isNullValue())
3759 // fold (sra -1, x) -> -1
3760 if (N0C && N0C->isAllOnesValue())
3762 // fold (sra x, (setge c, size(x))) -> undef
3763 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3764 return DAG.getUNDEF(VT);
3765 // fold (sra x, 0) -> x
3766 if (N1C && N1C->isNullValue())
3768 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
3770 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
3771 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
3772 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
3774 ExtVT = EVT::getVectorVT(*DAG.getContext(),
3775 ExtVT, VT.getVectorNumElements());
3776 if ((!LegalOperations ||
3777 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
3778 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
3779 N0.getOperand(0), DAG.getValueType(ExtVT));
3782 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
3783 if (N1C && N0.getOpcode() == ISD::SRA) {
3784 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3785 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
3786 if (Sum >= OpSizeInBits) Sum = OpSizeInBits-1;
3787 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0.getOperand(0),
3788 DAG.getConstant(Sum, N1C->getValueType(0)));
3792 // fold (sra (shl X, m), (sub result_size, n))
3793 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
3794 // result_size - n != m.
3795 // If truncate is free for the target sext(shl) is likely to result in better
3797 if (N0.getOpcode() == ISD::SHL) {
3798 // Get the two constanst of the shifts, CN0 = m, CN = n.
3799 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3801 // Determine what the truncate's result bitsize and type would be.
3803 EVT::getIntegerVT(*DAG.getContext(),
3804 OpSizeInBits - N1C->getZExtValue());
3805 // Determine the residual right-shift amount.
3806 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
3808 // If the shift is not a no-op (in which case this should be just a sign
3809 // extend already), the truncated to type is legal, sign_extend is legal
3810 // on that type, and the truncate to that type is both legal and free,
3811 // perform the transform.
3812 if ((ShiftAmt > 0) &&
3813 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
3814 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
3815 TLI.isTruncateFree(VT, TruncVT)) {
3817 SDValue Amt = DAG.getConstant(ShiftAmt,
3818 getShiftAmountTy(N0.getOperand(0).getValueType()));
3819 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0), VT,
3820 N0.getOperand(0), Amt);
3821 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), TruncVT,
3823 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N),
3824 N->getValueType(0), Trunc);
3829 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
3830 if (N1.getOpcode() == ISD::TRUNCATE &&
3831 N1.getOperand(0).getOpcode() == ISD::AND &&
3832 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3833 SDValue N101 = N1.getOperand(0).getOperand(1);
3834 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3835 EVT TruncVT = N1.getValueType();
3836 SDValue N100 = N1.getOperand(0).getOperand(0);
3837 APInt TruncC = N101C->getAPIntValue();
3838 TruncC = TruncC.trunc(TruncVT.getScalarType().getSizeInBits());
3839 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0,
3840 DAG.getNode(ISD::AND, SDLoc(N),
3842 DAG.getNode(ISD::TRUNCATE,
3845 DAG.getConstant(TruncC, TruncVT)));
3849 // fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2))
3850 // if c1 is equal to the number of bits the trunc removes
3851 if (N0.getOpcode() == ISD::TRUNCATE &&
3852 (N0.getOperand(0).getOpcode() == ISD::SRL ||
3853 N0.getOperand(0).getOpcode() == ISD::SRA) &&
3854 N0.getOperand(0).hasOneUse() &&
3855 N0.getOperand(0).getOperand(1).hasOneUse() &&
3856 N1C && isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
3857 EVT LargeVT = N0.getOperand(0).getValueType();
3858 ConstantSDNode *LargeShiftAmt =
3859 cast<ConstantSDNode>(N0.getOperand(0).getOperand(1));
3861 if (LargeVT.getScalarType().getSizeInBits() - OpSizeInBits ==
3862 LargeShiftAmt->getZExtValue()) {
3864 DAG.getConstant(LargeShiftAmt->getZExtValue() + N1C->getZExtValue(),
3865 getShiftAmountTy(N0.getOperand(0).getOperand(0).getValueType()));
3866 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), LargeVT,
3867 N0.getOperand(0).getOperand(0), Amt);
3868 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, SRA);
3872 // Simplify, based on bits shifted out of the LHS.
3873 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3874 return SDValue(N, 0);
3877 // If the sign bit is known to be zero, switch this to a SRL.
3878 if (DAG.SignBitIsZero(N0))
3879 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);
3882 SDValue NewSRA = visitShiftByConstant(N, N1C->getZExtValue());
3883 if (NewSRA.getNode())
3890 SDValue DAGCombiner::visitSRL(SDNode *N) {
3891 SDValue N0 = N->getOperand(0);
3892 SDValue N1 = N->getOperand(1);
3893 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3894 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3895 EVT VT = N0.getValueType();
3896 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3898 // fold (srl c1, c2) -> c1 >>u c2
3900 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
3901 // fold (srl 0, x) -> 0
3902 if (N0C && N0C->isNullValue())
3904 // fold (srl x, c >= size(x)) -> undef
3905 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3906 return DAG.getUNDEF(VT);
3907 // fold (srl x, 0) -> x
3908 if (N1C && N1C->isNullValue())
3910 // if (srl x, c) is known to be zero, return 0
3911 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
3912 APInt::getAllOnesValue(OpSizeInBits)))
3913 return DAG.getConstant(0, VT);
3915 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
3916 if (N1C && N0.getOpcode() == ISD::SRL &&
3917 N0.getOperand(1).getOpcode() == ISD::Constant) {
3918 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3919 uint64_t c2 = N1C->getZExtValue();
3920 if (c1 + c2 >= OpSizeInBits)
3921 return DAG.getConstant(0, VT);
3922 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
3923 DAG.getConstant(c1 + c2, N1.getValueType()));
3926 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
3927 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
3928 N0.getOperand(0).getOpcode() == ISD::SRL &&
3929 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3931 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3932 uint64_t c2 = N1C->getZExtValue();
3933 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3934 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
3935 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3936 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
3937 if (c1 + OpSizeInBits == InnerShiftSize) {
3938 if (c1 + c2 >= InnerShiftSize)
3939 return DAG.getConstant(0, VT);
3940 return DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT,
3941 DAG.getNode(ISD::SRL, SDLoc(N0), InnerShiftVT,
3942 N0.getOperand(0)->getOperand(0),
3943 DAG.getConstant(c1 + c2, ShiftCountVT)));
3947 // fold (srl (shl x, c), c) -> (and x, cst2)
3948 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
3949 N0.getValueSizeInBits() <= 64) {
3950 uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
3951 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
3952 DAG.getConstant(~0ULL >> ShAmt, VT));
3955 // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
3956 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
3957 // Shifting in all undef bits?
3958 EVT SmallVT = N0.getOperand(0).getValueType();
3959 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
3960 return DAG.getUNDEF(VT);
3962 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
3963 uint64_t ShiftAmt = N1C->getZExtValue();
3964 SDValue SmallShift = DAG.getNode(ISD::SRL, SDLoc(N0), SmallVT,
3966 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
3967 AddToWorkList(SmallShift.getNode());
3968 APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits()).lshr(ShiftAmt);
3969 return DAG.getNode(ISD::AND, SDLoc(N), VT,
3970 DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, SmallShift),
3971 DAG.getConstant(Mask, VT));
3975 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
3976 // bit, which is unmodified by sra.
3977 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
3978 if (N0.getOpcode() == ISD::SRA)
3979 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
3982 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
3983 if (N1C && N0.getOpcode() == ISD::CTLZ &&
3984 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
3985 APInt KnownZero, KnownOne;
3986 DAG.ComputeMaskedBits(N0.getOperand(0), KnownZero, KnownOne);
3988 // If any of the input bits are KnownOne, then the input couldn't be all
3989 // zeros, thus the result of the srl will always be zero.
3990 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
3992 // If all of the bits input the to ctlz node are known to be zero, then
3993 // the result of the ctlz is "32" and the result of the shift is one.
3994 APInt UnknownBits = ~KnownZero;
3995 if (UnknownBits == 0) return DAG.getConstant(1, VT);
3997 // Otherwise, check to see if there is exactly one bit input to the ctlz.
3998 if ((UnknownBits & (UnknownBits - 1)) == 0) {
3999 // Okay, we know that only that the single bit specified by UnknownBits
4000 // could be set on input to the CTLZ node. If this bit is set, the SRL
4001 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
4002 // to an SRL/XOR pair, which is likely to simplify more.
4003 unsigned ShAmt = UnknownBits.countTrailingZeros();
4004 SDValue Op = N0.getOperand(0);
4007 Op = DAG.getNode(ISD::SRL, SDLoc(N0), VT, Op,
4008 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
4009 AddToWorkList(Op.getNode());
4012 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
4013 Op, DAG.getConstant(1, VT));
4017 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
4018 if (N1.getOpcode() == ISD::TRUNCATE &&
4019 N1.getOperand(0).getOpcode() == ISD::AND &&
4020 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
4021 SDValue N101 = N1.getOperand(0).getOperand(1);
4022 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
4023 EVT TruncVT = N1.getValueType();
4024 SDValue N100 = N1.getOperand(0).getOperand(0);
4025 APInt TruncC = N101C->getAPIntValue();
4026 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
4027 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0,
4028 DAG.getNode(ISD::AND, SDLoc(N),
4030 DAG.getNode(ISD::TRUNCATE,
4033 DAG.getConstant(TruncC, TruncVT)));
4037 // fold operands of srl based on knowledge that the low bits are not
4039 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4040 return SDValue(N, 0);
4043 SDValue NewSRL = visitShiftByConstant(N, N1C->getZExtValue());
4044 if (NewSRL.getNode())
4048 // Attempt to convert a srl of a load into a narrower zero-extending load.
4049 SDValue NarrowLoad = ReduceLoadWidth(N);
4050 if (NarrowLoad.getNode())
4053 // Here is a common situation. We want to optimize:
4056 // %b = and i32 %a, 2
4057 // %c = srl i32 %b, 1
4058 // brcond i32 %c ...
4064 // %c = setcc eq %b, 0
4067 // However when after the source operand of SRL is optimized into AND, the SRL
4068 // itself may not be optimized further. Look for it and add the BRCOND into
4070 if (N->hasOneUse()) {
4071 SDNode *Use = *N->use_begin();
4072 if (Use->getOpcode() == ISD::BRCOND)
4074 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
4075 // Also look pass the truncate.
4076 Use = *Use->use_begin();
4077 if (Use->getOpcode() == ISD::BRCOND)
4085 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
4086 SDValue N0 = N->getOperand(0);
4087 EVT VT = N->getValueType(0);
4089 // fold (ctlz c1) -> c2
4090 if (isa<ConstantSDNode>(N0))
4091 return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);
4095 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
4096 SDValue N0 = N->getOperand(0);
4097 EVT VT = N->getValueType(0);
4099 // fold (ctlz_zero_undef c1) -> c2
4100 if (isa<ConstantSDNode>(N0))
4101 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4105 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4106 SDValue N0 = N->getOperand(0);
4107 EVT VT = N->getValueType(0);
4109 // fold (cttz c1) -> c2
4110 if (isa<ConstantSDNode>(N0))
4111 return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);
4115 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4116 SDValue N0 = N->getOperand(0);
4117 EVT VT = N->getValueType(0);
4119 // fold (cttz_zero_undef c1) -> c2
4120 if (isa<ConstantSDNode>(N0))
4121 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4125 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4126 SDValue N0 = N->getOperand(0);
4127 EVT VT = N->getValueType(0);
4129 // fold (ctpop c1) -> c2
4130 if (isa<ConstantSDNode>(N0))
4131 return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
4135 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4136 SDValue N0 = N->getOperand(0);
4137 SDValue N1 = N->getOperand(1);
4138 SDValue N2 = N->getOperand(2);
4139 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4140 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4141 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4142 EVT VT = N->getValueType(0);
4143 EVT VT0 = N0.getValueType();
4145 // fold (select C, X, X) -> X
4148 // fold (select true, X, Y) -> X
4149 if (N0C && !N0C->isNullValue())
4151 // fold (select false, X, Y) -> Y
4152 if (N0C && N0C->isNullValue())
4154 // fold (select C, 1, X) -> (or C, X)
4155 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4156 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4157 // fold (select C, 0, 1) -> (xor C, 1)
4158 if (VT.isInteger() &&
4161 TLI.getBooleanContents(false) ==
4162 TargetLowering::ZeroOrOneBooleanContent)) &&
4163 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4166 return DAG.getNode(ISD::XOR, SDLoc(N), VT0,
4167 N0, DAG.getConstant(1, VT0));
4168 XORNode = DAG.getNode(ISD::XOR, SDLoc(N0), VT0,
4169 N0, DAG.getConstant(1, VT0));
4170 AddToWorkList(XORNode.getNode());
4172 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, XORNode);
4173 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, XORNode);
4175 // fold (select C, 0, X) -> (and (not C), X)
4176 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4177 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4178 AddToWorkList(NOTNode.getNode());
4179 return DAG.getNode(ISD::AND, SDLoc(N), VT, NOTNode, N2);
4181 // fold (select C, X, 1) -> (or (not C), X)
4182 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4183 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4184 AddToWorkList(NOTNode.getNode());
4185 return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
4187 // fold (select C, X, 0) -> (and C, X)
4188 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4189 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4190 // fold (select X, X, Y) -> (or X, Y)
4191 // fold (select X, 1, Y) -> (or X, Y)
4192 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4193 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4194 // fold (select X, Y, X) -> (and X, Y)
4195 // fold (select X, Y, 0) -> (and X, Y)
4196 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4197 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4199 // If we can fold this based on the true/false value, do so.
4200 if (SimplifySelectOps(N, N1, N2))
4201 return SDValue(N, 0); // Don't revisit N.
4203 // fold selects based on a setcc into other things, such as min/max/abs
4204 if (N0.getOpcode() == ISD::SETCC) {
4206 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
4207 // having to say they don't support SELECT_CC on every type the DAG knows
4208 // about, since there is no way to mark an opcode illegal at all value types
4209 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other) &&
4210 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT))
4211 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
4212 N0.getOperand(0), N0.getOperand(1),
4213 N1, N2, N0.getOperand(2));
4214 return SimplifySelect(SDLoc(N), N0, N1, N2);
4220 SDValue DAGCombiner::visitVSELECT(SDNode *N) {
4221 SDValue N0 = N->getOperand(0);
4222 SDValue N1 = N->getOperand(1);
4223 SDValue N2 = N->getOperand(2);
4226 // Canonicalize integer abs.
4227 // vselect (setg[te] X, 0), X, -X ->
4228 // vselect (setgt X, -1), X, -X ->
4229 // vselect (setl[te] X, 0), -X, X ->
4230 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
4231 if (N0.getOpcode() == ISD::SETCC) {
4232 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4233 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
4235 bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());
4237 if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
4238 (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
4239 N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
4240 isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
4241 else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
4242 N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
4243 isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
4246 EVT VT = LHS.getValueType();
4247 SDValue Shift = DAG.getNode(
4248 ISD::SRA, DL, VT, LHS,
4249 DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, VT));
4250 SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
4251 AddToWorkList(Shift.getNode());
4252 AddToWorkList(Add.getNode());
4253 return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
4260 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4261 SDValue N0 = N->getOperand(0);
4262 SDValue N1 = N->getOperand(1);
4263 SDValue N2 = N->getOperand(2);
4264 SDValue N3 = N->getOperand(3);
4265 SDValue N4 = N->getOperand(4);
4266 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4268 // fold select_cc lhs, rhs, x, x, cc -> x
4272 // Determine if the condition we're dealing with is constant
4273 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
4274 N0, N1, CC, SDLoc(N), false);
4275 if (SCC.getNode()) {
4276 AddToWorkList(SCC.getNode());
4278 if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
4279 if (!SCCC->isNullValue())
4280 return N2; // cond always true -> true val
4282 return N3; // cond always false -> false val
4285 // Fold to a simpler select_cc
4286 if (SCC.getOpcode() == ISD::SETCC)
4287 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
4288 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4292 // If we can fold this based on the true/false value, do so.
4293 if (SimplifySelectOps(N, N2, N3))
4294 return SDValue(N, 0); // Don't revisit N.
4296 // fold select_cc into other things, such as min/max/abs
4297 return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
4300 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4301 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4302 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4306 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4307 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4308 // transformation. Returns true if extension are possible and the above
4309 // mentioned transformation is profitable.
4310 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4312 SmallVectorImpl<SDNode *> &ExtendNodes,
4313 const TargetLowering &TLI) {
4314 bool HasCopyToRegUses = false;
4315 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4316 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4317 UE = N0.getNode()->use_end();
4322 if (UI.getUse().getResNo() != N0.getResNo())
4324 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4325 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4326 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4327 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4328 // Sign bits will be lost after a zext.
4331 for (unsigned i = 0; i != 2; ++i) {
4332 SDValue UseOp = User->getOperand(i);
4335 if (!isa<ConstantSDNode>(UseOp))
4340 ExtendNodes.push_back(User);
4343 // If truncates aren't free and there are users we can't
4344 // extend, it isn't worthwhile.
4347 // Remember if this value is live-out.
4348 if (User->getOpcode() == ISD::CopyToReg)
4349 HasCopyToRegUses = true;
4352 if (HasCopyToRegUses) {
4353 bool BothLiveOut = false;
4354 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4356 SDUse &Use = UI.getUse();
4357 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4363 // Both unextended and extended values are live out. There had better be
4364 // a good reason for the transformation.
4365 return ExtendNodes.size();
4370 void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
4371 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
4372 ISD::NodeType ExtType) {
4373 // Extend SetCC uses if necessary.
4374 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4375 SDNode *SetCC = SetCCs[i];
4376 SmallVector<SDValue, 4> Ops;
4378 for (unsigned j = 0; j != 2; ++j) {
4379 SDValue SOp = SetCC->getOperand(j);
4381 Ops.push_back(ExtLoad);
4383 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4386 Ops.push_back(SetCC->getOperand(2));
4387 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
4388 &Ops[0], Ops.size()));
4392 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4393 SDValue N0 = N->getOperand(0);
4394 EVT VT = N->getValueType(0);
4396 // fold (sext c1) -> c1
4397 if (isa<ConstantSDNode>(N0))
4398 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N0);
4400 // fold (sext (sext x)) -> (sext x)
4401 // fold (sext (aext x)) -> (sext x)
4402 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4403 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT,
4406 if (N0.getOpcode() == ISD::TRUNCATE) {
4407 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4408 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4409 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4410 if (NarrowLoad.getNode()) {
4411 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4412 if (NarrowLoad.getNode() != N0.getNode()) {
4413 CombineTo(N0.getNode(), NarrowLoad);
4414 // CombineTo deleted the truncate, if needed, but not what's under it.
4417 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4420 // See if the value being truncated is already sign extended. If so, just
4421 // eliminate the trunc/sext pair.
4422 SDValue Op = N0.getOperand(0);
4423 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4424 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4425 unsigned DestBits = VT.getScalarType().getSizeInBits();
4426 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4428 if (OpBits == DestBits) {
4429 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4430 // bits, it is already ready.
4431 if (NumSignBits > DestBits-MidBits)
4433 } else if (OpBits < DestBits) {
4434 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4435 // bits, just sext from i32.
4436 if (NumSignBits > OpBits-MidBits)
4437 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, Op);
4439 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4440 // bits, just truncate to i32.
4441 if (NumSignBits > OpBits-MidBits)
4442 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4445 // fold (sext (truncate x)) -> (sextinreg x).
4446 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4447 N0.getValueType())) {
4448 if (OpBits < DestBits)
4449 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
4450 else if (OpBits > DestBits)
4451 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
4452 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, Op,
4453 DAG.getValueType(N0.getValueType()));
4457 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4458 // None of the supported targets knows how to perform load and sign extend
4459 // on vectors in one instruction. We only perform this transformation on
4461 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4462 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4463 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
4464 bool DoXform = true;
4465 SmallVector<SDNode*, 4> SetCCs;
4466 if (!N0.hasOneUse())
4467 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
4469 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4470 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
4472 LN0->getBasePtr(), LN0->getPointerInfo(),
4474 LN0->isVolatile(), LN0->isNonTemporal(),
4475 LN0->getAlignment());
4476 CombineTo(N, ExtLoad);
4477 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4478 N0.getValueType(), ExtLoad);
4479 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4480 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4482 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4486 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
4487 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
4488 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4489 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4490 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4491 EVT MemVT = LN0->getMemoryVT();
4492 if ((!LegalOperations && !LN0->isVolatile()) ||
4493 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
4494 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
4496 LN0->getBasePtr(), LN0->getPointerInfo(),
4498 LN0->isVolatile(), LN0->isNonTemporal(),
4499 LN0->getAlignment());
4500 CombineTo(N, ExtLoad);
4501 CombineTo(N0.getNode(),
4502 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4503 N0.getValueType(), ExtLoad),
4504 ExtLoad.getValue(1));
4505 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4509 // fold (sext (and/or/xor (load x), cst)) ->
4510 // (and/or/xor (sextload x), (sext cst))
4511 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4512 N0.getOpcode() == ISD::XOR) &&
4513 isa<LoadSDNode>(N0.getOperand(0)) &&
4514 N0.getOperand(1).getOpcode() == ISD::Constant &&
4515 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
4516 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4517 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4518 if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
4519 bool DoXform = true;
4520 SmallVector<SDNode*, 4> SetCCs;
4521 if (!N0.hasOneUse())
4522 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
4525 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
4526 LN0->getChain(), LN0->getBasePtr(),
4527 LN0->getPointerInfo(),
4530 LN0->isNonTemporal(),
4531 LN0->getAlignment());
4532 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4533 Mask = Mask.sext(VT.getSizeInBits());
4534 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
4535 ExtLoad, DAG.getConstant(Mask, VT));
4536 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4537 SDLoc(N0.getOperand(0)),
4538 N0.getOperand(0).getValueType(), ExtLoad);
4540 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4541 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4543 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4548 if (N0.getOpcode() == ISD::SETCC) {
4549 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
4550 // Only do this before legalize for now.
4551 if (VT.isVector() && !LegalOperations &&
4552 TLI.getBooleanContents(true) ==
4553 TargetLowering::ZeroOrNegativeOneBooleanContent) {
4554 EVT N0VT = N0.getOperand(0).getValueType();
4555 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
4556 // of the same size as the compared operands. Only optimize sext(setcc())
4557 // if this is the case.
4558 EVT SVT = getSetCCResultType(N0VT);
4560 // We know that the # elements of the results is the same as the
4561 // # elements of the compare (and the # elements of the compare result
4562 // for that matter). Check to see that they are the same size. If so,
4563 // we know that the element size of the sext'd result matches the
4564 // element size of the compare operands.
4565 if (VT.getSizeInBits() == SVT.getSizeInBits())
4566 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
4568 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4570 // If the desired elements are smaller or larger than the source
4571 // elements we can use a matching integer vector type and then
4572 // truncate/sign extend
4573 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
4574 if (SVT == MatchingVectorType) {
4575 SDValue VsetCC = DAG.getSetCC(SDLoc(N), MatchingVectorType,
4576 N0.getOperand(0), N0.getOperand(1),
4577 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4578 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
4582 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
4583 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
4585 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
4587 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
4588 NegOne, DAG.getConstant(0, VT),
4589 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4590 if (SCC.getNode()) return SCC;
4591 if (!VT.isVector() &&
4592 (!LegalOperations ||
4593 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(VT)))) {
4594 return DAG.getSelect(SDLoc(N), VT,
4595 DAG.getSetCC(SDLoc(N),
4596 getSetCCResultType(VT),
4597 N0.getOperand(0), N0.getOperand(1),
4598 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4599 NegOne, DAG.getConstant(0, VT));
4603 // fold (sext x) -> (zext x) if the sign bit is known zero.
4604 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
4605 DAG.SignBitIsZero(N0))
4606 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
4611 // isTruncateOf - If N is a truncate of some other value, return true, record
4612 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
4613 // This function computes KnownZero to avoid a duplicated call to
4614 // ComputeMaskedBits in the caller.
4615 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
4618 if (N->getOpcode() == ISD::TRUNCATE) {
4619 Op = N->getOperand(0);
4620 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4624 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
4625 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
4628 SDValue Op0 = N->getOperand(0);
4629 SDValue Op1 = N->getOperand(1);
4630 assert(Op0.getValueType() == Op1.getValueType());
4632 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
4633 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
4634 if (COp0 && COp0->isNullValue())
4636 else if (COp1 && COp1->isNullValue())
4641 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4643 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
4649 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
4650 SDValue N0 = N->getOperand(0);
4651 EVT VT = N->getValueType(0);
4653 // fold (zext c1) -> c1
4654 if (isa<ConstantSDNode>(N0))
4655 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
4656 // fold (zext (zext x)) -> (zext x)
4657 // fold (zext (aext x)) -> (zext x)
4658 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4659 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
4662 // fold (zext (truncate x)) -> (zext x) or
4663 // (zext (truncate x)) -> (truncate x)
4664 // This is valid when the truncated bits of x are already zero.
4665 // FIXME: We should extend this to work for vectors too.
4668 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
4669 APInt TruncatedBits =
4670 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
4671 APInt(Op.getValueSizeInBits(), 0) :
4672 APInt::getBitsSet(Op.getValueSizeInBits(),
4673 N0.getValueSizeInBits(),
4674 std::min(Op.getValueSizeInBits(),
4675 VT.getSizeInBits()));
4676 if (TruncatedBits == (KnownZero & TruncatedBits)) {
4677 if (VT.bitsGT(Op.getValueType()))
4678 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, Op);
4679 if (VT.bitsLT(Op.getValueType()))
4680 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4686 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4687 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
4688 if (N0.getOpcode() == ISD::TRUNCATE) {
4689 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4690 if (NarrowLoad.getNode()) {
4691 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4692 if (NarrowLoad.getNode() != N0.getNode()) {
4693 CombineTo(N0.getNode(), NarrowLoad);
4694 // CombineTo deleted the truncate, if needed, but not what's under it.
4697 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4701 // fold (zext (truncate x)) -> (and x, mask)
4702 if (N0.getOpcode() == ISD::TRUNCATE &&
4703 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
4705 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4706 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
4707 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4708 if (NarrowLoad.getNode()) {
4709 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4710 if (NarrowLoad.getNode() != N0.getNode()) {
4711 CombineTo(N0.getNode(), NarrowLoad);
4712 // CombineTo deleted the truncate, if needed, but not what's under it.
4715 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4718 SDValue Op = N0.getOperand(0);
4719 if (Op.getValueType().bitsLT(VT)) {
4720 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Op);
4721 AddToWorkList(Op.getNode());
4722 } else if (Op.getValueType().bitsGT(VT)) {
4723 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4724 AddToWorkList(Op.getNode());
4726 return DAG.getZeroExtendInReg(Op, SDLoc(N),
4727 N0.getValueType().getScalarType());
4730 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
4731 // if either of the casts is not free.
4732 if (N0.getOpcode() == ISD::AND &&
4733 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4734 N0.getOperand(1).getOpcode() == ISD::Constant &&
4735 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4736 N0.getValueType()) ||
4737 !TLI.isZExtFree(N0.getValueType(), VT))) {
4738 SDValue X = N0.getOperand(0).getOperand(0);
4739 if (X.getValueType().bitsLT(VT)) {
4740 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(X), VT, X);
4741 } else if (X.getValueType().bitsGT(VT)) {
4742 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
4744 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4745 Mask = Mask.zext(VT.getSizeInBits());
4746 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4747 X, DAG.getConstant(Mask, VT));
4750 // fold (zext (load x)) -> (zext (truncate (zextload x)))
4751 // None of the supported targets knows how to perform load and vector_zext
4752 // on vectors in one instruction. We only perform this transformation on
4754 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4755 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4756 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
4757 bool DoXform = true;
4758 SmallVector<SDNode*, 4> SetCCs;
4759 if (!N0.hasOneUse())
4760 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
4762 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4763 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
4765 LN0->getBasePtr(), LN0->getPointerInfo(),
4767 LN0->isVolatile(), LN0->isNonTemporal(),
4768 LN0->getAlignment());
4769 CombineTo(N, ExtLoad);
4770 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4771 N0.getValueType(), ExtLoad);
4772 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4774 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4776 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4780 // fold (zext (and/or/xor (load x), cst)) ->
4781 // (and/or/xor (zextload x), (zext cst))
4782 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4783 N0.getOpcode() == ISD::XOR) &&
4784 isa<LoadSDNode>(N0.getOperand(0)) &&
4785 N0.getOperand(1).getOpcode() == ISD::Constant &&
4786 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
4787 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4788 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4789 if (LN0->getExtensionType() != ISD::SEXTLOAD) {
4790 bool DoXform = true;
4791 SmallVector<SDNode*, 4> SetCCs;
4792 if (!N0.hasOneUse())
4793 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
4796 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
4797 LN0->getChain(), LN0->getBasePtr(),
4798 LN0->getPointerInfo(),
4801 LN0->isNonTemporal(),
4802 LN0->getAlignment());
4803 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4804 Mask = Mask.zext(VT.getSizeInBits());
4805 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
4806 ExtLoad, DAG.getConstant(Mask, VT));
4807 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4808 SDLoc(N0.getOperand(0)),
4809 N0.getOperand(0).getValueType(), ExtLoad);
4811 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4812 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4814 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4819 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
4820 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
4821 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4822 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4823 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4824 EVT MemVT = LN0->getMemoryVT();
4825 if ((!LegalOperations && !LN0->isVolatile()) ||
4826 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
4827 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
4829 LN0->getBasePtr(), LN0->getPointerInfo(),
4831 LN0->isVolatile(), LN0->isNonTemporal(),
4832 LN0->getAlignment());
4833 CombineTo(N, ExtLoad);
4834 CombineTo(N0.getNode(),
4835 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
4837 ExtLoad.getValue(1));
4838 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4842 if (N0.getOpcode() == ISD::SETCC) {
4843 if (!LegalOperations && VT.isVector()) {
4844 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
4845 // Only do this before legalize for now.
4846 EVT N0VT = N0.getOperand(0).getValueType();
4847 EVT EltVT = VT.getVectorElementType();
4848 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
4849 DAG.getConstant(1, EltVT));
4850 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4851 // We know that the # elements of the results is the same as the
4852 // # elements of the compare (and the # elements of the compare result
4853 // for that matter). Check to see that they are the same size. If so,
4854 // we know that the element size of the sext'd result matches the
4855 // element size of the compare operands.
4856 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4857 DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
4859 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4860 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT,
4861 &OneOps[0], OneOps.size()));
4863 // If the desired elements are smaller or larger than the source
4864 // elements we can use a matching integer vector type and then
4865 // truncate/sign extend
4866 EVT MatchingElementType =
4867 EVT::getIntegerVT(*DAG.getContext(),
4868 N0VT.getScalarType().getSizeInBits());
4869 EVT MatchingVectorType =
4870 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4871 N0VT.getVectorNumElements());
4873 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
4875 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4876 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4877 DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT),
4878 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT,
4879 &OneOps[0], OneOps.size()));
4882 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4884 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
4885 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4886 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4887 if (SCC.getNode()) return SCC;
4890 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
4891 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
4892 isa<ConstantSDNode>(N0.getOperand(1)) &&
4893 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
4895 SDValue ShAmt = N0.getOperand(1);
4896 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
4897 if (N0.getOpcode() == ISD::SHL) {
4898 SDValue InnerZExt = N0.getOperand(0);
4899 // If the original shl may be shifting out bits, do not perform this
4901 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
4902 InnerZExt.getOperand(0).getValueType().getSizeInBits();
4903 if (ShAmtVal > KnownZeroBits)
4909 // Ensure that the shift amount is wide enough for the shifted value.
4910 if (VT.getSizeInBits() >= 256)
4911 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
4913 return DAG.getNode(N0.getOpcode(), DL, VT,
4914 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
4921 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
4922 SDValue N0 = N->getOperand(0);
4923 EVT VT = N->getValueType(0);
4925 // fold (aext c1) -> c1
4926 if (isa<ConstantSDNode>(N0))
4927 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, N0);
4928 // fold (aext (aext x)) -> (aext x)
4929 // fold (aext (zext x)) -> (zext x)
4930 // fold (aext (sext x)) -> (sext x)
4931 if (N0.getOpcode() == ISD::ANY_EXTEND ||
4932 N0.getOpcode() == ISD::ZERO_EXTEND ||
4933 N0.getOpcode() == ISD::SIGN_EXTEND)
4934 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
4936 // fold (aext (truncate (load x))) -> (aext (smaller load x))
4937 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
4938 if (N0.getOpcode() == ISD::TRUNCATE) {
4939 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4940 if (NarrowLoad.getNode()) {
4941 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4942 if (NarrowLoad.getNode() != N0.getNode()) {
4943 CombineTo(N0.getNode(), NarrowLoad);
4944 // CombineTo deleted the truncate, if needed, but not what's under it.
4947 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4951 // fold (aext (truncate x))
4952 if (N0.getOpcode() == ISD::TRUNCATE) {
4953 SDValue TruncOp = N0.getOperand(0);
4954 if (TruncOp.getValueType() == VT)
4955 return TruncOp; // x iff x size == zext size.
4956 if (TruncOp.getValueType().bitsGT(VT))
4957 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, TruncOp);
4958 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, TruncOp);
4961 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
4962 // if the trunc is not free.
4963 if (N0.getOpcode() == ISD::AND &&
4964 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4965 N0.getOperand(1).getOpcode() == ISD::Constant &&
4966 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4967 N0.getValueType())) {
4968 SDValue X = N0.getOperand(0).getOperand(0);
4969 if (X.getValueType().bitsLT(VT)) {
4970 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, X);
4971 } else if (X.getValueType().bitsGT(VT)) {
4972 X = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, X);
4974 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4975 Mask = Mask.zext(VT.getSizeInBits());
4976 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4977 X, DAG.getConstant(Mask, VT));
4980 // fold (aext (load x)) -> (aext (truncate (extload x)))
4981 // None of the supported targets knows how to perform load and any_ext
4982 // on vectors in one instruction. We only perform this transformation on
4984 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4985 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4986 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
4987 bool DoXform = true;
4988 SmallVector<SDNode*, 4> SetCCs;
4989 if (!N0.hasOneUse())
4990 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
4992 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4993 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
4995 LN0->getBasePtr(), LN0->getPointerInfo(),
4997 LN0->isVolatile(), LN0->isNonTemporal(),
4998 LN0->getAlignment());
4999 CombineTo(N, ExtLoad);
5000 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5001 N0.getValueType(), ExtLoad);
5002 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5003 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5005 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5009 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
5010 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
5011 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
5012 if (N0.getOpcode() == ISD::LOAD &&
5013 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5015 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5016 EVT MemVT = LN0->getMemoryVT();
5017 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(N),
5018 VT, LN0->getChain(), LN0->getBasePtr(),
5019 LN0->getPointerInfo(), MemVT,
5020 LN0->isVolatile(), LN0->isNonTemporal(),
5021 LN0->getAlignment());
5022 CombineTo(N, ExtLoad);
5023 CombineTo(N0.getNode(),
5024 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5025 N0.getValueType(), ExtLoad),
5026 ExtLoad.getValue(1));
5027 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5030 if (N0.getOpcode() == ISD::SETCC) {
5031 // aext(setcc) -> sext_in_reg(vsetcc) for vectors.
5032 // Only do this before legalize for now.
5033 if (VT.isVector() && !LegalOperations) {
5034 EVT N0VT = N0.getOperand(0).getValueType();
5035 // We know that the # elements of the results is the same as the
5036 // # elements of the compare (and the # elements of the compare result
5037 // for that matter). Check to see that they are the same size. If so,
5038 // we know that the element size of the sext'd result matches the
5039 // element size of the compare operands.
5040 if (VT.getSizeInBits() == N0VT.getSizeInBits())
5041 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5043 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5044 // If the desired elements are smaller or larger than the source
5045 // elements we can use a matching integer vector type and then
5046 // truncate/sign extend
5048 EVT MatchingElementType =
5049 EVT::getIntegerVT(*DAG.getContext(),
5050 N0VT.getScalarType().getSizeInBits());
5051 EVT MatchingVectorType =
5052 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
5053 N0VT.getVectorNumElements());
5055 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
5057 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5058 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
5062 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
5064 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
5065 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
5066 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5074 /// GetDemandedBits - See if the specified operand can be simplified with the
5075 /// knowledge that only the bits specified by Mask are used. If so, return the
5076 /// simpler operand, otherwise return a null SDValue.
5077 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
5078 switch (V.getOpcode()) {
5080 case ISD::Constant: {
5081 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
5082 assert(CV != 0 && "Const value should be ConstSDNode.");
5083 const APInt &CVal = CV->getAPIntValue();
5084 APInt NewVal = CVal & Mask;
5086 return DAG.getConstant(NewVal, V.getValueType());
5091 // If the LHS or RHS don't contribute bits to the or, drop them.
5092 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
5093 return V.getOperand(1);
5094 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
5095 return V.getOperand(0);
5098 // Only look at single-use SRLs.
5099 if (!V.getNode()->hasOneUse())
5101 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
5102 // See if we can recursively simplify the LHS.
5103 unsigned Amt = RHSC->getZExtValue();
5105 // Watch out for shift count overflow though.
5106 if (Amt >= Mask.getBitWidth()) break;
5107 APInt NewMask = Mask << Amt;
5108 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
5109 if (SimplifyLHS.getNode())
5110 return DAG.getNode(ISD::SRL, SDLoc(V), V.getValueType(),
5111 SimplifyLHS, V.getOperand(1));
5117 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
5118 /// bits and then truncated to a narrower type and where N is a multiple
5119 /// of number of bits of the narrower type, transform it to a narrower load
5120 /// from address + N / num of bits of new type. If the result is to be
5121 /// extended, also fold the extension to form a extending load.
5122 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
5123 unsigned Opc = N->getOpcode();
5125 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
5126 SDValue N0 = N->getOperand(0);
5127 EVT VT = N->getValueType(0);
5130 // This transformation isn't valid for vector loads.
5134 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
5136 if (Opc == ISD::SIGN_EXTEND_INREG) {
5137 ExtType = ISD::SEXTLOAD;
5138 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
5139 } else if (Opc == ISD::SRL) {
5140 // Another special-case: SRL is basically zero-extending a narrower value.
5141 ExtType = ISD::ZEXTLOAD;
5143 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
5144 if (!N01) return SDValue();
5145 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
5146 VT.getSizeInBits() - N01->getZExtValue());
5148 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5151 unsigned EVTBits = ExtVT.getSizeInBits();
5153 // Do not generate loads of non-round integer types since these can
5154 // be expensive (and would be wrong if the type is not byte sized).
5155 if (!ExtVT.isRound())
5159 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5160 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5161 ShAmt = N01->getZExtValue();
5162 // Is the shift amount a multiple of size of VT?
5163 if ((ShAmt & (EVTBits-1)) == 0) {
5164 N0 = N0.getOperand(0);
5165 // Is the load width a multiple of size of VT?
5166 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5170 // At this point, we must have a load or else we can't do the transform.
5171 if (!isa<LoadSDNode>(N0)) return SDValue();
5173 // Because a SRL must be assumed to *need* to zero-extend the high bits
5174 // (as opposed to anyext the high bits), we can't combine the zextload
5175 // lowering of SRL and an sextload.
5176 if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
5179 // If the shift amount is larger than the input type then we're not
5180 // accessing any of the loaded bytes. If the load was a zextload/extload
5181 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5182 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5187 // If the load is shifted left (and the result isn't shifted back right),
5188 // we can fold the truncate through the shift.
5189 unsigned ShLeftAmt = 0;
5190 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5191 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5192 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5193 ShLeftAmt = N01->getZExtValue();
5194 N0 = N0.getOperand(0);
5198 // If we haven't found a load, we can't narrow it. Don't transform one with
5199 // multiple uses, this would require adding a new load.
5200 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse())
5203 // Don't change the width of a volatile load.
5204 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5205 if (LN0->isVolatile())
5208 // Verify that we are actually reducing a load width here.
5209 if (LN0->getMemoryVT().getSizeInBits() < EVTBits)
5212 // For the transform to be legal, the load must produce only two values
5213 // (the value loaded and the chain). Don't transform a pre-increment
5214 // load, for example, which produces an extra value. Otherwise the
5215 // transformation is not equivalent, and the downstream logic to replace
5216 // uses gets things wrong.
5217 if (LN0->getNumValues() > 2)
5220 // If the load that we're shrinking is an extload and we're not just
5221 // discarding the extension we can't simply shrink the load. Bail.
5222 // TODO: It would be possible to merge the extensions in some cases.
5223 if (LN0->getExtensionType() != ISD::NON_EXTLOAD &&
5224 LN0->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
5227 EVT PtrType = N0.getOperand(1).getValueType();
5229 if (PtrType == MVT::Untyped || PtrType.isExtended())
5230 // It's not possible to generate a constant of extended or untyped type.
5233 // For big endian targets, we need to adjust the offset to the pointer to
5234 // load the correct bytes.
5235 if (TLI.isBigEndian()) {
5236 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5237 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5238 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5241 uint64_t PtrOff = ShAmt / 8;
5242 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5243 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0),
5244 PtrType, LN0->getBasePtr(),
5245 DAG.getConstant(PtrOff, PtrType));
5246 AddToWorkList(NewPtr.getNode());
5249 if (ExtType == ISD::NON_EXTLOAD)
5250 Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
5251 LN0->getPointerInfo().getWithOffset(PtrOff),
5252 LN0->isVolatile(), LN0->isNonTemporal(),
5253 LN0->isInvariant(), NewAlign);
5255 Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
5256 LN0->getPointerInfo().getWithOffset(PtrOff),
5257 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5260 // Replace the old load's chain with the new load's chain.
5261 WorkListRemover DeadNodes(*this);
5262 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5264 // Shift the result left, if we've swallowed a left shift.
5265 SDValue Result = Load;
5266 if (ShLeftAmt != 0) {
5267 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5268 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5270 // If the shift amount is as large as the result size (but, presumably,
5271 // no larger than the source) then the useful bits of the result are
5272 // zero; we can't simply return the shortened shift, because the result
5273 // of that operation is undefined.
5274 if (ShLeftAmt >= VT.getSizeInBits())
5275 Result = DAG.getConstant(0, VT);
5277 Result = DAG.getNode(ISD::SHL, SDLoc(N0), VT,
5278 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5281 // Return the new loaded value.
5285 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5286 SDValue N0 = N->getOperand(0);
5287 SDValue N1 = N->getOperand(1);
5288 EVT VT = N->getValueType(0);
5289 EVT EVT = cast<VTSDNode>(N1)->getVT();
5290 unsigned VTBits = VT.getScalarType().getSizeInBits();
5291 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5293 // fold (sext_in_reg c1) -> c1
5294 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5295 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);
5297 // If the input is already sign extended, just drop the extension.
5298 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5301 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5302 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5303 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
5304 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5305 N0.getOperand(0), N1);
5307 // fold (sext_in_reg (sext x)) -> (sext x)
5308 // fold (sext_in_reg (aext x)) -> (sext x)
5309 // if x is small enough.
5310 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5311 SDValue N00 = N0.getOperand(0);
5312 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5313 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5314 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
5317 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5318 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5319 return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT);
5321 // fold operands of sext_in_reg based on knowledge that the top bits are not
5323 if (SimplifyDemandedBits(SDValue(N, 0)))
5324 return SDValue(N, 0);
5326 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5327 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5328 SDValue NarrowLoad = ReduceLoadWidth(N);
5329 if (NarrowLoad.getNode())
5332 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5333 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5334 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5335 if (N0.getOpcode() == ISD::SRL) {
5336 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5337 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5338 // We can turn this into an SRA iff the input to the SRL is already sign
5340 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5341 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5342 return DAG.getNode(ISD::SRA, SDLoc(N), VT,
5343 N0.getOperand(0), N0.getOperand(1));
5347 // fold (sext_inreg (extload x)) -> (sextload x)
5348 if (ISD::isEXTLoad(N0.getNode()) &&
5349 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5350 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5351 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5352 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5353 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5354 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5356 LN0->getBasePtr(), LN0->getPointerInfo(),
5358 LN0->isVolatile(), LN0->isNonTemporal(),
5359 LN0->getAlignment());
5360 CombineTo(N, ExtLoad);
5361 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5362 AddToWorkList(ExtLoad.getNode());
5363 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5365 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5366 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5368 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5369 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5370 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5371 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5372 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5374 LN0->getBasePtr(), LN0->getPointerInfo(),
5376 LN0->isVolatile(), LN0->isNonTemporal(),
5377 LN0->getAlignment());
5378 CombineTo(N, ExtLoad);
5379 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5380 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5383 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5384 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5385 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5386 N0.getOperand(1), false);
5387 if (BSwap.getNode() != 0)
5388 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5395 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5396 SDValue N0 = N->getOperand(0);
5397 EVT VT = N->getValueType(0);
5398 bool isLE = TLI.isLittleEndian();
5401 if (N0.getValueType() == N->getValueType(0))
5403 // fold (truncate c1) -> c1
5404 if (isa<ConstantSDNode>(N0))
5405 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
5406 // fold (truncate (truncate x)) -> (truncate x)
5407 if (N0.getOpcode() == ISD::TRUNCATE)
5408 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5409 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5410 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5411 N0.getOpcode() == ISD::SIGN_EXTEND ||
5412 N0.getOpcode() == ISD::ANY_EXTEND) {
5413 if (N0.getOperand(0).getValueType().bitsLT(VT))
5414 // if the source is smaller than the dest, we still need an extend
5415 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
5417 if (N0.getOperand(0).getValueType().bitsGT(VT))
5418 // if the source is larger than the dest, than we just need the truncate
5419 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5420 // if the source and dest are the same type, we can drop both the extend
5421 // and the truncate.
5422 return N0.getOperand(0);
5425 // Fold extract-and-trunc into a narrow extract. For example:
5426 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5427 // i32 y = TRUNCATE(i64 x)
5429 // v16i8 b = BITCAST (v2i64 val)
5430 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5432 // Note: We only run this optimization after type legalization (which often
5433 // creates this pattern) and before operation legalization after which
5434 // we need to be more careful about the vector instructions that we generate.
5435 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5436 LegalTypes && !LegalOperations && N0->hasOneUse()) {
5438 EVT VecTy = N0.getOperand(0).getValueType();
5439 EVT ExTy = N0.getValueType();
5440 EVT TrTy = N->getValueType(0);
5442 unsigned NumElem = VecTy.getVectorNumElements();
5443 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5445 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5446 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
5448 SDValue EltNo = N0->getOperand(1);
5449 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
5450 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5451 EVT IndexTy = N0->getOperand(1).getValueType();
5452 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
5454 SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
5455 NVT, N0.getOperand(0));
5457 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
5459 DAG.getConstant(Index, IndexTy));
5463 // Fold a series of buildvector, bitcast, and truncate if possible.
5465 // (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
5466 // (2xi32 (buildvector x, y)).
5467 if (Level == AfterLegalizeVectorOps && VT.isVector() &&
5468 N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
5469 N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
5470 N0.getOperand(0).hasOneUse()) {
5472 SDValue BuildVect = N0.getOperand(0);
5473 EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
5474 EVT TruncVecEltTy = VT.getVectorElementType();
5476 // Check that the element types match.
5477 if (BuildVectEltTy == TruncVecEltTy) {
5478 // Now we only need to compute the offset of the truncated elements.
5479 unsigned BuildVecNumElts = BuildVect.getNumOperands();
5480 unsigned TruncVecNumElts = VT.getVectorNumElements();
5481 unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;
5483 assert((BuildVecNumElts % TruncVecNumElts) == 0 &&
5484 "Invalid number of elements");
5486 SmallVector<SDValue, 8> Opnds;
5487 for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
5488 Opnds.push_back(BuildVect.getOperand(i));
5490 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, &Opnds[0],
5495 // See if we can simplify the input to this truncate through knowledge that
5496 // only the low bits are being used.
5497 // For example "trunc (or (shl x, 8), y)" // -> trunc y
5498 // Currently we only perform this optimization on scalars because vectors
5499 // may have different active low bits.
5500 if (!VT.isVector()) {
5502 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
5503 VT.getSizeInBits()));
5504 if (Shorter.getNode())
5505 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
5507 // fold (truncate (load x)) -> (smaller load x)
5508 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
5509 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
5510 SDValue Reduced = ReduceLoadWidth(N);
5511 if (Reduced.getNode())
5514 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
5515 // where ... are all 'undef'.
5516 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
5517 SmallVector<EVT, 8> VTs;
5520 unsigned NumDefs = 0;
5522 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
5523 SDValue X = N0.getOperand(i);
5524 if (X.getOpcode() != ISD::UNDEF) {
5529 // Stop if more than one members are non-undef.
5532 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
5533 VT.getVectorElementType(),
5534 X.getValueType().getVectorNumElements()));
5538 return DAG.getUNDEF(VT);
5541 assert(V.getNode() && "The single defined operand is empty!");
5542 SmallVector<SDValue, 8> Opnds;
5543 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
5545 Opnds.push_back(DAG.getUNDEF(VTs[i]));
5548 SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
5549 AddToWorkList(NV.getNode());
5550 Opnds.push_back(NV);
5552 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
5553 &Opnds[0], Opnds.size());
5557 // Simplify the operands using demanded-bits information.
5558 if (!VT.isVector() &&
5559 SimplifyDemandedBits(SDValue(N, 0)))
5560 return SDValue(N, 0);
5565 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
5566 SDValue Elt = N->getOperand(i);
5567 if (Elt.getOpcode() != ISD::MERGE_VALUES)
5568 return Elt.getNode();
5569 return Elt.getOperand(Elt.getResNo()).getNode();
5572 /// CombineConsecutiveLoads - build_pair (load, load) -> load
5573 /// if load locations are consecutive.
5574 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
5575 assert(N->getOpcode() == ISD::BUILD_PAIR);
5577 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
5578 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
5579 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
5580 LD1->getPointerInfo().getAddrSpace() !=
5581 LD2->getPointerInfo().getAddrSpace())
5583 EVT LD1VT = LD1->getValueType(0);
5585 if (ISD::isNON_EXTLoad(LD2) &&
5587 // If both are volatile this would reduce the number of volatile loads.
5588 // If one is volatile it might be ok, but play conservative and bail out.
5589 !LD1->isVolatile() &&
5590 !LD2->isVolatile() &&
5591 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
5592 unsigned Align = LD1->getAlignment();
5593 unsigned NewAlign = TLI.getDataLayout()->
5594 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5596 if (NewAlign <= Align &&
5597 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
5598 return DAG.getLoad(VT, SDLoc(N), LD1->getChain(),
5599 LD1->getBasePtr(), LD1->getPointerInfo(),
5600 false, false, false, Align);
5606 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
5607 SDValue N0 = N->getOperand(0);
5608 EVT VT = N->getValueType(0);
5610 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
5611 // Only do this before legalize, since afterward the target may be depending
5612 // on the bitconvert.
5613 // First check to see if this is all constant.
5615 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
5617 bool isSimple = true;
5618 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
5619 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
5620 N0.getOperand(i).getOpcode() != ISD::Constant &&
5621 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
5626 EVT DestEltVT = N->getValueType(0).getVectorElementType();
5627 assert(!DestEltVT.isVector() &&
5628 "Element type of vector ValueType must not be vector!");
5630 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
5633 // If the input is a constant, let getNode fold it.
5634 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
5635 SDValue Res = DAG.getNode(ISD::BITCAST, SDLoc(N), VT, N0);
5636 if (Res.getNode() != N) {
5637 if (!LegalOperations ||
5638 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
5641 // Folding it resulted in an illegal node, and it's too late to
5642 // do that. Clean up the old node and forego the transformation.
5643 // Ideally this won't happen very often, because instcombine
5644 // and the earlier dagcombine runs (where illegal nodes are
5645 // permitted) should have folded most of them already.
5646 DAG.DeleteNode(Res.getNode());
5650 // (conv (conv x, t1), t2) -> (conv x, t2)
5651 if (N0.getOpcode() == ISD::BITCAST)
5652 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT,
5655 // fold (conv (load x)) -> (load (conv*)x)
5656 // If the resultant load doesn't need a higher alignment than the original!
5657 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
5658 // Do not change the width of a volatile load.
5659 !cast<LoadSDNode>(N0)->isVolatile() &&
5660 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
5661 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5662 unsigned Align = TLI.getDataLayout()->
5663 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5664 unsigned OrigAlign = LN0->getAlignment();
5666 if (Align <= OrigAlign) {
5667 SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
5668 LN0->getBasePtr(), LN0->getPointerInfo(),
5669 LN0->isVolatile(), LN0->isNonTemporal(),
5670 LN0->isInvariant(), OrigAlign);
5672 CombineTo(N0.getNode(),
5673 DAG.getNode(ISD::BITCAST, SDLoc(N0),
5674 N0.getValueType(), Load),
5680 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
5681 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
5682 // This often reduces constant pool loads.
5683 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
5684 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
5685 N0.getNode()->hasOneUse() && VT.isInteger() &&
5686 !VT.isVector() && !N0.getValueType().isVector()) {
5687 SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
5689 AddToWorkList(NewConv.getNode());
5691 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5692 if (N0.getOpcode() == ISD::FNEG)
5693 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
5694 NewConv, DAG.getConstant(SignBit, VT));
5695 assert(N0.getOpcode() == ISD::FABS);
5696 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5697 NewConv, DAG.getConstant(~SignBit, VT));
5700 // fold (bitconvert (fcopysign cst, x)) ->
5701 // (or (and (bitconvert x), sign), (and cst, (not sign)))
5702 // Note that we don't handle (copysign x, cst) because this can always be
5703 // folded to an fneg or fabs.
5704 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
5705 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
5706 VT.isInteger() && !VT.isVector()) {
5707 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
5708 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
5709 if (isTypeLegal(IntXVT)) {
5710 SDValue X = DAG.getNode(ISD::BITCAST, SDLoc(N0),
5711 IntXVT, N0.getOperand(1));
5712 AddToWorkList(X.getNode());
5714 // If X has a different width than the result/lhs, sext it or truncate it.
5715 unsigned VTWidth = VT.getSizeInBits();
5716 if (OrigXWidth < VTWidth) {
5717 X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
5718 AddToWorkList(X.getNode());
5719 } else if (OrigXWidth > VTWidth) {
5720 // To get the sign bit in the right place, we have to shift it right
5721 // before truncating.
5722 X = DAG.getNode(ISD::SRL, SDLoc(X),
5723 X.getValueType(), X,
5724 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
5725 AddToWorkList(X.getNode());
5726 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
5727 AddToWorkList(X.getNode());
5730 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5731 X = DAG.getNode(ISD::AND, SDLoc(X), VT,
5732 X, DAG.getConstant(SignBit, VT));
5733 AddToWorkList(X.getNode());
5735 SDValue Cst = DAG.getNode(ISD::BITCAST, SDLoc(N0),
5736 VT, N0.getOperand(0));
5737 Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
5738 Cst, DAG.getConstant(~SignBit, VT));
5739 AddToWorkList(Cst.getNode());
5741 return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
5745 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
5746 if (N0.getOpcode() == ISD::BUILD_PAIR) {
5747 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
5748 if (CombineLD.getNode())
5755 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
5756 EVT VT = N->getValueType(0);
5757 return CombineConsecutiveLoads(N, VT);
5760 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
5761 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
5762 /// destination element value type.
5763 SDValue DAGCombiner::
5764 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
5765 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
5767 // If this is already the right type, we're done.
5768 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
5770 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
5771 unsigned DstBitSize = DstEltVT.getSizeInBits();
5773 // If this is a conversion of N elements of one type to N elements of another
5774 // type, convert each element. This handles FP<->INT cases.
5775 if (SrcBitSize == DstBitSize) {
5776 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5777 BV->getValueType(0).getVectorNumElements());
5779 // Due to the FP element handling below calling this routine recursively,
5780 // we can end up with a scalar-to-vector node here.
5781 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
5782 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
5783 DAG.getNode(ISD::BITCAST, SDLoc(BV),
5784 DstEltVT, BV->getOperand(0)));
5786 SmallVector<SDValue, 8> Ops;
5787 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5788 SDValue Op = BV->getOperand(i);
5789 // If the vector element type is not legal, the BUILD_VECTOR operands
5790 // are promoted and implicitly truncated. Make that explicit here.
5791 if (Op.getValueType() != SrcEltVT)
5792 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
5793 Ops.push_back(DAG.getNode(ISD::BITCAST, SDLoc(BV),
5795 AddToWorkList(Ops.back().getNode());
5797 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5798 &Ops[0], Ops.size());
5801 // Otherwise, we're growing or shrinking the elements. To avoid having to
5802 // handle annoying details of growing/shrinking FP values, we convert them to
5804 if (SrcEltVT.isFloatingPoint()) {
5805 // Convert the input float vector to a int vector where the elements are the
5807 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
5808 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
5809 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
5813 // Now we know the input is an integer vector. If the output is a FP type,
5814 // convert to integer first, then to FP of the right size.
5815 if (DstEltVT.isFloatingPoint()) {
5816 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
5817 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
5818 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
5820 // Next, convert to FP elements of the same size.
5821 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
5824 // Okay, we know the src/dst types are both integers of differing types.
5825 // Handling growing first.
5826 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
5827 if (SrcBitSize < DstBitSize) {
5828 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
5830 SmallVector<SDValue, 8> Ops;
5831 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
5832 i += NumInputsPerOutput) {
5833 bool isLE = TLI.isLittleEndian();
5834 APInt NewBits = APInt(DstBitSize, 0);
5835 bool EltIsUndef = true;
5836 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
5837 // Shift the previously computed bits over.
5838 NewBits <<= SrcBitSize;
5839 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
5840 if (Op.getOpcode() == ISD::UNDEF) continue;
5843 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
5844 zextOrTrunc(SrcBitSize).zext(DstBitSize);
5848 Ops.push_back(DAG.getUNDEF(DstEltVT));
5850 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
5853 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
5854 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5855 &Ops[0], Ops.size());
5858 // Finally, this must be the case where we are shrinking elements: each input
5859 // turns into multiple outputs.
5860 bool isS2V = ISD::isScalarToVector(BV);
5861 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
5862 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5863 NumOutputsPerInput*BV->getNumOperands());
5864 SmallVector<SDValue, 8> Ops;
5866 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5867 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
5868 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
5869 Ops.push_back(DAG.getUNDEF(DstEltVT));
5873 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
5874 getAPIntValue().zextOrTrunc(SrcBitSize);
5876 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
5877 APInt ThisVal = OpVal.trunc(DstBitSize);
5878 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
5879 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
5880 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
5881 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
5883 OpVal = OpVal.lshr(DstBitSize);
5886 // For big endian targets, swap the order of the pieces of each element.
5887 if (TLI.isBigEndian())
5888 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
5891 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5892 &Ops[0], Ops.size());
5895 SDValue DAGCombiner::visitFADD(SDNode *N) {
5896 SDValue N0 = N->getOperand(0);
5897 SDValue N1 = N->getOperand(1);
5898 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5899 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5900 EVT VT = N->getValueType(0);
5903 if (VT.isVector()) {
5904 SDValue FoldedVOp = SimplifyVBinOp(N);
5905 if (FoldedVOp.getNode()) return FoldedVOp;
5908 // fold (fadd c1, c2) -> c1 + c2
5910 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N1);
5911 // canonicalize constant to RHS
5912 if (N0CFP && !N1CFP)
5913 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N0);
5914 // fold (fadd A, 0) -> A
5915 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5916 N1CFP->getValueAPF().isZero())
5918 // fold (fadd A, (fneg B)) -> (fsub A, B)
5919 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5920 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5921 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0,
5922 GetNegatedExpression(N1, DAG, LegalOperations));
5923 // fold (fadd (fneg A), B) -> (fsub B, A)
5924 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5925 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5926 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N1,
5927 GetNegatedExpression(N0, DAG, LegalOperations));
5929 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
5930 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5931 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
5932 isa<ConstantFPSDNode>(N0.getOperand(1)))
5933 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0.getOperand(0),
5934 DAG.getNode(ISD::FADD, SDLoc(N), VT,
5935 N0.getOperand(1), N1));
5937 // No FP constant should be created after legalization as Instruction
5938 // Selection pass has hard time in dealing with FP constant.
5940 // We don't need test this condition for transformation like following, as
5941 // the DAG being transformed implies it is legal to take FP constant as
5944 // (fadd (fmul c, x), x) -> (fmul c+1, x)
5946 bool AllowNewFpConst = (Level < AfterLegalizeDAG);
5948 // If allow, fold (fadd (fneg x), x) -> 0.0
5949 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
5950 N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
5951 return DAG.getConstantFP(0.0, VT);
5953 // If allow, fold (fadd x, (fneg x)) -> 0.0
5954 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
5955 N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
5956 return DAG.getConstantFP(0.0, VT);
5958 // In unsafe math mode, we can fold chains of FADD's of the same value
5959 // into multiplications. This transform is not safe in general because
5960 // we are reducing the number of rounding steps.
5961 if (DAG.getTarget().Options.UnsafeFPMath &&
5962 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
5964 if (N0.getOpcode() == ISD::FMUL) {
5965 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
5966 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
5968 // (fadd (fmul c, x), x) -> (fmul x, c+1)
5969 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
5970 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
5972 DAG.getConstantFP(1.0, VT));
5973 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
5977 // (fadd (fmul x, c), x) -> (fmul x, c+1)
5978 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
5979 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
5981 DAG.getConstantFP(1.0, VT));
5982 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
5986 // (fadd (fmul c, x), (fadd x, x)) -> (fmul x, c+2)
5987 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
5988 N1.getOperand(0) == N1.getOperand(1) &&
5989 N0.getOperand(1) == N1.getOperand(0)) {
5990 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
5992 DAG.getConstantFP(2.0, VT));
5993 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
5994 N0.getOperand(1), NewCFP);
5997 // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
5998 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
5999 N1.getOperand(0) == N1.getOperand(1) &&
6000 N0.getOperand(0) == N1.getOperand(0)) {
6001 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6003 DAG.getConstantFP(2.0, VT));
6004 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6005 N0.getOperand(0), NewCFP);
6009 if (N1.getOpcode() == ISD::FMUL) {
6010 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6011 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
6013 // (fadd x, (fmul c, x)) -> (fmul x, c+1)
6014 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
6015 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6017 DAG.getConstantFP(1.0, VT));
6018 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6022 // (fadd x, (fmul x, c)) -> (fmul x, c+1)
6023 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
6024 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6026 DAG.getConstantFP(1.0, VT));
6027 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6032 // (fadd (fadd x, x), (fmul c, x)) -> (fmul x, c+2)
6033 if (CFP10 && !CFP11 && N0.getOpcode() == ISD::FADD &&
6034 N0.getOperand(0) == N0.getOperand(1) &&
6035 N1.getOperand(1) == N0.getOperand(0)) {
6036 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6038 DAG.getConstantFP(2.0, VT));
6039 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6040 N1.getOperand(1), NewCFP);
6043 // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
6044 if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
6045 N0.getOperand(0) == N0.getOperand(1) &&
6046 N1.getOperand(0) == N0.getOperand(0)) {
6047 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6049 DAG.getConstantFP(2.0, VT));
6050 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6051 N1.getOperand(0), NewCFP);
6055 if (N0.getOpcode() == ISD::FADD && AllowNewFpConst) {
6056 ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
6057 // (fadd (fadd x, x), x) -> (fmul x, 3.0)
6058 if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
6059 (N0.getOperand(0) == N1))
6060 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6061 N1, DAG.getConstantFP(3.0, VT));
6064 if (N1.getOpcode() == ISD::FADD && AllowNewFpConst) {
6065 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6066 // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
6067 if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
6068 N1.getOperand(0) == N0)
6069 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6070 N0, DAG.getConstantFP(3.0, VT));
6073 // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
6074 if (AllowNewFpConst &&
6075 N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
6076 N0.getOperand(0) == N0.getOperand(1) &&
6077 N1.getOperand(0) == N1.getOperand(1) &&
6078 N0.getOperand(0) == N1.getOperand(0))
6079 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6081 DAG.getConstantFP(4.0, VT));
6084 // FADD -> FMA combines:
6085 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6086 DAG.getTarget().Options.UnsafeFPMath) &&
6087 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6088 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6090 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
6091 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6092 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6093 N0.getOperand(0), N0.getOperand(1), N1);
6095 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
6096 // Note: Commutes FADD operands.
6097 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6098 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6099 N1.getOperand(0), N1.getOperand(1), N0);
6105 SDValue DAGCombiner::visitFSUB(SDNode *N) {
6106 SDValue N0 = N->getOperand(0);
6107 SDValue N1 = N->getOperand(1);
6108 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6109 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6110 EVT VT = N->getValueType(0);
6114 if (VT.isVector()) {
6115 SDValue FoldedVOp = SimplifyVBinOp(N);
6116 if (FoldedVOp.getNode()) return FoldedVOp;
6119 // fold (fsub c1, c2) -> c1-c2
6121 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0, N1);
6122 // fold (fsub A, 0) -> A
6123 if (DAG.getTarget().Options.UnsafeFPMath &&
6124 N1CFP && N1CFP->getValueAPF().isZero())
6126 // fold (fsub 0, B) -> -B
6127 if (DAG.getTarget().Options.UnsafeFPMath &&
6128 N0CFP && N0CFP->getValueAPF().isZero()) {
6129 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6130 return GetNegatedExpression(N1, DAG, LegalOperations);
6131 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6132 return DAG.getNode(ISD::FNEG, dl, VT, N1);
6134 // fold (fsub A, (fneg B)) -> (fadd A, B)
6135 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6136 return DAG.getNode(ISD::FADD, dl, VT, N0,
6137 GetNegatedExpression(N1, DAG, LegalOperations));
6139 // If 'unsafe math' is enabled, fold
6140 // (fsub x, x) -> 0.0 &
6141 // (fsub x, (fadd x, y)) -> (fneg y) &
6142 // (fsub x, (fadd y, x)) -> (fneg y)
6143 if (DAG.getTarget().Options.UnsafeFPMath) {
6145 return DAG.getConstantFP(0.0f, VT);
6147 if (N1.getOpcode() == ISD::FADD) {
6148 SDValue N10 = N1->getOperand(0);
6149 SDValue N11 = N1->getOperand(1);
6151 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
6152 &DAG.getTarget().Options))
6153 return GetNegatedExpression(N11, DAG, LegalOperations);
6155 if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
6156 &DAG.getTarget().Options))
6157 return GetNegatedExpression(N10, DAG, LegalOperations);
6161 // FSUB -> FMA combines:
6162 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6163 DAG.getTarget().Options.UnsafeFPMath) &&
6164 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6165 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6167 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
6168 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6169 return DAG.getNode(ISD::FMA, dl, VT,
6170 N0.getOperand(0), N0.getOperand(1),
6171 DAG.getNode(ISD::FNEG, dl, VT, N1));
6173 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
6174 // Note: Commutes FSUB operands.
6175 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6176 return DAG.getNode(ISD::FMA, dl, VT,
6177 DAG.getNode(ISD::FNEG, dl, VT,
6179 N1.getOperand(1), N0);
6181 // fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
6182 if (N0.getOpcode() == ISD::FNEG &&
6183 N0.getOperand(0).getOpcode() == ISD::FMUL &&
6184 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
6185 SDValue N00 = N0.getOperand(0).getOperand(0);
6186 SDValue N01 = N0.getOperand(0).getOperand(1);
6187 return DAG.getNode(ISD::FMA, dl, VT,
6188 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
6189 DAG.getNode(ISD::FNEG, dl, VT, N1));
6196 SDValue DAGCombiner::visitFMUL(SDNode *N) {
6197 SDValue N0 = N->getOperand(0);
6198 SDValue N1 = N->getOperand(1);
6199 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6200 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6201 EVT VT = N->getValueType(0);
6202 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6205 if (VT.isVector()) {
6206 SDValue FoldedVOp = SimplifyVBinOp(N);
6207 if (FoldedVOp.getNode()) return FoldedVOp;
6210 // fold (fmul c1, c2) -> c1*c2
6212 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0, N1);
6213 // canonicalize constant to RHS
6214 if (N0CFP && !N1CFP)
6215 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1, N0);
6216 // fold (fmul A, 0) -> 0
6217 if (DAG.getTarget().Options.UnsafeFPMath &&
6218 N1CFP && N1CFP->getValueAPF().isZero())
6220 // fold (fmul A, 0) -> 0, vector edition.
6221 if (DAG.getTarget().Options.UnsafeFPMath &&
6222 ISD::isBuildVectorAllZeros(N1.getNode()))
6224 // fold (fmul A, 1.0) -> A
6225 if (N1CFP && N1CFP->isExactlyValue(1.0))
6227 // fold (fmul X, 2.0) -> (fadd X, X)
6228 if (N1CFP && N1CFP->isExactlyValue(+2.0))
6229 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N0);
6230 // fold (fmul X, -1.0) -> (fneg X)
6231 if (N1CFP && N1CFP->isExactlyValue(-1.0))
6232 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6233 return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
6235 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
6236 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6237 &DAG.getTarget().Options)) {
6238 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6239 &DAG.getTarget().Options)) {
6240 // Both can be negated for free, check to see if at least one is cheaper
6242 if (LHSNeg == 2 || RHSNeg == 2)
6243 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6244 GetNegatedExpression(N0, DAG, LegalOperations),
6245 GetNegatedExpression(N1, DAG, LegalOperations));
6249 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
6250 if (DAG.getTarget().Options.UnsafeFPMath &&
6251 N1CFP && N0.getOpcode() == ISD::FMUL &&
6252 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
6253 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
6254 DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6255 N0.getOperand(1), N1));
6260 SDValue DAGCombiner::visitFMA(SDNode *N) {
6261 SDValue N0 = N->getOperand(0);
6262 SDValue N1 = N->getOperand(1);
6263 SDValue N2 = N->getOperand(2);
6264 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6265 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6266 EVT VT = N->getValueType(0);
6269 if (DAG.getTarget().Options.UnsafeFPMath) {
6270 if (N0CFP && N0CFP->isZero())
6272 if (N1CFP && N1CFP->isZero())
6275 if (N0CFP && N0CFP->isExactlyValue(1.0))
6276 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
6277 if (N1CFP && N1CFP->isExactlyValue(1.0))
6278 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);
6280 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6281 if (N0CFP && !N1CFP)
6282 return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
6284 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6285 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6286 N2.getOpcode() == ISD::FMUL &&
6287 N0 == N2.getOperand(0) &&
6288 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6289 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6290 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6294 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6295 if (DAG.getTarget().Options.UnsafeFPMath &&
6296 N0.getOpcode() == ISD::FMUL && N1CFP &&
6297 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6298 return DAG.getNode(ISD::FMA, dl, VT,
6300 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6304 // (fma x, 1, y) -> (fadd x, y)
6305 // (fma x, -1, y) -> (fadd (fneg x), y)
6307 if (N1CFP->isExactlyValue(1.0))
6308 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6310 if (N1CFP->isExactlyValue(-1.0) &&
6311 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6312 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6313 AddToWorkList(RHSNeg.getNode());
6314 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6318 // (fma x, c, x) -> (fmul x, (c+1))
6319 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2)
6320 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6321 DAG.getNode(ISD::FADD, dl, VT,
6322 N1, DAG.getConstantFP(1.0, VT)));
6324 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6325 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6326 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
6327 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6328 DAG.getNode(ISD::FADD, dl, VT,
6329 N1, DAG.getConstantFP(-1.0, VT)));
6335 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6336 SDValue N0 = N->getOperand(0);
6337 SDValue N1 = N->getOperand(1);
6338 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6339 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6340 EVT VT = N->getValueType(0);
6341 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6344 if (VT.isVector()) {
6345 SDValue FoldedVOp = SimplifyVBinOp(N);
6346 if (FoldedVOp.getNode()) return FoldedVOp;
6349 // fold (fdiv c1, c2) -> c1/c2
6351 return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
6353 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6354 if (N1CFP && DAG.getTarget().Options.UnsafeFPMath) {
6355 // Compute the reciprocal 1.0 / c2.
6356 APFloat N1APF = N1CFP->getValueAPF();
6357 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6358 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6359 // Only do the transform if the reciprocal is a legal fp immediate that
6360 // isn't too nasty (eg NaN, denormal, ...).
6361 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6362 (!LegalOperations ||
6363 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6364 // backend)... we should handle this gracefully after Legalize.
6365 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6366 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6367 TLI.isFPImmLegal(Recip, VT)))
6368 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0,
6369 DAG.getConstantFP(Recip, VT));
6372 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6373 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6374 &DAG.getTarget().Options)) {
6375 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6376 &DAG.getTarget().Options)) {
6377 // Both can be negated for free, check to see if at least one is cheaper
6379 if (LHSNeg == 2 || RHSNeg == 2)
6380 return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
6381 GetNegatedExpression(N0, DAG, LegalOperations),
6382 GetNegatedExpression(N1, DAG, LegalOperations));
6389 SDValue DAGCombiner::visitFREM(SDNode *N) {
6390 SDValue N0 = N->getOperand(0);
6391 SDValue N1 = N->getOperand(1);
6392 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6393 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6394 EVT VT = N->getValueType(0);
6396 // fold (frem c1, c2) -> fmod(c1,c2)
6398 return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1);
6403 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6404 SDValue N0 = N->getOperand(0);
6405 SDValue N1 = N->getOperand(1);
6406 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6407 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6408 EVT VT = N->getValueType(0);
6410 if (N0CFP && N1CFP) // Constant fold
6411 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);
6414 const APFloat& V = N1CFP->getValueAPF();
6415 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6416 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6417 if (!V.isNegative()) {
6418 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6419 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6421 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6422 return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
6423 DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
6427 // copysign(fabs(x), y) -> copysign(x, y)
6428 // copysign(fneg(x), y) -> copysign(x, y)
6429 // copysign(copysign(x,z), y) -> copysign(x, y)
6430 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
6431 N0.getOpcode() == ISD::FCOPYSIGN)
6432 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6433 N0.getOperand(0), N1);
6435 // copysign(x, abs(y)) -> abs(x)
6436 if (N1.getOpcode() == ISD::FABS)
6437 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6439 // copysign(x, copysign(y,z)) -> copysign(x, z)
6440 if (N1.getOpcode() == ISD::FCOPYSIGN)
6441 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6442 N0, N1.getOperand(1));
6444 // copysign(x, fp_extend(y)) -> copysign(x, y)
6445 // copysign(x, fp_round(y)) -> copysign(x, y)
6446 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
6447 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6448 N0, N1.getOperand(0));
6453 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
6454 SDValue N0 = N->getOperand(0);
6455 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6456 EVT VT = N->getValueType(0);
6457 EVT OpVT = N0.getValueType();
6459 // fold (sint_to_fp c1) -> c1fp
6461 // ...but only if the target supports immediate floating-point values
6462 (!LegalOperations ||
6463 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6464 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
6466 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
6467 // but UINT_TO_FP is legal on this target, try to convert.
6468 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
6469 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
6470 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
6471 if (DAG.SignBitIsZero(N0))
6472 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
6475 // The next optimizations are desireable only if SELECT_CC can be lowered.
6476 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6477 // having to say they don't support SELECT_CC on every type the DAG knows
6478 // about, since there is no way to mark an opcode illegal at all value types
6479 // (See also visitSELECT)
6480 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6481 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6482 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
6484 (!LegalOperations ||
6485 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6487 { N0.getOperand(0), N0.getOperand(1),
6488 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
6490 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6493 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
6494 // (select_cc x, y, 1.0, 0.0,, cc)
6495 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
6496 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
6497 (!LegalOperations ||
6498 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6500 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
6501 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
6502 N0.getOperand(0).getOperand(2) };
6503 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6510 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
6511 SDValue N0 = N->getOperand(0);
6512 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6513 EVT VT = N->getValueType(0);
6514 EVT OpVT = N0.getValueType();
6516 // fold (uint_to_fp c1) -> c1fp
6518 // ...but only if the target supports immediate floating-point values
6519 (!LegalOperations ||
6520 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6521 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
6523 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
6524 // but SINT_TO_FP is legal on this target, try to convert.
6525 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
6526 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
6527 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
6528 if (DAG.SignBitIsZero(N0))
6529 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
6532 // The next optimizations are desireable only if SELECT_CC can be lowered.
6533 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6534 // having to say they don't support SELECT_CC on every type the DAG knows
6535 // about, since there is no way to mark an opcode illegal at all value types
6536 // (See also visitSELECT)
6537 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6538 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6540 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
6541 (!LegalOperations ||
6542 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6544 { N0.getOperand(0), N0.getOperand(1),
6545 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
6547 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6554 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
6555 SDValue N0 = N->getOperand(0);
6556 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6557 EVT VT = N->getValueType(0);
6559 // fold (fp_to_sint c1fp) -> c1
6561 return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
6566 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
6567 SDValue N0 = N->getOperand(0);
6568 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6569 EVT VT = N->getValueType(0);
6571 // fold (fp_to_uint c1fp) -> c1
6573 return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);
6578 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
6579 SDValue N0 = N->getOperand(0);
6580 SDValue N1 = N->getOperand(1);
6581 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6582 EVT VT = N->getValueType(0);
6584 // fold (fp_round c1fp) -> c1fp
6586 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);
6588 // fold (fp_round (fp_extend x)) -> x
6589 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
6590 return N0.getOperand(0);
6592 // fold (fp_round (fp_round x)) -> (fp_round x)
6593 if (N0.getOpcode() == ISD::FP_ROUND) {
6594 // This is a value preserving truncation if both round's are.
6595 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
6596 N0.getNode()->getConstantOperandVal(1) == 1;
6597 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0.getOperand(0),
6598 DAG.getIntPtrConstant(IsTrunc));
6601 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
6602 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
6603 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
6604 N0.getOperand(0), N1);
6605 AddToWorkList(Tmp.getNode());
6606 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6607 Tmp, N0.getOperand(1));
6613 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
6614 SDValue N0 = N->getOperand(0);
6615 EVT VT = N->getValueType(0);
6616 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6617 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6619 // fold (fp_round_inreg c1fp) -> c1fp
6620 if (N0CFP && isTypeLegal(EVT)) {
6621 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
6622 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, Round);
6628 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
6629 SDValue N0 = N->getOperand(0);
6630 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6631 EVT VT = N->getValueType(0);
6633 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
6634 if (N->hasOneUse() &&
6635 N->use_begin()->getOpcode() == ISD::FP_ROUND)
6638 // fold (fp_extend c1fp) -> c1fp
6640 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);
6642 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
6644 if (N0.getOpcode() == ISD::FP_ROUND
6645 && N0.getNode()->getConstantOperandVal(1) == 1) {
6646 SDValue In = N0.getOperand(0);
6647 if (In.getValueType() == VT) return In;
6648 if (VT.bitsLT(In.getValueType()))
6649 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
6650 In, N0.getOperand(1));
6651 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
6654 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
6655 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
6656 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6657 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
6658 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6659 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
6661 LN0->getBasePtr(), LN0->getPointerInfo(),
6663 LN0->isVolatile(), LN0->isNonTemporal(),
6664 LN0->getAlignment());
6665 CombineTo(N, ExtLoad);
6666 CombineTo(N0.getNode(),
6667 DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
6668 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
6669 ExtLoad.getValue(1));
6670 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6676 SDValue DAGCombiner::visitFNEG(SDNode *N) {
6677 SDValue N0 = N->getOperand(0);
6678 EVT VT = N->getValueType(0);
6680 if (VT.isVector()) {
6681 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6682 if (FoldedVOp.getNode()) return FoldedVOp;
6685 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
6686 &DAG.getTarget().Options))
6687 return GetNegatedExpression(N0, DAG, LegalOperations);
6689 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
6690 // constant pool values.
6691 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
6693 N0.getNode()->hasOneUse() &&
6694 N0.getOperand(0).getValueType().isInteger()) {
6695 SDValue Int = N0.getOperand(0);
6696 EVT IntVT = Int.getValueType();
6697 if (IntVT.isInteger() && !IntVT.isVector()) {
6698 Int = DAG.getNode(ISD::XOR, SDLoc(N0), IntVT, Int,
6699 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6700 AddToWorkList(Int.getNode());
6701 return DAG.getNode(ISD::BITCAST, SDLoc(N),
6706 // (fneg (fmul c, x)) -> (fmul -c, x)
6707 if (N0.getOpcode() == ISD::FMUL) {
6708 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6710 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6712 DAG.getNode(ISD::FNEG, SDLoc(N), VT,
6719 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
6720 SDValue N0 = N->getOperand(0);
6721 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6722 EVT VT = N->getValueType(0);
6724 // fold (fceil c1) -> fceil(c1)
6726 return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
6731 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
6732 SDValue N0 = N->getOperand(0);
6733 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6734 EVT VT = N->getValueType(0);
6736 // fold (ftrunc c1) -> ftrunc(c1)
6738 return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
6743 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
6744 SDValue N0 = N->getOperand(0);
6745 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6746 EVT VT = N->getValueType(0);
6748 // fold (ffloor c1) -> ffloor(c1)
6750 return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
6755 SDValue DAGCombiner::visitFABS(SDNode *N) {
6756 SDValue N0 = N->getOperand(0);
6757 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6758 EVT VT = N->getValueType(0);
6760 if (VT.isVector()) {
6761 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6762 if (FoldedVOp.getNode()) return FoldedVOp;
6765 // fold (fabs c1) -> fabs(c1)
6767 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6768 // fold (fabs (fabs x)) -> (fabs x)
6769 if (N0.getOpcode() == ISD::FABS)
6770 return N->getOperand(0);
6771 // fold (fabs (fneg x)) -> (fabs x)
6772 // fold (fabs (fcopysign x, y)) -> (fabs x)
6773 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
6774 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));
6776 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
6777 // constant pool values.
6778 if (!TLI.isFAbsFree(VT) &&
6779 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
6780 N0.getOperand(0).getValueType().isInteger() &&
6781 !N0.getOperand(0).getValueType().isVector()) {
6782 SDValue Int = N0.getOperand(0);
6783 EVT IntVT = Int.getValueType();
6784 if (IntVT.isInteger() && !IntVT.isVector()) {
6785 Int = DAG.getNode(ISD::AND, SDLoc(N0), IntVT, Int,
6786 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6787 AddToWorkList(Int.getNode());
6788 return DAG.getNode(ISD::BITCAST, SDLoc(N),
6789 N->getValueType(0), Int);
6796 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
6797 SDValue Chain = N->getOperand(0);
6798 SDValue N1 = N->getOperand(1);
6799 SDValue N2 = N->getOperand(2);
6801 // If N is a constant we could fold this into a fallthrough or unconditional
6802 // branch. However that doesn't happen very often in normal code, because
6803 // Instcombine/SimplifyCFG should have handled the available opportunities.
6804 // If we did this folding here, it would be necessary to update the
6805 // MachineBasicBlock CFG, which is awkward.
6807 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
6809 if (N1.getOpcode() == ISD::SETCC &&
6810 TLI.isOperationLegalOrCustom(ISD::BR_CC,
6811 N1.getOperand(0).getValueType())) {
6812 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
6813 Chain, N1.getOperand(2),
6814 N1.getOperand(0), N1.getOperand(1), N2);
6817 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
6818 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
6819 (N1.getOperand(0).hasOneUse() &&
6820 N1.getOperand(0).getOpcode() == ISD::SRL))) {
6822 if (N1.getOpcode() == ISD::TRUNCATE) {
6823 // Look pass the truncate.
6824 Trunc = N1.getNode();
6825 N1 = N1.getOperand(0);
6828 // Match this pattern so that we can generate simpler code:
6831 // %b = and i32 %a, 2
6832 // %c = srl i32 %b, 1
6833 // brcond i32 %c ...
6838 // %b = and i32 %a, 2
6839 // %c = setcc eq %b, 0
6842 // This applies only when the AND constant value has one bit set and the
6843 // SRL constant is equal to the log2 of the AND constant. The back-end is
6844 // smart enough to convert the result into a TEST/JMP sequence.
6845 SDValue Op0 = N1.getOperand(0);
6846 SDValue Op1 = N1.getOperand(1);
6848 if (Op0.getOpcode() == ISD::AND &&
6849 Op1.getOpcode() == ISD::Constant) {
6850 SDValue AndOp1 = Op0.getOperand(1);
6852 if (AndOp1.getOpcode() == ISD::Constant) {
6853 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
6855 if (AndConst.isPowerOf2() &&
6856 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
6858 DAG.getSetCC(SDLoc(N),
6859 getSetCCResultType(Op0.getValueType()),
6860 Op0, DAG.getConstant(0, Op0.getValueType()),
6863 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, SDLoc(N),
6864 MVT::Other, Chain, SetCC, N2);
6865 // Don't add the new BRCond into the worklist or else SimplifySelectCC
6866 // will convert it back to (X & C1) >> C2.
6867 CombineTo(N, NewBRCond, false);
6868 // Truncate is dead.
6870 removeFromWorkList(Trunc);
6871 DAG.DeleteNode(Trunc);
6873 // Replace the uses of SRL with SETCC
6874 WorkListRemover DeadNodes(*this);
6875 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6876 removeFromWorkList(N1.getNode());
6877 DAG.DeleteNode(N1.getNode());
6878 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6884 // Restore N1 if the above transformation doesn't match.
6885 N1 = N->getOperand(1);
6888 // Transform br(xor(x, y)) -> br(x != y)
6889 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
6890 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
6891 SDNode *TheXor = N1.getNode();
6892 SDValue Op0 = TheXor->getOperand(0);
6893 SDValue Op1 = TheXor->getOperand(1);
6894 if (Op0.getOpcode() == Op1.getOpcode()) {
6895 // Avoid missing important xor optimizations.
6896 SDValue Tmp = visitXOR(TheXor);
6897 if (Tmp.getNode()) {
6898 if (Tmp.getNode() != TheXor) {
6899 DEBUG(dbgs() << "\nReplacing.8 ";
6901 dbgs() << "\nWith: ";
6902 Tmp.getNode()->dump(&DAG);
6904 WorkListRemover DeadNodes(*this);
6905 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
6906 removeFromWorkList(TheXor);
6907 DAG.DeleteNode(TheXor);
6908 return DAG.getNode(ISD::BRCOND, SDLoc(N),
6909 MVT::Other, Chain, Tmp, N2);
6912 // visitXOR has changed XOR's operands or replaced the XOR completely,
6914 return SDValue(N, 0);
6918 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
6920 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
6921 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
6922 Op0.getOpcode() == ISD::XOR) {
6923 TheXor = Op0.getNode();
6927 EVT SetCCVT = N1.getValueType();
6929 SetCCVT = getSetCCResultType(SetCCVT);
6930 SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
6933 Equal ? ISD::SETEQ : ISD::SETNE);
6934 // Replace the uses of XOR with SETCC
6935 WorkListRemover DeadNodes(*this);
6936 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6937 removeFromWorkList(N1.getNode());
6938 DAG.DeleteNode(N1.getNode());
6939 return DAG.getNode(ISD::BRCOND, SDLoc(N),
6940 MVT::Other, Chain, SetCC, N2);
6947 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
6949 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
6950 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
6951 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
6953 // If N is a constant we could fold this into a fallthrough or unconditional
6954 // branch. However that doesn't happen very often in normal code, because
6955 // Instcombine/SimplifyCFG should have handled the available opportunities.
6956 // If we did this folding here, it would be necessary to update the
6957 // MachineBasicBlock CFG, which is awkward.
6959 // Use SimplifySetCC to simplify SETCC's.
6960 SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
6961 CondLHS, CondRHS, CC->get(), SDLoc(N),
6963 if (Simp.getNode()) AddToWorkList(Simp.getNode());
6965 // fold to a simpler setcc
6966 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
6967 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
6968 N->getOperand(0), Simp.getOperand(2),
6969 Simp.getOperand(0), Simp.getOperand(1),
6975 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
6976 /// uses N as its base pointer and that N may be folded in the load / store
6977 /// addressing mode.
6978 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
6980 const TargetLowering &TLI) {
6982 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
6983 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
6985 VT = Use->getValueType(0);
6986 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
6987 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
6989 VT = ST->getValue().getValueType();
6993 TargetLowering::AddrMode AM;
6994 if (N->getOpcode() == ISD::ADD) {
6995 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6998 AM.BaseOffs = Offset->getSExtValue();
7002 } else if (N->getOpcode() == ISD::SUB) {
7003 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
7006 AM.BaseOffs = -Offset->getSExtValue();
7013 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
7016 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
7017 /// pre-indexed load / store when the base pointer is an add or subtract
7018 /// and it has other uses besides the load / store. After the
7019 /// transformation, the new indexed load / store has effectively folded
7020 /// the add / subtract in and all of its other uses are redirected to the
7021 /// new load / store.
7022 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
7023 if (Level < AfterLegalizeDAG)
7029 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7030 if (LD->isIndexed())
7032 VT = LD->getMemoryVT();
7033 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
7034 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
7036 Ptr = LD->getBasePtr();
7037 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7038 if (ST->isIndexed())
7040 VT = ST->getMemoryVT();
7041 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
7042 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
7044 Ptr = ST->getBasePtr();
7050 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
7051 // out. There is no reason to make this a preinc/predec.
7052 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
7053 Ptr.getNode()->hasOneUse())
7056 // Ask the target to do addressing mode selection.
7059 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7060 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
7063 // Backends without true r+i pre-indexed forms may need to pass a
7064 // constant base with a variable offset so that constant coercion
7065 // will work with the patterns in canonical form.
7066 bool Swapped = false;
7067 if (isa<ConstantSDNode>(BasePtr)) {
7068 std::swap(BasePtr, Offset);
7072 // Don't create a indexed load / store with zero offset.
7073 if (isa<ConstantSDNode>(Offset) &&
7074 cast<ConstantSDNode>(Offset)->isNullValue())
7077 // Try turning it into a pre-indexed load / store except when:
7078 // 1) The new base ptr is a frame index.
7079 // 2) If N is a store and the new base ptr is either the same as or is a
7080 // predecessor of the value being stored.
7081 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
7082 // that would create a cycle.
7083 // 4) All uses are load / store ops that use it as old base ptr.
7085 // Check #1. Preinc'ing a frame index would require copying the stack pointer
7086 // (plus the implicit offset) to a register to preinc anyway.
7087 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7092 SDValue Val = cast<StoreSDNode>(N)->getValue();
7093 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
7097 // If the offset is a constant, there may be other adds of constants that
7098 // can be folded with this one. We should do this to avoid having to keep
7099 // a copy of the original base pointer.
7100 SmallVector<SDNode *, 16> OtherUses;
7101 if (isa<ConstantSDNode>(Offset))
7102 for (SDNode::use_iterator I = BasePtr.getNode()->use_begin(),
7103 E = BasePtr.getNode()->use_end(); I != E; ++I) {
7105 if (Use == Ptr.getNode())
7108 if (Use->isPredecessorOf(N))
7111 if (Use->getOpcode() != ISD::ADD && Use->getOpcode() != ISD::SUB) {
7116 SDValue Op0 = Use->getOperand(0), Op1 = Use->getOperand(1);
7117 if (Op1.getNode() == BasePtr.getNode())
7118 std::swap(Op0, Op1);
7119 assert(Op0.getNode() == BasePtr.getNode() &&
7120 "Use of ADD/SUB but not an operand");
7122 if (!isa<ConstantSDNode>(Op1)) {
7127 // FIXME: In some cases, we can be smarter about this.
7128 if (Op1.getValueType() != Offset.getValueType()) {
7133 OtherUses.push_back(Use);
7137 std::swap(BasePtr, Offset);
7139 // Now check for #3 and #4.
7140 bool RealUse = false;
7142 // Caches for hasPredecessorHelper
7143 SmallPtrSet<const SDNode *, 32> Visited;
7144 SmallVector<const SDNode *, 16> Worklist;
7146 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
7147 E = Ptr.getNode()->use_end(); I != E; ++I) {
7151 if (N->hasPredecessorHelper(Use, Visited, Worklist))
7154 // If Ptr may be folded in addressing mode of other use, then it's
7155 // not profitable to do this transformation.
7156 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
7165 Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7166 BasePtr, Offset, AM);
7168 Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7169 BasePtr, Offset, AM);
7172 DEBUG(dbgs() << "\nReplacing.4 ";
7174 dbgs() << "\nWith: ";
7175 Result.getNode()->dump(&DAG);
7177 WorkListRemover DeadNodes(*this);
7179 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7180 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7182 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7185 // Finally, since the node is now dead, remove it from the graph.
7189 std::swap(BasePtr, Offset);
7191 // Replace other uses of BasePtr that can be updated to use Ptr
7192 for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
7193 unsigned OffsetIdx = 1;
7194 if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
7196 assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==
7197 BasePtr.getNode() && "Expected BasePtr operand");
7199 // We need to replace ptr0 in the following expression:
7200 // x0 * offset0 + y0 * ptr0 = t0
7202 // x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
7204 // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
7205 // indexed load/store and the expresion that needs to be re-written.
7207 // Therefore, we have:
7208 // t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1
7210 ConstantSDNode *CN =
7211 cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
7213 APInt Offset0 = CN->getAPIntValue();
7214 APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();
7216 X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
7217 Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
7218 X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
7219 Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;
7221 unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;
7223 APInt CNV = Offset0;
7224 if (X0 < 0) CNV = -CNV;
7225 if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
7226 else CNV = CNV - Offset1;
7228 // We can now generate the new expression.
7229 SDValue NewOp1 = DAG.getConstant(CNV, CN->getValueType(0));
7230 SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);
7232 SDValue NewUse = DAG.getNode(Opcode,
7233 SDLoc(OtherUses[i]),
7234 OtherUses[i]->getValueType(0), NewOp1, NewOp2);
7235 DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
7236 removeFromWorkList(OtherUses[i]);
7237 DAG.DeleteNode(OtherUses[i]);
7240 // Replace the uses of Ptr with uses of the updated base value.
7241 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
7242 removeFromWorkList(Ptr.getNode());
7243 DAG.DeleteNode(Ptr.getNode());
7248 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
7249 /// add / sub of the base pointer node into a post-indexed load / store.
7250 /// The transformation folded the add / subtract into the new indexed
7251 /// load / store effectively and all of its uses are redirected to the
7252 /// new load / store.
7253 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
7254 if (Level < AfterLegalizeDAG)
7260 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7261 if (LD->isIndexed())
7263 VT = LD->getMemoryVT();
7264 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
7265 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
7267 Ptr = LD->getBasePtr();
7268 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7269 if (ST->isIndexed())
7271 VT = ST->getMemoryVT();
7272 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
7273 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
7275 Ptr = ST->getBasePtr();
7281 if (Ptr.getNode()->hasOneUse())
7284 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
7285 E = Ptr.getNode()->use_end(); I != E; ++I) {
7288 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
7293 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7294 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
7295 // Don't create a indexed load / store with zero offset.
7296 if (isa<ConstantSDNode>(Offset) &&
7297 cast<ConstantSDNode>(Offset)->isNullValue())
7300 // Try turning it into a post-indexed load / store except when
7301 // 1) All uses are load / store ops that use it as base ptr (and
7302 // it may be folded as addressing mmode).
7303 // 2) Op must be independent of N, i.e. Op is neither a predecessor
7304 // nor a successor of N. Otherwise, if Op is folded that would
7307 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7311 bool TryNext = false;
7312 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
7313 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
7315 if (Use == Ptr.getNode())
7318 // If all the uses are load / store addresses, then don't do the
7320 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
7321 bool RealUse = false;
7322 for (SDNode::use_iterator III = Use->use_begin(),
7323 EEE = Use->use_end(); III != EEE; ++III) {
7324 SDNode *UseUse = *III;
7325 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
7340 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
7341 SDValue Result = isLoad
7342 ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7343 BasePtr, Offset, AM)
7344 : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7345 BasePtr, Offset, AM);
7348 DEBUG(dbgs() << "\nReplacing.5 ";
7350 dbgs() << "\nWith: ";
7351 Result.getNode()->dump(&DAG);
7353 WorkListRemover DeadNodes(*this);
7355 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7356 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7358 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7361 // Finally, since the node is now dead, remove it from the graph.
7364 // Replace the uses of Use with uses of the updated base value.
7365 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
7366 Result.getValue(isLoad ? 1 : 0));
7367 removeFromWorkList(Op);
7377 SDValue DAGCombiner::visitLOAD(SDNode *N) {
7378 LoadSDNode *LD = cast<LoadSDNode>(N);
7379 SDValue Chain = LD->getChain();
7380 SDValue Ptr = LD->getBasePtr();
7382 // If load is not volatile and there are no uses of the loaded value (and
7383 // the updated indexed value in case of indexed loads), change uses of the
7384 // chain value into uses of the chain input (i.e. delete the dead load).
7385 if (!LD->isVolatile()) {
7386 if (N->getValueType(1) == MVT::Other) {
7388 if (!N->hasAnyUseOfValue(0)) {
7389 // It's not safe to use the two value CombineTo variant here. e.g.
7390 // v1, chain2 = load chain1, loc
7391 // v2, chain3 = load chain2, loc
7393 // Now we replace use of chain2 with chain1. This makes the second load
7394 // isomorphic to the one we are deleting, and thus makes this load live.
7395 DEBUG(dbgs() << "\nReplacing.6 ";
7397 dbgs() << "\nWith chain: ";
7398 Chain.getNode()->dump(&DAG);
7400 WorkListRemover DeadNodes(*this);
7401 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7403 if (N->use_empty()) {
7404 removeFromWorkList(N);
7408 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7412 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7413 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7414 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7415 DEBUG(dbgs() << "\nReplacing.7 ";
7417 dbgs() << "\nWith: ";
7418 Undef.getNode()->dump(&DAG);
7419 dbgs() << " and 2 other values\n");
7420 WorkListRemover DeadNodes(*this);
7421 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7422 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7423 DAG.getUNDEF(N->getValueType(1)));
7424 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7425 removeFromWorkList(N);
7427 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7432 // If this load is directly stored, replace the load value with the stored
7434 // TODO: Handle store large -> read small portion.
7435 // TODO: Handle TRUNCSTORE/LOADEXT
7436 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7437 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7438 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7439 if (PrevST->getBasePtr() == Ptr &&
7440 PrevST->getValue().getValueType() == N->getValueType(0))
7441 return CombineTo(N, Chain.getOperand(1), Chain);
7445 // Try to infer better alignment information than the load already has.
7446 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
7447 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7448 if (Align > LD->getMemOperand()->getBaseAlignment()) {
7450 DAG.getExtLoad(LD->getExtensionType(), SDLoc(N),
7451 LD->getValueType(0),
7452 Chain, Ptr, LD->getPointerInfo(),
7454 LD->isVolatile(), LD->isNonTemporal(), Align);
7455 return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
7461 // Walk up chain skipping non-aliasing memory nodes.
7462 SDValue BetterChain = FindBetterChain(N, Chain);
7464 // If there is a better chain.
7465 if (Chain != BetterChain) {
7468 // Replace the chain to void dependency.
7469 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
7470 ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
7471 BetterChain, Ptr, LD->getPointerInfo(),
7472 LD->isVolatile(), LD->isNonTemporal(),
7473 LD->isInvariant(), LD->getAlignment());
7475 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
7476 LD->getValueType(0),
7477 BetterChain, Ptr, LD->getPointerInfo(),
7480 LD->isNonTemporal(),
7481 LD->getAlignment());
7484 // Create token factor to keep old chain connected.
7485 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
7486 MVT::Other, Chain, ReplLoad.getValue(1));
7488 // Make sure the new and old chains are cleaned up.
7489 AddToWorkList(Token.getNode());
7491 // Replace uses with load result and token factor. Don't add users
7493 return CombineTo(N, ReplLoad.getValue(0), Token, false);
7497 // Try transforming N to an indexed load.
7498 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7499 return SDValue(N, 0);
7504 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
7505 /// load is having specific bytes cleared out. If so, return the byte size
7506 /// being masked out and the shift amount.
7507 static std::pair<unsigned, unsigned>
7508 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
7509 std::pair<unsigned, unsigned> Result(0, 0);
7511 // Check for the structure we're looking for.
7512 if (V->getOpcode() != ISD::AND ||
7513 !isa<ConstantSDNode>(V->getOperand(1)) ||
7514 !ISD::isNormalLoad(V->getOperand(0).getNode()))
7517 // Check the chain and pointer.
7518 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
7519 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
7521 // The store should be chained directly to the load or be an operand of a
7523 if (LD == Chain.getNode())
7525 else if (Chain->getOpcode() != ISD::TokenFactor)
7526 return Result; // Fail.
7529 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
7530 if (Chain->getOperand(i).getNode() == LD) {
7534 if (!isOk) return Result;
7537 // This only handles simple types.
7538 if (V.getValueType() != MVT::i16 &&
7539 V.getValueType() != MVT::i32 &&
7540 V.getValueType() != MVT::i64)
7543 // Check the constant mask. Invert it so that the bits being masked out are
7544 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
7545 // follow the sign bit for uniformity.
7546 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
7547 unsigned NotMaskLZ = countLeadingZeros(NotMask);
7548 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
7549 unsigned NotMaskTZ = countTrailingZeros(NotMask);
7550 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
7551 if (NotMaskLZ == 64) return Result; // All zero mask.
7553 // See if we have a continuous run of bits. If so, we have 0*1+0*
7554 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
7557 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
7558 if (V.getValueType() != MVT::i64 && NotMaskLZ)
7559 NotMaskLZ -= 64-V.getValueSizeInBits();
7561 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
7562 switch (MaskedBytes) {
7566 default: return Result; // All one mask, or 5-byte mask.
7569 // Verify that the first bit starts at a multiple of mask so that the access
7570 // is aligned the same as the access width.
7571 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
7573 Result.first = MaskedBytes;
7574 Result.second = NotMaskTZ/8;
7579 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
7580 /// provides a value as specified by MaskInfo. If so, replace the specified
7581 /// store with a narrower store of truncated IVal.
7583 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
7584 SDValue IVal, StoreSDNode *St,
7586 unsigned NumBytes = MaskInfo.first;
7587 unsigned ByteShift = MaskInfo.second;
7588 SelectionDAG &DAG = DC->getDAG();
7590 // Check to see if IVal is all zeros in the part being masked in by the 'or'
7591 // that uses this. If not, this is not a replacement.
7592 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
7593 ByteShift*8, (ByteShift+NumBytes)*8);
7594 if (!DAG.MaskedValueIsZero(IVal, Mask)) return 0;
7596 // Check that it is legal on the target to do this. It is legal if the new
7597 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
7599 MVT VT = MVT::getIntegerVT(NumBytes*8);
7600 if (!DC->isTypeLegal(VT))
7603 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
7604 // shifted by ByteShift and truncated down to NumBytes.
7606 IVal = DAG.getNode(ISD::SRL, SDLoc(IVal), IVal.getValueType(), IVal,
7607 DAG.getConstant(ByteShift*8,
7608 DC->getShiftAmountTy(IVal.getValueType())));
7610 // Figure out the offset for the store and the alignment of the access.
7612 unsigned NewAlign = St->getAlignment();
7614 if (DAG.getTargetLoweringInfo().isLittleEndian())
7615 StOffset = ByteShift;
7617 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
7619 SDValue Ptr = St->getBasePtr();
7621 Ptr = DAG.getNode(ISD::ADD, SDLoc(IVal), Ptr.getValueType(),
7622 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
7623 NewAlign = MinAlign(NewAlign, StOffset);
7626 // Truncate down to the new size.
7627 IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);
7630 return DAG.getStore(St->getChain(), SDLoc(St), IVal, Ptr,
7631 St->getPointerInfo().getWithOffset(StOffset),
7632 false, false, NewAlign).getNode();
7636 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
7637 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
7638 /// of the loaded bits, try narrowing the load and store if it would end up
7639 /// being a win for performance or code size.
7640 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
7641 StoreSDNode *ST = cast<StoreSDNode>(N);
7642 if (ST->isVolatile())
7645 SDValue Chain = ST->getChain();
7646 SDValue Value = ST->getValue();
7647 SDValue Ptr = ST->getBasePtr();
7648 EVT VT = Value.getValueType();
7650 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
7653 unsigned Opc = Value.getOpcode();
7655 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
7656 // is a byte mask indicating a consecutive number of bytes, check to see if
7657 // Y is known to provide just those bytes. If so, we try to replace the
7658 // load + replace + store sequence with a single (narrower) store, which makes
7660 if (Opc == ISD::OR) {
7661 std::pair<unsigned, unsigned> MaskedLoad;
7662 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
7663 if (MaskedLoad.first)
7664 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7665 Value.getOperand(1), ST,this))
7666 return SDValue(NewST, 0);
7668 // Or is commutative, so try swapping X and Y.
7669 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
7670 if (MaskedLoad.first)
7671 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7672 Value.getOperand(0), ST,this))
7673 return SDValue(NewST, 0);
7676 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
7677 Value.getOperand(1).getOpcode() != ISD::Constant)
7680 SDValue N0 = Value.getOperand(0);
7681 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7682 Chain == SDValue(N0.getNode(), 1)) {
7683 LoadSDNode *LD = cast<LoadSDNode>(N0);
7684 if (LD->getBasePtr() != Ptr ||
7685 LD->getPointerInfo().getAddrSpace() !=
7686 ST->getPointerInfo().getAddrSpace())
7689 // Find the type to narrow it the load / op / store to.
7690 SDValue N1 = Value.getOperand(1);
7691 unsigned BitWidth = N1.getValueSizeInBits();
7692 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
7693 if (Opc == ISD::AND)
7694 Imm ^= APInt::getAllOnesValue(BitWidth);
7695 if (Imm == 0 || Imm.isAllOnesValue())
7697 unsigned ShAmt = Imm.countTrailingZeros();
7698 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
7699 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
7700 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7701 while (NewBW < BitWidth &&
7702 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
7703 TLI.isNarrowingProfitable(VT, NewVT))) {
7704 NewBW = NextPowerOf2(NewBW);
7705 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7707 if (NewBW >= BitWidth)
7710 // If the lsb changed does not start at the type bitwidth boundary,
7711 // start at the previous one.
7713 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
7714 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
7715 std::min(BitWidth, ShAmt + NewBW));
7716 if ((Imm & Mask) == Imm) {
7717 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
7718 if (Opc == ISD::AND)
7719 NewImm ^= APInt::getAllOnesValue(NewBW);
7720 uint64_t PtrOff = ShAmt / 8;
7721 // For big endian targets, we need to adjust the offset to the pointer to
7722 // load the correct bytes.
7723 if (TLI.isBigEndian())
7724 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
7726 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
7727 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
7728 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
7731 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
7732 Ptr.getValueType(), Ptr,
7733 DAG.getConstant(PtrOff, Ptr.getValueType()));
7734 SDValue NewLD = DAG.getLoad(NewVT, SDLoc(N0),
7735 LD->getChain(), NewPtr,
7736 LD->getPointerInfo().getWithOffset(PtrOff),
7737 LD->isVolatile(), LD->isNonTemporal(),
7738 LD->isInvariant(), NewAlign);
7739 SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
7740 DAG.getConstant(NewImm, NewVT));
7741 SDValue NewST = DAG.getStore(Chain, SDLoc(N),
7743 ST->getPointerInfo().getWithOffset(PtrOff),
7744 false, false, NewAlign);
7746 AddToWorkList(NewPtr.getNode());
7747 AddToWorkList(NewLD.getNode());
7748 AddToWorkList(NewVal.getNode());
7749 WorkListRemover DeadNodes(*this);
7750 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
7759 /// TransformFPLoadStorePair - For a given floating point load / store pair,
7760 /// if the load value isn't used by any other operations, then consider
7761 /// transforming the pair to integer load / store operations if the target
7762 /// deems the transformation profitable.
7763 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
7764 StoreSDNode *ST = cast<StoreSDNode>(N);
7765 SDValue Chain = ST->getChain();
7766 SDValue Value = ST->getValue();
7767 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
7768 Value.hasOneUse() &&
7769 Chain == SDValue(Value.getNode(), 1)) {
7770 LoadSDNode *LD = cast<LoadSDNode>(Value);
7771 EVT VT = LD->getMemoryVT();
7772 if (!VT.isFloatingPoint() ||
7773 VT != ST->getMemoryVT() ||
7774 LD->isNonTemporal() ||
7775 ST->isNonTemporal() ||
7776 LD->getPointerInfo().getAddrSpace() != 0 ||
7777 ST->getPointerInfo().getAddrSpace() != 0)
7780 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
7781 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
7782 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
7783 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
7784 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
7787 unsigned LDAlign = LD->getAlignment();
7788 unsigned STAlign = ST->getAlignment();
7789 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
7790 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
7791 if (LDAlign < ABIAlign || STAlign < ABIAlign)
7794 SDValue NewLD = DAG.getLoad(IntVT, SDLoc(Value),
7795 LD->getChain(), LD->getBasePtr(),
7796 LD->getPointerInfo(),
7797 false, false, false, LDAlign);
7799 SDValue NewST = DAG.getStore(NewLD.getValue(1), SDLoc(N),
7800 NewLD, ST->getBasePtr(),
7801 ST->getPointerInfo(),
7802 false, false, STAlign);
7804 AddToWorkList(NewLD.getNode());
7805 AddToWorkList(NewST.getNode());
7806 WorkListRemover DeadNodes(*this);
7807 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
7815 /// Helper struct to parse and store a memory address as base + index + offset.
7816 /// We ignore sign extensions when it is safe to do so.
7817 /// The following two expressions are not equivalent. To differentiate we need
7818 /// to store whether there was a sign extension involved in the index
7820 /// (load (i64 add (i64 copyfromreg %c)
7821 /// (i64 signextend (add (i8 load %index)
7825 /// (load (i64 add (i64 copyfromreg %c)
7826 /// (i64 signextend (i32 add (i32 signextend (i8 load %index))
7828 struct BaseIndexOffset {
7832 bool IsIndexSignExt;
7834 BaseIndexOffset() : Offset(0), IsIndexSignExt(false) {}
7836 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
7837 bool IsIndexSignExt) :
7838 Base(Base), Index(Index), Offset(Offset), IsIndexSignExt(IsIndexSignExt) {}
7840 bool equalBaseIndex(const BaseIndexOffset &Other) {
7841 return Other.Base == Base && Other.Index == Index &&
7842 Other.IsIndexSignExt == IsIndexSignExt;
7845 /// Parses tree in Ptr for base, index, offset addresses.
7846 static BaseIndexOffset match(SDValue Ptr) {
7847 bool IsIndexSignExt = false;
7849 // Just Base or possibly anything else.
7850 if (Ptr->getOpcode() != ISD::ADD)
7851 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
7854 if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
7855 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
7856 return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
7860 // Look at Base + Index + Offset cases.
7861 SDValue Base = Ptr->getOperand(0);
7862 SDValue IndexOffset = Ptr->getOperand(1);
7864 // Skip signextends.
7865 if (IndexOffset->getOpcode() == ISD::SIGN_EXTEND) {
7866 IndexOffset = IndexOffset->getOperand(0);
7867 IsIndexSignExt = true;
7870 // Either the case of Base + Index (no offset) or something else.
7871 if (IndexOffset->getOpcode() != ISD::ADD)
7872 return BaseIndexOffset(Base, IndexOffset, 0, IsIndexSignExt);
7874 // Now we have the case of Base + Index + offset.
7875 SDValue Index = IndexOffset->getOperand(0);
7876 SDValue Offset = IndexOffset->getOperand(1);
7878 if (!isa<ConstantSDNode>(Offset))
7879 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
7881 // Ignore signextends.
7882 if (Index->getOpcode() == ISD::SIGN_EXTEND) {
7883 Index = Index->getOperand(0);
7884 IsIndexSignExt = true;
7885 } else IsIndexSignExt = false;
7887 int64_t Off = cast<ConstantSDNode>(Offset)->getSExtValue();
7888 return BaseIndexOffset(Base, Index, Off, IsIndexSignExt);
7892 /// Holds a pointer to an LSBaseSDNode as well as information on where it
7893 /// is located in a sequence of memory operations connected by a chain.
7895 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
7896 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
7897 // Ptr to the mem node.
7898 LSBaseSDNode *MemNode;
7899 // Offset from the base ptr.
7900 int64_t OffsetFromBase;
7901 // What is the sequence number of this mem node.
7902 // Lowest mem operand in the DAG starts at zero.
7903 unsigned SequenceNum;
7906 /// Sorts store nodes in a link according to their offset from a shared
7908 struct ConsecutiveMemoryChainSorter {
7909 bool operator()(MemOpLink LHS, MemOpLink RHS) {
7910 return LHS.OffsetFromBase < RHS.OffsetFromBase;
7914 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
7915 EVT MemVT = St->getMemoryVT();
7916 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
7917 bool NoVectors = DAG.getMachineFunction().getFunction()->getAttributes().
7918 hasAttribute(AttributeSet::FunctionIndex, Attribute::NoImplicitFloat);
7920 // Don't merge vectors into wider inputs.
7921 if (MemVT.isVector() || !MemVT.isSimple())
7924 // Perform an early exit check. Do not bother looking at stored values that
7925 // are not constants or loads.
7926 SDValue StoredVal = St->getValue();
7927 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
7928 if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
7932 // Only look at ends of store sequences.
7933 SDValue Chain = SDValue(St, 1);
7934 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
7937 // This holds the base pointer, index, and the offset in bytes from the base
7939 BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
7941 // We must have a base and an offset.
7942 if (!BasePtr.Base.getNode())
7945 // Do not handle stores to undef base pointers.
7946 if (BasePtr.Base.getOpcode() == ISD::UNDEF)
7949 // Save the LoadSDNodes that we find in the chain.
7950 // We need to make sure that these nodes do not interfere with
7951 // any of the store nodes.
7952 SmallVector<LSBaseSDNode*, 8> AliasLoadNodes;
7954 // Save the StoreSDNodes that we find in the chain.
7955 SmallVector<MemOpLink, 8> StoreNodes;
7957 // Walk up the chain and look for nodes with offsets from the same
7958 // base pointer. Stop when reaching an instruction with a different kind
7959 // or instruction which has a different base pointer.
7961 StoreSDNode *Index = St;
7963 // If the chain has more than one use, then we can't reorder the mem ops.
7964 if (Index != St && !SDValue(Index, 1)->hasOneUse())
7967 // Find the base pointer and offset for this memory node.
7968 BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
7970 // Check that the base pointer is the same as the original one.
7971 if (!Ptr.equalBaseIndex(BasePtr))
7974 // Check that the alignment is the same.
7975 if (Index->getAlignment() != St->getAlignment())
7978 // The memory operands must not be volatile.
7979 if (Index->isVolatile() || Index->isIndexed())
7983 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
7984 if (St->isTruncatingStore())
7987 // The stored memory type must be the same.
7988 if (Index->getMemoryVT() != MemVT)
7991 // We do not allow unaligned stores because we want to prevent overriding
7993 if (Index->getAlignment()*8 != MemVT.getSizeInBits())
7996 // We found a potential memory operand to merge.
7997 StoreNodes.push_back(MemOpLink(Index, Ptr.Offset, Seq++));
7999 // Find the next memory operand in the chain. If the next operand in the
8000 // chain is a store then move up and continue the scan with the next
8001 // memory operand. If the next operand is a load save it and use alias
8002 // information to check if it interferes with anything.
8003 SDNode *NextInChain = Index->getChain().getNode();
8005 if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
8006 // We found a store node. Use it for the next iteration.
8009 } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
8010 // Save the load node for later. Continue the scan.
8011 AliasLoadNodes.push_back(Ldn);
8012 NextInChain = Ldn->getChain().getNode();
8021 // Check if there is anything to merge.
8022 if (StoreNodes.size() < 2)
8025 // Sort the memory operands according to their distance from the base pointer.
8026 std::sort(StoreNodes.begin(), StoreNodes.end(),
8027 ConsecutiveMemoryChainSorter());
8029 // Scan the memory operations on the chain and find the first non-consecutive
8030 // store memory address.
8031 unsigned LastConsecutiveStore = 0;
8032 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
8033 for (unsigned i = 0, e = StoreNodes.size(); i < e; ++i) {
8035 // Check that the addresses are consecutive starting from the second
8036 // element in the list of stores.
8038 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
8039 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
8044 // Check if this store interferes with any of the loads that we found.
8045 for (unsigned ld = 0, lde = AliasLoadNodes.size(); ld < lde; ++ld)
8046 if (isAlias(AliasLoadNodes[ld], StoreNodes[i].MemNode)) {
8050 // We found a load that alias with this store. Stop the sequence.
8054 // Mark this node as useful.
8055 LastConsecutiveStore = i;
8058 // The node with the lowest store address.
8059 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
8061 // Store the constants into memory as one consecutive store.
8063 unsigned LastLegalType = 0;
8064 unsigned LastLegalVectorType = 0;
8065 bool NonZero = false;
8066 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
8067 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8068 SDValue StoredVal = St->getValue();
8070 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
8071 NonZero |= !C->isNullValue();
8072 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
8073 NonZero |= !C->getConstantFPValue()->isNullValue();
8079 // Find a legal type for the constant store.
8080 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
8081 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8082 if (TLI.isTypeLegal(StoreTy))
8083 LastLegalType = i+1;
8084 // Or check whether a truncstore is legal.
8085 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
8086 TargetLowering::TypePromoteInteger) {
8087 EVT LegalizedStoredValueTy =
8088 TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
8089 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy))
8090 LastLegalType = i+1;
8093 // Find a legal type for the vector store.
8094 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
8095 if (TLI.isTypeLegal(Ty))
8096 LastLegalVectorType = i + 1;
8099 // We only use vectors if the constant is known to be zero and the
8100 // function is not marked with the noimplicitfloat attribute.
8101 if (NonZero || NoVectors)
8102 LastLegalVectorType = 0;
8104 // Check if we found a legal integer type to store.
8105 if (LastLegalType == 0 && LastLegalVectorType == 0)
8108 bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
8109 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
8111 // Make sure we have something to merge.
8115 unsigned EarliestNodeUsed = 0;
8116 for (unsigned i=0; i < NumElem; ++i) {
8117 // Find a chain for the new wide-store operand. Notice that some
8118 // of the store nodes that we found may not be selected for inclusion
8119 // in the wide store. The chain we use needs to be the chain of the
8120 // earliest store node which is *used* and replaced by the wide store.
8121 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
8122 EarliestNodeUsed = i;
8125 // The earliest Node in the DAG.
8126 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
8127 SDLoc DL(StoreNodes[0].MemNode);
8131 // Find a legal type for the vector store.
8132 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
8133 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
8134 StoredVal = DAG.getConstant(0, Ty);
8136 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
8137 APInt StoreInt(StoreBW, 0);
8139 // Construct a single integer constant which is made of the smaller
8141 bool IsLE = TLI.isLittleEndian();
8142 for (unsigned i = 0; i < NumElem ; ++i) {
8143 unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
8144 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
8145 SDValue Val = St->getValue();
8146 StoreInt<<=ElementSizeBytes*8;
8147 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
8148 StoreInt|=C->getAPIntValue().zext(StoreBW);
8149 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
8150 StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
8152 assert(false && "Invalid constant element type");
8156 // Create the new Load and Store operations.
8157 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8158 StoredVal = DAG.getConstant(StoreInt, StoreTy);
8161 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, StoredVal,
8162 FirstInChain->getBasePtr(),
8163 FirstInChain->getPointerInfo(),
8165 FirstInChain->getAlignment());
8167 // Replace the first store with the new store
8168 CombineTo(EarliestOp, NewStore);
8169 // Erase all other stores.
8170 for (unsigned i = 0; i < NumElem ; ++i) {
8171 if (StoreNodes[i].MemNode == EarliestOp)
8173 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8174 // ReplaceAllUsesWith will replace all uses that existed when it was
8175 // called, but graph optimizations may cause new ones to appear. For
8176 // example, the case in pr14333 looks like
8178 // St's chain -> St -> another store -> X
8180 // And the only difference from St to the other store is the chain.
8181 // When we change it's chain to be St's chain they become identical,
8182 // get CSEed and the net result is that X is now a use of St.
8183 // Since we know that St is redundant, just iterate.
8184 while (!St->use_empty())
8185 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
8186 removeFromWorkList(St);
8193 // Below we handle the case of multiple consecutive stores that
8194 // come from multiple consecutive loads. We merge them into a single
8195 // wide load and a single wide store.
8197 // Look for load nodes which are used by the stored values.
8198 SmallVector<MemOpLink, 8> LoadNodes;
8200 // Find acceptable loads. Loads need to have the same chain (token factor),
8201 // must not be zext, volatile, indexed, and they must be consecutive.
8202 BaseIndexOffset LdBasePtr;
8203 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
8204 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8205 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
8208 // Loads must only have one use.
8209 if (!Ld->hasNUsesOfValue(1, 0))
8212 // Check that the alignment is the same as the stores.
8213 if (Ld->getAlignment() != St->getAlignment())
8216 // The memory operands must not be volatile.
8217 if (Ld->isVolatile() || Ld->isIndexed())
8220 // We do not accept ext loads.
8221 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
8224 // The stored memory type must be the same.
8225 if (Ld->getMemoryVT() != MemVT)
8228 BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
8229 // If this is not the first ptr that we check.
8230 if (LdBasePtr.Base.getNode()) {
8231 // The base ptr must be the same.
8232 if (!LdPtr.equalBaseIndex(LdBasePtr))
8235 // Check that all other base pointers are the same as this one.
8239 // We found a potential memory operand to merge.
8240 LoadNodes.push_back(MemOpLink(Ld, LdPtr.Offset, 0));
8243 if (LoadNodes.size() < 2)
8246 // Scan the memory operations on the chain and find the first non-consecutive
8247 // load memory address. These variables hold the index in the store node
8249 unsigned LastConsecutiveLoad = 0;
8250 // This variable refers to the size and not index in the array.
8251 unsigned LastLegalVectorType = 0;
8252 unsigned LastLegalIntegerType = 0;
8253 StartAddress = LoadNodes[0].OffsetFromBase;
8254 SDValue FirstChain = LoadNodes[0].MemNode->getChain();
8255 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
8256 // All loads much share the same chain.
8257 if (LoadNodes[i].MemNode->getChain() != FirstChain)
8260 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
8261 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
8263 LastConsecutiveLoad = i;
8265 // Find a legal type for the vector store.
8266 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
8267 if (TLI.isTypeLegal(StoreTy))
8268 LastLegalVectorType = i + 1;
8270 // Find a legal type for the integer store.
8271 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
8272 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8273 if (TLI.isTypeLegal(StoreTy))
8274 LastLegalIntegerType = i + 1;
8275 // Or check whether a truncstore and extload is legal.
8276 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
8277 TargetLowering::TypePromoteInteger) {
8278 EVT LegalizedStoredValueTy =
8279 TLI.getTypeToTransformTo(*DAG.getContext(), StoreTy);
8280 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
8281 TLI.isLoadExtLegal(ISD::ZEXTLOAD, StoreTy) &&
8282 TLI.isLoadExtLegal(ISD::SEXTLOAD, StoreTy) &&
8283 TLI.isLoadExtLegal(ISD::EXTLOAD, StoreTy))
8284 LastLegalIntegerType = i+1;
8288 // Only use vector types if the vector type is larger than the integer type.
8289 // If they are the same, use integers.
8290 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
8291 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
8293 // We add +1 here because the LastXXX variables refer to location while
8294 // the NumElem refers to array/index size.
8295 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
8296 NumElem = std::min(LastLegalType, NumElem);
8301 // The earliest Node in the DAG.
8302 unsigned EarliestNodeUsed = 0;
8303 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
8304 for (unsigned i=1; i<NumElem; ++i) {
8305 // Find a chain for the new wide-store operand. Notice that some
8306 // of the store nodes that we found may not be selected for inclusion
8307 // in the wide store. The chain we use needs to be the chain of the
8308 // earliest store node which is *used* and replaced by the wide store.
8309 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
8310 EarliestNodeUsed = i;
8313 // Find if it is better to use vectors or integers to load and store
8317 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
8319 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
8320 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8323 SDLoc LoadDL(LoadNodes[0].MemNode);
8324 SDLoc StoreDL(StoreNodes[0].MemNode);
8326 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
8327 SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
8328 FirstLoad->getChain(),
8329 FirstLoad->getBasePtr(),
8330 FirstLoad->getPointerInfo(),
8331 false, false, false,
8332 FirstLoad->getAlignment());
8334 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
8335 FirstInChain->getBasePtr(),
8336 FirstInChain->getPointerInfo(), false, false,
8337 FirstInChain->getAlignment());
8339 // Replace one of the loads with the new load.
8340 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
8341 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
8342 SDValue(NewLoad.getNode(), 1));
8344 // Remove the rest of the load chains.
8345 for (unsigned i = 1; i < NumElem ; ++i) {
8346 // Replace all chain users of the old load nodes with the chain of the new
8348 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
8349 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
8352 // Replace the first store with the new store.
8353 CombineTo(EarliestOp, NewStore);
8354 // Erase all other stores.
8355 for (unsigned i = 0; i < NumElem ; ++i) {
8356 // Remove all Store nodes.
8357 if (StoreNodes[i].MemNode == EarliestOp)
8359 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8360 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
8361 removeFromWorkList(St);
8368 SDValue DAGCombiner::visitSTORE(SDNode *N) {
8369 StoreSDNode *ST = cast<StoreSDNode>(N);
8370 SDValue Chain = ST->getChain();
8371 SDValue Value = ST->getValue();
8372 SDValue Ptr = ST->getBasePtr();
8374 // If this is a store of a bit convert, store the input value if the
8375 // resultant store does not need a higher alignment than the original.
8376 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
8377 ST->isUnindexed()) {
8378 unsigned OrigAlign = ST->getAlignment();
8379 EVT SVT = Value.getOperand(0).getValueType();
8380 unsigned Align = TLI.getDataLayout()->
8381 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
8382 if (Align <= OrigAlign &&
8383 ((!LegalOperations && !ST->isVolatile()) ||
8384 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
8385 return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
8386 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8387 ST->isNonTemporal(), OrigAlign);
8390 // Turn 'store undef, Ptr' -> nothing.
8391 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
8394 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
8395 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
8396 // NOTE: If the original store is volatile, this transform must not increase
8397 // the number of stores. For example, on x86-32 an f64 can be stored in one
8398 // processor operation but an i64 (which is not legal) requires two. So the
8399 // transform should not be done in this case.
8400 if (Value.getOpcode() != ISD::TargetConstantFP) {
8402 switch (CFP->getValueType(0).getSimpleVT().SimpleTy) {
8403 default: llvm_unreachable("Unknown FP type");
8404 case MVT::f16: // We don't do this for these yet.
8410 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
8411 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
8412 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
8413 bitcastToAPInt().getZExtValue(), MVT::i32);
8414 return DAG.getStore(Chain, SDLoc(N), Tmp,
8415 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8416 ST->isNonTemporal(), ST->getAlignment());
8420 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
8421 !ST->isVolatile()) ||
8422 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
8423 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
8424 getZExtValue(), MVT::i64);
8425 return DAG.getStore(Chain, SDLoc(N), Tmp,
8426 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8427 ST->isNonTemporal(), ST->getAlignment());
8430 if (!ST->isVolatile() &&
8431 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
8432 // Many FP stores are not made apparent until after legalize, e.g. for
8433 // argument passing. Since this is so common, custom legalize the
8434 // 64-bit integer store into two 32-bit stores.
8435 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
8436 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
8437 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
8438 if (TLI.isBigEndian()) std::swap(Lo, Hi);
8440 unsigned Alignment = ST->getAlignment();
8441 bool isVolatile = ST->isVolatile();
8442 bool isNonTemporal = ST->isNonTemporal();
8444 SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
8445 Ptr, ST->getPointerInfo(),
8446 isVolatile, isNonTemporal,
8447 ST->getAlignment());
8448 Ptr = DAG.getNode(ISD::ADD, SDLoc(N), Ptr.getValueType(), Ptr,
8449 DAG.getConstant(4, Ptr.getValueType()));
8450 Alignment = MinAlign(Alignment, 4U);
8451 SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
8452 Ptr, ST->getPointerInfo().getWithOffset(4),
8453 isVolatile, isNonTemporal,
8455 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
8464 // Try to infer better alignment information than the store already has.
8465 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
8466 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
8467 if (Align > ST->getAlignment())
8468 return DAG.getTruncStore(Chain, SDLoc(N), Value,
8469 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8470 ST->isVolatile(), ST->isNonTemporal(), Align);
8474 // Try transforming a pair floating point load / store ops to integer
8475 // load / store ops.
8476 SDValue NewST = TransformFPLoadStorePair(N);
8477 if (NewST.getNode())
8481 // Walk up chain skipping non-aliasing memory nodes.
8482 SDValue BetterChain = FindBetterChain(N, Chain);
8484 // If there is a better chain.
8485 if (Chain != BetterChain) {
8488 // Replace the chain to avoid dependency.
8489 if (ST->isTruncatingStore()) {
8490 ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
8491 ST->getPointerInfo(),
8492 ST->getMemoryVT(), ST->isVolatile(),
8493 ST->isNonTemporal(), ST->getAlignment());
8495 ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
8496 ST->getPointerInfo(),
8497 ST->isVolatile(), ST->isNonTemporal(),
8498 ST->getAlignment());
8501 // Create token to keep both nodes around.
8502 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
8503 MVT::Other, Chain, ReplStore);
8505 // Make sure the new and old chains are cleaned up.
8506 AddToWorkList(Token.getNode());
8508 // Don't add users to work list.
8509 return CombineTo(N, Token, false);
8513 // Try transforming N to an indexed store.
8514 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
8515 return SDValue(N, 0);
8517 // FIXME: is there such a thing as a truncating indexed store?
8518 if (ST->isTruncatingStore() && ST->isUnindexed() &&
8519 Value.getValueType().isInteger()) {
8520 // See if we can simplify the input to this truncstore with knowledge that
8521 // only the low bits are being used. For example:
8522 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
8524 GetDemandedBits(Value,
8525 APInt::getLowBitsSet(
8526 Value.getValueType().getScalarType().getSizeInBits(),
8527 ST->getMemoryVT().getScalarType().getSizeInBits()));
8528 AddToWorkList(Value.getNode());
8529 if (Shorter.getNode())
8530 return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
8531 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8532 ST->isVolatile(), ST->isNonTemporal(),
8533 ST->getAlignment());
8535 // Otherwise, see if we can simplify the operation with
8536 // SimplifyDemandedBits, which only works if the value has a single use.
8537 if (SimplifyDemandedBits(Value,
8538 APInt::getLowBitsSet(
8539 Value.getValueType().getScalarType().getSizeInBits(),
8540 ST->getMemoryVT().getScalarType().getSizeInBits())))
8541 return SDValue(N, 0);
8544 // If this is a load followed by a store to the same location, then the store
8546 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
8547 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
8548 ST->isUnindexed() && !ST->isVolatile() &&
8549 // There can't be any side effects between the load and store, such as
8551 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
8552 // The store is dead, remove it.
8557 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
8558 // truncating store. We can do this even if this is already a truncstore.
8559 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
8560 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
8561 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
8562 ST->getMemoryVT())) {
8563 return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
8564 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8565 ST->isVolatile(), ST->isNonTemporal(),
8566 ST->getAlignment());
8569 // Only perform this optimization before the types are legal, because we
8570 // don't want to perform this optimization on every DAGCombine invocation.
8572 bool EverChanged = false;
8575 // There can be multiple store sequences on the same chain.
8576 // Keep trying to merge store sequences until we are unable to do so
8577 // or until we merge the last store on the chain.
8578 bool Changed = MergeConsecutiveStores(ST);
8579 EverChanged |= Changed;
8580 if (!Changed) break;
8581 } while (ST->getOpcode() != ISD::DELETED_NODE);
8584 return SDValue(N, 0);
8587 return ReduceLoadOpStoreWidth(N);
8590 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
8591 SDValue InVec = N->getOperand(0);
8592 SDValue InVal = N->getOperand(1);
8593 SDValue EltNo = N->getOperand(2);
8596 // If the inserted element is an UNDEF, just use the input vector.
8597 if (InVal.getOpcode() == ISD::UNDEF)
8600 EVT VT = InVec.getValueType();
8602 // If we can't generate a legal BUILD_VECTOR, exit
8603 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
8606 // Check that we know which element is being inserted
8607 if (!isa<ConstantSDNode>(EltNo))
8609 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8611 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
8612 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
8614 SmallVector<SDValue, 8> Ops;
8615 // Do not combine these two vectors if the output vector will not replace
8616 // the input vector.
8617 if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
8618 Ops.append(InVec.getNode()->op_begin(),
8619 InVec.getNode()->op_end());
8620 } else if (InVec.getOpcode() == ISD::UNDEF) {
8621 unsigned NElts = VT.getVectorNumElements();
8622 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
8627 // Insert the element
8628 if (Elt < Ops.size()) {
8629 // All the operands of BUILD_VECTOR must have the same type;
8630 // we enforce that here.
8631 EVT OpVT = Ops[0].getValueType();
8632 if (InVal.getValueType() != OpVT)
8633 InVal = OpVT.bitsGT(InVal.getValueType()) ?
8634 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
8635 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
8639 // Return the new vector
8640 return DAG.getNode(ISD::BUILD_VECTOR, dl,
8641 VT, &Ops[0], Ops.size());
8644 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
8645 // (vextract (scalar_to_vector val, 0) -> val
8646 SDValue InVec = N->getOperand(0);
8647 EVT VT = InVec.getValueType();
8648 EVT NVT = N->getValueType(0);
8650 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
8651 // Check if the result type doesn't match the inserted element type. A
8652 // SCALAR_TO_VECTOR may truncate the inserted element and the
8653 // EXTRACT_VECTOR_ELT may widen the extracted vector.
8654 SDValue InOp = InVec.getOperand(0);
8655 if (InOp.getValueType() != NVT) {
8656 assert(InOp.getValueType().isInteger() && NVT.isInteger());
8657 return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
8662 SDValue EltNo = N->getOperand(1);
8663 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
8665 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
8666 // We only perform this optimization before the op legalization phase because
8667 // we may introduce new vector instructions which are not backed by TD
8668 // patterns. For example on AVX, extracting elements from a wide vector
8669 // without using extract_subvector.
8670 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
8671 && ConstEltNo && !LegalOperations) {
8672 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8673 int NumElem = VT.getVectorNumElements();
8674 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
8675 // Find the new index to extract from.
8676 int OrigElt = SVOp->getMaskElt(Elt);
8678 // Extracting an undef index is undef.
8680 return DAG.getUNDEF(NVT);
8682 // Select the right vector half to extract from.
8683 if (OrigElt < NumElem) {
8684 InVec = InVec->getOperand(0);
8686 InVec = InVec->getOperand(1);
8690 EVT IndexTy = N->getOperand(1).getValueType();
8691 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT,
8692 InVec, DAG.getConstant(OrigElt, IndexTy));
8695 // Perform only after legalization to ensure build_vector / vector_shuffle
8696 // optimizations have already been done.
8697 if (!LegalOperations) return SDValue();
8699 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
8700 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
8701 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
8704 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8705 bool NewLoad = false;
8706 bool BCNumEltsChanged = false;
8707 EVT ExtVT = VT.getVectorElementType();
8710 // If the result of load has to be truncated, then it's not necessarily
8712 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
8715 if (InVec.getOpcode() == ISD::BITCAST) {
8716 // Don't duplicate a load with other uses.
8717 if (!InVec.hasOneUse())
8720 EVT BCVT = InVec.getOperand(0).getValueType();
8721 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
8723 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
8724 BCNumEltsChanged = true;
8725 InVec = InVec.getOperand(0);
8726 ExtVT = BCVT.getVectorElementType();
8730 LoadSDNode *LN0 = NULL;
8731 const ShuffleVectorSDNode *SVN = NULL;
8732 if (ISD::isNormalLoad(InVec.getNode())) {
8733 LN0 = cast<LoadSDNode>(InVec);
8734 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
8735 InVec.getOperand(0).getValueType() == ExtVT &&
8736 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
8737 // Don't duplicate a load with other uses.
8738 if (!InVec.hasOneUse())
8741 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
8742 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
8743 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
8745 // (load $addr+1*size)
8747 // Don't duplicate a load with other uses.
8748 if (!InVec.hasOneUse())
8751 // If the bit convert changed the number of elements, it is unsafe
8752 // to examine the mask.
8753 if (BCNumEltsChanged)
8756 // Select the input vector, guarding against out of range extract vector.
8757 unsigned NumElems = VT.getVectorNumElements();
8758 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
8759 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
8761 if (InVec.getOpcode() == ISD::BITCAST) {
8762 // Don't duplicate a load with other uses.
8763 if (!InVec.hasOneUse())
8766 InVec = InVec.getOperand(0);
8768 if (ISD::isNormalLoad(InVec.getNode())) {
8769 LN0 = cast<LoadSDNode>(InVec);
8770 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
8774 // Make sure we found a non-volatile load and the extractelement is
8776 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
8779 // If Idx was -1 above, Elt is going to be -1, so just return undef.
8781 return DAG.getUNDEF(LVT);
8783 unsigned Align = LN0->getAlignment();
8785 // Check the resultant load doesn't need a higher alignment than the
8789 ->getABITypeAlignment(LVT.getTypeForEVT(*DAG.getContext()));
8791 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
8797 SDValue NewPtr = LN0->getBasePtr();
8798 unsigned PtrOff = 0;
8801 PtrOff = LVT.getSizeInBits() * Elt / 8;
8802 EVT PtrType = NewPtr.getValueType();
8803 if (TLI.isBigEndian())
8804 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
8805 NewPtr = DAG.getNode(ISD::ADD, SDLoc(N), PtrType, NewPtr,
8806 DAG.getConstant(PtrOff, PtrType));
8809 // The replacement we need to do here is a little tricky: we need to
8810 // replace an extractelement of a load with a load.
8811 // Use ReplaceAllUsesOfValuesWith to do the replacement.
8812 // Note that this replacement assumes that the extractvalue is the only
8813 // use of the load; that's okay because we don't want to perform this
8814 // transformation in other cases anyway.
8817 if (NVT.bitsGT(LVT)) {
8818 // If the result type of vextract is wider than the load, then issue an
8819 // extending load instead.
8820 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, LVT)
8821 ? ISD::ZEXTLOAD : ISD::EXTLOAD;
8822 Load = DAG.getExtLoad(ExtType, SDLoc(N), NVT, LN0->getChain(),
8823 NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
8824 LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
8825 Chain = Load.getValue(1);
8827 Load = DAG.getLoad(LVT, SDLoc(N), LN0->getChain(), NewPtr,
8828 LN0->getPointerInfo().getWithOffset(PtrOff),
8829 LN0->isVolatile(), LN0->isNonTemporal(),
8830 LN0->isInvariant(), Align);
8831 Chain = Load.getValue(1);
8832 if (NVT.bitsLT(LVT))
8833 Load = DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, Load);
8835 Load = DAG.getNode(ISD::BITCAST, SDLoc(N), NVT, Load);
8837 WorkListRemover DeadNodes(*this);
8838 SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
8839 SDValue To[] = { Load, Chain };
8840 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
8841 // Since we're explcitly calling ReplaceAllUses, add the new node to the
8842 // worklist explicitly as well.
8843 AddToWorkList(Load.getNode());
8844 AddUsersToWorkList(Load.getNode()); // Add users too
8845 // Make sure to revisit this node to clean it up; it will usually be dead.
8847 return SDValue(N, 0);
8853 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
8854 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
8855 // We perform this optimization post type-legalization because
8856 // the type-legalizer often scalarizes integer-promoted vectors.
8857 // Performing this optimization before may create bit-casts which
8858 // will be type-legalized to complex code sequences.
8859 // We perform this optimization only before the operation legalizer because we
8860 // may introduce illegal operations.
8861 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
8864 unsigned NumInScalars = N->getNumOperands();
8866 EVT VT = N->getValueType(0);
8868 // Check to see if this is a BUILD_VECTOR of a bunch of values
8869 // which come from any_extend or zero_extend nodes. If so, we can create
8870 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
8871 // optimizations. We do not handle sign-extend because we can't fill the sign
8873 EVT SourceType = MVT::Other;
8874 bool AllAnyExt = true;
8876 for (unsigned i = 0; i != NumInScalars; ++i) {
8877 SDValue In = N->getOperand(i);
8878 // Ignore undef inputs.
8879 if (In.getOpcode() == ISD::UNDEF) continue;
8881 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
8882 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
8884 // Abort if the element is not an extension.
8885 if (!ZeroExt && !AnyExt) {
8886 SourceType = MVT::Other;
8890 // The input is a ZeroExt or AnyExt. Check the original type.
8891 EVT InTy = In.getOperand(0).getValueType();
8893 // Check that all of the widened source types are the same.
8894 if (SourceType == MVT::Other)
8897 else if (InTy != SourceType) {
8898 // Multiple income types. Abort.
8899 SourceType = MVT::Other;
8903 // Check if all of the extends are ANY_EXTENDs.
8904 AllAnyExt &= AnyExt;
8907 // In order to have valid types, all of the inputs must be extended from the
8908 // same source type and all of the inputs must be any or zero extend.
8909 // Scalar sizes must be a power of two.
8910 EVT OutScalarTy = VT.getScalarType();
8911 bool ValidTypes = SourceType != MVT::Other &&
8912 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
8913 isPowerOf2_32(SourceType.getSizeInBits());
8915 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
8916 // turn into a single shuffle instruction.
8920 bool isLE = TLI.isLittleEndian();
8921 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
8922 assert(ElemRatio > 1 && "Invalid element size ratio");
8923 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
8924 DAG.getConstant(0, SourceType);
8926 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
8927 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
8929 // Populate the new build_vector
8930 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
8931 SDValue Cast = N->getOperand(i);
8932 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
8933 Cast.getOpcode() == ISD::ZERO_EXTEND ||
8934 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
8936 if (Cast.getOpcode() == ISD::UNDEF)
8937 In = DAG.getUNDEF(SourceType);
8939 In = Cast->getOperand(0);
8940 unsigned Index = isLE ? (i * ElemRatio) :
8941 (i * ElemRatio + (ElemRatio - 1));
8943 assert(Index < Ops.size() && "Invalid index");
8947 // The type of the new BUILD_VECTOR node.
8948 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
8949 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
8950 "Invalid vector size");
8951 // Check if the new vector type is legal.
8952 if (!isTypeLegal(VecVT)) return SDValue();
8954 // Make the new BUILD_VECTOR.
8955 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, &Ops[0], Ops.size());
8957 // The new BUILD_VECTOR node has the potential to be further optimized.
8958 AddToWorkList(BV.getNode());
8959 // Bitcast to the desired type.
8960 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
8963 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
8964 EVT VT = N->getValueType(0);
8966 unsigned NumInScalars = N->getNumOperands();
8969 EVT SrcVT = MVT::Other;
8970 unsigned Opcode = ISD::DELETED_NODE;
8971 unsigned NumDefs = 0;
8973 for (unsigned i = 0; i != NumInScalars; ++i) {
8974 SDValue In = N->getOperand(i);
8975 unsigned Opc = In.getOpcode();
8977 if (Opc == ISD::UNDEF)
8980 // If all scalar values are floats and converted from integers.
8981 if (Opcode == ISD::DELETED_NODE &&
8982 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
8989 EVT InVT = In.getOperand(0).getValueType();
8991 // If all scalar values are typed differently, bail out. It's chosen to
8992 // simplify BUILD_VECTOR of integer types.
8993 if (SrcVT == MVT::Other)
9000 // If the vector has just one element defined, it's not worth to fold it into
9001 // a vectorized one.
9005 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
9006 && "Should only handle conversion from integer to float.");
9007 assert(SrcVT != MVT::Other && "Cannot determine source type!");
9009 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
9011 if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
9014 SmallVector<SDValue, 8> Opnds;
9015 for (unsigned i = 0; i != NumInScalars; ++i) {
9016 SDValue In = N->getOperand(i);
9018 if (In.getOpcode() == ISD::UNDEF)
9019 Opnds.push_back(DAG.getUNDEF(SrcVT));
9021 Opnds.push_back(In.getOperand(0));
9023 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
9024 &Opnds[0], Opnds.size());
9025 AddToWorkList(BV.getNode());
9027 return DAG.getNode(Opcode, dl, VT, BV);
9030 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
9031 unsigned NumInScalars = N->getNumOperands();
9033 EVT VT = N->getValueType(0);
9035 // A vector built entirely of undefs is undef.
9036 if (ISD::allOperandsUndef(N))
9037 return DAG.getUNDEF(VT);
9039 SDValue V = reduceBuildVecExtToExtBuildVec(N);
9043 V = reduceBuildVecConvertToConvertBuildVec(N);
9047 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
9048 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
9049 // at most two distinct vectors, turn this into a shuffle node.
9051 // May only combine to shuffle after legalize if shuffle is legal.
9052 if (LegalOperations &&
9053 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
9056 SDValue VecIn1, VecIn2;
9057 for (unsigned i = 0; i != NumInScalars; ++i) {
9058 // Ignore undef inputs.
9059 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
9061 // If this input is something other than a EXTRACT_VECTOR_ELT with a
9062 // constant index, bail out.
9063 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
9064 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
9065 VecIn1 = VecIn2 = SDValue(0, 0);
9069 // We allow up to two distinct input vectors.
9070 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
9071 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
9074 if (VecIn1.getNode() == 0) {
9075 VecIn1 = ExtractedFromVec;
9076 } else if (VecIn2.getNode() == 0) {
9077 VecIn2 = ExtractedFromVec;
9080 VecIn1 = VecIn2 = SDValue(0, 0);
9085 // If everything is good, we can make a shuffle operation.
9086 if (VecIn1.getNode()) {
9087 SmallVector<int, 8> Mask;
9088 for (unsigned i = 0; i != NumInScalars; ++i) {
9089 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
9094 // If extracting from the first vector, just use the index directly.
9095 SDValue Extract = N->getOperand(i);
9096 SDValue ExtVal = Extract.getOperand(1);
9097 if (Extract.getOperand(0) == VecIn1) {
9098 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
9099 if (ExtIndex > VT.getVectorNumElements())
9102 Mask.push_back(ExtIndex);
9106 // Otherwise, use InIdx + VecSize
9107 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
9108 Mask.push_back(Idx+NumInScalars);
9111 // We can't generate a shuffle node with mismatched input and output types.
9112 // Attempt to transform a single input vector to the correct type.
9113 if ((VT != VecIn1.getValueType())) {
9114 // We don't support shuffeling between TWO values of different types.
9115 if (VecIn2.getNode() != 0)
9118 // We only support widening of vectors which are half the size of the
9119 // output registers. For example XMM->YMM widening on X86 with AVX.
9120 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
9123 // If the input vector type has a different base type to the output
9124 // vector type, bail out.
9125 if (VecIn1.getValueType().getVectorElementType() !=
9126 VT.getVectorElementType())
9129 // Widen the input vector by adding undef values.
9130 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
9131 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
9134 // If VecIn2 is unused then change it to undef.
9135 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
9137 // Check that we were able to transform all incoming values to the same
9139 if (VecIn2.getValueType() != VecIn1.getValueType() ||
9140 VecIn1.getValueType() != VT)
9143 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
9144 if (!isTypeLegal(VT))
9147 // Return the new VECTOR_SHUFFLE node.
9151 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
9157 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
9158 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
9159 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
9160 // inputs come from at most two distinct vectors, turn this into a shuffle
9163 // If we only have one input vector, we don't need to do any concatenation.
9164 if (N->getNumOperands() == 1)
9165 return N->getOperand(0);
9167 // Check if all of the operands are undefs.
9168 if (ISD::allOperandsUndef(N))
9169 return DAG.getUNDEF(N->getValueType(0));
9171 // Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
9172 // nodes often generate nop CONCAT_VECTOR nodes.
9173 // Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
9174 // place the incoming vectors at the exact same location.
9175 SDValue SingleSource = SDValue();
9176 unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();
9178 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
9179 SDValue Op = N->getOperand(i);
9181 if (Op.getOpcode() == ISD::UNDEF)
9184 // Check if this is the identity extract:
9185 if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
9188 // Find the single incoming vector for the extract_subvector.
9189 if (SingleSource.getNode()) {
9190 if (Op.getOperand(0) != SingleSource)
9193 SingleSource = Op.getOperand(0);
9195 // Check the source type is the same as the type of the result.
9196 // If not, this concat may extend the vector, so we can not
9197 // optimize it away.
9198 if (SingleSource.getValueType() != N->getValueType(0))
9202 unsigned IdentityIndex = i * PartNumElem;
9203 ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
9204 // The extract index must be constant.
9208 // Check that we are reading from the identity index.
9209 if (CS->getZExtValue() != IdentityIndex)
9213 if (SingleSource.getNode())
9214 return SingleSource;
9219 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
9220 EVT NVT = N->getValueType(0);
9221 SDValue V = N->getOperand(0);
9223 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
9225 // (extract_subvec (concat V1, V2, ...), i)
9228 // Only operand 0 is checked as 'concat' assumes all inputs of the same type.
9229 if (V->getOperand(0).getValueType() != NVT)
9231 unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
9232 unsigned NumElems = NVT.getVectorNumElements();
9233 assert((Idx % NumElems) == 0 &&
9234 "IDX in concat is not a multiple of the result vector length.");
9235 return V->getOperand(Idx / NumElems);
9239 if (V->getOpcode() == ISD::BITCAST)
9240 V = V.getOperand(0);
9242 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
9244 // Handle only simple case where vector being inserted and vector
9245 // being extracted are of same type, and are half size of larger vectors.
9246 EVT BigVT = V->getOperand(0).getValueType();
9247 EVT SmallVT = V->getOperand(1).getValueType();
9248 if (!NVT.bitsEq(SmallVT) || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
9251 // Only handle cases where both indexes are constants with the same type.
9252 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
9253 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
9255 if (InsIdx && ExtIdx &&
9256 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
9257 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
9259 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
9261 // indices are equal or bit offsets are equal => V1
9262 // otherwise => (extract_subvec V1, ExtIdx)
9263 if (InsIdx->getZExtValue() * SmallVT.getScalarType().getSizeInBits() ==
9264 ExtIdx->getZExtValue() * NVT.getScalarType().getSizeInBits())
9265 return DAG.getNode(ISD::BITCAST, dl, NVT, V->getOperand(1));
9266 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT,
9267 DAG.getNode(ISD::BITCAST, dl,
9268 N->getOperand(0).getValueType(),
9269 V->getOperand(0)), N->getOperand(1));
9276 // Tries to turn a shuffle of two CONCAT_VECTORS into a single concat.
9277 static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
9278 EVT VT = N->getValueType(0);
9279 unsigned NumElts = VT.getVectorNumElements();
9281 SDValue N0 = N->getOperand(0);
9282 SDValue N1 = N->getOperand(1);
9283 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
9285 SmallVector<SDValue, 4> Ops;
9286 EVT ConcatVT = N0.getOperand(0).getValueType();
9287 unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
9288 unsigned NumConcats = NumElts / NumElemsPerConcat;
9290 // Look at every vector that's inserted. We're looking for exact
9291 // subvector-sized copies from a concatenated vector
9292 for (unsigned I = 0; I != NumConcats; ++I) {
9293 // Make sure we're dealing with a copy.
9294 unsigned Begin = I * NumElemsPerConcat;
9295 bool AllUndef = true, NoUndef = true;
9296 for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
9297 if (SVN->getMaskElt(J) >= 0)
9304 if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
9307 for (unsigned J = 1; J != NumElemsPerConcat; ++J)
9308 if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
9311 unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
9312 if (FirstElt < N0.getNumOperands())
9313 Ops.push_back(N0.getOperand(FirstElt));
9315 Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));
9317 } else if (AllUndef) {
9318 Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
9319 } else { // Mixed with general masks and undefs, can't do optimization.
9324 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops.data(),
9328 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
9329 EVT VT = N->getValueType(0);
9330 unsigned NumElts = VT.getVectorNumElements();
9332 SDValue N0 = N->getOperand(0);
9333 SDValue N1 = N->getOperand(1);
9335 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
9337 // Canonicalize shuffle undef, undef -> undef
9338 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
9339 return DAG.getUNDEF(VT);
9341 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
9343 // Canonicalize shuffle v, v -> v, undef
9345 SmallVector<int, 8> NewMask;
9346 for (unsigned i = 0; i != NumElts; ++i) {
9347 int Idx = SVN->getMaskElt(i);
9348 if (Idx >= (int)NumElts) Idx -= NumElts;
9349 NewMask.push_back(Idx);
9351 return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT),
9355 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
9356 if (N0.getOpcode() == ISD::UNDEF) {
9357 SmallVector<int, 8> NewMask;
9358 for (unsigned i = 0; i != NumElts; ++i) {
9359 int Idx = SVN->getMaskElt(i);
9361 if (Idx < (int)NumElts)
9366 NewMask.push_back(Idx);
9368 return DAG.getVectorShuffle(VT, SDLoc(N), N1, DAG.getUNDEF(VT),
9372 // Remove references to rhs if it is undef
9373 if (N1.getOpcode() == ISD::UNDEF) {
9374 bool Changed = false;
9375 SmallVector<int, 8> NewMask;
9376 for (unsigned i = 0; i != NumElts; ++i) {
9377 int Idx = SVN->getMaskElt(i);
9378 if (Idx >= (int)NumElts) {
9382 NewMask.push_back(Idx);
9385 return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, &NewMask[0]);
9388 // If it is a splat, check if the argument vector is another splat or a
9389 // build_vector with all scalar elements the same.
9390 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
9391 SDNode *V = N0.getNode();
9393 // If this is a bit convert that changes the element type of the vector but
9394 // not the number of vector elements, look through it. Be careful not to
9395 // look though conversions that change things like v4f32 to v2f64.
9396 if (V->getOpcode() == ISD::BITCAST) {
9397 SDValue ConvInput = V->getOperand(0);
9398 if (ConvInput.getValueType().isVector() &&
9399 ConvInput.getValueType().getVectorNumElements() == NumElts)
9400 V = ConvInput.getNode();
9403 if (V->getOpcode() == ISD::BUILD_VECTOR) {
9404 assert(V->getNumOperands() == NumElts &&
9405 "BUILD_VECTOR has wrong number of operands");
9407 bool AllSame = true;
9408 for (unsigned i = 0; i != NumElts; ++i) {
9409 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
9410 Base = V->getOperand(i);
9414 // Splat of <u, u, u, u>, return <u, u, u, u>
9415 if (!Base.getNode())
9417 for (unsigned i = 0; i != NumElts; ++i) {
9418 if (V->getOperand(i) != Base) {
9423 // Splat of <x, x, x, x>, return <x, x, x, x>
9429 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
9430 Level < AfterLegalizeVectorOps &&
9431 (N1.getOpcode() == ISD::UNDEF ||
9432 (N1.getOpcode() == ISD::CONCAT_VECTORS &&
9433 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
9434 SDValue V = partitionShuffleOfConcats(N, DAG);
9440 // If this shuffle node is simply a swizzle of another shuffle node,
9441 // and it reverses the swizzle of the previous shuffle then we can
9442 // optimize shuffle(shuffle(x, undef), undef) -> x.
9443 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
9444 N1.getOpcode() == ISD::UNDEF) {
9446 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
9448 // Shuffle nodes can only reverse shuffles with a single non-undef value.
9449 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
9452 // The incoming shuffle must be of the same type as the result of the
9454 assert(OtherSV->getOperand(0).getValueType() == VT &&
9455 "Shuffle types don't match");
9457 for (unsigned i = 0; i != NumElts; ++i) {
9458 int Idx = SVN->getMaskElt(i);
9459 assert(Idx < (int)NumElts && "Index references undef operand");
9460 // Next, this index comes from the first value, which is the incoming
9461 // shuffle. Adopt the incoming index.
9463 Idx = OtherSV->getMaskElt(Idx);
9465 // The combined shuffle must map each index to itself.
9466 if (Idx >= 0 && (unsigned)Idx != i)
9470 return OtherSV->getOperand(0);
9476 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
9477 /// an AND to a vector_shuffle with the destination vector and a zero vector.
9478 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
9479 /// vector_shuffle V, Zero, <0, 4, 2, 4>
9480 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
9481 EVT VT = N->getValueType(0);
9483 SDValue LHS = N->getOperand(0);
9484 SDValue RHS = N->getOperand(1);
9485 if (N->getOpcode() == ISD::AND) {
9486 if (RHS.getOpcode() == ISD::BITCAST)
9487 RHS = RHS.getOperand(0);
9488 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
9489 SmallVector<int, 8> Indices;
9490 unsigned NumElts = RHS.getNumOperands();
9491 for (unsigned i = 0; i != NumElts; ++i) {
9492 SDValue Elt = RHS.getOperand(i);
9493 if (!isa<ConstantSDNode>(Elt))
9496 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
9497 Indices.push_back(i);
9498 else if (cast<ConstantSDNode>(Elt)->isNullValue())
9499 Indices.push_back(NumElts);
9504 // Let's see if the target supports this vector_shuffle.
9505 EVT RVT = RHS.getValueType();
9506 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
9509 // Return the new VECTOR_SHUFFLE node.
9510 EVT EltVT = RVT.getVectorElementType();
9511 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
9512 DAG.getConstant(0, EltVT));
9513 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9514 RVT, &ZeroOps[0], ZeroOps.size());
9515 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
9516 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
9517 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
9524 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
9525 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
9526 assert(N->getValueType(0).isVector() &&
9527 "SimplifyVBinOp only works on vectors!");
9529 SDValue LHS = N->getOperand(0);
9530 SDValue RHS = N->getOperand(1);
9531 SDValue Shuffle = XformToShuffleWithZero(N);
9532 if (Shuffle.getNode()) return Shuffle;
9534 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
9536 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
9537 RHS.getOpcode() == ISD::BUILD_VECTOR) {
9538 SmallVector<SDValue, 8> Ops;
9539 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
9540 SDValue LHSOp = LHS.getOperand(i);
9541 SDValue RHSOp = RHS.getOperand(i);
9542 // If these two elements can't be folded, bail out.
9543 if ((LHSOp.getOpcode() != ISD::UNDEF &&
9544 LHSOp.getOpcode() != ISD::Constant &&
9545 LHSOp.getOpcode() != ISD::ConstantFP) ||
9546 (RHSOp.getOpcode() != ISD::UNDEF &&
9547 RHSOp.getOpcode() != ISD::Constant &&
9548 RHSOp.getOpcode() != ISD::ConstantFP))
9551 // Can't fold divide by zero.
9552 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
9553 N->getOpcode() == ISD::FDIV) {
9554 if ((RHSOp.getOpcode() == ISD::Constant &&
9555 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
9556 (RHSOp.getOpcode() == ISD::ConstantFP &&
9557 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
9561 EVT VT = LHSOp.getValueType();
9562 EVT RVT = RHSOp.getValueType();
9564 // Integer BUILD_VECTOR operands may have types larger than the element
9565 // size (e.g., when the element type is not legal). Prior to type
9566 // legalization, the types may not match between the two BUILD_VECTORS.
9567 // Truncate one of the operands to make them match.
9568 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
9569 RHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, RHSOp);
9571 LHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), RVT, LHSOp);
9575 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(LHS), VT,
9577 if (FoldOp.getOpcode() != ISD::UNDEF &&
9578 FoldOp.getOpcode() != ISD::Constant &&
9579 FoldOp.getOpcode() != ISD::ConstantFP)
9581 Ops.push_back(FoldOp);
9582 AddToWorkList(FoldOp.getNode());
9585 if (Ops.size() == LHS.getNumOperands())
9586 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9587 LHS.getValueType(), &Ops[0], Ops.size());
9593 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
9594 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
9595 assert(N->getValueType(0).isVector() &&
9596 "SimplifyVUnaryOp only works on vectors!");
9598 SDValue N0 = N->getOperand(0);
9600 if (N0.getOpcode() != ISD::BUILD_VECTOR)
9603 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
9604 SmallVector<SDValue, 8> Ops;
9605 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
9606 SDValue Op = N0.getOperand(i);
9607 if (Op.getOpcode() != ISD::UNDEF &&
9608 Op.getOpcode() != ISD::ConstantFP)
9610 EVT EltVT = Op.getValueType();
9611 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(N0), EltVT, Op);
9612 if (FoldOp.getOpcode() != ISD::UNDEF &&
9613 FoldOp.getOpcode() != ISD::ConstantFP)
9615 Ops.push_back(FoldOp);
9616 AddToWorkList(FoldOp.getNode());
9619 if (Ops.size() != N0.getNumOperands())
9622 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9623 N0.getValueType(), &Ops[0], Ops.size());
9626 SDValue DAGCombiner::SimplifySelect(SDLoc DL, SDValue N0,
9627 SDValue N1, SDValue N2){
9628 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
9630 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
9631 cast<CondCodeSDNode>(N0.getOperand(2))->get());
9633 // If we got a simplified select_cc node back from SimplifySelectCC, then
9634 // break it down into a new SETCC node, and a new SELECT node, and then return
9635 // the SELECT node, since we were called with a SELECT node.
9636 if (SCC.getNode()) {
9637 // Check to see if we got a select_cc back (to turn into setcc/select).
9638 // Otherwise, just return whatever node we got back, like fabs.
9639 if (SCC.getOpcode() == ISD::SELECT_CC) {
9640 SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
9642 SCC.getOperand(0), SCC.getOperand(1),
9644 AddToWorkList(SETCC.getNode());
9645 return DAG.getSelect(SDLoc(SCC), SCC.getValueType(),
9646 SCC.getOperand(2), SCC.getOperand(3), SETCC);
9654 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
9655 /// are the two values being selected between, see if we can simplify the
9656 /// select. Callers of this should assume that TheSelect is deleted if this
9657 /// returns true. As such, they should return the appropriate thing (e.g. the
9658 /// node) back to the top-level of the DAG combiner loop to avoid it being
9660 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
9663 // Cannot simplify select with vector condition
9664 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
9666 // If this is a select from two identical things, try to pull the operation
9667 // through the select.
9668 if (LHS.getOpcode() != RHS.getOpcode() ||
9669 !LHS.hasOneUse() || !RHS.hasOneUse())
9672 // If this is a load and the token chain is identical, replace the select
9673 // of two loads with a load through a select of the address to load from.
9674 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
9675 // constants have been dropped into the constant pool.
9676 if (LHS.getOpcode() == ISD::LOAD) {
9677 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
9678 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
9680 // Token chains must be identical.
9681 if (LHS.getOperand(0) != RHS.getOperand(0) ||
9682 // Do not let this transformation reduce the number of volatile loads.
9683 LLD->isVolatile() || RLD->isVolatile() ||
9684 // If this is an EXTLOAD, the VT's must match.
9685 LLD->getMemoryVT() != RLD->getMemoryVT() ||
9686 // If this is an EXTLOAD, the kind of extension must match.
9687 (LLD->getExtensionType() != RLD->getExtensionType() &&
9688 // The only exception is if one of the extensions is anyext.
9689 LLD->getExtensionType() != ISD::EXTLOAD &&
9690 RLD->getExtensionType() != ISD::EXTLOAD) ||
9691 // FIXME: this discards src value information. This is
9692 // over-conservative. It would be beneficial to be able to remember
9693 // both potential memory locations. Since we are discarding
9694 // src value info, don't do the transformation if the memory
9695 // locations are not in the default address space.
9696 LLD->getPointerInfo().getAddrSpace() != 0 ||
9697 RLD->getPointerInfo().getAddrSpace() != 0 ||
9698 !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
9699 LLD->getBasePtr().getValueType()))
9702 // Check that the select condition doesn't reach either load. If so,
9703 // folding this will induce a cycle into the DAG. If not, this is safe to
9704 // xform, so create a select of the addresses.
9706 if (TheSelect->getOpcode() == ISD::SELECT) {
9707 SDNode *CondNode = TheSelect->getOperand(0).getNode();
9708 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
9709 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
9711 // The loads must not depend on one another.
9712 if (LLD->isPredecessorOf(RLD) ||
9713 RLD->isPredecessorOf(LLD))
9715 Addr = DAG.getSelect(SDLoc(TheSelect),
9716 LLD->getBasePtr().getValueType(),
9717 TheSelect->getOperand(0), LLD->getBasePtr(),
9719 } else { // Otherwise SELECT_CC
9720 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
9721 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
9723 if ((LLD->hasAnyUseOfValue(1) &&
9724 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
9725 (RLD->hasAnyUseOfValue(1) &&
9726 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
9729 Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
9730 LLD->getBasePtr().getValueType(),
9731 TheSelect->getOperand(0),
9732 TheSelect->getOperand(1),
9733 LLD->getBasePtr(), RLD->getBasePtr(),
9734 TheSelect->getOperand(4));
9738 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
9739 Load = DAG.getLoad(TheSelect->getValueType(0),
9741 // FIXME: Discards pointer info.
9742 LLD->getChain(), Addr, MachinePointerInfo(),
9743 LLD->isVolatile(), LLD->isNonTemporal(),
9744 LLD->isInvariant(), LLD->getAlignment());
9746 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
9747 RLD->getExtensionType() : LLD->getExtensionType(),
9749 TheSelect->getValueType(0),
9750 // FIXME: Discards pointer info.
9751 LLD->getChain(), Addr, MachinePointerInfo(),
9752 LLD->getMemoryVT(), LLD->isVolatile(),
9753 LLD->isNonTemporal(), LLD->getAlignment());
9756 // Users of the select now use the result of the load.
9757 CombineTo(TheSelect, Load);
9759 // Users of the old loads now use the new load's chain. We know the
9760 // old-load value is dead now.
9761 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
9762 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
9769 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
9770 /// where 'cond' is the comparison specified by CC.
9771 SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
9772 SDValue N2, SDValue N3,
9773 ISD::CondCode CC, bool NotExtCompare) {
9774 // (x ? y : y) -> y.
9775 if (N2 == N3) return N2;
9777 EVT VT = N2.getValueType();
9778 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
9779 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
9780 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
9782 // Determine if the condition we're dealing with is constant
9783 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
9784 N0, N1, CC, DL, false);
9785 if (SCC.getNode()) AddToWorkList(SCC.getNode());
9786 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
9788 // fold select_cc true, x, y -> x
9789 if (SCCC && !SCCC->isNullValue())
9791 // fold select_cc false, x, y -> y
9792 if (SCCC && SCCC->isNullValue())
9795 // Check to see if we can simplify the select into an fabs node
9796 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
9797 // Allow either -0.0 or 0.0
9798 if (CFP->getValueAPF().isZero()) {
9799 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
9800 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
9801 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
9802 N2 == N3.getOperand(0))
9803 return DAG.getNode(ISD::FABS, DL, VT, N0);
9805 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
9806 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
9807 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
9808 N2.getOperand(0) == N3)
9809 return DAG.getNode(ISD::FABS, DL, VT, N3);
9813 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
9814 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
9815 // in it. This is a win when the constant is not otherwise available because
9816 // it replaces two constant pool loads with one. We only do this if the FP
9817 // type is known to be legal, because if it isn't, then we are before legalize
9818 // types an we want the other legalization to happen first (e.g. to avoid
9819 // messing with soft float) and if the ConstantFP is not legal, because if
9820 // it is legal, we may not need to store the FP constant in a constant pool.
9821 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
9822 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
9823 if (TLI.isTypeLegal(N2.getValueType()) &&
9824 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
9825 TargetLowering::Legal) &&
9826 // If both constants have multiple uses, then we won't need to do an
9827 // extra load, they are likely around in registers for other users.
9828 (TV->hasOneUse() || FV->hasOneUse())) {
9829 Constant *Elts[] = {
9830 const_cast<ConstantFP*>(FV->getConstantFPValue()),
9831 const_cast<ConstantFP*>(TV->getConstantFPValue())
9833 Type *FPTy = Elts[0]->getType();
9834 const DataLayout &TD = *TLI.getDataLayout();
9836 // Create a ConstantArray of the two constants.
9837 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
9838 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
9839 TD.getPrefTypeAlignment(FPTy));
9840 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
9842 // Get the offsets to the 0 and 1 element of the array so that we can
9843 // select between them.
9844 SDValue Zero = DAG.getIntPtrConstant(0);
9845 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
9846 SDValue One = DAG.getIntPtrConstant(EltSize);
9848 SDValue Cond = DAG.getSetCC(DL,
9849 getSetCCResultType(N0.getValueType()),
9851 AddToWorkList(Cond.getNode());
9852 SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
9854 AddToWorkList(CstOffset.getNode());
9855 CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
9857 AddToWorkList(CPIdx.getNode());
9858 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
9859 MachinePointerInfo::getConstantPool(), false,
9860 false, false, Alignment);
9865 // Check to see if we can perform the "gzip trick", transforming
9866 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
9867 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
9868 (N1C->isNullValue() || // (a < 0) ? b : 0
9869 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
9870 EVT XType = N0.getValueType();
9871 EVT AType = N2.getValueType();
9872 if (XType.bitsGE(AType)) {
9873 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
9874 // single-bit constant.
9875 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
9876 unsigned ShCtV = N2C->getAPIntValue().logBase2();
9877 ShCtV = XType.getSizeInBits()-ShCtV-1;
9878 SDValue ShCt = DAG.getConstant(ShCtV,
9879 getShiftAmountTy(N0.getValueType()));
9880 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0),
9882 AddToWorkList(Shift.getNode());
9884 if (XType.bitsGT(AType)) {
9885 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9886 AddToWorkList(Shift.getNode());
9889 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9892 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0),
9894 DAG.getConstant(XType.getSizeInBits()-1,
9895 getShiftAmountTy(N0.getValueType())));
9896 AddToWorkList(Shift.getNode());
9898 if (XType.bitsGT(AType)) {
9899 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9900 AddToWorkList(Shift.getNode());
9903 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9907 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
9908 // where y is has a single bit set.
9909 // A plaintext description would be, we can turn the SELECT_CC into an AND
9910 // when the condition can be materialized as an all-ones register. Any
9911 // single bit-test can be materialized as an all-ones register with
9912 // shift-left and shift-right-arith.
9913 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
9914 N0->getValueType(0) == VT &&
9915 N1C && N1C->isNullValue() &&
9916 N2C && N2C->isNullValue()) {
9917 SDValue AndLHS = N0->getOperand(0);
9918 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
9919 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
9920 // Shift the tested bit over the sign bit.
9921 APInt AndMask = ConstAndRHS->getAPIntValue();
9923 DAG.getConstant(AndMask.countLeadingZeros(),
9924 getShiftAmountTy(AndLHS.getValueType()));
9925 SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);
9927 // Now arithmetic right shift it all the way over, so the result is either
9928 // all-ones, or zero.
9930 DAG.getConstant(AndMask.getBitWidth()-1,
9931 getShiftAmountTy(Shl.getValueType()));
9932 SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);
9934 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
9938 // fold select C, 16, 0 -> shl C, 4
9939 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
9940 TLI.getBooleanContents(N0.getValueType().isVector()) ==
9941 TargetLowering::ZeroOrOneBooleanContent) {
9943 // If the caller doesn't want us to simplify this into a zext of a compare,
9945 if (NotExtCompare && N2C->getAPIntValue() == 1)
9948 // Get a SetCC of the condition
9949 // NOTE: Don't create a SETCC if it's not legal on this target.
9950 if (!LegalOperations ||
9951 TLI.isOperationLegal(ISD::SETCC,
9952 LegalTypes ? getSetCCResultType(N0.getValueType()) : MVT::i1)) {
9954 // cast from setcc result type to select result type
9956 SCC = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
9958 if (N2.getValueType().bitsLT(SCC.getValueType()))
9959 Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
9962 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
9963 N2.getValueType(), SCC);
9965 SCC = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
9966 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
9967 N2.getValueType(), SCC);
9970 AddToWorkList(SCC.getNode());
9971 AddToWorkList(Temp.getNode());
9973 if (N2C->getAPIntValue() == 1)
9976 // shl setcc result by log2 n2c
9977 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
9978 DAG.getConstant(N2C->getAPIntValue().logBase2(),
9979 getShiftAmountTy(Temp.getValueType())));
9983 // Check to see if this is the equivalent of setcc
9984 // FIXME: Turn all of these into setcc if setcc if setcc is legal
9985 // otherwise, go ahead with the folds.
9986 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
9987 EVT XType = N0.getValueType();
9988 if (!LegalOperations ||
9989 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(XType))) {
9990 SDValue Res = DAG.getSetCC(DL, getSetCCResultType(XType), N0, N1, CC);
9991 if (Res.getValueType() != VT)
9992 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
9996 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
9997 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
9998 (!LegalOperations ||
9999 TLI.isOperationLegal(ISD::CTLZ, XType))) {
10000 SDValue Ctlz = DAG.getNode(ISD::CTLZ, SDLoc(N0), XType, N0);
10001 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
10002 DAG.getConstant(Log2_32(XType.getSizeInBits()),
10003 getShiftAmountTy(Ctlz.getValueType())));
10005 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
10006 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
10007 SDValue NegN0 = DAG.getNode(ISD::SUB, SDLoc(N0),
10008 XType, DAG.getConstant(0, XType), N0);
10009 SDValue NotN0 = DAG.getNOT(SDLoc(N0), N0, XType);
10010 return DAG.getNode(ISD::SRL, DL, XType,
10011 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
10012 DAG.getConstant(XType.getSizeInBits()-1,
10013 getShiftAmountTy(XType)));
10015 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
10016 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
10017 SDValue Sign = DAG.getNode(ISD::SRL, SDLoc(N0), XType, N0,
10018 DAG.getConstant(XType.getSizeInBits()-1,
10019 getShiftAmountTy(N0.getValueType())));
10020 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
10024 // Check to see if this is an integer abs.
10025 // select_cc setg[te] X, 0, X, -X ->
10026 // select_cc setgt X, -1, X, -X ->
10027 // select_cc setl[te] X, 0, -X, X ->
10028 // select_cc setlt X, 1, -X, X ->
10029 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
10031 ConstantSDNode *SubC = NULL;
10032 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
10033 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
10034 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
10035 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
10036 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
10037 (N1C->isOne() && CC == ISD::SETLT)) &&
10038 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
10039 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
10041 EVT XType = N0.getValueType();
10042 if (SubC && SubC->isNullValue() && XType.isInteger()) {
10043 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0), XType,
10045 DAG.getConstant(XType.getSizeInBits()-1,
10046 getShiftAmountTy(N0.getValueType())));
10047 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N0),
10049 AddToWorkList(Shift.getNode());
10050 AddToWorkList(Add.getNode());
10051 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
10058 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
10059 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
10060 SDValue N1, ISD::CondCode Cond,
10061 SDLoc DL, bool foldBooleans) {
10062 TargetLowering::DAGCombinerInfo
10063 DagCombineInfo(DAG, Level, false, this);
10064 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
10067 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
10068 /// return a DAG expression to select that will generate the same value by
10069 /// multiplying by a magic number. See:
10070 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
10071 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
10072 std::vector<SDNode*> Built;
10073 SDValue S = TLI.BuildSDIV(N, DAG, LegalOperations, &Built);
10075 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
10077 AddToWorkList(*ii);
10081 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
10082 /// return a DAG expression to select that will generate the same value by
10083 /// multiplying by a magic number. See:
10084 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
10085 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
10086 std::vector<SDNode*> Built;
10087 SDValue S = TLI.BuildUDIV(N, DAG, LegalOperations, &Built);
10089 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
10091 AddToWorkList(*ii);
10095 /// FindBaseOffset - Return true if base is a frame index, which is known not
10096 // to alias with anything but itself. Provides base object and offset as
10098 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
10099 const GlobalValue *&GV, const void *&CV) {
10100 // Assume it is a primitive operation.
10101 Base = Ptr; Offset = 0; GV = 0; CV = 0;
10103 // If it's an adding a simple constant then integrate the offset.
10104 if (Base.getOpcode() == ISD::ADD) {
10105 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
10106 Base = Base.getOperand(0);
10107 Offset += C->getZExtValue();
10111 // Return the underlying GlobalValue, and update the Offset. Return false
10112 // for GlobalAddressSDNode since the same GlobalAddress may be represented
10113 // by multiple nodes with different offsets.
10114 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
10115 GV = G->getGlobal();
10116 Offset += G->getOffset();
10120 // Return the underlying Constant value, and update the Offset. Return false
10121 // for ConstantSDNodes since the same constant pool entry may be represented
10122 // by multiple nodes with different offsets.
10123 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
10124 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
10125 : (const void *)C->getConstVal();
10126 Offset += C->getOffset();
10129 // If it's any of the following then it can't alias with anything but itself.
10130 return isa<FrameIndexSDNode>(Base);
10133 /// isAlias - Return true if there is any possibility that the two addresses
10135 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
10136 const Value *SrcValue1, int SrcValueOffset1,
10137 unsigned SrcValueAlign1,
10138 const MDNode *TBAAInfo1,
10139 SDValue Ptr2, int64_t Size2,
10140 const Value *SrcValue2, int SrcValueOffset2,
10141 unsigned SrcValueAlign2,
10142 const MDNode *TBAAInfo2) const {
10143 // If they are the same then they must be aliases.
10144 if (Ptr1 == Ptr2) return true;
10146 // Gather base node and offset information.
10147 SDValue Base1, Base2;
10148 int64_t Offset1, Offset2;
10149 const GlobalValue *GV1, *GV2;
10150 const void *CV1, *CV2;
10151 bool isFrameIndex1 = FindBaseOffset(Ptr1, Base1, Offset1, GV1, CV1);
10152 bool isFrameIndex2 = FindBaseOffset(Ptr2, Base2, Offset2, GV2, CV2);
10154 // If they have a same base address then check to see if they overlap.
10155 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
10156 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
10158 // It is possible for different frame indices to alias each other, mostly
10159 // when tail call optimization reuses return address slots for arguments.
10160 // To catch this case, look up the actual index of frame indices to compute
10161 // the real alias relationship.
10162 if (isFrameIndex1 && isFrameIndex2) {
10163 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
10164 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
10165 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
10166 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
10169 // Otherwise, if we know what the bases are, and they aren't identical, then
10170 // we know they cannot alias.
10171 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
10174 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
10175 // compared to the size and offset of the access, we may be able to prove they
10176 // do not alias. This check is conservative for now to catch cases created by
10177 // splitting vector types.
10178 if ((SrcValueAlign1 == SrcValueAlign2) &&
10179 (SrcValueOffset1 != SrcValueOffset2) &&
10180 (Size1 == Size2) && (SrcValueAlign1 > Size1)) {
10181 int64_t OffAlign1 = SrcValueOffset1 % SrcValueAlign1;
10182 int64_t OffAlign2 = SrcValueOffset2 % SrcValueAlign1;
10184 // There is no overlap between these relatively aligned accesses of similar
10185 // size, return no alias.
10186 if ((OffAlign1 + Size1) <= OffAlign2 || (OffAlign2 + Size2) <= OffAlign1)
10190 if (CombinerGlobalAA) {
10191 // Use alias analysis information.
10192 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
10193 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
10194 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
10195 AliasAnalysis::AliasResult AAResult =
10196 AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
10197 AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
10198 if (AAResult == AliasAnalysis::NoAlias)
10202 // Otherwise we have to assume they alias.
10206 bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) {
10207 SDValue Ptr0, Ptr1;
10208 int64_t Size0, Size1;
10209 const Value *SrcValue0, *SrcValue1;
10210 int SrcValueOffset0, SrcValueOffset1;
10211 unsigned SrcValueAlign0, SrcValueAlign1;
10212 const MDNode *SrcTBAAInfo0, *SrcTBAAInfo1;
10213 FindAliasInfo(Op0, Ptr0, Size0, SrcValue0, SrcValueOffset0,
10214 SrcValueAlign0, SrcTBAAInfo0);
10215 FindAliasInfo(Op1, Ptr1, Size1, SrcValue1, SrcValueOffset1,
10216 SrcValueAlign1, SrcTBAAInfo1);
10217 return isAlias(Ptr0, Size0, SrcValue0, SrcValueOffset0,
10218 SrcValueAlign0, SrcTBAAInfo0,
10219 Ptr1, Size1, SrcValue1, SrcValueOffset1,
10220 SrcValueAlign1, SrcTBAAInfo1);
10223 /// FindAliasInfo - Extracts the relevant alias information from the memory
10224 /// node. Returns true if the operand was a load.
10225 bool DAGCombiner::FindAliasInfo(SDNode *N,
10226 SDValue &Ptr, int64_t &Size,
10227 const Value *&SrcValue,
10228 int &SrcValueOffset,
10229 unsigned &SrcValueAlign,
10230 const MDNode *&TBAAInfo) const {
10231 LSBaseSDNode *LS = cast<LSBaseSDNode>(N);
10233 Ptr = LS->getBasePtr();
10234 Size = LS->getMemoryVT().getSizeInBits() >> 3;
10235 SrcValue = LS->getSrcValue();
10236 SrcValueOffset = LS->getSrcValueOffset();
10237 SrcValueAlign = LS->getOriginalAlignment();
10238 TBAAInfo = LS->getTBAAInfo();
10239 return isa<LoadSDNode>(LS);
10242 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
10243 /// looking for aliasing nodes and adding them to the Aliases vector.
10244 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
10245 SmallVectorImpl<SDValue> &Aliases) {
10246 SmallVector<SDValue, 8> Chains; // List of chains to visit.
10247 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
10249 // Get alias information for node.
10252 const Value *SrcValue;
10253 int SrcValueOffset;
10254 unsigned SrcValueAlign;
10255 const MDNode *SrcTBAAInfo;
10256 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
10257 SrcValueAlign, SrcTBAAInfo);
10260 Chains.push_back(OriginalChain);
10261 unsigned Depth = 0;
10263 // Look at each chain and determine if it is an alias. If so, add it to the
10264 // aliases list. If not, then continue up the chain looking for the next
10266 while (!Chains.empty()) {
10267 SDValue Chain = Chains.back();
10270 // For TokenFactor nodes, look at each operand and only continue up the
10271 // chain until we find two aliases. If we've seen two aliases, assume we'll
10272 // find more and revert to original chain since the xform is unlikely to be
10275 // FIXME: The depth check could be made to return the last non-aliasing
10276 // chain we found before we hit a tokenfactor rather than the original
10278 if (Depth > 6 || Aliases.size() == 2) {
10280 Aliases.push_back(OriginalChain);
10284 // Don't bother if we've been before.
10285 if (!Visited.insert(Chain.getNode()))
10288 switch (Chain.getOpcode()) {
10289 case ISD::EntryToken:
10290 // Entry token is ideal chain operand, but handled in FindBetterChain.
10295 // Get alias information for Chain.
10298 const Value *OpSrcValue;
10299 int OpSrcValueOffset;
10300 unsigned OpSrcValueAlign;
10301 const MDNode *OpSrcTBAAInfo;
10302 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
10303 OpSrcValue, OpSrcValueOffset,
10307 // If chain is alias then stop here.
10308 if (!(IsLoad && IsOpLoad) &&
10309 isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
10311 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
10312 OpSrcValueAlign, OpSrcTBAAInfo)) {
10313 Aliases.push_back(Chain);
10315 // Look further up the chain.
10316 Chains.push_back(Chain.getOperand(0));
10322 case ISD::TokenFactor:
10323 // We have to check each of the operands of the token factor for "small"
10324 // token factors, so we queue them up. Adding the operands to the queue
10325 // (stack) in reverse order maintains the original order and increases the
10326 // likelihood that getNode will find a matching token factor (CSE.)
10327 if (Chain.getNumOperands() > 16) {
10328 Aliases.push_back(Chain);
10331 for (unsigned n = Chain.getNumOperands(); n;)
10332 Chains.push_back(Chain.getOperand(--n));
10337 // For all other instructions we will just have to take what we can get.
10338 Aliases.push_back(Chain);
10344 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
10345 /// for a better chain (aliasing node.)
10346 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
10347 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
10349 // Accumulate all the aliases to this node.
10350 GatherAllAliases(N, OldChain, Aliases);
10352 // If no operands then chain to entry token.
10353 if (Aliases.size() == 0)
10354 return DAG.getEntryNode();
10356 // If a single operand then chain to it. We don't need to revisit it.
10357 if (Aliases.size() == 1)
10360 // Construct a custom tailored token factor.
10361 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
10362 &Aliases[0], Aliases.size());
10365 // SelectionDAG::Combine - This is the entry point for the file.
10367 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
10368 CodeGenOpt::Level OptLevel) {
10369 /// run - This is the main entry point to this class.
10371 DAGCombiner(*this, AA, OptLevel).Run(Level);