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"
38 #include "llvm/Target/TargetSubtargetInfo.h"
42 STATISTIC(NodesCombined , "Number of dag nodes combined");
43 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
44 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
45 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
46 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
50 CombinerAA("combiner-alias-analysis", cl::Hidden,
51 cl::desc("Turn on alias analysis during testing"));
54 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
55 cl::desc("Include global information in alias analysis"));
57 //------------------------------ DAGCombiner ---------------------------------//
61 const TargetLowering &TLI;
63 CodeGenOpt::Level OptLevel;
67 // Worklist of all of the nodes that need to be simplified.
69 // This has the semantics that when adding to the worklist,
70 // the item added must be next to be processed. It should
71 // also only appear once. The naive approach to this takes
74 // To reduce the insert/remove time to logarithmic, we use
75 // a set and a vector to maintain our worklist.
77 // The set contains the items on the worklist, but does not
78 // maintain the order they should be visited.
80 // The vector maintains the order nodes should be visited, but may
81 // contain duplicate or removed nodes. When choosing a node to
82 // visit, we pop off the order stack until we find an item that is
83 // also in the contents set. All operations are O(log N).
84 SmallPtrSet<SDNode*, 64> WorkListContents;
85 SmallVector<SDNode*, 64> WorkListOrder;
87 // AA - Used for DAG load/store alias analysis.
90 /// AddUsersToWorkList - When an instruction is simplified, add all users of
91 /// the instruction to the work lists because they might get more simplified
94 void AddUsersToWorkList(SDNode *N) {
95 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
100 /// visit - call the node-specific routine that knows how to fold each
101 /// particular type of node.
102 SDValue visit(SDNode *N);
105 /// AddToWorkList - Add to the work list making sure its instance is at the
106 /// back (next to be processed.)
107 void AddToWorkList(SDNode *N) {
108 WorkListContents.insert(N);
109 WorkListOrder.push_back(N);
112 /// removeFromWorkList - remove all instances of N from the worklist.
114 void removeFromWorkList(SDNode *N) {
115 WorkListContents.erase(N);
118 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
121 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
122 return CombineTo(N, &Res, 1, AddTo);
125 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
127 SDValue To[] = { Res0, Res1 };
128 return CombineTo(N, To, 2, AddTo);
131 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
135 /// SimplifyDemandedBits - Check the specified integer node value to see if
136 /// it can be simplified or if things it uses can be simplified by bit
137 /// propagation. If so, return true.
138 bool SimplifyDemandedBits(SDValue Op) {
139 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
140 APInt Demanded = APInt::getAllOnesValue(BitWidth);
141 return SimplifyDemandedBits(Op, Demanded);
144 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
146 bool CombineToPreIndexedLoadStore(SDNode *N);
147 bool CombineToPostIndexedLoadStore(SDNode *N);
149 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
150 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
151 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
152 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
153 SDValue PromoteIntBinOp(SDValue Op);
154 SDValue PromoteIntShiftOp(SDValue Op);
155 SDValue PromoteExtend(SDValue Op);
156 bool PromoteLoad(SDValue Op);
158 void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
159 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
160 ISD::NodeType ExtType);
162 /// combine - call the node-specific routine that knows how to fold each
163 /// particular type of node. If that doesn't do anything, try the
164 /// target-specific DAG combines.
165 SDValue combine(SDNode *N);
167 // Visitation implementation - Implement dag node combining for different
168 // node types. The semantics are as follows:
170 // SDValue.getNode() == 0 - No change was made
171 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
172 // otherwise - N should be replaced by the returned Operand.
174 SDValue visitTokenFactor(SDNode *N);
175 SDValue visitMERGE_VALUES(SDNode *N);
176 SDValue visitADD(SDNode *N);
177 SDValue visitSUB(SDNode *N);
178 SDValue visitADDC(SDNode *N);
179 SDValue visitSUBC(SDNode *N);
180 SDValue visitADDE(SDNode *N);
181 SDValue visitSUBE(SDNode *N);
182 SDValue visitMUL(SDNode *N);
183 SDValue visitSDIV(SDNode *N);
184 SDValue visitUDIV(SDNode *N);
185 SDValue visitSREM(SDNode *N);
186 SDValue visitUREM(SDNode *N);
187 SDValue visitMULHU(SDNode *N);
188 SDValue visitMULHS(SDNode *N);
189 SDValue visitSMUL_LOHI(SDNode *N);
190 SDValue visitUMUL_LOHI(SDNode *N);
191 SDValue visitSMULO(SDNode *N);
192 SDValue visitUMULO(SDNode *N);
193 SDValue visitSDIVREM(SDNode *N);
194 SDValue visitUDIVREM(SDNode *N);
195 SDValue visitAND(SDNode *N);
196 SDValue visitOR(SDNode *N);
197 SDValue visitXOR(SDNode *N);
198 SDValue SimplifyVBinOp(SDNode *N);
199 SDValue SimplifyVUnaryOp(SDNode *N);
200 SDValue visitSHL(SDNode *N);
201 SDValue visitSRA(SDNode *N);
202 SDValue visitSRL(SDNode *N);
203 SDValue visitCTLZ(SDNode *N);
204 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
205 SDValue visitCTTZ(SDNode *N);
206 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
207 SDValue visitCTPOP(SDNode *N);
208 SDValue visitSELECT(SDNode *N);
209 SDValue visitVSELECT(SDNode *N);
210 SDValue visitSELECT_CC(SDNode *N);
211 SDValue visitSETCC(SDNode *N);
212 SDValue visitSIGN_EXTEND(SDNode *N);
213 SDValue visitZERO_EXTEND(SDNode *N);
214 SDValue visitANY_EXTEND(SDNode *N);
215 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
216 SDValue visitTRUNCATE(SDNode *N);
217 SDValue visitBITCAST(SDNode *N);
218 SDValue visitBUILD_PAIR(SDNode *N);
219 SDValue visitFADD(SDNode *N);
220 SDValue visitFSUB(SDNode *N);
221 SDValue visitFMUL(SDNode *N);
222 SDValue visitFMA(SDNode *N);
223 SDValue visitFDIV(SDNode *N);
224 SDValue visitFREM(SDNode *N);
225 SDValue visitFCOPYSIGN(SDNode *N);
226 SDValue visitSINT_TO_FP(SDNode *N);
227 SDValue visitUINT_TO_FP(SDNode *N);
228 SDValue visitFP_TO_SINT(SDNode *N);
229 SDValue visitFP_TO_UINT(SDNode *N);
230 SDValue visitFP_ROUND(SDNode *N);
231 SDValue visitFP_ROUND_INREG(SDNode *N);
232 SDValue visitFP_EXTEND(SDNode *N);
233 SDValue visitFNEG(SDNode *N);
234 SDValue visitFABS(SDNode *N);
235 SDValue visitFCEIL(SDNode *N);
236 SDValue visitFTRUNC(SDNode *N);
237 SDValue visitFFLOOR(SDNode *N);
238 SDValue visitBRCOND(SDNode *N);
239 SDValue visitBR_CC(SDNode *N);
240 SDValue visitLOAD(SDNode *N);
241 SDValue visitSTORE(SDNode *N);
242 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
243 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
244 SDValue visitBUILD_VECTOR(SDNode *N);
245 SDValue visitCONCAT_VECTORS(SDNode *N);
246 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
247 SDValue visitVECTOR_SHUFFLE(SDNode *N);
249 SDValue XformToShuffleWithZero(SDNode *N);
250 SDValue ReassociateOps(unsigned Opc, SDLoc DL, SDValue LHS, SDValue RHS);
252 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
254 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
255 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
256 SDValue SimplifySelect(SDLoc DL, SDValue N0, SDValue N1, SDValue N2);
257 SDValue SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1, SDValue N2,
258 SDValue N3, ISD::CondCode CC,
259 bool NotExtCompare = false);
260 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
261 SDLoc DL, bool foldBooleans = true);
262 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
264 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
265 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
266 SDValue BuildSDIV(SDNode *N);
267 SDValue BuildUDIV(SDNode *N);
268 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
269 bool DemandHighBits = true);
270 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
271 SDNode *MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL);
272 SDValue ReduceLoadWidth(SDNode *N);
273 SDValue ReduceLoadOpStoreWidth(SDNode *N);
274 SDValue TransformFPLoadStorePair(SDNode *N);
275 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
276 SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
278 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
280 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
281 /// looking for aliasing nodes and adding them to the Aliases vector.
282 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
283 SmallVectorImpl<SDValue> &Aliases);
285 /// isAlias - Return true if there is any possibility that the two addresses
287 bool isAlias(SDValue Ptr1, int64_t Size1,
288 const Value *SrcValue1, int SrcValueOffset1,
289 unsigned SrcValueAlign1,
290 const MDNode *TBAAInfo1,
291 SDValue Ptr2, int64_t Size2,
292 const Value *SrcValue2, int SrcValueOffset2,
293 unsigned SrcValueAlign2,
294 const MDNode *TBAAInfo2) const;
296 /// isAlias - Return true if there is any possibility that the two addresses
298 bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1);
300 /// FindAliasInfo - Extracts the relevant alias information from the memory
301 /// node. Returns true if the operand was a load.
302 bool FindAliasInfo(SDNode *N,
303 SDValue &Ptr, int64_t &Size,
304 const Value *&SrcValue, int &SrcValueOffset,
305 unsigned &SrcValueAlignment,
306 const MDNode *&TBAAInfo) const;
308 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
309 /// looking for a better chain (aliasing node.)
310 SDValue FindBetterChain(SDNode *N, SDValue Chain);
312 /// Merge consecutive store operations into a wide store.
313 /// This optimization uses wide integers or vectors when possible.
314 /// \return True if some memory operations were changed.
315 bool MergeConsecutiveStores(StoreSDNode *N);
318 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
319 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
320 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
322 /// Run - runs the dag combiner on all nodes in the work list
323 void Run(CombineLevel AtLevel);
325 SelectionDAG &getDAG() const { return DAG; }
327 /// getShiftAmountTy - Returns a type large enough to hold any valid
328 /// shift amount - before type legalization these can be huge.
329 EVT getShiftAmountTy(EVT LHSTy) {
330 assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
331 if (LHSTy.isVector())
333 return LegalTypes ? TLI.getScalarShiftAmountTy(LHSTy) : TLI.getPointerTy();
336 /// isTypeLegal - This method returns true if we are running before type
337 /// legalization or if the specified VT is legal.
338 bool isTypeLegal(const EVT &VT) {
339 if (!LegalTypes) return true;
340 return TLI.isTypeLegal(VT);
343 /// getSetCCResultType - Convenience wrapper around
344 /// TargetLowering::getSetCCResultType
345 EVT getSetCCResultType(EVT VT) const {
346 return TLI.getSetCCResultType(*DAG.getContext(), VT);
353 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
354 /// nodes from the worklist.
355 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
358 explicit WorkListRemover(DAGCombiner &dc)
359 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
361 virtual void NodeDeleted(SDNode *N, SDNode *E) {
362 DC.removeFromWorkList(N);
367 //===----------------------------------------------------------------------===//
368 // TargetLowering::DAGCombinerInfo implementation
369 //===----------------------------------------------------------------------===//
371 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
372 ((DAGCombiner*)DC)->AddToWorkList(N);
375 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
376 ((DAGCombiner*)DC)->removeFromWorkList(N);
379 SDValue TargetLowering::DAGCombinerInfo::
380 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
381 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
384 SDValue TargetLowering::DAGCombinerInfo::
385 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
386 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
390 SDValue TargetLowering::DAGCombinerInfo::
391 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
392 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
395 void TargetLowering::DAGCombinerInfo::
396 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
397 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
400 //===----------------------------------------------------------------------===//
402 //===----------------------------------------------------------------------===//
404 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
405 /// specified expression for the same cost as the expression itself, or 2 if we
406 /// can compute the negated form more cheaply than the expression itself.
407 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
408 const TargetLowering &TLI,
409 const TargetOptions *Options,
410 unsigned Depth = 0) {
411 // fneg is removable even if it has multiple uses.
412 if (Op.getOpcode() == ISD::FNEG) return 2;
414 // Don't allow anything with multiple uses.
415 if (!Op.hasOneUse()) return 0;
417 // Don't recurse exponentially.
418 if (Depth > 6) return 0;
420 switch (Op.getOpcode()) {
421 default: return false;
422 case ISD::ConstantFP:
423 // Don't invert constant FP values after legalize. The negated constant
424 // isn't necessarily legal.
425 return LegalOperations ? 0 : 1;
427 // FIXME: determine better conditions for this xform.
428 if (!Options->UnsafeFPMath) return 0;
430 // After operation legalization, it might not be legal to create new FSUBs.
431 if (LegalOperations &&
432 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
435 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
436 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
439 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
440 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
443 // We can't turn -(A-B) into B-A when we honor signed zeros.
444 if (!Options->UnsafeFPMath) return 0;
446 // fold (fneg (fsub A, B)) -> (fsub B, A)
451 if (Options->HonorSignDependentRoundingFPMath()) return 0;
453 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
454 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
458 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
464 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
469 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
470 /// returns the newly negated expression.
471 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
472 bool LegalOperations, unsigned Depth = 0) {
473 // fneg is removable even if it has multiple uses.
474 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
476 // Don't allow anything with multiple uses.
477 assert(Op.hasOneUse() && "Unknown reuse!");
479 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
480 switch (Op.getOpcode()) {
481 default: llvm_unreachable("Unknown code");
482 case ISD::ConstantFP: {
483 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
485 return DAG.getConstantFP(V, Op.getValueType());
488 // FIXME: determine better conditions for this xform.
489 assert(DAG.getTarget().Options.UnsafeFPMath);
491 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
492 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
493 DAG.getTargetLoweringInfo(),
494 &DAG.getTarget().Options, Depth+1))
495 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
496 GetNegatedExpression(Op.getOperand(0), DAG,
497 LegalOperations, Depth+1),
499 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
500 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
501 GetNegatedExpression(Op.getOperand(1), DAG,
502 LegalOperations, Depth+1),
505 // We can't turn -(A-B) into B-A when we honor signed zeros.
506 assert(DAG.getTarget().Options.UnsafeFPMath);
508 // fold (fneg (fsub 0, B)) -> B
509 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
510 if (N0CFP->getValueAPF().isZero())
511 return Op.getOperand(1);
513 // fold (fneg (fsub A, B)) -> (fsub B, A)
514 return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
515 Op.getOperand(1), Op.getOperand(0));
519 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
521 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
522 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
523 DAG.getTargetLoweringInfo(),
524 &DAG.getTarget().Options, Depth+1))
525 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
526 GetNegatedExpression(Op.getOperand(0), DAG,
527 LegalOperations, Depth+1),
530 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
531 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
533 GetNegatedExpression(Op.getOperand(1), DAG,
534 LegalOperations, Depth+1));
538 return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
539 GetNegatedExpression(Op.getOperand(0), DAG,
540 LegalOperations, Depth+1));
542 return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
543 GetNegatedExpression(Op.getOperand(0), DAG,
544 LegalOperations, Depth+1),
550 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
551 // that selects between the values 1 and 0, making it equivalent to a setcc.
552 // Also, set the incoming LHS, RHS, and CC references to the appropriate
553 // nodes based on the type of node we are checking. This simplifies life a
554 // bit for the callers.
555 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
557 if (N.getOpcode() == ISD::SETCC) {
558 LHS = N.getOperand(0);
559 RHS = N.getOperand(1);
560 CC = N.getOperand(2);
563 if (N.getOpcode() == ISD::SELECT_CC &&
564 N.getOperand(2).getOpcode() == ISD::Constant &&
565 N.getOperand(3).getOpcode() == ISD::Constant &&
566 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
567 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
568 LHS = N.getOperand(0);
569 RHS = N.getOperand(1);
570 CC = N.getOperand(4);
576 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
577 // one use. If this is true, it allows the users to invert the operation for
578 // free when it is profitable to do so.
579 static bool isOneUseSetCC(SDValue N) {
581 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
586 SDValue DAGCombiner::ReassociateOps(unsigned Opc, SDLoc DL,
587 SDValue N0, SDValue N1) {
588 EVT VT = N0.getValueType();
589 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
590 if (isa<ConstantSDNode>(N1)) {
591 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
593 DAG.FoldConstantArithmetic(Opc, VT,
594 cast<ConstantSDNode>(N0.getOperand(1)),
595 cast<ConstantSDNode>(N1));
596 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
598 if (N0.hasOneUse()) {
599 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
600 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
601 N0.getOperand(0), N1);
602 AddToWorkList(OpNode.getNode());
603 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
607 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
608 if (isa<ConstantSDNode>(N0)) {
609 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
611 DAG.FoldConstantArithmetic(Opc, VT,
612 cast<ConstantSDNode>(N1.getOperand(1)),
613 cast<ConstantSDNode>(N0));
614 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
616 if (N1.hasOneUse()) {
617 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
618 SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT,
619 N1.getOperand(0), N0);
620 AddToWorkList(OpNode.getNode());
621 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
628 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
630 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
632 DEBUG(dbgs() << "\nReplacing.1 ";
634 dbgs() << "\nWith: ";
635 To[0].getNode()->dump(&DAG);
636 dbgs() << " and " << NumTo-1 << " other values\n";
637 for (unsigned i = 0, e = NumTo; i != e; ++i)
638 assert((!To[i].getNode() ||
639 N->getValueType(i) == To[i].getValueType()) &&
640 "Cannot combine value to value of different type!"));
641 WorkListRemover DeadNodes(*this);
642 DAG.ReplaceAllUsesWith(N, To);
644 // Push the new nodes and any users onto the worklist
645 for (unsigned i = 0, e = NumTo; i != e; ++i) {
646 if (To[i].getNode()) {
647 AddToWorkList(To[i].getNode());
648 AddUsersToWorkList(To[i].getNode());
653 // Finally, if the node is now dead, remove it from the graph. The node
654 // may not be dead if the replacement process recursively simplified to
655 // something else needing this node.
656 if (N->use_empty()) {
657 // Nodes can be reintroduced into the worklist. Make sure we do not
658 // process a node that has been replaced.
659 removeFromWorkList(N);
661 // Finally, since the node is now dead, remove it from the graph.
664 return SDValue(N, 0);
668 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
669 // Replace all uses. If any nodes become isomorphic to other nodes and
670 // are deleted, make sure to remove them from our worklist.
671 WorkListRemover DeadNodes(*this);
672 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
674 // Push the new node and any (possibly new) users onto the worklist.
675 AddToWorkList(TLO.New.getNode());
676 AddUsersToWorkList(TLO.New.getNode());
678 // Finally, if the node is now dead, remove it from the graph. The node
679 // may not be dead if the replacement process recursively simplified to
680 // something else needing this node.
681 if (TLO.Old.getNode()->use_empty()) {
682 removeFromWorkList(TLO.Old.getNode());
684 // If the operands of this node are only used by the node, they will now
685 // be dead. Make sure to visit them first to delete dead nodes early.
686 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
687 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
688 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
690 DAG.DeleteNode(TLO.Old.getNode());
694 /// SimplifyDemandedBits - Check the specified integer node value to see if
695 /// it can be simplified or if things it uses can be simplified by bit
696 /// propagation. If so, return true.
697 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
698 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
699 APInt KnownZero, KnownOne;
700 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
704 AddToWorkList(Op.getNode());
706 // Replace the old value with the new one.
708 DEBUG(dbgs() << "\nReplacing.2 ";
709 TLO.Old.getNode()->dump(&DAG);
710 dbgs() << "\nWith: ";
711 TLO.New.getNode()->dump(&DAG);
714 CommitTargetLoweringOpt(TLO);
718 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
720 EVT VT = Load->getValueType(0);
721 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
723 DEBUG(dbgs() << "\nReplacing.9 ";
725 dbgs() << "\nWith: ";
726 Trunc.getNode()->dump(&DAG);
728 WorkListRemover DeadNodes(*this);
729 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
730 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
731 removeFromWorkList(Load);
732 DAG.DeleteNode(Load);
733 AddToWorkList(Trunc.getNode());
736 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
739 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
740 EVT MemVT = LD->getMemoryVT();
741 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
742 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
744 : LD->getExtensionType();
746 return DAG.getExtLoad(ExtType, dl, PVT,
747 LD->getChain(), LD->getBasePtr(),
748 LD->getPointerInfo(),
749 MemVT, LD->isVolatile(),
750 LD->isNonTemporal(), LD->getAlignment());
753 unsigned Opc = Op.getOpcode();
756 case ISD::AssertSext:
757 return DAG.getNode(ISD::AssertSext, dl, PVT,
758 SExtPromoteOperand(Op.getOperand(0), PVT),
760 case ISD::AssertZext:
761 return DAG.getNode(ISD::AssertZext, dl, PVT,
762 ZExtPromoteOperand(Op.getOperand(0), PVT),
764 case ISD::Constant: {
766 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
767 return DAG.getNode(ExtOpc, dl, PVT, Op);
771 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
773 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
776 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
777 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
779 EVT OldVT = Op.getValueType();
781 bool Replace = false;
782 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
783 if (NewOp.getNode() == 0)
785 AddToWorkList(NewOp.getNode());
788 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
789 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
790 DAG.getValueType(OldVT));
793 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
794 EVT OldVT = Op.getValueType();
796 bool Replace = false;
797 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
798 if (NewOp.getNode() == 0)
800 AddToWorkList(NewOp.getNode());
803 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
804 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
807 /// PromoteIntBinOp - Promote the specified integer binary operation if the
808 /// target indicates it is beneficial. e.g. On x86, it's usually better to
809 /// promote i16 operations to i32 since i16 instructions are longer.
810 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
811 if (!LegalOperations)
814 EVT VT = Op.getValueType();
815 if (VT.isVector() || !VT.isInteger())
818 // If operation type is 'undesirable', e.g. i16 on x86, consider
820 unsigned Opc = Op.getOpcode();
821 if (TLI.isTypeDesirableForOp(Opc, VT))
825 // Consult target whether it is a good idea to promote this operation and
826 // what's the right type to promote it to.
827 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
828 assert(PVT != VT && "Don't know what type to promote to!");
830 bool Replace0 = false;
831 SDValue N0 = Op.getOperand(0);
832 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
833 if (NN0.getNode() == 0)
836 bool Replace1 = false;
837 SDValue N1 = Op.getOperand(1);
842 NN1 = PromoteOperand(N1, PVT, Replace1);
843 if (NN1.getNode() == 0)
847 AddToWorkList(NN0.getNode());
849 AddToWorkList(NN1.getNode());
852 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
854 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
856 DEBUG(dbgs() << "\nPromoting ";
857 Op.getNode()->dump(&DAG));
859 return DAG.getNode(ISD::TRUNCATE, dl, VT,
860 DAG.getNode(Opc, dl, PVT, NN0, NN1));
865 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
866 /// target indicates it is beneficial. e.g. On x86, it's usually better to
867 /// promote i16 operations to i32 since i16 instructions are longer.
868 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
869 if (!LegalOperations)
872 EVT VT = Op.getValueType();
873 if (VT.isVector() || !VT.isInteger())
876 // If operation type is 'undesirable', e.g. i16 on x86, consider
878 unsigned Opc = Op.getOpcode();
879 if (TLI.isTypeDesirableForOp(Opc, VT))
883 // Consult target whether it is a good idea to promote this operation and
884 // what's the right type to promote it to.
885 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
886 assert(PVT != VT && "Don't know what type to promote to!");
888 bool Replace = false;
889 SDValue N0 = Op.getOperand(0);
891 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
892 else if (Opc == ISD::SRL)
893 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
895 N0 = PromoteOperand(N0, PVT, Replace);
896 if (N0.getNode() == 0)
899 AddToWorkList(N0.getNode());
901 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
903 DEBUG(dbgs() << "\nPromoting ";
904 Op.getNode()->dump(&DAG));
906 return DAG.getNode(ISD::TRUNCATE, dl, VT,
907 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
912 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
913 if (!LegalOperations)
916 EVT VT = Op.getValueType();
917 if (VT.isVector() || !VT.isInteger())
920 // If operation type is 'undesirable', e.g. i16 on x86, consider
922 unsigned Opc = Op.getOpcode();
923 if (TLI.isTypeDesirableForOp(Opc, VT))
927 // Consult target whether it is a good idea to promote this operation and
928 // what's the right type to promote it to.
929 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
930 assert(PVT != VT && "Don't know what type to promote to!");
931 // fold (aext (aext x)) -> (aext x)
932 // fold (aext (zext x)) -> (zext x)
933 // fold (aext (sext x)) -> (sext x)
934 DEBUG(dbgs() << "\nPromoting ";
935 Op.getNode()->dump(&DAG));
936 return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
941 bool DAGCombiner::PromoteLoad(SDValue Op) {
942 if (!LegalOperations)
945 EVT VT = Op.getValueType();
946 if (VT.isVector() || !VT.isInteger())
949 // If operation type is 'undesirable', e.g. i16 on x86, consider
951 unsigned Opc = Op.getOpcode();
952 if (TLI.isTypeDesirableForOp(Opc, VT))
956 // Consult target whether it is a good idea to promote this operation and
957 // what's the right type to promote it to.
958 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
959 assert(PVT != VT && "Don't know what type to promote to!");
962 SDNode *N = Op.getNode();
963 LoadSDNode *LD = cast<LoadSDNode>(N);
964 EVT MemVT = LD->getMemoryVT();
965 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
966 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
968 : LD->getExtensionType();
969 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
970 LD->getChain(), LD->getBasePtr(),
971 LD->getPointerInfo(),
972 MemVT, LD->isVolatile(),
973 LD->isNonTemporal(), LD->getAlignment());
974 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
976 DEBUG(dbgs() << "\nPromoting ";
979 Result.getNode()->dump(&DAG);
981 WorkListRemover DeadNodes(*this);
982 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
983 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
984 removeFromWorkList(N);
986 AddToWorkList(Result.getNode());
993 //===----------------------------------------------------------------------===//
994 // Main DAG Combiner implementation
995 //===----------------------------------------------------------------------===//
997 void DAGCombiner::Run(CombineLevel AtLevel) {
998 // set the instance variables, so that the various visit routines may use it.
1000 LegalOperations = Level >= AfterLegalizeVectorOps;
1001 LegalTypes = Level >= AfterLegalizeTypes;
1003 // Add all the dag nodes to the worklist.
1004 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
1005 E = DAG.allnodes_end(); I != E; ++I)
1008 // Create a dummy node (which is not added to allnodes), that adds a reference
1009 // to the root node, preventing it from being deleted, and tracking any
1010 // changes of the root.
1011 HandleSDNode Dummy(DAG.getRoot());
1013 // The root of the dag may dangle to deleted nodes until the dag combiner is
1014 // done. Set it to null to avoid confusion.
1015 DAG.setRoot(SDValue());
1017 // while the worklist isn't empty, find a node and
1018 // try and combine it.
1019 while (!WorkListContents.empty()) {
1021 // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
1022 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1023 // worklist *should* contain, and check the node we want to visit is should
1024 // actually be visited.
1026 N = WorkListOrder.pop_back_val();
1027 } while (!WorkListContents.erase(N));
1029 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1030 // N is deleted from the DAG, since they too may now be dead or may have a
1031 // reduced number of uses, allowing other xforms.
1032 if (N->use_empty() && N != &Dummy) {
1033 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1034 AddToWorkList(N->getOperand(i).getNode());
1040 SDValue RV = combine(N);
1042 if (RV.getNode() == 0)
1047 // If we get back the same node we passed in, rather than a new node or
1048 // zero, we know that the node must have defined multiple values and
1049 // CombineTo was used. Since CombineTo takes care of the worklist
1050 // mechanics for us, we have no work to do in this case.
1051 if (RV.getNode() == N)
1054 assert(N->getOpcode() != ISD::DELETED_NODE &&
1055 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1056 "Node was deleted but visit returned new node!");
1058 DEBUG(dbgs() << "\nReplacing.3 ";
1060 dbgs() << "\nWith: ";
1061 RV.getNode()->dump(&DAG);
1064 // Transfer debug value.
1065 DAG.TransferDbgValues(SDValue(N, 0), RV);
1066 WorkListRemover DeadNodes(*this);
1067 if (N->getNumValues() == RV.getNode()->getNumValues())
1068 DAG.ReplaceAllUsesWith(N, RV.getNode());
1070 assert(N->getValueType(0) == RV.getValueType() &&
1071 N->getNumValues() == 1 && "Type mismatch");
1073 DAG.ReplaceAllUsesWith(N, &OpV);
1076 // Push the new node and any users onto the worklist
1077 AddToWorkList(RV.getNode());
1078 AddUsersToWorkList(RV.getNode());
1080 // Add any uses of the old node to the worklist in case this node is the
1081 // last one that uses them. They may become dead after this node is
1083 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1084 AddToWorkList(N->getOperand(i).getNode());
1086 // Finally, if the node is now dead, remove it from the graph. The node
1087 // may not be dead if the replacement process recursively simplified to
1088 // something else needing this node.
1089 if (N->use_empty()) {
1090 // Nodes can be reintroduced into the worklist. Make sure we do not
1091 // process a node that has been replaced.
1092 removeFromWorkList(N);
1094 // Finally, since the node is now dead, remove it from the graph.
1099 // If the root changed (e.g. it was a dead load, update the root).
1100 DAG.setRoot(Dummy.getValue());
1101 DAG.RemoveDeadNodes();
1104 SDValue DAGCombiner::visit(SDNode *N) {
1105 switch (N->getOpcode()) {
1107 case ISD::TokenFactor: return visitTokenFactor(N);
1108 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1109 case ISD::ADD: return visitADD(N);
1110 case ISD::SUB: return visitSUB(N);
1111 case ISD::ADDC: return visitADDC(N);
1112 case ISD::SUBC: return visitSUBC(N);
1113 case ISD::ADDE: return visitADDE(N);
1114 case ISD::SUBE: return visitSUBE(N);
1115 case ISD::MUL: return visitMUL(N);
1116 case ISD::SDIV: return visitSDIV(N);
1117 case ISD::UDIV: return visitUDIV(N);
1118 case ISD::SREM: return visitSREM(N);
1119 case ISD::UREM: return visitUREM(N);
1120 case ISD::MULHU: return visitMULHU(N);
1121 case ISD::MULHS: return visitMULHS(N);
1122 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1123 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1124 case ISD::SMULO: return visitSMULO(N);
1125 case ISD::UMULO: return visitUMULO(N);
1126 case ISD::SDIVREM: return visitSDIVREM(N);
1127 case ISD::UDIVREM: return visitUDIVREM(N);
1128 case ISD::AND: return visitAND(N);
1129 case ISD::OR: return visitOR(N);
1130 case ISD::XOR: return visitXOR(N);
1131 case ISD::SHL: return visitSHL(N);
1132 case ISD::SRA: return visitSRA(N);
1133 case ISD::SRL: return visitSRL(N);
1134 case ISD::CTLZ: return visitCTLZ(N);
1135 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1136 case ISD::CTTZ: return visitCTTZ(N);
1137 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1138 case ISD::CTPOP: return visitCTPOP(N);
1139 case ISD::SELECT: return visitSELECT(N);
1140 case ISD::VSELECT: return visitVSELECT(N);
1141 case ISD::SELECT_CC: return visitSELECT_CC(N);
1142 case ISD::SETCC: return visitSETCC(N);
1143 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1144 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1145 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1146 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1147 case ISD::TRUNCATE: return visitTRUNCATE(N);
1148 case ISD::BITCAST: return visitBITCAST(N);
1149 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1150 case ISD::FADD: return visitFADD(N);
1151 case ISD::FSUB: return visitFSUB(N);
1152 case ISD::FMUL: return visitFMUL(N);
1153 case ISD::FMA: return visitFMA(N);
1154 case ISD::FDIV: return visitFDIV(N);
1155 case ISD::FREM: return visitFREM(N);
1156 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1157 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1158 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1159 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1160 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1161 case ISD::FP_ROUND: return visitFP_ROUND(N);
1162 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1163 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1164 case ISD::FNEG: return visitFNEG(N);
1165 case ISD::FABS: return visitFABS(N);
1166 case ISD::FFLOOR: return visitFFLOOR(N);
1167 case ISD::FCEIL: return visitFCEIL(N);
1168 case ISD::FTRUNC: return visitFTRUNC(N);
1169 case ISD::BRCOND: return visitBRCOND(N);
1170 case ISD::BR_CC: return visitBR_CC(N);
1171 case ISD::LOAD: return visitLOAD(N);
1172 case ISD::STORE: return visitSTORE(N);
1173 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1174 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1175 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1176 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1177 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1178 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1183 SDValue DAGCombiner::combine(SDNode *N) {
1184 SDValue RV = visit(N);
1186 // If nothing happened, try a target-specific DAG combine.
1187 if (RV.getNode() == 0) {
1188 assert(N->getOpcode() != ISD::DELETED_NODE &&
1189 "Node was deleted but visit returned NULL!");
1191 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1192 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1194 // Expose the DAG combiner to the target combiner impls.
1195 TargetLowering::DAGCombinerInfo
1196 DagCombineInfo(DAG, Level, false, this);
1198 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1202 // If nothing happened still, try promoting the operation.
1203 if (RV.getNode() == 0) {
1204 switch (N->getOpcode()) {
1212 RV = PromoteIntBinOp(SDValue(N, 0));
1217 RV = PromoteIntShiftOp(SDValue(N, 0));
1219 case ISD::SIGN_EXTEND:
1220 case ISD::ZERO_EXTEND:
1221 case ISD::ANY_EXTEND:
1222 RV = PromoteExtend(SDValue(N, 0));
1225 if (PromoteLoad(SDValue(N, 0)))
1231 // If N is a commutative binary node, try commuting it to enable more
1233 if (RV.getNode() == 0 &&
1234 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1235 N->getNumValues() == 1) {
1236 SDValue N0 = N->getOperand(0);
1237 SDValue N1 = N->getOperand(1);
1239 // Constant operands are canonicalized to RHS.
1240 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1241 SDValue Ops[] = { N1, N0 };
1242 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
1245 return SDValue(CSENode, 0);
1252 /// getInputChainForNode - Given a node, return its input chain if it has one,
1253 /// otherwise return a null sd operand.
1254 static SDValue getInputChainForNode(SDNode *N) {
1255 if (unsigned NumOps = N->getNumOperands()) {
1256 if (N->getOperand(0).getValueType() == MVT::Other)
1257 return N->getOperand(0);
1258 if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1259 return N->getOperand(NumOps-1);
1260 for (unsigned i = 1; i < NumOps-1; ++i)
1261 if (N->getOperand(i).getValueType() == MVT::Other)
1262 return N->getOperand(i);
1267 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1268 // If N has two operands, where one has an input chain equal to the other,
1269 // the 'other' chain is redundant.
1270 if (N->getNumOperands() == 2) {
1271 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1272 return N->getOperand(0);
1273 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1274 return N->getOperand(1);
1277 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1278 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1279 SmallPtrSet<SDNode*, 16> SeenOps;
1280 bool Changed = false; // If we should replace this token factor.
1282 // Start out with this token factor.
1285 // Iterate through token factors. The TFs grows when new token factors are
1287 for (unsigned i = 0; i < TFs.size(); ++i) {
1288 SDNode *TF = TFs[i];
1290 // Check each of the operands.
1291 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1292 SDValue Op = TF->getOperand(i);
1294 switch (Op.getOpcode()) {
1295 case ISD::EntryToken:
1296 // Entry tokens don't need to be added to the list. They are
1301 case ISD::TokenFactor:
1302 if (Op.hasOneUse() &&
1303 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1304 // Queue up for processing.
1305 TFs.push_back(Op.getNode());
1306 // Clean up in case the token factor is removed.
1307 AddToWorkList(Op.getNode());
1314 // Only add if it isn't already in the list.
1315 if (SeenOps.insert(Op.getNode()))
1326 // If we've change things around then replace token factor.
1329 // The entry token is the only possible outcome.
1330 Result = DAG.getEntryNode();
1332 // New and improved token factor.
1333 Result = DAG.getNode(ISD::TokenFactor, SDLoc(N),
1334 MVT::Other, &Ops[0], Ops.size());
1337 // Don't add users to work list.
1338 return CombineTo(N, Result, false);
1344 /// MERGE_VALUES can always be eliminated.
1345 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1346 WorkListRemover DeadNodes(*this);
1347 // Replacing results may cause a different MERGE_VALUES to suddenly
1348 // be CSE'd with N, and carry its uses with it. Iterate until no
1349 // uses remain, to ensure that the node can be safely deleted.
1350 // First add the users of this node to the work list so that they
1351 // can be tried again once they have new operands.
1352 AddUsersToWorkList(N);
1354 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1355 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1356 } while (!N->use_empty());
1357 removeFromWorkList(N);
1359 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1363 SDValue combineShlAddConstant(SDLoc DL, SDValue N0, SDValue N1,
1364 SelectionDAG &DAG) {
1365 EVT VT = N0.getValueType();
1366 SDValue N00 = N0.getOperand(0);
1367 SDValue N01 = N0.getOperand(1);
1368 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1370 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1371 isa<ConstantSDNode>(N00.getOperand(1))) {
1372 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1373 N0 = DAG.getNode(ISD::ADD, SDLoc(N0), VT,
1374 DAG.getNode(ISD::SHL, SDLoc(N00), VT,
1375 N00.getOperand(0), N01),
1376 DAG.getNode(ISD::SHL, SDLoc(N01), VT,
1377 N00.getOperand(1), N01));
1378 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1384 SDValue DAGCombiner::visitADD(SDNode *N) {
1385 SDValue N0 = N->getOperand(0);
1386 SDValue N1 = N->getOperand(1);
1387 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1388 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1389 EVT VT = N0.getValueType();
1392 if (VT.isVector()) {
1393 SDValue FoldedVOp = SimplifyVBinOp(N);
1394 if (FoldedVOp.getNode()) return FoldedVOp;
1396 // fold (add x, 0) -> x, vector edition
1397 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1399 if (ISD::isBuildVectorAllZeros(N0.getNode()))
1403 // fold (add x, undef) -> undef
1404 if (N0.getOpcode() == ISD::UNDEF)
1406 if (N1.getOpcode() == ISD::UNDEF)
1408 // fold (add c1, c2) -> c1+c2
1410 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1411 // canonicalize constant to RHS
1413 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N1, N0);
1414 // fold (add x, 0) -> x
1415 if (N1C && N1C->isNullValue())
1417 // fold (add Sym, c) -> Sym+c
1418 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1419 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1420 GA->getOpcode() == ISD::GlobalAddress)
1421 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1423 (uint64_t)N1C->getSExtValue());
1424 // fold ((c1-A)+c2) -> (c1+c2)-A
1425 if (N1C && N0.getOpcode() == ISD::SUB)
1426 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1427 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1428 DAG.getConstant(N1C->getAPIntValue()+
1429 N0C->getAPIntValue(), VT),
1432 SDValue RADD = ReassociateOps(ISD::ADD, SDLoc(N), N0, N1);
1433 if (RADD.getNode() != 0)
1435 // fold ((0-A) + B) -> B-A
1436 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1437 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1438 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1, N0.getOperand(1));
1439 // fold (A + (0-B)) -> A-B
1440 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1441 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1442 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1.getOperand(1));
1443 // fold (A+(B-A)) -> B
1444 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1445 return N1.getOperand(0);
1446 // fold ((B-A)+A) -> B
1447 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1448 return N0.getOperand(0);
1449 // fold (A+(B-(A+C))) to (B-C)
1450 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1451 N0 == N1.getOperand(1).getOperand(0))
1452 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1453 N1.getOperand(1).getOperand(1));
1454 // fold (A+(B-(C+A))) to (B-C)
1455 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1456 N0 == N1.getOperand(1).getOperand(1))
1457 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1.getOperand(0),
1458 N1.getOperand(1).getOperand(0));
1459 // fold (A+((B-A)+or-C)) to (B+or-C)
1460 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1461 N1.getOperand(0).getOpcode() == ISD::SUB &&
1462 N0 == N1.getOperand(0).getOperand(1))
1463 return DAG.getNode(N1.getOpcode(), SDLoc(N), VT,
1464 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1466 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1467 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1468 SDValue N00 = N0.getOperand(0);
1469 SDValue N01 = N0.getOperand(1);
1470 SDValue N10 = N1.getOperand(0);
1471 SDValue N11 = N1.getOperand(1);
1473 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1474 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1475 DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
1476 DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
1479 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1480 return SDValue(N, 0);
1482 // fold (a+b) -> (a|b) iff a and b share no bits.
1483 if (VT.isInteger() && !VT.isVector()) {
1484 APInt LHSZero, LHSOne;
1485 APInt RHSZero, RHSOne;
1486 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1488 if (LHSZero.getBoolValue()) {
1489 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1491 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1492 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1493 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1494 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1);
1498 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1499 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1500 SDValue Result = combineShlAddConstant(SDLoc(N), N0, N1, DAG);
1501 if (Result.getNode()) return Result;
1503 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1504 SDValue Result = combineShlAddConstant(SDLoc(N), N1, N0, DAG);
1505 if (Result.getNode()) return Result;
1508 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1509 if (N1.getOpcode() == ISD::SHL &&
1510 N1.getOperand(0).getOpcode() == ISD::SUB)
1511 if (ConstantSDNode *C =
1512 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1513 if (C->getAPIntValue() == 0)
1514 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N0,
1515 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1516 N1.getOperand(0).getOperand(1),
1518 if (N0.getOpcode() == ISD::SHL &&
1519 N0.getOperand(0).getOpcode() == ISD::SUB)
1520 if (ConstantSDNode *C =
1521 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1522 if (C->getAPIntValue() == 0)
1523 return DAG.getNode(ISD::SUB, SDLoc(N), VT, N1,
1524 DAG.getNode(ISD::SHL, SDLoc(N), VT,
1525 N0.getOperand(0).getOperand(1),
1528 if (N1.getOpcode() == ISD::AND) {
1529 SDValue AndOp0 = N1.getOperand(0);
1530 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1531 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1532 unsigned DestBits = VT.getScalarType().getSizeInBits();
1534 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1535 // and similar xforms where the inner op is either ~0 or 0.
1536 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1538 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1542 // add (sext i1), X -> sub X, (zext i1)
1543 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1544 N0.getOperand(0).getValueType() == MVT::i1 &&
1545 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1547 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1548 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1554 SDValue DAGCombiner::visitADDC(SDNode *N) {
1555 SDValue N0 = N->getOperand(0);
1556 SDValue N1 = N->getOperand(1);
1557 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1558 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1559 EVT VT = N0.getValueType();
1561 // If the flag result is dead, turn this into an ADD.
1562 if (!N->hasAnyUseOfValue(1))
1563 return CombineTo(N, DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N1),
1564 DAG.getNode(ISD::CARRY_FALSE,
1565 SDLoc(N), MVT::Glue));
1567 // canonicalize constant to RHS.
1569 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N1, N0);
1571 // fold (addc x, 0) -> x + no carry out
1572 if (N1C && N1C->isNullValue())
1573 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1574 SDLoc(N), MVT::Glue));
1576 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1577 APInt LHSZero, LHSOne;
1578 APInt RHSZero, RHSOne;
1579 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1581 if (LHSZero.getBoolValue()) {
1582 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1584 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1585 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1586 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1587 return CombineTo(N, DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N1),
1588 DAG.getNode(ISD::CARRY_FALSE,
1589 SDLoc(N), MVT::Glue));
1595 SDValue DAGCombiner::visitADDE(SDNode *N) {
1596 SDValue N0 = N->getOperand(0);
1597 SDValue N1 = N->getOperand(1);
1598 SDValue CarryIn = N->getOperand(2);
1599 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1600 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1602 // canonicalize constant to RHS
1604 return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
1607 // fold (adde x, y, false) -> (addc x, y)
1608 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1609 return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);
1614 // Since it may not be valid to emit a fold to zero for vector initializers
1615 // check if we can before folding.
1616 static SDValue tryFoldToZero(SDLoc DL, const TargetLowering &TLI, EVT VT,
1618 bool LegalOperations, bool LegalTypes) {
1620 return DAG.getConstant(0, VT);
1621 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1622 // Produce a vector of zeros.
1623 EVT ElemTy = VT.getVectorElementType();
1624 if (LegalTypes && TLI.getTypeAction(*DAG.getContext(), ElemTy) ==
1625 TargetLowering::TypePromoteInteger)
1626 ElemTy = TLI.getTypeToTransformTo(*DAG.getContext(), ElemTy);
1627 assert((!LegalTypes || TLI.isTypeLegal(ElemTy)) &&
1628 "Type for zero vector elements is not legal");
1629 SDValue El = DAG.getConstant(0, ElemTy);
1630 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
1631 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
1632 &Ops[0], Ops.size());
1637 SDValue DAGCombiner::visitSUB(SDNode *N) {
1638 SDValue N0 = N->getOperand(0);
1639 SDValue N1 = N->getOperand(1);
1640 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1641 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1642 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? 0 :
1643 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1644 EVT VT = N0.getValueType();
1647 if (VT.isVector()) {
1648 SDValue FoldedVOp = SimplifyVBinOp(N);
1649 if (FoldedVOp.getNode()) return FoldedVOp;
1651 // fold (sub x, 0) -> x, vector edition
1652 if (ISD::isBuildVectorAllZeros(N1.getNode()))
1656 // fold (sub x, x) -> 0
1657 // FIXME: Refactor this and xor and other similar operations together.
1659 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
1660 // fold (sub c1, c2) -> c1-c2
1662 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1663 // fold (sub x, c) -> (add x, -c)
1665 return DAG.getNode(ISD::ADD, SDLoc(N), VT, N0,
1666 DAG.getConstant(-N1C->getAPIntValue(), VT));
1667 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1668 if (N0C && N0C->isAllOnesValue())
1669 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
1670 // fold A-(A-B) -> B
1671 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1672 return N1.getOperand(1);
1673 // fold (A+B)-A -> B
1674 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1675 return N0.getOperand(1);
1676 // fold (A+B)-B -> A
1677 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1678 return N0.getOperand(0);
1679 // fold C2-(A+C1) -> (C2-C1)-A
1680 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1681 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1683 return DAG.getNode(ISD::SUB, SDLoc(N), VT, NewC,
1686 // fold ((A+(B+or-C))-B) -> A+or-C
1687 if (N0.getOpcode() == ISD::ADD &&
1688 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1689 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1690 N0.getOperand(1).getOperand(0) == N1)
1691 return DAG.getNode(N0.getOperand(1).getOpcode(), SDLoc(N), VT,
1692 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1693 // fold ((A+(C+B))-B) -> A+C
1694 if (N0.getOpcode() == ISD::ADD &&
1695 N0.getOperand(1).getOpcode() == ISD::ADD &&
1696 N0.getOperand(1).getOperand(1) == N1)
1697 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1698 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1699 // fold ((A-(B-C))-C) -> A-B
1700 if (N0.getOpcode() == ISD::SUB &&
1701 N0.getOperand(1).getOpcode() == ISD::SUB &&
1702 N0.getOperand(1).getOperand(1) == N1)
1703 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1704 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1706 // If either operand of a sub is undef, the result is undef
1707 if (N0.getOpcode() == ISD::UNDEF)
1709 if (N1.getOpcode() == ISD::UNDEF)
1712 // If the relocation model supports it, consider symbol offsets.
1713 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1714 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1715 // fold (sub Sym, c) -> Sym-c
1716 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1717 return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
1719 (uint64_t)N1C->getSExtValue());
1720 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1721 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1722 if (GA->getGlobal() == GB->getGlobal())
1723 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1730 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1731 SDValue N0 = N->getOperand(0);
1732 SDValue N1 = N->getOperand(1);
1733 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1734 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1735 EVT VT = N0.getValueType();
1737 // If the flag result is dead, turn this into an SUB.
1738 if (!N->hasAnyUseOfValue(1))
1739 return CombineTo(N, DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, N1),
1740 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1743 // fold (subc x, x) -> 0 + no borrow
1745 return CombineTo(N, DAG.getConstant(0, VT),
1746 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1749 // fold (subc x, 0) -> x + no borrow
1750 if (N1C && N1C->isNullValue())
1751 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1754 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1755 if (N0C && N0C->isAllOnesValue())
1756 return CombineTo(N, DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0),
1757 DAG.getNode(ISD::CARRY_FALSE, SDLoc(N),
1763 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1764 SDValue N0 = N->getOperand(0);
1765 SDValue N1 = N->getOperand(1);
1766 SDValue CarryIn = N->getOperand(2);
1768 // fold (sube x, y, false) -> (subc x, y)
1769 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1770 return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);
1775 /// isConstantSplatVector - Returns true if N is a BUILD_VECTOR node whose elements are
1776 /// all the same constant or undefined.
1777 static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
1778 BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
1783 unsigned SplatBitSize;
1785 EVT EltVT = N->getValueType(0).getVectorElementType();
1786 return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
1788 EltVT.getSizeInBits() >= SplatBitSize);
1791 SDValue DAGCombiner::visitMUL(SDNode *N) {
1792 SDValue N0 = N->getOperand(0);
1793 SDValue N1 = N->getOperand(1);
1794 EVT VT = N0.getValueType();
1796 // fold (mul x, undef) -> 0
1797 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1798 return DAG.getConstant(0, VT);
1800 bool N0IsConst = false;
1801 bool N1IsConst = false;
1802 APInt ConstValue0, ConstValue1;
1804 if (VT.isVector()) {
1805 SDValue FoldedVOp = SimplifyVBinOp(N);
1806 if (FoldedVOp.getNode()) return FoldedVOp;
1808 N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
1809 N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
1811 N0IsConst = dyn_cast<ConstantSDNode>(N0) != 0;
1812 ConstValue0 = N0IsConst? (dyn_cast<ConstantSDNode>(N0))->getAPIntValue() : APInt();
1813 N1IsConst = dyn_cast<ConstantSDNode>(N1) != 0;
1814 ConstValue1 = N1IsConst? (dyn_cast<ConstantSDNode>(N1))->getAPIntValue() : APInt();
1817 // fold (mul c1, c2) -> c1*c2
1818 if (N0IsConst && N1IsConst)
1819 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0.getNode(), N1.getNode());
1821 // canonicalize constant to RHS
1822 if (N0IsConst && !N1IsConst)
1823 return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
1824 // fold (mul x, 0) -> 0
1825 if (N1IsConst && ConstValue1 == 0)
1827 // We require a splat of the entire scalar bit width for non-contiguous
1830 ConstValue1.getBitWidth() == VT.getScalarType().getSizeInBits();
1831 // fold (mul x, 1) -> x
1832 if (N1IsConst && ConstValue1 == 1 && IsFullSplat)
1834 // fold (mul x, -1) -> 0-x
1835 if (N1IsConst && ConstValue1.isAllOnesValue())
1836 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1837 DAG.getConstant(0, VT), N0);
1838 // fold (mul x, (1 << c)) -> x << c
1839 if (N1IsConst && ConstValue1.isPowerOf2() && IsFullSplat)
1840 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1841 DAG.getConstant(ConstValue1.logBase2(),
1842 getShiftAmountTy(N0.getValueType())));
1843 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1844 if (N1IsConst && (-ConstValue1).isPowerOf2() && IsFullSplat) {
1845 unsigned Log2Val = (-ConstValue1).logBase2();
1846 // FIXME: If the input is something that is easily negated (e.g. a
1847 // single-use add), we should put the negate there.
1848 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1849 DAG.getConstant(0, VT),
1850 DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
1851 DAG.getConstant(Log2Val,
1852 getShiftAmountTy(N0.getValueType()))));
1856 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1857 if (N1IsConst && N0.getOpcode() == ISD::SHL &&
1858 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1859 isa<ConstantSDNode>(N0.getOperand(1)))) {
1860 SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
1861 N1, N0.getOperand(1));
1862 AddToWorkList(C3.getNode());
1863 return DAG.getNode(ISD::MUL, SDLoc(N), VT,
1864 N0.getOperand(0), C3);
1867 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1870 SDValue Sh(0,0), Y(0,0);
1871 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1872 if (N0.getOpcode() == ISD::SHL &&
1873 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1874 isa<ConstantSDNode>(N0.getOperand(1))) &&
1875 N0.getNode()->hasOneUse()) {
1877 } else if (N1.getOpcode() == ISD::SHL &&
1878 isa<ConstantSDNode>(N1.getOperand(1)) &&
1879 N1.getNode()->hasOneUse()) {
1884 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
1885 Sh.getOperand(0), Y);
1886 return DAG.getNode(ISD::SHL, SDLoc(N), VT,
1887 Mul, Sh.getOperand(1));
1891 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1892 if (N1IsConst && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1893 (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
1894 isa<ConstantSDNode>(N0.getOperand(1))))
1895 return DAG.getNode(ISD::ADD, SDLoc(N), VT,
1896 DAG.getNode(ISD::MUL, SDLoc(N0), VT,
1897 N0.getOperand(0), N1),
1898 DAG.getNode(ISD::MUL, SDLoc(N1), VT,
1899 N0.getOperand(1), N1));
1902 SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1);
1903 if (RMUL.getNode() != 0)
1909 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1910 SDValue N0 = N->getOperand(0);
1911 SDValue N1 = N->getOperand(1);
1912 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1913 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1914 EVT VT = N->getValueType(0);
1917 if (VT.isVector()) {
1918 SDValue FoldedVOp = SimplifyVBinOp(N);
1919 if (FoldedVOp.getNode()) return FoldedVOp;
1922 // fold (sdiv c1, c2) -> c1/c2
1923 if (N0C && N1C && !N1C->isNullValue())
1924 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1925 // fold (sdiv X, 1) -> X
1926 if (N1C && N1C->getAPIntValue() == 1LL)
1928 // fold (sdiv X, -1) -> 0-X
1929 if (N1C && N1C->isAllOnesValue())
1930 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1931 DAG.getConstant(0, VT), N0);
1932 // If we know the sign bits of both operands are zero, strength reduce to a
1933 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1934 if (!VT.isVector()) {
1935 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1936 return DAG.getNode(ISD::UDIV, SDLoc(N), N1.getValueType(),
1939 // fold (sdiv X, pow2) -> simple ops after legalize
1940 if (N1C && !N1C->isNullValue() &&
1941 (N1C->getAPIntValue().isPowerOf2() ||
1942 (-N1C->getAPIntValue()).isPowerOf2())) {
1943 // If dividing by powers of two is cheap, then don't perform the following
1945 if (TLI.isPow2DivCheap())
1948 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
1950 // Splat the sign bit into the register
1951 SDValue SGN = DAG.getNode(ISD::SRA, SDLoc(N), VT, N0,
1952 DAG.getConstant(VT.getSizeInBits()-1,
1953 getShiftAmountTy(N0.getValueType())));
1954 AddToWorkList(SGN.getNode());
1956 // Add (N0 < 0) ? abs2 - 1 : 0;
1957 SDValue SRL = DAG.getNode(ISD::SRL, SDLoc(N), VT, SGN,
1958 DAG.getConstant(VT.getSizeInBits() - lg2,
1959 getShiftAmountTy(SGN.getValueType())));
1960 SDValue ADD = DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, SRL);
1961 AddToWorkList(SRL.getNode());
1962 AddToWorkList(ADD.getNode()); // Divide by pow2
1963 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), VT, ADD,
1964 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
1966 // If we're dividing by a positive value, we're done. Otherwise, we must
1967 // negate the result.
1968 if (N1C->getAPIntValue().isNonNegative())
1971 AddToWorkList(SRA.getNode());
1972 return DAG.getNode(ISD::SUB, SDLoc(N), VT,
1973 DAG.getConstant(0, VT), SRA);
1976 // if integer divide is expensive and we satisfy the requirements, emit an
1977 // alternate sequence.
1978 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1979 SDValue Op = BuildSDIV(N);
1980 if (Op.getNode()) return Op;
1984 if (N0.getOpcode() == ISD::UNDEF)
1985 return DAG.getConstant(0, VT);
1986 // X / undef -> undef
1987 if (N1.getOpcode() == ISD::UNDEF)
1993 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1994 SDValue N0 = N->getOperand(0);
1995 SDValue N1 = N->getOperand(1);
1996 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1997 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1998 EVT VT = N->getValueType(0);
2001 if (VT.isVector()) {
2002 SDValue FoldedVOp = SimplifyVBinOp(N);
2003 if (FoldedVOp.getNode()) return FoldedVOp;
2006 // fold (udiv c1, c2) -> c1/c2
2007 if (N0C && N1C && !N1C->isNullValue())
2008 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
2009 // fold (udiv x, (1 << c)) -> x >>u c
2010 if (N1C && N1C->getAPIntValue().isPowerOf2())
2011 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0,
2012 DAG.getConstant(N1C->getAPIntValue().logBase2(),
2013 getShiftAmountTy(N0.getValueType())));
2014 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
2015 if (N1.getOpcode() == ISD::SHL) {
2016 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2017 if (SHC->getAPIntValue().isPowerOf2()) {
2018 EVT ADDVT = N1.getOperand(1).getValueType();
2019 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N), ADDVT,
2021 DAG.getConstant(SHC->getAPIntValue()
2024 AddToWorkList(Add.getNode());
2025 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, Add);
2029 // fold (udiv x, c) -> alternate
2030 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
2031 SDValue Op = BuildUDIV(N);
2032 if (Op.getNode()) return Op;
2036 if (N0.getOpcode() == ISD::UNDEF)
2037 return DAG.getConstant(0, VT);
2038 // X / undef -> undef
2039 if (N1.getOpcode() == ISD::UNDEF)
2045 SDValue DAGCombiner::visitSREM(SDNode *N) {
2046 SDValue N0 = N->getOperand(0);
2047 SDValue N1 = N->getOperand(1);
2048 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2049 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2050 EVT VT = N->getValueType(0);
2052 // fold (srem c1, c2) -> c1%c2
2053 if (N0C && N1C && !N1C->isNullValue())
2054 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
2055 // If we know the sign bits of both operands are zero, strength reduce to a
2056 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
2057 if (!VT.isVector()) {
2058 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
2059 return DAG.getNode(ISD::UREM, SDLoc(N), VT, N0, N1);
2062 // If X/C can be simplified by the division-by-constant logic, lower
2063 // X%C to the equivalent of X-X/C*C.
2064 if (N1C && !N1C->isNullValue()) {
2065 SDValue Div = DAG.getNode(ISD::SDIV, SDLoc(N), VT, N0, N1);
2066 AddToWorkList(Div.getNode());
2067 SDValue OptimizedDiv = combine(Div.getNode());
2068 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2069 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2071 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2072 AddToWorkList(Mul.getNode());
2078 if (N0.getOpcode() == ISD::UNDEF)
2079 return DAG.getConstant(0, VT);
2080 // X % undef -> undef
2081 if (N1.getOpcode() == ISD::UNDEF)
2087 SDValue DAGCombiner::visitUREM(SDNode *N) {
2088 SDValue N0 = N->getOperand(0);
2089 SDValue N1 = N->getOperand(1);
2090 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2091 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2092 EVT VT = N->getValueType(0);
2094 // fold (urem c1, c2) -> c1%c2
2095 if (N0C && N1C && !N1C->isNullValue())
2096 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2097 // fold (urem x, pow2) -> (and x, pow2-1)
2098 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2099 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0,
2100 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2101 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2102 if (N1.getOpcode() == ISD::SHL) {
2103 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2104 if (SHC->getAPIntValue().isPowerOf2()) {
2106 DAG.getNode(ISD::ADD, SDLoc(N), VT, N1,
2107 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2109 AddToWorkList(Add.getNode());
2110 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, Add);
2115 // If X/C can be simplified by the division-by-constant logic, lower
2116 // X%C to the equivalent of X-X/C*C.
2117 if (N1C && !N1C->isNullValue()) {
2118 SDValue Div = DAG.getNode(ISD::UDIV, SDLoc(N), VT, N0, N1);
2119 AddToWorkList(Div.getNode());
2120 SDValue OptimizedDiv = combine(Div.getNode());
2121 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2122 SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
2124 SDValue Sub = DAG.getNode(ISD::SUB, SDLoc(N), VT, N0, Mul);
2125 AddToWorkList(Mul.getNode());
2131 if (N0.getOpcode() == ISD::UNDEF)
2132 return DAG.getConstant(0, VT);
2133 // X % undef -> undef
2134 if (N1.getOpcode() == ISD::UNDEF)
2140 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2141 SDValue N0 = N->getOperand(0);
2142 SDValue N1 = N->getOperand(1);
2143 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2144 EVT VT = N->getValueType(0);
2147 // fold (mulhs x, 0) -> 0
2148 if (N1C && N1C->isNullValue())
2150 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2151 if (N1C && N1C->getAPIntValue() == 1)
2152 return DAG.getNode(ISD::SRA, SDLoc(N), N0.getValueType(), N0,
2153 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2154 getShiftAmountTy(N0.getValueType())));
2155 // fold (mulhs x, undef) -> 0
2156 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2157 return DAG.getConstant(0, VT);
2159 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2161 if (VT.isSimple() && !VT.isVector()) {
2162 MVT Simple = VT.getSimpleVT();
2163 unsigned SimpleSize = Simple.getSizeInBits();
2164 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2165 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2166 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2167 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2168 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2169 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2170 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2171 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2178 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2179 SDValue N0 = N->getOperand(0);
2180 SDValue N1 = N->getOperand(1);
2181 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2182 EVT VT = N->getValueType(0);
2185 // fold (mulhu x, 0) -> 0
2186 if (N1C && N1C->isNullValue())
2188 // fold (mulhu x, 1) -> 0
2189 if (N1C && N1C->getAPIntValue() == 1)
2190 return DAG.getConstant(0, N0.getValueType());
2191 // fold (mulhu x, undef) -> 0
2192 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2193 return DAG.getConstant(0, VT);
2195 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2197 if (VT.isSimple() && !VT.isVector()) {
2198 MVT Simple = VT.getSimpleVT();
2199 unsigned SimpleSize = Simple.getSizeInBits();
2200 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2201 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2202 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2203 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2204 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2205 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2206 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2207 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2214 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2215 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2216 /// that are being performed. Return true if a simplification was made.
2218 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2220 // If the high half is not needed, just compute the low half.
2221 bool HiExists = N->hasAnyUseOfValue(1);
2223 (!LegalOperations ||
2224 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
2225 SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2226 N->op_begin(), N->getNumOperands());
2227 return CombineTo(N, Res, Res);
2230 // If the low half is not needed, just compute the high half.
2231 bool LoExists = N->hasAnyUseOfValue(0);
2233 (!LegalOperations ||
2234 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2235 SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2236 N->op_begin(), N->getNumOperands());
2237 return CombineTo(N, Res, Res);
2240 // If both halves are used, return as it is.
2241 if (LoExists && HiExists)
2244 // If the two computed results can be simplified separately, separate them.
2246 SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0),
2247 N->op_begin(), N->getNumOperands());
2248 AddToWorkList(Lo.getNode());
2249 SDValue LoOpt = combine(Lo.getNode());
2250 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2251 (!LegalOperations ||
2252 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2253 return CombineTo(N, LoOpt, LoOpt);
2257 SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1),
2258 N->op_begin(), N->getNumOperands());
2259 AddToWorkList(Hi.getNode());
2260 SDValue HiOpt = combine(Hi.getNode());
2261 if (HiOpt.getNode() && HiOpt != Hi &&
2262 (!LegalOperations ||
2263 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2264 return CombineTo(N, HiOpt, HiOpt);
2270 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2271 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2272 if (Res.getNode()) return Res;
2274 EVT VT = N->getValueType(0);
2277 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2279 if (VT.isSimple() && !VT.isVector()) {
2280 MVT Simple = VT.getSimpleVT();
2281 unsigned SimpleSize = Simple.getSizeInBits();
2282 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2283 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2284 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2285 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2286 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2287 // Compute the high part as N1.
2288 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2289 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2290 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2291 // Compute the low part as N0.
2292 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2293 return CombineTo(N, Lo, Hi);
2300 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2301 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2302 if (Res.getNode()) return Res;
2304 EVT VT = N->getValueType(0);
2307 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2309 if (VT.isSimple() && !VT.isVector()) {
2310 MVT Simple = VT.getSimpleVT();
2311 unsigned SimpleSize = Simple.getSizeInBits();
2312 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2313 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2314 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2315 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2316 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2317 // Compute the high part as N1.
2318 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2319 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2320 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2321 // Compute the low part as N0.
2322 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2323 return CombineTo(N, Lo, Hi);
2330 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2331 // (smulo x, 2) -> (saddo x, x)
2332 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2333 if (C2->getAPIntValue() == 2)
2334 return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
2335 N->getOperand(0), N->getOperand(0));
2340 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2341 // (umulo x, 2) -> (uaddo x, x)
2342 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2343 if (C2->getAPIntValue() == 2)
2344 return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
2345 N->getOperand(0), N->getOperand(0));
2350 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2351 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2352 if (Res.getNode()) return Res;
2357 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2358 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2359 if (Res.getNode()) return Res;
2364 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2365 /// two operands of the same opcode, try to simplify it.
2366 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2367 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2368 EVT VT = N0.getValueType();
2369 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2371 // Bail early if none of these transforms apply.
2372 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2374 // For each of OP in AND/OR/XOR:
2375 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2376 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2377 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2378 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2380 // do not sink logical op inside of a vector extend, since it may combine
2382 EVT Op0VT = N0.getOperand(0).getValueType();
2383 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2384 N0.getOpcode() == ISD::SIGN_EXTEND ||
2385 // Avoid infinite looping with PromoteIntBinOp.
2386 (N0.getOpcode() == ISD::ANY_EXTEND &&
2387 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2388 (N0.getOpcode() == ISD::TRUNCATE &&
2389 (!TLI.isZExtFree(VT, Op0VT) ||
2390 !TLI.isTruncateFree(Op0VT, VT)) &&
2391 TLI.isTypeLegal(Op0VT))) &&
2393 Op0VT == N1.getOperand(0).getValueType() &&
2394 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2395 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2396 N0.getOperand(0).getValueType(),
2397 N0.getOperand(0), N1.getOperand(0));
2398 AddToWorkList(ORNode.getNode());
2399 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
2402 // For each of OP in SHL/SRL/SRA/AND...
2403 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2404 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2405 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2406 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2407 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2408 N0.getOperand(1) == N1.getOperand(1)) {
2409 SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
2410 N0.getOperand(0).getValueType(),
2411 N0.getOperand(0), N1.getOperand(0));
2412 AddToWorkList(ORNode.getNode());
2413 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
2414 ORNode, N0.getOperand(1));
2417 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2418 // Only perform this optimization after type legalization and before
2419 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2420 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2421 // we don't want to undo this promotion.
2422 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2424 if ((N0.getOpcode() == ISD::BITCAST ||
2425 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2426 Level == AfterLegalizeTypes) {
2427 SDValue In0 = N0.getOperand(0);
2428 SDValue In1 = N1.getOperand(0);
2429 EVT In0Ty = In0.getValueType();
2430 EVT In1Ty = In1.getValueType();
2432 // If both incoming values are integers, and the original types are the
2434 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2435 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2436 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2437 AddToWorkList(Op.getNode());
2442 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2443 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2444 // If both shuffles use the same mask, and both shuffle within a single
2445 // vector, then it is worthwhile to move the swizzle after the operation.
2446 // The type-legalizer generates this pattern when loading illegal
2447 // vector types from memory. In many cases this allows additional shuffle
2449 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
2450 N0.getOperand(1).getOpcode() == ISD::UNDEF &&
2451 N1.getOperand(1).getOpcode() == ISD::UNDEF) {
2452 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2453 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2455 assert(N0.getOperand(0).getValueType() == N1.getOperand(1).getValueType() &&
2456 "Inputs to shuffles are not the same type");
2458 unsigned NumElts = VT.getVectorNumElements();
2460 // Check that both shuffles use the same mask. The masks are known to be of
2461 // the same length because the result vector type is the same.
2462 bool SameMask = true;
2463 for (unsigned i = 0; i != NumElts; ++i) {
2464 int Idx0 = SVN0->getMaskElt(i);
2465 int Idx1 = SVN1->getMaskElt(i);
2473 SDValue Op = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
2474 N0.getOperand(0), N1.getOperand(0));
2475 AddToWorkList(Op.getNode());
2476 return DAG.getVectorShuffle(VT, SDLoc(N), Op,
2477 DAG.getUNDEF(VT), &SVN0->getMask()[0]);
2484 SDValue DAGCombiner::visitAND(SDNode *N) {
2485 SDValue N0 = N->getOperand(0);
2486 SDValue N1 = N->getOperand(1);
2487 SDValue LL, LR, RL, RR, CC0, CC1;
2488 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2489 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2490 EVT VT = N1.getValueType();
2491 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2494 if (VT.isVector()) {
2495 SDValue FoldedVOp = SimplifyVBinOp(N);
2496 if (FoldedVOp.getNode()) return FoldedVOp;
2498 // fold (and x, 0) -> 0, vector edition
2499 if (ISD::isBuildVectorAllZeros(N0.getNode()))
2501 if (ISD::isBuildVectorAllZeros(N1.getNode()))
2504 // fold (and x, -1) -> x, vector edition
2505 if (ISD::isBuildVectorAllOnes(N0.getNode()))
2507 if (ISD::isBuildVectorAllOnes(N1.getNode()))
2511 // fold (and x, undef) -> 0
2512 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2513 return DAG.getConstant(0, VT);
2514 // fold (and c1, c2) -> c1&c2
2516 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2517 // canonicalize constant to RHS
2519 return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
2520 // fold (and x, -1) -> x
2521 if (N1C && N1C->isAllOnesValue())
2523 // if (and x, c) is known to be zero, return 0
2524 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2525 APInt::getAllOnesValue(BitWidth)))
2526 return DAG.getConstant(0, VT);
2528 SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1);
2529 if (RAND.getNode() != 0)
2531 // fold (and (or x, C), D) -> D if (C & D) == D
2532 if (N1C && N0.getOpcode() == ISD::OR)
2533 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2534 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2536 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2537 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2538 SDValue N0Op0 = N0.getOperand(0);
2539 APInt Mask = ~N1C->getAPIntValue();
2540 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2541 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2542 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
2543 N0.getValueType(), N0Op0);
2545 // Replace uses of the AND with uses of the Zero extend node.
2548 // We actually want to replace all uses of the any_extend with the
2549 // zero_extend, to avoid duplicating things. This will later cause this
2550 // AND to be folded.
2551 CombineTo(N0.getNode(), Zext);
2552 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2555 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2556 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2557 // already be zero by virtue of the width of the base type of the load.
2559 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2561 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2562 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2563 N0.getOpcode() == ISD::LOAD) {
2564 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2565 N0 : N0.getOperand(0) );
2567 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2568 // This can be a pure constant or a vector splat, in which case we treat the
2569 // vector as a scalar and use the splat value.
2570 APInt Constant = APInt::getNullValue(1);
2571 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2572 Constant = C->getAPIntValue();
2573 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2574 APInt SplatValue, SplatUndef;
2575 unsigned SplatBitSize;
2577 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2578 SplatBitSize, HasAnyUndefs);
2580 // Undef bits can contribute to a possible optimisation if set, so
2582 SplatValue |= SplatUndef;
2584 // The splat value may be something like "0x00FFFFFF", which means 0 for
2585 // the first vector value and FF for the rest, repeating. We need a mask
2586 // that will apply equally to all members of the vector, so AND all the
2587 // lanes of the constant together.
2588 EVT VT = Vector->getValueType(0);
2589 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2591 // If the splat value has been compressed to a bitlength lower
2592 // than the size of the vector lane, we need to re-expand it to
2594 if (BitWidth > SplatBitSize)
2595 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2596 SplatBitSize < BitWidth;
2597 SplatBitSize = SplatBitSize * 2)
2598 SplatValue |= SplatValue.shl(SplatBitSize);
2600 Constant = APInt::getAllOnesValue(BitWidth);
2601 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2602 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2606 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2607 // actually legal and isn't going to get expanded, else this is a false
2609 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2610 Load->getMemoryVT());
2612 // Resize the constant to the same size as the original memory access before
2613 // extension. If it is still the AllOnesValue then this AND is completely
2616 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2619 switch (Load->getExtensionType()) {
2620 default: B = false; break;
2621 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2623 case ISD::NON_EXTLOAD: B = true; break;
2626 if (B && Constant.isAllOnesValue()) {
2627 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2628 // preserve semantics once we get rid of the AND.
2629 SDValue NewLoad(Load, 0);
2630 if (Load->getExtensionType() == ISD::EXTLOAD) {
2631 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2632 Load->getValueType(0), SDLoc(Load),
2633 Load->getChain(), Load->getBasePtr(),
2634 Load->getOffset(), Load->getMemoryVT(),
2635 Load->getMemOperand());
2636 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2637 if (Load->getNumValues() == 3) {
2638 // PRE/POST_INC loads have 3 values.
2639 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2640 NewLoad.getValue(2) };
2641 CombineTo(Load, To, 3, true);
2643 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2647 // Fold the AND away, taking care not to fold to the old load node if we
2649 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2651 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2654 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2655 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2656 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2657 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2659 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2660 LL.getValueType().isInteger()) {
2661 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2662 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2663 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2664 LR.getValueType(), LL, RL);
2665 AddToWorkList(ORNode.getNode());
2666 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2668 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2669 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2670 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(N0),
2671 LR.getValueType(), LL, RL);
2672 AddToWorkList(ANDNode.getNode());
2673 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
2675 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2676 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2677 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(N0),
2678 LR.getValueType(), LL, RL);
2679 AddToWorkList(ORNode.getNode());
2680 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
2683 // Simplify (and (setne X, 0), (setne X, -1)) -> (setuge (add X, 1), 2)
2684 if (LL == RL && isa<ConstantSDNode>(LR) && isa<ConstantSDNode>(RR) &&
2685 Op0 == Op1 && LL.getValueType().isInteger() &&
2686 Op0 == ISD::SETNE && ((cast<ConstantSDNode>(LR)->isNullValue() &&
2687 cast<ConstantSDNode>(RR)->isAllOnesValue()) ||
2688 (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
2689 cast<ConstantSDNode>(RR)->isNullValue()))) {
2690 SDValue ADDNode = DAG.getNode(ISD::ADD, SDLoc(N0), LL.getValueType(),
2691 LL, DAG.getConstant(1, LL.getValueType()));
2692 AddToWorkList(ADDNode.getNode());
2693 return DAG.getSetCC(SDLoc(N), VT, ADDNode,
2694 DAG.getConstant(2, LL.getValueType()), ISD::SETUGE);
2696 // canonicalize equivalent to ll == rl
2697 if (LL == RR && LR == RL) {
2698 Op1 = ISD::getSetCCSwappedOperands(Op1);
2701 if (LL == RL && LR == RR) {
2702 bool isInteger = LL.getValueType().isInteger();
2703 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2704 if (Result != ISD::SETCC_INVALID &&
2705 (!LegalOperations ||
2706 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
2707 TLI.isOperationLegal(ISD::SETCC,
2708 getSetCCResultType(N0.getSimpleValueType())))))
2709 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
2714 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2715 if (N0.getOpcode() == N1.getOpcode()) {
2716 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2717 if (Tmp.getNode()) return Tmp;
2720 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2721 // fold (and (sra)) -> (and (srl)) when possible.
2722 if (!VT.isVector() &&
2723 SimplifyDemandedBits(SDValue(N, 0)))
2724 return SDValue(N, 0);
2726 // fold (zext_inreg (extload x)) -> (zextload x)
2727 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2728 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2729 EVT MemVT = LN0->getMemoryVT();
2730 // If we zero all the possible extended bits, then we can turn this into
2731 // a zextload if we are running before legalize or the operation is legal.
2732 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2733 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2734 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2735 ((!LegalOperations && !LN0->isVolatile()) ||
2736 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2737 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2738 LN0->getChain(), LN0->getBasePtr(),
2739 LN0->getPointerInfo(), MemVT,
2740 LN0->isVolatile(), LN0->isNonTemporal(),
2741 LN0->getAlignment());
2743 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2744 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2747 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2748 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2750 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2751 EVT MemVT = LN0->getMemoryVT();
2752 // If we zero all the possible extended bits, then we can turn this into
2753 // a zextload if we are running before legalize or the operation is legal.
2754 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2755 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2756 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2757 ((!LegalOperations && !LN0->isVolatile()) ||
2758 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2759 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
2761 LN0->getBasePtr(), LN0->getPointerInfo(),
2763 LN0->isVolatile(), LN0->isNonTemporal(),
2764 LN0->getAlignment());
2766 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2767 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2771 // fold (and (load x), 255) -> (zextload x, i8)
2772 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2773 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2774 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2775 (N0.getOpcode() == ISD::ANY_EXTEND &&
2776 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2777 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2778 LoadSDNode *LN0 = HasAnyExt
2779 ? cast<LoadSDNode>(N0.getOperand(0))
2780 : cast<LoadSDNode>(N0);
2781 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2782 LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
2783 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2784 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2785 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2786 EVT LoadedVT = LN0->getMemoryVT();
2788 if (ExtVT == LoadedVT &&
2789 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2790 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2793 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2794 LN0->getChain(), LN0->getBasePtr(),
2795 LN0->getPointerInfo(),
2796 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2797 LN0->getAlignment());
2799 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2800 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2803 // Do not change the width of a volatile load.
2804 // Do not generate loads of non-round integer types since these can
2805 // be expensive (and would be wrong if the type is not byte sized).
2806 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2807 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2808 EVT PtrType = LN0->getOperand(1).getValueType();
2810 unsigned Alignment = LN0->getAlignment();
2811 SDValue NewPtr = LN0->getBasePtr();
2813 // For big endian targets, we need to add an offset to the pointer
2814 // to load the correct bytes. For little endian systems, we merely
2815 // need to read fewer bytes from the same pointer.
2816 if (TLI.isBigEndian()) {
2817 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2818 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2819 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2820 NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0), PtrType,
2821 NewPtr, DAG.getConstant(PtrOff, PtrType));
2822 Alignment = MinAlign(Alignment, PtrOff);
2825 AddToWorkList(NewPtr.getNode());
2827 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2829 DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), LoadResultTy,
2830 LN0->getChain(), NewPtr,
2831 LN0->getPointerInfo(),
2832 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2835 CombineTo(LN0, Load, Load.getValue(1));
2836 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2842 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2843 VT.getSizeInBits() <= 64) {
2844 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2845 APInt ADDC = ADDI->getAPIntValue();
2846 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2847 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2848 // immediate for an add, but it is legal if its top c2 bits are set,
2849 // transform the ADD so the immediate doesn't need to be materialized
2851 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2852 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2853 SRLI->getZExtValue());
2854 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2856 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2858 DAG.getNode(ISD::ADD, SDLoc(N0), VT,
2859 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2860 CombineTo(N0.getNode(), NewAdd);
2861 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2869 // fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
2870 if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
2871 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
2872 N0.getOperand(1), false);
2873 if (BSwap.getNode())
2880 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2882 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2883 bool DemandHighBits) {
2884 if (!LegalOperations)
2887 EVT VT = N->getValueType(0);
2888 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2890 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2893 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2894 bool LookPassAnd0 = false;
2895 bool LookPassAnd1 = false;
2896 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2898 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2900 if (N0.getOpcode() == ISD::AND) {
2901 if (!N0.getNode()->hasOneUse())
2903 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2904 if (!N01C || N01C->getZExtValue() != 0xFF00)
2906 N0 = N0.getOperand(0);
2907 LookPassAnd0 = true;
2910 if (N1.getOpcode() == ISD::AND) {
2911 if (!N1.getNode()->hasOneUse())
2913 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2914 if (!N11C || N11C->getZExtValue() != 0xFF)
2916 N1 = N1.getOperand(0);
2917 LookPassAnd1 = true;
2920 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
2922 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
2924 if (!N0.getNode()->hasOneUse() ||
2925 !N1.getNode()->hasOneUse())
2928 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2929 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2932 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
2935 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
2936 SDValue N00 = N0->getOperand(0);
2937 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
2938 if (!N00.getNode()->hasOneUse())
2940 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
2941 if (!N001C || N001C->getZExtValue() != 0xFF)
2943 N00 = N00.getOperand(0);
2944 LookPassAnd0 = true;
2947 SDValue N10 = N1->getOperand(0);
2948 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
2949 if (!N10.getNode()->hasOneUse())
2951 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
2952 if (!N101C || N101C->getZExtValue() != 0xFF00)
2954 N10 = N10.getOperand(0);
2955 LookPassAnd1 = true;
2961 // Make sure everything beyond the low halfword gets set to zero since the SRL
2962 // 16 will clear the top bits.
2963 unsigned OpSizeInBits = VT.getSizeInBits();
2964 if (DemandHighBits && OpSizeInBits > 16) {
2965 // If the left-shift isn't masked out then the only way this is a bswap is
2966 // if all bits beyond the low 8 are 0. In that case the entire pattern
2967 // reduces to a left shift anyway: leave it for other parts of the combiner.
2971 // However, if the right shift isn't masked out then it might be because
2972 // it's not needed. See if we can spot that too.
2973 if (!LookPassAnd1 &&
2974 !DAG.MaskedValueIsZero(
2975 N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
2979 SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
2980 if (OpSizeInBits > 16)
2981 Res = DAG.getNode(ISD::SRL, SDLoc(N), VT, Res,
2982 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
2986 /// isBSwapHWordElement - Return true if the specified node is an element
2987 /// that makes up a 32-bit packed halfword byteswap. i.e.
2988 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2989 static bool isBSwapHWordElement(SDValue N, SmallVectorImpl<SDNode *> &Parts) {
2990 if (!N.getNode()->hasOneUse())
2993 unsigned Opc = N.getOpcode();
2994 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
2997 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3002 switch (N1C->getZExtValue()) {
3005 case 0xFF: Num = 0; break;
3006 case 0xFF00: Num = 1; break;
3007 case 0xFF0000: Num = 2; break;
3008 case 0xFF000000: Num = 3; break;
3011 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
3012 SDValue N0 = N.getOperand(0);
3013 if (Opc == ISD::AND) {
3014 if (Num == 0 || Num == 2) {
3016 // (x >> 8) & 0xff0000
3017 if (N0.getOpcode() != ISD::SRL)
3019 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3020 if (!C || C->getZExtValue() != 8)
3023 // (x << 8) & 0xff00
3024 // (x << 8) & 0xff000000
3025 if (N0.getOpcode() != ISD::SHL)
3027 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3028 if (!C || C->getZExtValue() != 8)
3031 } else if (Opc == ISD::SHL) {
3033 // (x & 0xff0000) << 8
3034 if (Num != 0 && Num != 2)
3036 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3037 if (!C || C->getZExtValue() != 8)
3039 } else { // Opc == ISD::SRL
3040 // (x & 0xff00) >> 8
3041 // (x & 0xff000000) >> 8
3042 if (Num != 1 && Num != 3)
3044 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
3045 if (!C || C->getZExtValue() != 8)
3052 Parts[Num] = N0.getOperand(0).getNode();
3056 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
3057 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
3058 /// => (rotl (bswap x), 16)
3059 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
3060 if (!LegalOperations)
3063 EVT VT = N->getValueType(0);
3066 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
3069 SmallVector<SDNode*,4> Parts(4, (SDNode*)0);
3071 // (or (or (and), (and)), (or (and), (and)))
3072 // (or (or (or (and), (and)), (and)), (and))
3073 if (N0.getOpcode() != ISD::OR)
3075 SDValue N00 = N0.getOperand(0);
3076 SDValue N01 = N0.getOperand(1);
3078 if (N1.getOpcode() == ISD::OR &&
3079 N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
3080 // (or (or (and), (and)), (or (and), (and)))
3081 SDValue N000 = N00.getOperand(0);
3082 if (!isBSwapHWordElement(N000, Parts))
3085 SDValue N001 = N00.getOperand(1);
3086 if (!isBSwapHWordElement(N001, Parts))
3088 SDValue N010 = N01.getOperand(0);
3089 if (!isBSwapHWordElement(N010, Parts))
3091 SDValue N011 = N01.getOperand(1);
3092 if (!isBSwapHWordElement(N011, Parts))
3095 // (or (or (or (and), (and)), (and)), (and))
3096 if (!isBSwapHWordElement(N1, Parts))
3098 if (!isBSwapHWordElement(N01, Parts))
3100 if (N00.getOpcode() != ISD::OR)
3102 SDValue N000 = N00.getOperand(0);
3103 if (!isBSwapHWordElement(N000, Parts))
3105 SDValue N001 = N00.getOperand(1);
3106 if (!isBSwapHWordElement(N001, Parts))
3110 // Make sure the parts are all coming from the same node.
3111 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3114 SDValue BSwap = DAG.getNode(ISD::BSWAP, SDLoc(N), VT,
3115 SDValue(Parts[0],0));
3117 // Result of the bswap should be rotated by 16. If it's not legal, than
3118 // do (x << 16) | (x >> 16).
3119 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3120 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3121 return DAG.getNode(ISD::ROTL, SDLoc(N), VT, BSwap, ShAmt);
3122 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3123 return DAG.getNode(ISD::ROTR, SDLoc(N), VT, BSwap, ShAmt);
3124 return DAG.getNode(ISD::OR, SDLoc(N), VT,
3125 DAG.getNode(ISD::SHL, SDLoc(N), VT, BSwap, ShAmt),
3126 DAG.getNode(ISD::SRL, SDLoc(N), VT, BSwap, ShAmt));
3129 SDValue DAGCombiner::visitOR(SDNode *N) {
3130 SDValue N0 = N->getOperand(0);
3131 SDValue N1 = N->getOperand(1);
3132 SDValue LL, LR, RL, RR, CC0, CC1;
3133 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3134 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3135 EVT VT = N1.getValueType();
3138 if (VT.isVector()) {
3139 SDValue FoldedVOp = SimplifyVBinOp(N);
3140 if (FoldedVOp.getNode()) return FoldedVOp;
3142 // fold (or x, 0) -> x, vector edition
3143 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3145 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3148 // fold (or x, -1) -> -1, vector edition
3149 if (ISD::isBuildVectorAllOnes(N0.getNode()))
3151 if (ISD::isBuildVectorAllOnes(N1.getNode()))
3155 // fold (or x, undef) -> -1
3156 if (!LegalOperations &&
3157 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3158 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3159 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3161 // fold (or c1, c2) -> c1|c2
3163 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3164 // canonicalize constant to RHS
3166 return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
3167 // fold (or x, 0) -> x
3168 if (N1C && N1C->isNullValue())
3170 // fold (or x, -1) -> -1
3171 if (N1C && N1C->isAllOnesValue())
3173 // fold (or x, c) -> c iff (x & ~c) == 0
3174 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3177 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3178 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3179 if (BSwap.getNode() != 0)
3181 BSwap = MatchBSwapHWordLow(N, N0, N1);
3182 if (BSwap.getNode() != 0)
3186 SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1);
3187 if (ROR.getNode() != 0)
3189 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3190 // iff (c1 & c2) == 0.
3191 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3192 isa<ConstantSDNode>(N0.getOperand(1))) {
3193 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3194 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
3195 return DAG.getNode(ISD::AND, SDLoc(N), VT,
3196 DAG.getNode(ISD::OR, SDLoc(N0), VT,
3197 N0.getOperand(0), N1),
3198 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
3200 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3201 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3202 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3203 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3205 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3206 LL.getValueType().isInteger()) {
3207 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3208 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3209 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3210 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3211 SDValue ORNode = DAG.getNode(ISD::OR, SDLoc(LR),
3212 LR.getValueType(), LL, RL);
3213 AddToWorkList(ORNode.getNode());
3214 return DAG.getSetCC(SDLoc(N), VT, ORNode, LR, Op1);
3216 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3217 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3218 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3219 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3220 SDValue ANDNode = DAG.getNode(ISD::AND, SDLoc(LR),
3221 LR.getValueType(), LL, RL);
3222 AddToWorkList(ANDNode.getNode());
3223 return DAG.getSetCC(SDLoc(N), VT, ANDNode, LR, Op1);
3226 // canonicalize equivalent to ll == rl
3227 if (LL == RR && LR == RL) {
3228 Op1 = ISD::getSetCCSwappedOperands(Op1);
3231 if (LL == RL && LR == RR) {
3232 bool isInteger = LL.getValueType().isInteger();
3233 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3234 if (Result != ISD::SETCC_INVALID &&
3235 (!LegalOperations ||
3236 (TLI.isCondCodeLegal(Result, LL.getSimpleValueType()) &&
3237 TLI.isOperationLegal(ISD::SETCC,
3238 getSetCCResultType(N0.getValueType())))))
3239 return DAG.getSetCC(SDLoc(N), N0.getValueType(),
3244 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3245 if (N0.getOpcode() == N1.getOpcode()) {
3246 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3247 if (Tmp.getNode()) return Tmp;
3250 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3251 if (N0.getOpcode() == ISD::AND &&
3252 N1.getOpcode() == ISD::AND &&
3253 N0.getOperand(1).getOpcode() == ISD::Constant &&
3254 N1.getOperand(1).getOpcode() == ISD::Constant &&
3255 // Don't increase # computations.
3256 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3257 // We can only do this xform if we know that bits from X that are set in C2
3258 // but not in C1 are already zero. Likewise for Y.
3259 const APInt &LHSMask =
3260 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3261 const APInt &RHSMask =
3262 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3264 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3265 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3266 SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
3267 N0.getOperand(0), N1.getOperand(0));
3268 return DAG.getNode(ISD::AND, SDLoc(N), VT, X,
3269 DAG.getConstant(LHSMask | RHSMask, VT));
3273 // See if this is some rotate idiom.
3274 if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
3275 return SDValue(Rot, 0);
3277 // Simplify the operands using demanded-bits information.
3278 if (!VT.isVector() &&
3279 SimplifyDemandedBits(SDValue(N, 0)))
3280 return SDValue(N, 0);
3285 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3286 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3287 if (Op.getOpcode() == ISD::AND) {
3288 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3289 Mask = Op.getOperand(1);
3290 Op = Op.getOperand(0);
3296 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3304 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3305 // idioms for rotate, and if the target supports rotation instructions, generate
3307 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, SDLoc DL) {
3308 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3309 EVT VT = LHS.getValueType();
3310 if (!TLI.isTypeLegal(VT)) return 0;
3312 // The target must have at least one rotate flavor.
3313 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3314 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3315 if (!HasROTL && !HasROTR) return 0;
3317 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3318 SDValue LHSShift; // The shift.
3319 SDValue LHSMask; // AND value if any.
3320 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3321 return 0; // Not part of a rotate.
3323 SDValue RHSShift; // The shift.
3324 SDValue RHSMask; // AND value if any.
3325 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3326 return 0; // Not part of a rotate.
3328 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3329 return 0; // Not shifting the same value.
3331 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3332 return 0; // Shifts must disagree.
3334 // Canonicalize shl to left side in a shl/srl pair.
3335 if (RHSShift.getOpcode() == ISD::SHL) {
3336 std::swap(LHS, RHS);
3337 std::swap(LHSShift, RHSShift);
3338 std::swap(LHSMask , RHSMask );
3341 unsigned OpSizeInBits = VT.getSizeInBits();
3342 SDValue LHSShiftArg = LHSShift.getOperand(0);
3343 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3344 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3346 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3347 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3348 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3349 RHSShiftAmt.getOpcode() == ISD::Constant) {
3350 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3351 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3352 if ((LShVal + RShVal) != OpSizeInBits)
3355 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3356 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3358 // If there is an AND of either shifted operand, apply it to the result.
3359 if (LHSMask.getNode() || RHSMask.getNode()) {
3360 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3362 if (LHSMask.getNode()) {
3363 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3364 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3366 if (RHSMask.getNode()) {
3367 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3368 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3371 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3374 return Rot.getNode();
3377 // If there is a mask here, and we have a variable shift, we can't be sure
3378 // that we're masking out the right stuff.
3379 if (LHSMask.getNode() || RHSMask.getNode())
3382 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
3383 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
3384 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
3385 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
3386 if (ConstantSDNode *SUBC =
3387 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
3388 if (SUBC->getAPIntValue() == OpSizeInBits)
3389 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
3390 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3394 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
3395 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
3396 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
3397 RHSShiftAmt == LHSShiftAmt.getOperand(1))
3398 if (ConstantSDNode *SUBC =
3399 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0)))
3400 if (SUBC->getAPIntValue() == OpSizeInBits)
3401 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
3402 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3404 // Look for sign/zext/any-extended or truncate cases:
3405 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3406 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3407 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3408 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3409 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3410 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3411 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3412 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3413 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
3414 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
3415 if (RExtOp0.getOpcode() == ISD::SUB &&
3416 RExtOp0.getOperand(1) == LExtOp0) {
3417 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3419 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3420 // (rotr x, (sub 32, y))
3421 if (ConstantSDNode *SUBC =
3422 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0)))
3423 if (SUBC->getAPIntValue() == OpSizeInBits)
3424 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3426 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3427 } else if (LExtOp0.getOpcode() == ISD::SUB &&
3428 RExtOp0 == LExtOp0.getOperand(1)) {
3429 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3431 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3432 // (rotl x, (sub 32, y))
3433 if (ConstantSDNode *SUBC =
3434 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0)))
3435 if (SUBC->getAPIntValue() == OpSizeInBits)
3436 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
3438 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3445 SDValue DAGCombiner::visitXOR(SDNode *N) {
3446 SDValue N0 = N->getOperand(0);
3447 SDValue N1 = N->getOperand(1);
3448 SDValue LHS, RHS, CC;
3449 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3450 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3451 EVT VT = N0.getValueType();
3454 if (VT.isVector()) {
3455 SDValue FoldedVOp = SimplifyVBinOp(N);
3456 if (FoldedVOp.getNode()) return FoldedVOp;
3458 // fold (xor x, 0) -> x, vector edition
3459 if (ISD::isBuildVectorAllZeros(N0.getNode()))
3461 if (ISD::isBuildVectorAllZeros(N1.getNode()))
3465 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3466 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3467 return DAG.getConstant(0, VT);
3468 // fold (xor x, undef) -> undef
3469 if (N0.getOpcode() == ISD::UNDEF)
3471 if (N1.getOpcode() == ISD::UNDEF)
3473 // fold (xor c1, c2) -> c1^c2
3475 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3476 // canonicalize constant to RHS
3478 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
3479 // fold (xor x, 0) -> x
3480 if (N1C && N1C->isNullValue())
3483 SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1);
3484 if (RXOR.getNode() != 0)
3487 // fold !(x cc y) -> (x !cc y)
3488 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3489 bool isInt = LHS.getValueType().isInteger();
3490 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3493 if (!LegalOperations ||
3494 TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
3495 switch (N0.getOpcode()) {
3497 llvm_unreachable("Unhandled SetCC Equivalent!");
3499 return DAG.getSetCC(SDLoc(N), VT, LHS, RHS, NotCC);
3500 case ISD::SELECT_CC:
3501 return DAG.getSelectCC(SDLoc(N), LHS, RHS, N0.getOperand(2),
3502 N0.getOperand(3), NotCC);
3507 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3508 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3509 N0.getNode()->hasOneUse() &&
3510 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3511 SDValue V = N0.getOperand(0);
3512 V = DAG.getNode(ISD::XOR, SDLoc(N0), V.getValueType(), V,
3513 DAG.getConstant(1, V.getValueType()));
3514 AddToWorkList(V.getNode());
3515 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
3518 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3519 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3520 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3521 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3522 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3523 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3524 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3525 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3526 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3527 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3530 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3531 if (N1C && N1C->isAllOnesValue() &&
3532 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3533 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3534 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3535 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3536 LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
3537 RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
3538 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3539 return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
3542 // fold (xor (and x, y), y) -> (and (not x), y)
3543 if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3544 N0->getOperand(1) == N1) {
3545 SDValue X = N0->getOperand(0);
3546 SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
3547 AddToWorkList(NotX.getNode());
3548 return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
3550 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3551 if (N1C && N0.getOpcode() == ISD::XOR) {
3552 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3553 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3555 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(1),
3556 DAG.getConstant(N1C->getAPIntValue() ^
3557 N00C->getAPIntValue(), VT));
3559 return DAG.getNode(ISD::XOR, SDLoc(N), VT, N0.getOperand(0),
3560 DAG.getConstant(N1C->getAPIntValue() ^
3561 N01C->getAPIntValue(), VT));
3563 // fold (xor x, x) -> 0
3565 return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);
3567 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3568 if (N0.getOpcode() == N1.getOpcode()) {
3569 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3570 if (Tmp.getNode()) return Tmp;
3573 // Simplify the expression using non-local knowledge.
3574 if (!VT.isVector() &&
3575 SimplifyDemandedBits(SDValue(N, 0)))
3576 return SDValue(N, 0);
3581 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3582 /// the shift amount is a constant.
3583 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
3584 SDNode *LHS = N->getOperand(0).getNode();
3585 if (!LHS->hasOneUse()) return SDValue();
3587 // We want to pull some binops through shifts, so that we have (and (shift))
3588 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3589 // thing happens with address calculations, so it's important to canonicalize
3591 bool HighBitSet = false; // Can we transform this if the high bit is set?
3593 switch (LHS->getOpcode()) {
3594 default: return SDValue();
3597 HighBitSet = false; // We can only transform sra if the high bit is clear.
3600 HighBitSet = true; // We can only transform sra if the high bit is set.
3603 if (N->getOpcode() != ISD::SHL)
3604 return SDValue(); // only shl(add) not sr[al](add).
3605 HighBitSet = false; // We can only transform sra if the high bit is clear.
3609 // We require the RHS of the binop to be a constant as well.
3610 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3611 if (!BinOpCst) return SDValue();
3613 // FIXME: disable this unless the input to the binop is a shift by a constant.
3614 // If it is not a shift, it pessimizes some common cases like:
3616 // void foo(int *X, int i) { X[i & 1235] = 1; }
3617 // int bar(int *X, int i) { return X[i & 255]; }
3618 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3619 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3620 BinOpLHSVal->getOpcode() != ISD::SRA &&
3621 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3622 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3625 EVT VT = N->getValueType(0);
3627 // If this is a signed shift right, and the high bit is modified by the
3628 // logical operation, do not perform the transformation. The highBitSet
3629 // boolean indicates the value of the high bit of the constant which would
3630 // cause it to be modified for this operation.
3631 if (N->getOpcode() == ISD::SRA) {
3632 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3633 if (BinOpRHSSignSet != HighBitSet)
3637 // Fold the constants, shifting the binop RHS by the shift amount.
3638 SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
3640 LHS->getOperand(1), N->getOperand(1));
3642 // Create the new shift.
3643 SDValue NewShift = DAG.getNode(N->getOpcode(),
3644 SDLoc(LHS->getOperand(0)),
3645 VT, LHS->getOperand(0), N->getOperand(1));
3647 // Create the new binop.
3648 return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
3651 SDValue DAGCombiner::visitSHL(SDNode *N) {
3652 SDValue N0 = N->getOperand(0);
3653 SDValue N1 = N->getOperand(1);
3654 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3655 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3656 EVT VT = N0.getValueType();
3657 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3659 // fold (shl c1, c2) -> c1<<c2
3661 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3662 // fold (shl 0, x) -> 0
3663 if (N0C && N0C->isNullValue())
3665 // fold (shl x, c >= size(x)) -> undef
3666 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3667 return DAG.getUNDEF(VT);
3668 // fold (shl x, 0) -> x
3669 if (N1C && N1C->isNullValue())
3671 // fold (shl undef, x) -> 0
3672 if (N0.getOpcode() == ISD::UNDEF)
3673 return DAG.getConstant(0, VT);
3674 // if (shl x, c) is known to be zero, return 0
3675 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3676 APInt::getAllOnesValue(OpSizeInBits)))
3677 return DAG.getConstant(0, VT);
3678 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3679 if (N1.getOpcode() == ISD::TRUNCATE &&
3680 N1.getOperand(0).getOpcode() == ISD::AND &&
3681 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3682 SDValue N101 = N1.getOperand(0).getOperand(1);
3683 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3684 EVT TruncVT = N1.getValueType();
3685 SDValue N100 = N1.getOperand(0).getOperand(0);
3686 APInt TruncC = N101C->getAPIntValue();
3687 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3688 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0,
3689 DAG.getNode(ISD::AND, SDLoc(N), TruncVT,
3690 DAG.getNode(ISD::TRUNCATE,
3693 DAG.getConstant(TruncC, TruncVT)));
3697 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3698 return SDValue(N, 0);
3700 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
3701 if (N1C && N0.getOpcode() == ISD::SHL &&
3702 N0.getOperand(1).getOpcode() == ISD::Constant) {
3703 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3704 uint64_t c2 = N1C->getZExtValue();
3705 if (c1 + c2 >= OpSizeInBits)
3706 return DAG.getConstant(0, VT);
3707 return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
3708 DAG.getConstant(c1 + c2, N1.getValueType()));
3711 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
3712 // For this to be valid, the second form must not preserve any of the bits
3713 // that are shifted out by the inner shift in the first form. This means
3714 // the outer shift size must be >= the number of bits added by the ext.
3715 // As a corollary, we don't care what kind of ext it is.
3716 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
3717 N0.getOpcode() == ISD::ANY_EXTEND ||
3718 N0.getOpcode() == ISD::SIGN_EXTEND) &&
3719 N0.getOperand(0).getOpcode() == ISD::SHL &&
3720 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3722 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3723 uint64_t c2 = N1C->getZExtValue();
3724 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3725 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3726 if (c2 >= OpSizeInBits - InnerShiftSize) {
3727 if (c1 + c2 >= OpSizeInBits)
3728 return DAG.getConstant(0, VT);
3729 return DAG.getNode(ISD::SHL, SDLoc(N0), VT,
3730 DAG.getNode(N0.getOpcode(), SDLoc(N0), VT,
3731 N0.getOperand(0)->getOperand(0)),
3732 DAG.getConstant(c1 + c2, N1.getValueType()));
3736 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
3737 // (and (srl x, (sub c1, c2), MASK)
3738 // Only fold this if the inner shift has no other uses -- if it does, folding
3739 // this will increase the total number of instructions.
3740 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse() &&
3741 N0.getOperand(1).getOpcode() == ISD::Constant) {
3742 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3743 if (c1 < VT.getSizeInBits()) {
3744 uint64_t c2 = N1C->getZExtValue();
3745 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
3746 VT.getSizeInBits() - c1);
3749 Mask = Mask.shl(c2-c1);
3750 Shift = DAG.getNode(ISD::SHL, SDLoc(N), VT, N0.getOperand(0),
3751 DAG.getConstant(c2-c1, N1.getValueType()));
3753 Mask = Mask.lshr(c1-c2);
3754 Shift = DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
3755 DAG.getConstant(c1-c2, N1.getValueType()));
3757 return DAG.getNode(ISD::AND, SDLoc(N0), VT, Shift,
3758 DAG.getConstant(Mask, VT));
3761 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
3762 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
3763 SDValue HiBitsMask =
3764 DAG.getConstant(APInt::getHighBitsSet(VT.getSizeInBits(),
3765 VT.getSizeInBits() -
3766 N1C->getZExtValue()),
3768 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
3773 SDValue NewSHL = visitShiftByConstant(N, N1C->getZExtValue());
3774 if (NewSHL.getNode())
3781 SDValue DAGCombiner::visitSRA(SDNode *N) {
3782 SDValue N0 = N->getOperand(0);
3783 SDValue N1 = N->getOperand(1);
3784 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3785 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3786 EVT VT = N0.getValueType();
3787 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3789 // fold (sra c1, c2) -> (sra c1, c2)
3791 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
3792 // fold (sra 0, x) -> 0
3793 if (N0C && N0C->isNullValue())
3795 // fold (sra -1, x) -> -1
3796 if (N0C && N0C->isAllOnesValue())
3798 // fold (sra x, (setge c, size(x))) -> undef
3799 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3800 return DAG.getUNDEF(VT);
3801 // fold (sra x, 0) -> x
3802 if (N1C && N1C->isNullValue())
3804 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
3806 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
3807 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
3808 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
3810 ExtVT = EVT::getVectorVT(*DAG.getContext(),
3811 ExtVT, VT.getVectorNumElements());
3812 if ((!LegalOperations ||
3813 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
3814 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
3815 N0.getOperand(0), DAG.getValueType(ExtVT));
3818 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
3819 if (N1C && N0.getOpcode() == ISD::SRA) {
3820 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3821 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
3822 if (Sum >= OpSizeInBits) Sum = OpSizeInBits-1;
3823 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0.getOperand(0),
3824 DAG.getConstant(Sum, N1C->getValueType(0)));
3828 // fold (sra (shl X, m), (sub result_size, n))
3829 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
3830 // result_size - n != m.
3831 // If truncate is free for the target sext(shl) is likely to result in better
3833 if (N0.getOpcode() == ISD::SHL) {
3834 // Get the two constanst of the shifts, CN0 = m, CN = n.
3835 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3837 // Determine what the truncate's result bitsize and type would be.
3839 EVT::getIntegerVT(*DAG.getContext(),
3840 OpSizeInBits - N1C->getZExtValue());
3841 // Determine the residual right-shift amount.
3842 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
3844 // If the shift is not a no-op (in which case this should be just a sign
3845 // extend already), the truncated to type is legal, sign_extend is legal
3846 // on that type, and the truncate to that type is both legal and free,
3847 // perform the transform.
3848 if ((ShiftAmt > 0) &&
3849 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
3850 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
3851 TLI.isTruncateFree(VT, TruncVT)) {
3853 SDValue Amt = DAG.getConstant(ShiftAmt,
3854 getShiftAmountTy(N0.getOperand(0).getValueType()));
3855 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0), VT,
3856 N0.getOperand(0), Amt);
3857 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), TruncVT,
3859 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N),
3860 N->getValueType(0), Trunc);
3865 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
3866 if (N1.getOpcode() == ISD::TRUNCATE &&
3867 N1.getOperand(0).getOpcode() == ISD::AND &&
3868 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3869 SDValue N101 = N1.getOperand(0).getOperand(1);
3870 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3871 EVT TruncVT = N1.getValueType();
3872 SDValue N100 = N1.getOperand(0).getOperand(0);
3873 APInt TruncC = N101C->getAPIntValue();
3874 TruncC = TruncC.trunc(TruncVT.getScalarType().getSizeInBits());
3875 return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0,
3876 DAG.getNode(ISD::AND, SDLoc(N),
3878 DAG.getNode(ISD::TRUNCATE,
3881 DAG.getConstant(TruncC, TruncVT)));
3885 // fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2))
3886 // if c1 is equal to the number of bits the trunc removes
3887 if (N0.getOpcode() == ISD::TRUNCATE &&
3888 (N0.getOperand(0).getOpcode() == ISD::SRL ||
3889 N0.getOperand(0).getOpcode() == ISD::SRA) &&
3890 N0.getOperand(0).hasOneUse() &&
3891 N0.getOperand(0).getOperand(1).hasOneUse() &&
3892 N1C && isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
3893 EVT LargeVT = N0.getOperand(0).getValueType();
3894 ConstantSDNode *LargeShiftAmt =
3895 cast<ConstantSDNode>(N0.getOperand(0).getOperand(1));
3897 if (LargeVT.getScalarType().getSizeInBits() - OpSizeInBits ==
3898 LargeShiftAmt->getZExtValue()) {
3900 DAG.getConstant(LargeShiftAmt->getZExtValue() + N1C->getZExtValue(),
3901 getShiftAmountTy(N0.getOperand(0).getOperand(0).getValueType()));
3902 SDValue SRA = DAG.getNode(ISD::SRA, SDLoc(N), LargeVT,
3903 N0.getOperand(0).getOperand(0), Amt);
3904 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, SRA);
3908 // Simplify, based on bits shifted out of the LHS.
3909 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3910 return SDValue(N, 0);
3913 // If the sign bit is known to be zero, switch this to a SRL.
3914 if (DAG.SignBitIsZero(N0))
3915 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);
3918 SDValue NewSRA = visitShiftByConstant(N, N1C->getZExtValue());
3919 if (NewSRA.getNode())
3926 SDValue DAGCombiner::visitSRL(SDNode *N) {
3927 SDValue N0 = N->getOperand(0);
3928 SDValue N1 = N->getOperand(1);
3929 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3930 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3931 EVT VT = N0.getValueType();
3932 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3934 // fold (srl c1, c2) -> c1 >>u c2
3936 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
3937 // fold (srl 0, x) -> 0
3938 if (N0C && N0C->isNullValue())
3940 // fold (srl x, c >= size(x)) -> undef
3941 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3942 return DAG.getUNDEF(VT);
3943 // fold (srl x, 0) -> x
3944 if (N1C && N1C->isNullValue())
3946 // if (srl x, c) is known to be zero, return 0
3947 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
3948 APInt::getAllOnesValue(OpSizeInBits)))
3949 return DAG.getConstant(0, VT);
3951 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
3952 if (N1C && N0.getOpcode() == ISD::SRL &&
3953 N0.getOperand(1).getOpcode() == ISD::Constant) {
3954 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3955 uint64_t c2 = N1C->getZExtValue();
3956 if (c1 + c2 >= OpSizeInBits)
3957 return DAG.getConstant(0, VT);
3958 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0),
3959 DAG.getConstant(c1 + c2, N1.getValueType()));
3962 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
3963 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
3964 N0.getOperand(0).getOpcode() == ISD::SRL &&
3965 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3967 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3968 uint64_t c2 = N1C->getZExtValue();
3969 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3970 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
3971 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3972 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
3973 if (c1 + OpSizeInBits == InnerShiftSize) {
3974 if (c1 + c2 >= InnerShiftSize)
3975 return DAG.getConstant(0, VT);
3976 return DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT,
3977 DAG.getNode(ISD::SRL, SDLoc(N0), InnerShiftVT,
3978 N0.getOperand(0)->getOperand(0),
3979 DAG.getConstant(c1 + c2, ShiftCountVT)));
3983 // fold (srl (shl x, c), c) -> (and x, cst2)
3984 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
3985 N0.getValueSizeInBits() <= 64) {
3986 uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
3987 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0.getOperand(0),
3988 DAG.getConstant(~0ULL >> ShAmt, VT));
3991 // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
3992 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
3993 // Shifting in all undef bits?
3994 EVT SmallVT = N0.getOperand(0).getValueType();
3995 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
3996 return DAG.getUNDEF(VT);
3998 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
3999 uint64_t ShiftAmt = N1C->getZExtValue();
4000 SDValue SmallShift = DAG.getNode(ISD::SRL, SDLoc(N0), SmallVT,
4002 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
4003 AddToWorkList(SmallShift.getNode());
4004 APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits()).lshr(ShiftAmt);
4005 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4006 DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, SmallShift),
4007 DAG.getConstant(Mask, VT));
4011 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
4012 // bit, which is unmodified by sra.
4013 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
4014 if (N0.getOpcode() == ISD::SRA)
4015 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
4018 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
4019 if (N1C && N0.getOpcode() == ISD::CTLZ &&
4020 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
4021 APInt KnownZero, KnownOne;
4022 DAG.ComputeMaskedBits(N0.getOperand(0), KnownZero, KnownOne);
4024 // If any of the input bits are KnownOne, then the input couldn't be all
4025 // zeros, thus the result of the srl will always be zero.
4026 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
4028 // If all of the bits input the to ctlz node are known to be zero, then
4029 // the result of the ctlz is "32" and the result of the shift is one.
4030 APInt UnknownBits = ~KnownZero;
4031 if (UnknownBits == 0) return DAG.getConstant(1, VT);
4033 // Otherwise, check to see if there is exactly one bit input to the ctlz.
4034 if ((UnknownBits & (UnknownBits - 1)) == 0) {
4035 // Okay, we know that only that the single bit specified by UnknownBits
4036 // could be set on input to the CTLZ node. If this bit is set, the SRL
4037 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
4038 // to an SRL/XOR pair, which is likely to simplify more.
4039 unsigned ShAmt = UnknownBits.countTrailingZeros();
4040 SDValue Op = N0.getOperand(0);
4043 Op = DAG.getNode(ISD::SRL, SDLoc(N0), VT, Op,
4044 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
4045 AddToWorkList(Op.getNode());
4048 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
4049 Op, DAG.getConstant(1, VT));
4053 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
4054 if (N1.getOpcode() == ISD::TRUNCATE &&
4055 N1.getOperand(0).getOpcode() == ISD::AND &&
4056 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
4057 SDValue N101 = N1.getOperand(0).getOperand(1);
4058 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
4059 EVT TruncVT = N1.getValueType();
4060 SDValue N100 = N1.getOperand(0).getOperand(0);
4061 APInt TruncC = N101C->getAPIntValue();
4062 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
4063 return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0,
4064 DAG.getNode(ISD::AND, SDLoc(N),
4066 DAG.getNode(ISD::TRUNCATE,
4069 DAG.getConstant(TruncC, TruncVT)));
4073 // fold operands of srl based on knowledge that the low bits are not
4075 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
4076 return SDValue(N, 0);
4079 SDValue NewSRL = visitShiftByConstant(N, N1C->getZExtValue());
4080 if (NewSRL.getNode())
4084 // Attempt to convert a srl of a load into a narrower zero-extending load.
4085 SDValue NarrowLoad = ReduceLoadWidth(N);
4086 if (NarrowLoad.getNode())
4089 // Here is a common situation. We want to optimize:
4092 // %b = and i32 %a, 2
4093 // %c = srl i32 %b, 1
4094 // brcond i32 %c ...
4100 // %c = setcc eq %b, 0
4103 // However when after the source operand of SRL is optimized into AND, the SRL
4104 // itself may not be optimized further. Look for it and add the BRCOND into
4106 if (N->hasOneUse()) {
4107 SDNode *Use = *N->use_begin();
4108 if (Use->getOpcode() == ISD::BRCOND)
4110 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
4111 // Also look pass the truncate.
4112 Use = *Use->use_begin();
4113 if (Use->getOpcode() == ISD::BRCOND)
4121 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
4122 SDValue N0 = N->getOperand(0);
4123 EVT VT = N->getValueType(0);
4125 // fold (ctlz c1) -> c2
4126 if (isa<ConstantSDNode>(N0))
4127 return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);
4131 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
4132 SDValue N0 = N->getOperand(0);
4133 EVT VT = N->getValueType(0);
4135 // fold (ctlz_zero_undef c1) -> c2
4136 if (isa<ConstantSDNode>(N0))
4137 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4141 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4142 SDValue N0 = N->getOperand(0);
4143 EVT VT = N->getValueType(0);
4145 // fold (cttz c1) -> c2
4146 if (isa<ConstantSDNode>(N0))
4147 return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);
4151 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4152 SDValue N0 = N->getOperand(0);
4153 EVT VT = N->getValueType(0);
4155 // fold (cttz_zero_undef c1) -> c2
4156 if (isa<ConstantSDNode>(N0))
4157 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
4161 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4162 SDValue N0 = N->getOperand(0);
4163 EVT VT = N->getValueType(0);
4165 // fold (ctpop c1) -> c2
4166 if (isa<ConstantSDNode>(N0))
4167 return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
4171 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4172 SDValue N0 = N->getOperand(0);
4173 SDValue N1 = N->getOperand(1);
4174 SDValue N2 = N->getOperand(2);
4175 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4176 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4177 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4178 EVT VT = N->getValueType(0);
4179 EVT VT0 = N0.getValueType();
4181 // fold (select C, X, X) -> X
4184 // fold (select true, X, Y) -> X
4185 if (N0C && !N0C->isNullValue())
4187 // fold (select false, X, Y) -> Y
4188 if (N0C && N0C->isNullValue())
4190 // fold (select C, 1, X) -> (or C, X)
4191 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4192 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4193 // fold (select C, 0, 1) -> (xor C, 1)
4194 if (VT.isInteger() &&
4197 TLI.getBooleanContents(false) ==
4198 TargetLowering::ZeroOrOneBooleanContent)) &&
4199 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4202 return DAG.getNode(ISD::XOR, SDLoc(N), VT0,
4203 N0, DAG.getConstant(1, VT0));
4204 XORNode = DAG.getNode(ISD::XOR, SDLoc(N0), VT0,
4205 N0, DAG.getConstant(1, VT0));
4206 AddToWorkList(XORNode.getNode());
4208 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, XORNode);
4209 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, XORNode);
4211 // fold (select C, 0, X) -> (and (not C), X)
4212 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4213 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4214 AddToWorkList(NOTNode.getNode());
4215 return DAG.getNode(ISD::AND, SDLoc(N), VT, NOTNode, N2);
4217 // fold (select C, X, 1) -> (or (not C), X)
4218 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4219 SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
4220 AddToWorkList(NOTNode.getNode());
4221 return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
4223 // fold (select C, X, 0) -> (and C, X)
4224 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4225 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4226 // fold (select X, X, Y) -> (or X, Y)
4227 // fold (select X, 1, Y) -> (or X, Y)
4228 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4229 return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
4230 // fold (select X, Y, X) -> (and X, Y)
4231 // fold (select X, Y, 0) -> (and X, Y)
4232 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4233 return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
4235 // If we can fold this based on the true/false value, do so.
4236 if (SimplifySelectOps(N, N1, N2))
4237 return SDValue(N, 0); // Don't revisit N.
4239 // fold selects based on a setcc into other things, such as min/max/abs
4240 if (N0.getOpcode() == ISD::SETCC) {
4242 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
4243 // having to say they don't support SELECT_CC on every type the DAG knows
4244 // about, since there is no way to mark an opcode illegal at all value types
4245 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other) &&
4246 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT))
4247 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT,
4248 N0.getOperand(0), N0.getOperand(1),
4249 N1, N2, N0.getOperand(2));
4250 return SimplifySelect(SDLoc(N), N0, N1, N2);
4256 SDValue DAGCombiner::visitVSELECT(SDNode *N) {
4257 SDValue N0 = N->getOperand(0);
4258 SDValue N1 = N->getOperand(1);
4259 SDValue N2 = N->getOperand(2);
4262 // Canonicalize integer abs.
4263 // vselect (setg[te] X, 0), X, -X ->
4264 // vselect (setgt X, -1), X, -X ->
4265 // vselect (setl[te] X, 0), -X, X ->
4266 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
4267 if (N0.getOpcode() == ISD::SETCC) {
4268 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
4269 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
4271 bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());
4273 if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
4274 (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
4275 N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
4276 isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
4277 else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
4278 N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
4279 isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
4282 EVT VT = LHS.getValueType();
4283 SDValue Shift = DAG.getNode(
4284 ISD::SRA, DL, VT, LHS,
4285 DAG.getConstant(VT.getScalarType().getSizeInBits() - 1, VT));
4286 SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
4287 AddToWorkList(Shift.getNode());
4288 AddToWorkList(Add.getNode());
4289 return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
4296 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4297 SDValue N0 = N->getOperand(0);
4298 SDValue N1 = N->getOperand(1);
4299 SDValue N2 = N->getOperand(2);
4300 SDValue N3 = N->getOperand(3);
4301 SDValue N4 = N->getOperand(4);
4302 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4304 // fold select_cc lhs, rhs, x, x, cc -> x
4308 // Determine if the condition we're dealing with is constant
4309 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
4310 N0, N1, CC, SDLoc(N), false);
4311 if (SCC.getNode()) {
4312 AddToWorkList(SCC.getNode());
4314 if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
4315 if (!SCCC->isNullValue())
4316 return N2; // cond always true -> true val
4318 return N3; // cond always false -> false val
4321 // Fold to a simpler select_cc
4322 if (SCC.getOpcode() == ISD::SETCC)
4323 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
4324 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4328 // If we can fold this based on the true/false value, do so.
4329 if (SimplifySelectOps(N, N2, N3))
4330 return SDValue(N, 0); // Don't revisit N.
4332 // fold select_cc into other things, such as min/max/abs
4333 return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
4336 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4337 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4338 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4342 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4343 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4344 // transformation. Returns true if extension are possible and the above
4345 // mentioned transformation is profitable.
4346 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4348 SmallVectorImpl<SDNode *> &ExtendNodes,
4349 const TargetLowering &TLI) {
4350 bool HasCopyToRegUses = false;
4351 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4352 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4353 UE = N0.getNode()->use_end();
4358 if (UI.getUse().getResNo() != N0.getResNo())
4360 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4361 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4362 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4363 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4364 // Sign bits will be lost after a zext.
4367 for (unsigned i = 0; i != 2; ++i) {
4368 SDValue UseOp = User->getOperand(i);
4371 if (!isa<ConstantSDNode>(UseOp))
4376 ExtendNodes.push_back(User);
4379 // If truncates aren't free and there are users we can't
4380 // extend, it isn't worthwhile.
4383 // Remember if this value is live-out.
4384 if (User->getOpcode() == ISD::CopyToReg)
4385 HasCopyToRegUses = true;
4388 if (HasCopyToRegUses) {
4389 bool BothLiveOut = false;
4390 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4392 SDUse &Use = UI.getUse();
4393 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4399 // Both unextended and extended values are live out. There had better be
4400 // a good reason for the transformation.
4401 return ExtendNodes.size();
4406 void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
4407 SDValue Trunc, SDValue ExtLoad, SDLoc DL,
4408 ISD::NodeType ExtType) {
4409 // Extend SetCC uses if necessary.
4410 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4411 SDNode *SetCC = SetCCs[i];
4412 SmallVector<SDValue, 4> Ops;
4414 for (unsigned j = 0; j != 2; ++j) {
4415 SDValue SOp = SetCC->getOperand(j);
4417 Ops.push_back(ExtLoad);
4419 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4422 Ops.push_back(SetCC->getOperand(2));
4423 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
4424 &Ops[0], Ops.size()));
4428 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4429 SDValue N0 = N->getOperand(0);
4430 EVT VT = N->getValueType(0);
4432 // fold (sext c1) -> c1
4433 if (isa<ConstantSDNode>(N0))
4434 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N0);
4436 // fold (sext (sext x)) -> (sext x)
4437 // fold (sext (aext x)) -> (sext x)
4438 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4439 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT,
4442 if (N0.getOpcode() == ISD::TRUNCATE) {
4443 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4444 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4445 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4446 if (NarrowLoad.getNode()) {
4447 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4448 if (NarrowLoad.getNode() != N0.getNode()) {
4449 CombineTo(N0.getNode(), NarrowLoad);
4450 // CombineTo deleted the truncate, if needed, but not what's under it.
4453 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4456 // See if the value being truncated is already sign extended. If so, just
4457 // eliminate the trunc/sext pair.
4458 SDValue Op = N0.getOperand(0);
4459 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4460 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4461 unsigned DestBits = VT.getScalarType().getSizeInBits();
4462 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4464 if (OpBits == DestBits) {
4465 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4466 // bits, it is already ready.
4467 if (NumSignBits > DestBits-MidBits)
4469 } else if (OpBits < DestBits) {
4470 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4471 // bits, just sext from i32.
4472 if (NumSignBits > OpBits-MidBits)
4473 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, Op);
4475 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4476 // bits, just truncate to i32.
4477 if (NumSignBits > OpBits-MidBits)
4478 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4481 // fold (sext (truncate x)) -> (sextinreg x).
4482 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4483 N0.getValueType())) {
4484 if (OpBits < DestBits)
4485 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
4486 else if (OpBits > DestBits)
4487 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
4488 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, Op,
4489 DAG.getValueType(N0.getValueType()));
4493 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4494 // None of the supported targets knows how to perform load and sign extend
4495 // on vectors in one instruction. We only perform this transformation on
4497 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4498 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4499 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
4500 bool DoXform = true;
4501 SmallVector<SDNode*, 4> SetCCs;
4502 if (!N0.hasOneUse())
4503 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
4505 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4506 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
4508 LN0->getBasePtr(), LN0->getPointerInfo(),
4510 LN0->isVolatile(), LN0->isNonTemporal(),
4511 LN0->getAlignment());
4512 CombineTo(N, ExtLoad);
4513 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4514 N0.getValueType(), ExtLoad);
4515 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4516 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4518 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4522 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
4523 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
4524 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4525 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4526 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4527 EVT MemVT = LN0->getMemoryVT();
4528 if ((!LegalOperations && !LN0->isVolatile()) ||
4529 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
4530 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
4532 LN0->getBasePtr(), LN0->getPointerInfo(),
4534 LN0->isVolatile(), LN0->isNonTemporal(),
4535 LN0->getAlignment());
4536 CombineTo(N, ExtLoad);
4537 CombineTo(N0.getNode(),
4538 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4539 N0.getValueType(), ExtLoad),
4540 ExtLoad.getValue(1));
4541 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4545 // fold (sext (and/or/xor (load x), cst)) ->
4546 // (and/or/xor (sextload x), (sext cst))
4547 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4548 N0.getOpcode() == ISD::XOR) &&
4549 isa<LoadSDNode>(N0.getOperand(0)) &&
4550 N0.getOperand(1).getOpcode() == ISD::Constant &&
4551 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
4552 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4553 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4554 if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
4555 bool DoXform = true;
4556 SmallVector<SDNode*, 4> SetCCs;
4557 if (!N0.hasOneUse())
4558 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
4561 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN0), VT,
4562 LN0->getChain(), LN0->getBasePtr(),
4563 LN0->getPointerInfo(),
4566 LN0->isNonTemporal(),
4567 LN0->getAlignment());
4568 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4569 Mask = Mask.sext(VT.getSizeInBits());
4570 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
4571 ExtLoad, DAG.getConstant(Mask, VT));
4572 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4573 SDLoc(N0.getOperand(0)),
4574 N0.getOperand(0).getValueType(), ExtLoad);
4576 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4577 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4579 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4584 if (N0.getOpcode() == ISD::SETCC) {
4585 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
4586 // Only do this before legalize for now.
4587 if (VT.isVector() && !LegalOperations &&
4588 TLI.getBooleanContents(true) ==
4589 TargetLowering::ZeroOrNegativeOneBooleanContent) {
4590 EVT N0VT = N0.getOperand(0).getValueType();
4591 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
4592 // of the same size as the compared operands. Only optimize sext(setcc())
4593 // if this is the case.
4594 EVT SVT = getSetCCResultType(N0VT);
4596 // We know that the # elements of the results is the same as the
4597 // # elements of the compare (and the # elements of the compare result
4598 // for that matter). Check to see that they are the same size. If so,
4599 // we know that the element size of the sext'd result matches the
4600 // element size of the compare operands.
4601 if (VT.getSizeInBits() == SVT.getSizeInBits())
4602 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
4604 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4606 // If the desired elements are smaller or larger than the source
4607 // elements we can use a matching integer vector type and then
4608 // truncate/sign extend
4609 EVT MatchingVectorType = N0VT.changeVectorElementTypeToInteger();
4610 if (SVT == MatchingVectorType) {
4611 SDValue VsetCC = DAG.getSetCC(SDLoc(N), MatchingVectorType,
4612 N0.getOperand(0), N0.getOperand(1),
4613 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4614 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
4618 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
4619 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
4621 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
4623 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
4624 NegOne, DAG.getConstant(0, VT),
4625 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4626 if (SCC.getNode()) return SCC;
4627 if (!VT.isVector() &&
4628 (!LegalOperations ||
4629 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(VT)))) {
4630 return DAG.getSelect(SDLoc(N), VT,
4631 DAG.getSetCC(SDLoc(N),
4632 getSetCCResultType(VT),
4633 N0.getOperand(0), N0.getOperand(1),
4634 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4635 NegOne, DAG.getConstant(0, VT));
4639 // fold (sext x) -> (zext x) if the sign bit is known zero.
4640 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
4641 DAG.SignBitIsZero(N0))
4642 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
4647 // isTruncateOf - If N is a truncate of some other value, return true, record
4648 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
4649 // This function computes KnownZero to avoid a duplicated call to
4650 // ComputeMaskedBits in the caller.
4651 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
4654 if (N->getOpcode() == ISD::TRUNCATE) {
4655 Op = N->getOperand(0);
4656 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4660 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
4661 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
4664 SDValue Op0 = N->getOperand(0);
4665 SDValue Op1 = N->getOperand(1);
4666 assert(Op0.getValueType() == Op1.getValueType());
4668 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
4669 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
4670 if (COp0 && COp0->isNullValue())
4672 else if (COp1 && COp1->isNullValue())
4677 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4679 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
4685 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
4686 SDValue N0 = N->getOperand(0);
4687 EVT VT = N->getValueType(0);
4689 // fold (zext c1) -> c1
4690 if (isa<ConstantSDNode>(N0))
4691 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, N0);
4692 // fold (zext (zext x)) -> (zext x)
4693 // fold (zext (aext x)) -> (zext x)
4694 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4695 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
4698 // fold (zext (truncate x)) -> (zext x) or
4699 // (zext (truncate x)) -> (truncate x)
4700 // This is valid when the truncated bits of x are already zero.
4701 // FIXME: We should extend this to work for vectors too.
4704 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
4705 APInt TruncatedBits =
4706 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
4707 APInt(Op.getValueSizeInBits(), 0) :
4708 APInt::getBitsSet(Op.getValueSizeInBits(),
4709 N0.getValueSizeInBits(),
4710 std::min(Op.getValueSizeInBits(),
4711 VT.getSizeInBits()));
4712 if (TruncatedBits == (KnownZero & TruncatedBits)) {
4713 if (VT.bitsGT(Op.getValueType()))
4714 return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, Op);
4715 if (VT.bitsLT(Op.getValueType()))
4716 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4722 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4723 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
4724 if (N0.getOpcode() == ISD::TRUNCATE) {
4725 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4726 if (NarrowLoad.getNode()) {
4727 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4728 if (NarrowLoad.getNode() != N0.getNode()) {
4729 CombineTo(N0.getNode(), NarrowLoad);
4730 // CombineTo deleted the truncate, if needed, but not what's under it.
4733 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4737 // fold (zext (truncate x)) -> (and x, mask)
4738 if (N0.getOpcode() == ISD::TRUNCATE &&
4739 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
4741 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4742 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
4743 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4744 if (NarrowLoad.getNode()) {
4745 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4746 if (NarrowLoad.getNode() != N0.getNode()) {
4747 CombineTo(N0.getNode(), NarrowLoad);
4748 // CombineTo deleted the truncate, if needed, but not what's under it.
4751 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4754 SDValue Op = N0.getOperand(0);
4755 if (Op.getValueType().bitsLT(VT)) {
4756 Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, Op);
4757 AddToWorkList(Op.getNode());
4758 } else if (Op.getValueType().bitsGT(VT)) {
4759 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Op);
4760 AddToWorkList(Op.getNode());
4762 return DAG.getZeroExtendInReg(Op, SDLoc(N),
4763 N0.getValueType().getScalarType());
4766 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
4767 // if either of the casts is not free.
4768 if (N0.getOpcode() == ISD::AND &&
4769 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4770 N0.getOperand(1).getOpcode() == ISD::Constant &&
4771 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4772 N0.getValueType()) ||
4773 !TLI.isZExtFree(N0.getValueType(), VT))) {
4774 SDValue X = N0.getOperand(0).getOperand(0);
4775 if (X.getValueType().bitsLT(VT)) {
4776 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(X), VT, X);
4777 } else if (X.getValueType().bitsGT(VT)) {
4778 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
4780 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4781 Mask = Mask.zext(VT.getSizeInBits());
4782 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4783 X, DAG.getConstant(Mask, VT));
4786 // fold (zext (load x)) -> (zext (truncate (zextload x)))
4787 // None of the supported targets knows how to perform load and vector_zext
4788 // on vectors in one instruction. We only perform this transformation on
4790 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4791 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4792 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
4793 bool DoXform = true;
4794 SmallVector<SDNode*, 4> SetCCs;
4795 if (!N0.hasOneUse())
4796 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
4798 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4799 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
4801 LN0->getBasePtr(), LN0->getPointerInfo(),
4803 LN0->isVolatile(), LN0->isNonTemporal(),
4804 LN0->getAlignment());
4805 CombineTo(N, ExtLoad);
4806 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
4807 N0.getValueType(), ExtLoad);
4808 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4810 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4812 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4816 // fold (zext (and/or/xor (load x), cst)) ->
4817 // (and/or/xor (zextload x), (zext cst))
4818 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4819 N0.getOpcode() == ISD::XOR) &&
4820 isa<LoadSDNode>(N0.getOperand(0)) &&
4821 N0.getOperand(1).getOpcode() == ISD::Constant &&
4822 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
4823 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4824 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4825 if (LN0->getExtensionType() != ISD::SEXTLOAD) {
4826 bool DoXform = true;
4827 SmallVector<SDNode*, 4> SetCCs;
4828 if (!N0.hasOneUse())
4829 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
4832 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN0), VT,
4833 LN0->getChain(), LN0->getBasePtr(),
4834 LN0->getPointerInfo(),
4837 LN0->isNonTemporal(),
4838 LN0->getAlignment());
4839 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4840 Mask = Mask.zext(VT.getSizeInBits());
4841 SDValue And = DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
4842 ExtLoad, DAG.getConstant(Mask, VT));
4843 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4844 SDLoc(N0.getOperand(0)),
4845 N0.getOperand(0).getValueType(), ExtLoad);
4847 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4848 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
4850 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4855 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
4856 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
4857 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4858 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4859 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4860 EVT MemVT = LN0->getMemoryVT();
4861 if ((!LegalOperations && !LN0->isVolatile()) ||
4862 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
4863 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
4865 LN0->getBasePtr(), LN0->getPointerInfo(),
4867 LN0->isVolatile(), LN0->isNonTemporal(),
4868 LN0->getAlignment());
4869 CombineTo(N, ExtLoad);
4870 CombineTo(N0.getNode(),
4871 DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(),
4873 ExtLoad.getValue(1));
4874 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4878 if (N0.getOpcode() == ISD::SETCC) {
4879 if (!LegalOperations && VT.isVector()) {
4880 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
4881 // Only do this before legalize for now.
4882 EVT N0VT = N0.getOperand(0).getValueType();
4883 EVT EltVT = VT.getVectorElementType();
4884 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
4885 DAG.getConstant(1, EltVT));
4886 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4887 // We know that the # elements of the results is the same as the
4888 // # elements of the compare (and the # elements of the compare result
4889 // for that matter). Check to see that they are the same size. If so,
4890 // we know that the element size of the sext'd result matches the
4891 // element size of the compare operands.
4892 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4893 DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
4895 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4896 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT,
4897 &OneOps[0], OneOps.size()));
4899 // If the desired elements are smaller or larger than the source
4900 // elements we can use a matching integer vector type and then
4901 // truncate/sign extend
4902 EVT MatchingElementType =
4903 EVT::getIntegerVT(*DAG.getContext(),
4904 N0VT.getScalarType().getSizeInBits());
4905 EVT MatchingVectorType =
4906 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4907 N0VT.getVectorNumElements());
4909 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
4911 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4912 return DAG.getNode(ISD::AND, SDLoc(N), VT,
4913 DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT),
4914 DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT,
4915 &OneOps[0], OneOps.size()));
4918 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4920 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
4921 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4922 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4923 if (SCC.getNode()) return SCC;
4926 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
4927 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
4928 isa<ConstantSDNode>(N0.getOperand(1)) &&
4929 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
4931 SDValue ShAmt = N0.getOperand(1);
4932 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
4933 if (N0.getOpcode() == ISD::SHL) {
4934 SDValue InnerZExt = N0.getOperand(0);
4935 // If the original shl may be shifting out bits, do not perform this
4937 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
4938 InnerZExt.getOperand(0).getValueType().getSizeInBits();
4939 if (ShAmtVal > KnownZeroBits)
4945 // Ensure that the shift amount is wide enough for the shifted value.
4946 if (VT.getSizeInBits() >= 256)
4947 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
4949 return DAG.getNode(N0.getOpcode(), DL, VT,
4950 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
4957 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
4958 SDValue N0 = N->getOperand(0);
4959 EVT VT = N->getValueType(0);
4961 // fold (aext c1) -> c1
4962 if (isa<ConstantSDNode>(N0))
4963 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, N0);
4964 // fold (aext (aext x)) -> (aext x)
4965 // fold (aext (zext x)) -> (zext x)
4966 // fold (aext (sext x)) -> (sext x)
4967 if (N0.getOpcode() == ISD::ANY_EXTEND ||
4968 N0.getOpcode() == ISD::ZERO_EXTEND ||
4969 N0.getOpcode() == ISD::SIGN_EXTEND)
4970 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
4972 // fold (aext (truncate (load x))) -> (aext (smaller load x))
4973 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
4974 if (N0.getOpcode() == ISD::TRUNCATE) {
4975 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4976 if (NarrowLoad.getNode()) {
4977 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4978 if (NarrowLoad.getNode() != N0.getNode()) {
4979 CombineTo(N0.getNode(), NarrowLoad);
4980 // CombineTo deleted the truncate, if needed, but not what's under it.
4983 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4987 // fold (aext (truncate x))
4988 if (N0.getOpcode() == ISD::TRUNCATE) {
4989 SDValue TruncOp = N0.getOperand(0);
4990 if (TruncOp.getValueType() == VT)
4991 return TruncOp; // x iff x size == zext size.
4992 if (TruncOp.getValueType().bitsGT(VT))
4993 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, TruncOp);
4994 return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, TruncOp);
4997 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
4998 // if the trunc is not free.
4999 if (N0.getOpcode() == ISD::AND &&
5000 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
5001 N0.getOperand(1).getOpcode() == ISD::Constant &&
5002 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
5003 N0.getValueType())) {
5004 SDValue X = N0.getOperand(0).getOperand(0);
5005 if (X.getValueType().bitsLT(VT)) {
5006 X = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, X);
5007 } else if (X.getValueType().bitsGT(VT)) {
5008 X = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, X);
5010 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
5011 Mask = Mask.zext(VT.getSizeInBits());
5012 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5013 X, DAG.getConstant(Mask, VT));
5016 // fold (aext (load x)) -> (aext (truncate (extload x)))
5017 // None of the supported targets knows how to perform load and any_ext
5018 // on vectors in one instruction. We only perform this transformation on
5020 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
5021 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5022 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
5023 bool DoXform = true;
5024 SmallVector<SDNode*, 4> SetCCs;
5025 if (!N0.hasOneUse())
5026 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
5028 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5029 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
5031 LN0->getBasePtr(), LN0->getPointerInfo(),
5033 LN0->isVolatile(), LN0->isNonTemporal(),
5034 LN0->getAlignment());
5035 CombineTo(N, ExtLoad);
5036 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5037 N0.getValueType(), ExtLoad);
5038 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
5039 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, SDLoc(N),
5041 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5045 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
5046 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
5047 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
5048 if (N0.getOpcode() == ISD::LOAD &&
5049 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5051 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5052 EVT MemVT = LN0->getMemoryVT();
5053 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(N),
5054 VT, LN0->getChain(), LN0->getBasePtr(),
5055 LN0->getPointerInfo(), MemVT,
5056 LN0->isVolatile(), LN0->isNonTemporal(),
5057 LN0->getAlignment());
5058 CombineTo(N, ExtLoad);
5059 CombineTo(N0.getNode(),
5060 DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
5061 N0.getValueType(), ExtLoad),
5062 ExtLoad.getValue(1));
5063 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5066 if (N0.getOpcode() == ISD::SETCC) {
5067 // aext(setcc) -> sext_in_reg(vsetcc) for vectors.
5068 // Only do this before legalize for now.
5069 if (VT.isVector() && !LegalOperations) {
5070 EVT N0VT = N0.getOperand(0).getValueType();
5071 // We know that the # elements of the results is the same as the
5072 // # elements of the compare (and the # elements of the compare result
5073 // for that matter). Check to see that they are the same size. If so,
5074 // we know that the element size of the sext'd result matches the
5075 // element size of the compare operands.
5076 if (VT.getSizeInBits() == N0VT.getSizeInBits())
5077 return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
5079 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5080 // If the desired elements are smaller or larger than the source
5081 // elements we can use a matching integer vector type and then
5082 // truncate/sign extend
5084 EVT MatchingElementType =
5085 EVT::getIntegerVT(*DAG.getContext(),
5086 N0VT.getScalarType().getSizeInBits());
5087 EVT MatchingVectorType =
5088 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
5089 N0VT.getVectorNumElements());
5091 DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
5093 cast<CondCodeSDNode>(N0.getOperand(2))->get());
5094 return DAG.getSExtOrTrunc(VsetCC, SDLoc(N), VT);
5098 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
5100 SimplifySelectCC(SDLoc(N), N0.getOperand(0), N0.getOperand(1),
5101 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
5102 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
5110 /// GetDemandedBits - See if the specified operand can be simplified with the
5111 /// knowledge that only the bits specified by Mask are used. If so, return the
5112 /// simpler operand, otherwise return a null SDValue.
5113 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
5114 switch (V.getOpcode()) {
5116 case ISD::Constant: {
5117 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
5118 assert(CV != 0 && "Const value should be ConstSDNode.");
5119 const APInt &CVal = CV->getAPIntValue();
5120 APInt NewVal = CVal & Mask;
5122 return DAG.getConstant(NewVal, V.getValueType());
5127 // If the LHS or RHS don't contribute bits to the or, drop them.
5128 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
5129 return V.getOperand(1);
5130 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
5131 return V.getOperand(0);
5134 // Only look at single-use SRLs.
5135 if (!V.getNode()->hasOneUse())
5137 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
5138 // See if we can recursively simplify the LHS.
5139 unsigned Amt = RHSC->getZExtValue();
5141 // Watch out for shift count overflow though.
5142 if (Amt >= Mask.getBitWidth()) break;
5143 APInt NewMask = Mask << Amt;
5144 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
5145 if (SimplifyLHS.getNode())
5146 return DAG.getNode(ISD::SRL, SDLoc(V), V.getValueType(),
5147 SimplifyLHS, V.getOperand(1));
5153 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
5154 /// bits and then truncated to a narrower type and where N is a multiple
5155 /// of number of bits of the narrower type, transform it to a narrower load
5156 /// from address + N / num of bits of new type. If the result is to be
5157 /// extended, also fold the extension to form a extending load.
5158 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
5159 unsigned Opc = N->getOpcode();
5161 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
5162 SDValue N0 = N->getOperand(0);
5163 EVT VT = N->getValueType(0);
5166 // This transformation isn't valid for vector loads.
5170 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
5172 if (Opc == ISD::SIGN_EXTEND_INREG) {
5173 ExtType = ISD::SEXTLOAD;
5174 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
5175 } else if (Opc == ISD::SRL) {
5176 // Another special-case: SRL is basically zero-extending a narrower value.
5177 ExtType = ISD::ZEXTLOAD;
5179 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
5180 if (!N01) return SDValue();
5181 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
5182 VT.getSizeInBits() - N01->getZExtValue());
5184 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5187 unsigned EVTBits = ExtVT.getSizeInBits();
5189 // Do not generate loads of non-round integer types since these can
5190 // be expensive (and would be wrong if the type is not byte sized).
5191 if (!ExtVT.isRound())
5195 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5196 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5197 ShAmt = N01->getZExtValue();
5198 // Is the shift amount a multiple of size of VT?
5199 if ((ShAmt & (EVTBits-1)) == 0) {
5200 N0 = N0.getOperand(0);
5201 // Is the load width a multiple of size of VT?
5202 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5206 // At this point, we must have a load or else we can't do the transform.
5207 if (!isa<LoadSDNode>(N0)) return SDValue();
5209 // Because a SRL must be assumed to *need* to zero-extend the high bits
5210 // (as opposed to anyext the high bits), we can't combine the zextload
5211 // lowering of SRL and an sextload.
5212 if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
5215 // If the shift amount is larger than the input type then we're not
5216 // accessing any of the loaded bytes. If the load was a zextload/extload
5217 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5218 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5223 // If the load is shifted left (and the result isn't shifted back right),
5224 // we can fold the truncate through the shift.
5225 unsigned ShLeftAmt = 0;
5226 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5227 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5228 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5229 ShLeftAmt = N01->getZExtValue();
5230 N0 = N0.getOperand(0);
5234 // If we haven't found a load, we can't narrow it. Don't transform one with
5235 // multiple uses, this would require adding a new load.
5236 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse())
5239 // Don't change the width of a volatile load.
5240 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5241 if (LN0->isVolatile())
5244 // Verify that we are actually reducing a load width here.
5245 if (LN0->getMemoryVT().getSizeInBits() < EVTBits)
5248 // For the transform to be legal, the load must produce only two values
5249 // (the value loaded and the chain). Don't transform a pre-increment
5250 // load, for example, which produces an extra value. Otherwise the
5251 // transformation is not equivalent, and the downstream logic to replace
5252 // uses gets things wrong.
5253 if (LN0->getNumValues() > 2)
5256 // If the load that we're shrinking is an extload and we're not just
5257 // discarding the extension we can't simply shrink the load. Bail.
5258 // TODO: It would be possible to merge the extensions in some cases.
5259 if (LN0->getExtensionType() != ISD::NON_EXTLOAD &&
5260 LN0->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
5263 EVT PtrType = N0.getOperand(1).getValueType();
5265 if (PtrType == MVT::Untyped || PtrType.isExtended())
5266 // It's not possible to generate a constant of extended or untyped type.
5269 // For big endian targets, we need to adjust the offset to the pointer to
5270 // load the correct bytes.
5271 if (TLI.isBigEndian()) {
5272 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5273 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5274 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5277 uint64_t PtrOff = ShAmt / 8;
5278 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5279 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LN0),
5280 PtrType, LN0->getBasePtr(),
5281 DAG.getConstant(PtrOff, PtrType));
5282 AddToWorkList(NewPtr.getNode());
5285 if (ExtType == ISD::NON_EXTLOAD)
5286 Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
5287 LN0->getPointerInfo().getWithOffset(PtrOff),
5288 LN0->isVolatile(), LN0->isNonTemporal(),
5289 LN0->isInvariant(), NewAlign);
5291 Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(),NewPtr,
5292 LN0->getPointerInfo().getWithOffset(PtrOff),
5293 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5296 // Replace the old load's chain with the new load's chain.
5297 WorkListRemover DeadNodes(*this);
5298 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5300 // Shift the result left, if we've swallowed a left shift.
5301 SDValue Result = Load;
5302 if (ShLeftAmt != 0) {
5303 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5304 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5306 // If the shift amount is as large as the result size (but, presumably,
5307 // no larger than the source) then the useful bits of the result are
5308 // zero; we can't simply return the shortened shift, because the result
5309 // of that operation is undefined.
5310 if (ShLeftAmt >= VT.getSizeInBits())
5311 Result = DAG.getConstant(0, VT);
5313 Result = DAG.getNode(ISD::SHL, SDLoc(N0), VT,
5314 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5317 // Return the new loaded value.
5321 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5322 SDValue N0 = N->getOperand(0);
5323 SDValue N1 = N->getOperand(1);
5324 EVT VT = N->getValueType(0);
5325 EVT EVT = cast<VTSDNode>(N1)->getVT();
5326 unsigned VTBits = VT.getScalarType().getSizeInBits();
5327 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5329 // fold (sext_in_reg c1) -> c1
5330 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5331 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);
5333 // If the input is already sign extended, just drop the extension.
5334 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5337 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5338 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5339 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
5340 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5341 N0.getOperand(0), N1);
5343 // fold (sext_in_reg (sext x)) -> (sext x)
5344 // fold (sext_in_reg (aext x)) -> (sext x)
5345 // if x is small enough.
5346 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5347 SDValue N00 = N0.getOperand(0);
5348 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5349 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5350 return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
5353 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5354 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5355 return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT);
5357 // fold operands of sext_in_reg based on knowledge that the top bits are not
5359 if (SimplifyDemandedBits(SDValue(N, 0)))
5360 return SDValue(N, 0);
5362 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5363 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5364 SDValue NarrowLoad = ReduceLoadWidth(N);
5365 if (NarrowLoad.getNode())
5368 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5369 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5370 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5371 if (N0.getOpcode() == ISD::SRL) {
5372 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5373 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5374 // We can turn this into an SRA iff the input to the SRL is already sign
5376 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5377 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5378 return DAG.getNode(ISD::SRA, SDLoc(N), VT,
5379 N0.getOperand(0), N0.getOperand(1));
5383 // fold (sext_inreg (extload x)) -> (sextload x)
5384 if (ISD::isEXTLoad(N0.getNode()) &&
5385 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5386 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5387 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5388 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5389 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5390 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5392 LN0->getBasePtr(), LN0->getPointerInfo(),
5394 LN0->isVolatile(), LN0->isNonTemporal(),
5395 LN0->getAlignment());
5396 CombineTo(N, ExtLoad);
5397 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5398 AddToWorkList(ExtLoad.getNode());
5399 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5401 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5402 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5404 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5405 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5406 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5407 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5408 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
5410 LN0->getBasePtr(), LN0->getPointerInfo(),
5412 LN0->isVolatile(), LN0->isNonTemporal(),
5413 LN0->getAlignment());
5414 CombineTo(N, ExtLoad);
5415 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5416 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5419 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5420 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5421 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5422 N0.getOperand(1), false);
5423 if (BSwap.getNode() != 0)
5424 return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
5431 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5432 SDValue N0 = N->getOperand(0);
5433 EVT VT = N->getValueType(0);
5434 bool isLE = TLI.isLittleEndian();
5437 if (N0.getValueType() == N->getValueType(0))
5439 // fold (truncate c1) -> c1
5440 if (isa<ConstantSDNode>(N0))
5441 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
5442 // fold (truncate (truncate x)) -> (truncate x)
5443 if (N0.getOpcode() == ISD::TRUNCATE)
5444 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5445 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5446 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5447 N0.getOpcode() == ISD::SIGN_EXTEND ||
5448 N0.getOpcode() == ISD::ANY_EXTEND) {
5449 if (N0.getOperand(0).getValueType().bitsLT(VT))
5450 // if the source is smaller than the dest, we still need an extend
5451 return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
5453 if (N0.getOperand(0).getValueType().bitsGT(VT))
5454 // if the source is larger than the dest, than we just need the truncate
5455 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
5456 // if the source and dest are the same type, we can drop both the extend
5457 // and the truncate.
5458 return N0.getOperand(0);
5461 // Fold extract-and-trunc into a narrow extract. For example:
5462 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5463 // i32 y = TRUNCATE(i64 x)
5465 // v16i8 b = BITCAST (v2i64 val)
5466 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5468 // Note: We only run this optimization after type legalization (which often
5469 // creates this pattern) and before operation legalization after which
5470 // we need to be more careful about the vector instructions that we generate.
5471 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5472 LegalTypes && !LegalOperations && N0->hasOneUse()) {
5474 EVT VecTy = N0.getOperand(0).getValueType();
5475 EVT ExTy = N0.getValueType();
5476 EVT TrTy = N->getValueType(0);
5478 unsigned NumElem = VecTy.getVectorNumElements();
5479 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5481 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5482 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
5484 SDValue EltNo = N0->getOperand(1);
5485 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
5486 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5487 EVT IndexTy = TLI.getVectorIdxTy();
5488 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
5490 SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
5491 NVT, N0.getOperand(0));
5493 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
5495 DAG.getConstant(Index, IndexTy));
5499 // Fold a series of buildvector, bitcast, and truncate if possible.
5501 // (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
5502 // (2xi32 (buildvector x, y)).
5503 if (Level == AfterLegalizeVectorOps && VT.isVector() &&
5504 N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
5505 N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
5506 N0.getOperand(0).hasOneUse()) {
5508 SDValue BuildVect = N0.getOperand(0);
5509 EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
5510 EVT TruncVecEltTy = VT.getVectorElementType();
5512 // Check that the element types match.
5513 if (BuildVectEltTy == TruncVecEltTy) {
5514 // Now we only need to compute the offset of the truncated elements.
5515 unsigned BuildVecNumElts = BuildVect.getNumOperands();
5516 unsigned TruncVecNumElts = VT.getVectorNumElements();
5517 unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;
5519 assert((BuildVecNumElts % TruncVecNumElts) == 0 &&
5520 "Invalid number of elements");
5522 SmallVector<SDValue, 8> Opnds;
5523 for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
5524 Opnds.push_back(BuildVect.getOperand(i));
5526 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, &Opnds[0],
5531 // See if we can simplify the input to this truncate through knowledge that
5532 // only the low bits are being used.
5533 // For example "trunc (or (shl x, 8), y)" // -> trunc y
5534 // Currently we only perform this optimization on scalars because vectors
5535 // may have different active low bits.
5536 if (!VT.isVector()) {
5538 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
5539 VT.getSizeInBits()));
5540 if (Shorter.getNode())
5541 return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
5543 // fold (truncate (load x)) -> (smaller load x)
5544 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
5545 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
5546 SDValue Reduced = ReduceLoadWidth(N);
5547 if (Reduced.getNode())
5550 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
5551 // where ... are all 'undef'.
5552 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
5553 SmallVector<EVT, 8> VTs;
5556 unsigned NumDefs = 0;
5558 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
5559 SDValue X = N0.getOperand(i);
5560 if (X.getOpcode() != ISD::UNDEF) {
5565 // Stop if more than one members are non-undef.
5568 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
5569 VT.getVectorElementType(),
5570 X.getValueType().getVectorNumElements()));
5574 return DAG.getUNDEF(VT);
5577 assert(V.getNode() && "The single defined operand is empty!");
5578 SmallVector<SDValue, 8> Opnds;
5579 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
5581 Opnds.push_back(DAG.getUNDEF(VTs[i]));
5584 SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
5585 AddToWorkList(NV.getNode());
5586 Opnds.push_back(NV);
5588 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
5589 &Opnds[0], Opnds.size());
5593 // Simplify the operands using demanded-bits information.
5594 if (!VT.isVector() &&
5595 SimplifyDemandedBits(SDValue(N, 0)))
5596 return SDValue(N, 0);
5601 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
5602 SDValue Elt = N->getOperand(i);
5603 if (Elt.getOpcode() != ISD::MERGE_VALUES)
5604 return Elt.getNode();
5605 return Elt.getOperand(Elt.getResNo()).getNode();
5608 /// CombineConsecutiveLoads - build_pair (load, load) -> load
5609 /// if load locations are consecutive.
5610 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
5611 assert(N->getOpcode() == ISD::BUILD_PAIR);
5613 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
5614 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
5615 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
5616 LD1->getPointerInfo().getAddrSpace() !=
5617 LD2->getPointerInfo().getAddrSpace())
5619 EVT LD1VT = LD1->getValueType(0);
5621 if (ISD::isNON_EXTLoad(LD2) &&
5623 // If both are volatile this would reduce the number of volatile loads.
5624 // If one is volatile it might be ok, but play conservative and bail out.
5625 !LD1->isVolatile() &&
5626 !LD2->isVolatile() &&
5627 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
5628 unsigned Align = LD1->getAlignment();
5629 unsigned NewAlign = TLI.getDataLayout()->
5630 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5632 if (NewAlign <= Align &&
5633 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
5634 return DAG.getLoad(VT, SDLoc(N), LD1->getChain(),
5635 LD1->getBasePtr(), LD1->getPointerInfo(),
5636 false, false, false, Align);
5642 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
5643 SDValue N0 = N->getOperand(0);
5644 EVT VT = N->getValueType(0);
5646 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
5647 // Only do this before legalize, since afterward the target may be depending
5648 // on the bitconvert.
5649 // First check to see if this is all constant.
5651 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
5653 bool isSimple = true;
5654 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
5655 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
5656 N0.getOperand(i).getOpcode() != ISD::Constant &&
5657 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
5662 EVT DestEltVT = N->getValueType(0).getVectorElementType();
5663 assert(!DestEltVT.isVector() &&
5664 "Element type of vector ValueType must not be vector!");
5666 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
5669 // If the input is a constant, let getNode fold it.
5670 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
5671 SDValue Res = DAG.getNode(ISD::BITCAST, SDLoc(N), VT, N0);
5672 if (Res.getNode() != N) {
5673 if (!LegalOperations ||
5674 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
5677 // Folding it resulted in an illegal node, and it's too late to
5678 // do that. Clean up the old node and forego the transformation.
5679 // Ideally this won't happen very often, because instcombine
5680 // and the earlier dagcombine runs (where illegal nodes are
5681 // permitted) should have folded most of them already.
5682 DAG.DeleteNode(Res.getNode());
5686 // (conv (conv x, t1), t2) -> (conv x, t2)
5687 if (N0.getOpcode() == ISD::BITCAST)
5688 return DAG.getNode(ISD::BITCAST, SDLoc(N), VT,
5691 // fold (conv (load x)) -> (load (conv*)x)
5692 // If the resultant load doesn't need a higher alignment than the original!
5693 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
5694 // Do not change the width of a volatile load.
5695 !cast<LoadSDNode>(N0)->isVolatile() &&
5696 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
5697 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5698 unsigned Align = TLI.getDataLayout()->
5699 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5700 unsigned OrigAlign = LN0->getAlignment();
5702 if (Align <= OrigAlign) {
5703 SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(),
5704 LN0->getBasePtr(), LN0->getPointerInfo(),
5705 LN0->isVolatile(), LN0->isNonTemporal(),
5706 LN0->isInvariant(), OrigAlign);
5708 CombineTo(N0.getNode(),
5709 DAG.getNode(ISD::BITCAST, SDLoc(N0),
5710 N0.getValueType(), Load),
5716 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
5717 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
5718 // This often reduces constant pool loads.
5719 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
5720 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
5721 N0.getNode()->hasOneUse() && VT.isInteger() &&
5722 !VT.isVector() && !N0.getValueType().isVector()) {
5723 SDValue NewConv = DAG.getNode(ISD::BITCAST, SDLoc(N0), VT,
5725 AddToWorkList(NewConv.getNode());
5727 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5728 if (N0.getOpcode() == ISD::FNEG)
5729 return DAG.getNode(ISD::XOR, SDLoc(N), VT,
5730 NewConv, DAG.getConstant(SignBit, VT));
5731 assert(N0.getOpcode() == ISD::FABS);
5732 return DAG.getNode(ISD::AND, SDLoc(N), VT,
5733 NewConv, DAG.getConstant(~SignBit, VT));
5736 // fold (bitconvert (fcopysign cst, x)) ->
5737 // (or (and (bitconvert x), sign), (and cst, (not sign)))
5738 // Note that we don't handle (copysign x, cst) because this can always be
5739 // folded to an fneg or fabs.
5740 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
5741 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
5742 VT.isInteger() && !VT.isVector()) {
5743 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
5744 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
5745 if (isTypeLegal(IntXVT)) {
5746 SDValue X = DAG.getNode(ISD::BITCAST, SDLoc(N0),
5747 IntXVT, N0.getOperand(1));
5748 AddToWorkList(X.getNode());
5750 // If X has a different width than the result/lhs, sext it or truncate it.
5751 unsigned VTWidth = VT.getSizeInBits();
5752 if (OrigXWidth < VTWidth) {
5753 X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
5754 AddToWorkList(X.getNode());
5755 } else if (OrigXWidth > VTWidth) {
5756 // To get the sign bit in the right place, we have to shift it right
5757 // before truncating.
5758 X = DAG.getNode(ISD::SRL, SDLoc(X),
5759 X.getValueType(), X,
5760 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
5761 AddToWorkList(X.getNode());
5762 X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
5763 AddToWorkList(X.getNode());
5766 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5767 X = DAG.getNode(ISD::AND, SDLoc(X), VT,
5768 X, DAG.getConstant(SignBit, VT));
5769 AddToWorkList(X.getNode());
5771 SDValue Cst = DAG.getNode(ISD::BITCAST, SDLoc(N0),
5772 VT, N0.getOperand(0));
5773 Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
5774 Cst, DAG.getConstant(~SignBit, VT));
5775 AddToWorkList(Cst.getNode());
5777 return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
5781 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
5782 if (N0.getOpcode() == ISD::BUILD_PAIR) {
5783 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
5784 if (CombineLD.getNode())
5791 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
5792 EVT VT = N->getValueType(0);
5793 return CombineConsecutiveLoads(N, VT);
5796 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
5797 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
5798 /// destination element value type.
5799 SDValue DAGCombiner::
5800 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
5801 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
5803 // If this is already the right type, we're done.
5804 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
5806 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
5807 unsigned DstBitSize = DstEltVT.getSizeInBits();
5809 // If this is a conversion of N elements of one type to N elements of another
5810 // type, convert each element. This handles FP<->INT cases.
5811 if (SrcBitSize == DstBitSize) {
5812 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5813 BV->getValueType(0).getVectorNumElements());
5815 // Due to the FP element handling below calling this routine recursively,
5816 // we can end up with a scalar-to-vector node here.
5817 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
5818 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
5819 DAG.getNode(ISD::BITCAST, SDLoc(BV),
5820 DstEltVT, BV->getOperand(0)));
5822 SmallVector<SDValue, 8> Ops;
5823 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5824 SDValue Op = BV->getOperand(i);
5825 // If the vector element type is not legal, the BUILD_VECTOR operands
5826 // are promoted and implicitly truncated. Make that explicit here.
5827 if (Op.getValueType() != SrcEltVT)
5828 Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
5829 Ops.push_back(DAG.getNode(ISD::BITCAST, SDLoc(BV),
5831 AddToWorkList(Ops.back().getNode());
5833 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5834 &Ops[0], Ops.size());
5837 // Otherwise, we're growing or shrinking the elements. To avoid having to
5838 // handle annoying details of growing/shrinking FP values, we convert them to
5840 if (SrcEltVT.isFloatingPoint()) {
5841 // Convert the input float vector to a int vector where the elements are the
5843 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
5844 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
5845 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
5849 // Now we know the input is an integer vector. If the output is a FP type,
5850 // convert to integer first, then to FP of the right size.
5851 if (DstEltVT.isFloatingPoint()) {
5852 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
5853 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
5854 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
5856 // Next, convert to FP elements of the same size.
5857 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
5860 // Okay, we know the src/dst types are both integers of differing types.
5861 // Handling growing first.
5862 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
5863 if (SrcBitSize < DstBitSize) {
5864 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
5866 SmallVector<SDValue, 8> Ops;
5867 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
5868 i += NumInputsPerOutput) {
5869 bool isLE = TLI.isLittleEndian();
5870 APInt NewBits = APInt(DstBitSize, 0);
5871 bool EltIsUndef = true;
5872 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
5873 // Shift the previously computed bits over.
5874 NewBits <<= SrcBitSize;
5875 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
5876 if (Op.getOpcode() == ISD::UNDEF) continue;
5879 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
5880 zextOrTrunc(SrcBitSize).zext(DstBitSize);
5884 Ops.push_back(DAG.getUNDEF(DstEltVT));
5886 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
5889 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
5890 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5891 &Ops[0], Ops.size());
5894 // Finally, this must be the case where we are shrinking elements: each input
5895 // turns into multiple outputs.
5896 bool isS2V = ISD::isScalarToVector(BV);
5897 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
5898 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5899 NumOutputsPerInput*BV->getNumOperands());
5900 SmallVector<SDValue, 8> Ops;
5902 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5903 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
5904 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
5905 Ops.push_back(DAG.getUNDEF(DstEltVT));
5909 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
5910 getAPIntValue().zextOrTrunc(SrcBitSize);
5912 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
5913 APInt ThisVal = OpVal.trunc(DstBitSize);
5914 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
5915 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
5916 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
5917 return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
5919 OpVal = OpVal.lshr(DstBitSize);
5922 // For big endian targets, swap the order of the pieces of each element.
5923 if (TLI.isBigEndian())
5924 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
5927 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(BV), VT,
5928 &Ops[0], Ops.size());
5931 SDValue DAGCombiner::visitFADD(SDNode *N) {
5932 SDValue N0 = N->getOperand(0);
5933 SDValue N1 = N->getOperand(1);
5934 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5935 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5936 EVT VT = N->getValueType(0);
5939 if (VT.isVector()) {
5940 SDValue FoldedVOp = SimplifyVBinOp(N);
5941 if (FoldedVOp.getNode()) return FoldedVOp;
5944 // fold (fadd c1, c2) -> c1 + c2
5946 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N1);
5947 // canonicalize constant to RHS
5948 if (N0CFP && !N1CFP)
5949 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N0);
5950 // fold (fadd A, 0) -> A
5951 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5952 N1CFP->getValueAPF().isZero())
5954 // fold (fadd A, (fneg B)) -> (fsub A, B)
5955 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5956 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5957 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0,
5958 GetNegatedExpression(N1, DAG, LegalOperations));
5959 // fold (fadd (fneg A), B) -> (fsub B, A)
5960 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5961 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5962 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N1,
5963 GetNegatedExpression(N0, DAG, LegalOperations));
5965 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
5966 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5967 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
5968 isa<ConstantFPSDNode>(N0.getOperand(1)))
5969 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0.getOperand(0),
5970 DAG.getNode(ISD::FADD, SDLoc(N), VT,
5971 N0.getOperand(1), N1));
5973 // No FP constant should be created after legalization as Instruction
5974 // Selection pass has hard time in dealing with FP constant.
5976 // We don't need test this condition for transformation like following, as
5977 // the DAG being transformed implies it is legal to take FP constant as
5980 // (fadd (fmul c, x), x) -> (fmul c+1, x)
5982 bool AllowNewFpConst = (Level < AfterLegalizeDAG);
5984 // If allow, fold (fadd (fneg x), x) -> 0.0
5985 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
5986 N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
5987 return DAG.getConstantFP(0.0, VT);
5989 // If allow, fold (fadd x, (fneg x)) -> 0.0
5990 if (AllowNewFpConst && DAG.getTarget().Options.UnsafeFPMath &&
5991 N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
5992 return DAG.getConstantFP(0.0, VT);
5994 // In unsafe math mode, we can fold chains of FADD's of the same value
5995 // into multiplications. This transform is not safe in general because
5996 // we are reducing the number of rounding steps.
5997 if (DAG.getTarget().Options.UnsafeFPMath &&
5998 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
6000 if (N0.getOpcode() == ISD::FMUL) {
6001 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
6002 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6004 // (fadd (fmul c, x), x) -> (fmul x, c+1)
6005 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
6006 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6008 DAG.getConstantFP(1.0, VT));
6009 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6013 // (fadd (fmul x, c), x) -> (fmul x, c+1)
6014 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
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 (fmul c, x), (fadd x, x)) -> (fmul x, c+2)
6023 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
6024 N1.getOperand(0) == N1.getOperand(1) &&
6025 N0.getOperand(1) == N1.getOperand(0)) {
6026 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6028 DAG.getConstantFP(2.0, VT));
6029 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6030 N0.getOperand(1), NewCFP);
6033 // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
6034 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
6035 N1.getOperand(0) == N1.getOperand(1) &&
6036 N0.getOperand(0) == N1.getOperand(0)) {
6037 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6039 DAG.getConstantFP(2.0, VT));
6040 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6041 N0.getOperand(0), NewCFP);
6045 if (N1.getOpcode() == ISD::FMUL) {
6046 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6047 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
6049 // (fadd x, (fmul c, x)) -> (fmul x, c+1)
6050 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
6051 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6053 DAG.getConstantFP(1.0, VT));
6054 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6058 // (fadd x, (fmul x, c)) -> (fmul x, c+1)
6059 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
6060 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6062 DAG.getConstantFP(1.0, VT));
6063 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6068 // (fadd (fadd x, x), (fmul c, x)) -> (fmul x, c+2)
6069 if (CFP10 && !CFP11 && N0.getOpcode() == ISD::FADD &&
6070 N0.getOperand(0) == N0.getOperand(1) &&
6071 N1.getOperand(1) == N0.getOperand(0)) {
6072 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6074 DAG.getConstantFP(2.0, VT));
6075 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6076 N1.getOperand(1), NewCFP);
6079 // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
6080 if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
6081 N0.getOperand(0) == N0.getOperand(1) &&
6082 N1.getOperand(0) == N0.getOperand(0)) {
6083 SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
6085 DAG.getConstantFP(2.0, VT));
6086 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6087 N1.getOperand(0), NewCFP);
6091 if (N0.getOpcode() == ISD::FADD && AllowNewFpConst) {
6092 ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
6093 // (fadd (fadd x, x), x) -> (fmul x, 3.0)
6094 if (!CFP && N0.getOperand(0) == N0.getOperand(1) &&
6095 (N0.getOperand(0) == N1))
6096 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6097 N1, DAG.getConstantFP(3.0, VT));
6100 if (N1.getOpcode() == ISD::FADD && AllowNewFpConst) {
6101 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
6102 // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
6103 if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
6104 N1.getOperand(0) == N0)
6105 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6106 N0, DAG.getConstantFP(3.0, VT));
6109 // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
6110 if (AllowNewFpConst &&
6111 N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
6112 N0.getOperand(0) == N0.getOperand(1) &&
6113 N1.getOperand(0) == N1.getOperand(1) &&
6114 N0.getOperand(0) == N1.getOperand(0))
6115 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6117 DAG.getConstantFP(4.0, VT));
6120 // FADD -> FMA combines:
6121 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6122 DAG.getTarget().Options.UnsafeFPMath) &&
6123 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6124 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6126 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
6127 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6128 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6129 N0.getOperand(0), N0.getOperand(1), N1);
6131 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
6132 // Note: Commutes FADD operands.
6133 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6134 return DAG.getNode(ISD::FMA, SDLoc(N), VT,
6135 N1.getOperand(0), N1.getOperand(1), N0);
6141 SDValue DAGCombiner::visitFSUB(SDNode *N) {
6142 SDValue N0 = N->getOperand(0);
6143 SDValue N1 = N->getOperand(1);
6144 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6145 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6146 EVT VT = N->getValueType(0);
6150 if (VT.isVector()) {
6151 SDValue FoldedVOp = SimplifyVBinOp(N);
6152 if (FoldedVOp.getNode()) return FoldedVOp;
6155 // fold (fsub c1, c2) -> c1-c2
6157 return DAG.getNode(ISD::FSUB, SDLoc(N), VT, N0, N1);
6158 // fold (fsub A, 0) -> A
6159 if (DAG.getTarget().Options.UnsafeFPMath &&
6160 N1CFP && N1CFP->getValueAPF().isZero())
6162 // fold (fsub 0, B) -> -B
6163 if (DAG.getTarget().Options.UnsafeFPMath &&
6164 N0CFP && N0CFP->getValueAPF().isZero()) {
6165 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6166 return GetNegatedExpression(N1, DAG, LegalOperations);
6167 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6168 return DAG.getNode(ISD::FNEG, dl, VT, N1);
6170 // fold (fsub A, (fneg B)) -> (fadd A, B)
6171 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
6172 return DAG.getNode(ISD::FADD, dl, VT, N0,
6173 GetNegatedExpression(N1, DAG, LegalOperations));
6175 // If 'unsafe math' is enabled, fold
6176 // (fsub x, x) -> 0.0 &
6177 // (fsub x, (fadd x, y)) -> (fneg y) &
6178 // (fsub x, (fadd y, x)) -> (fneg y)
6179 if (DAG.getTarget().Options.UnsafeFPMath) {
6181 return DAG.getConstantFP(0.0f, VT);
6183 if (N1.getOpcode() == ISD::FADD) {
6184 SDValue N10 = N1->getOperand(0);
6185 SDValue N11 = N1->getOperand(1);
6187 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
6188 &DAG.getTarget().Options))
6189 return GetNegatedExpression(N11, DAG, LegalOperations);
6191 if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
6192 &DAG.getTarget().Options))
6193 return GetNegatedExpression(N10, DAG, LegalOperations);
6197 // FSUB -> FMA combines:
6198 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
6199 DAG.getTarget().Options.UnsafeFPMath) &&
6200 DAG.getTarget().getTargetLowering()->isFMAFasterThanFMulAndFAdd(VT) &&
6201 (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT))) {
6203 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
6204 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse())
6205 return DAG.getNode(ISD::FMA, dl, VT,
6206 N0.getOperand(0), N0.getOperand(1),
6207 DAG.getNode(ISD::FNEG, dl, VT, N1));
6209 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
6210 // Note: Commutes FSUB operands.
6211 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse())
6212 return DAG.getNode(ISD::FMA, dl, VT,
6213 DAG.getNode(ISD::FNEG, dl, VT,
6215 N1.getOperand(1), N0);
6217 // fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
6218 if (N0.getOpcode() == ISD::FNEG &&
6219 N0.getOperand(0).getOpcode() == ISD::FMUL &&
6220 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
6221 SDValue N00 = N0.getOperand(0).getOperand(0);
6222 SDValue N01 = N0.getOperand(0).getOperand(1);
6223 return DAG.getNode(ISD::FMA, dl, VT,
6224 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
6225 DAG.getNode(ISD::FNEG, dl, VT, N1));
6232 SDValue DAGCombiner::visitFMUL(SDNode *N) {
6233 SDValue N0 = N->getOperand(0);
6234 SDValue N1 = N->getOperand(1);
6235 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6236 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6237 EVT VT = N->getValueType(0);
6238 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6241 if (VT.isVector()) {
6242 SDValue FoldedVOp = SimplifyVBinOp(N);
6243 if (FoldedVOp.getNode()) return FoldedVOp;
6246 // fold (fmul c1, c2) -> c1*c2
6248 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0, N1);
6249 // canonicalize constant to RHS
6250 if (N0CFP && !N1CFP)
6251 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N1, N0);
6252 // fold (fmul A, 0) -> 0
6253 if (DAG.getTarget().Options.UnsafeFPMath &&
6254 N1CFP && N1CFP->getValueAPF().isZero())
6256 // fold (fmul A, 0) -> 0, vector edition.
6257 if (DAG.getTarget().Options.UnsafeFPMath &&
6258 ISD::isBuildVectorAllZeros(N1.getNode()))
6260 // fold (fmul A, 1.0) -> A
6261 if (N1CFP && N1CFP->isExactlyValue(1.0))
6263 // fold (fmul X, 2.0) -> (fadd X, X)
6264 if (N1CFP && N1CFP->isExactlyValue(+2.0))
6265 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N0);
6266 // fold (fmul X, -1.0) -> (fneg X)
6267 if (N1CFP && N1CFP->isExactlyValue(-1.0))
6268 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6269 return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);
6271 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
6272 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6273 &DAG.getTarget().Options)) {
6274 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6275 &DAG.getTarget().Options)) {
6276 // Both can be negated for free, check to see if at least one is cheaper
6278 if (LHSNeg == 2 || RHSNeg == 2)
6279 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6280 GetNegatedExpression(N0, DAG, LegalOperations),
6281 GetNegatedExpression(N1, DAG, LegalOperations));
6285 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
6286 if (DAG.getTarget().Options.UnsafeFPMath &&
6287 N1CFP && N0.getOpcode() == ISD::FMUL &&
6288 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
6289 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
6290 DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6291 N0.getOperand(1), N1));
6296 SDValue DAGCombiner::visitFMA(SDNode *N) {
6297 SDValue N0 = N->getOperand(0);
6298 SDValue N1 = N->getOperand(1);
6299 SDValue N2 = N->getOperand(2);
6300 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6301 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6302 EVT VT = N->getValueType(0);
6305 if (DAG.getTarget().Options.UnsafeFPMath) {
6306 if (N0CFP && N0CFP->isZero())
6308 if (N1CFP && N1CFP->isZero())
6311 if (N0CFP && N0CFP->isExactlyValue(1.0))
6312 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
6313 if (N1CFP && N1CFP->isExactlyValue(1.0))
6314 return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);
6316 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6317 if (N0CFP && !N1CFP)
6318 return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);
6320 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6321 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6322 N2.getOpcode() == ISD::FMUL &&
6323 N0 == N2.getOperand(0) &&
6324 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6325 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6326 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6330 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6331 if (DAG.getTarget().Options.UnsafeFPMath &&
6332 N0.getOpcode() == ISD::FMUL && N1CFP &&
6333 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6334 return DAG.getNode(ISD::FMA, dl, VT,
6336 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6340 // (fma x, 1, y) -> (fadd x, y)
6341 // (fma x, -1, y) -> (fadd (fneg x), y)
6343 if (N1CFP->isExactlyValue(1.0))
6344 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6346 if (N1CFP->isExactlyValue(-1.0) &&
6347 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6348 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6349 AddToWorkList(RHSNeg.getNode());
6350 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6354 // (fma x, c, x) -> (fmul x, (c+1))
6355 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2)
6356 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6357 DAG.getNode(ISD::FADD, dl, VT,
6358 N1, DAG.getConstantFP(1.0, VT)));
6360 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6361 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6362 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0)
6363 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6364 DAG.getNode(ISD::FADD, dl, VT,
6365 N1, DAG.getConstantFP(-1.0, VT)));
6371 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6372 SDValue N0 = N->getOperand(0);
6373 SDValue N1 = N->getOperand(1);
6374 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6375 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6376 EVT VT = N->getValueType(0);
6377 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6380 if (VT.isVector()) {
6381 SDValue FoldedVOp = SimplifyVBinOp(N);
6382 if (FoldedVOp.getNode()) return FoldedVOp;
6385 // fold (fdiv c1, c2) -> c1/c2
6387 return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1);
6389 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6390 if (N1CFP && DAG.getTarget().Options.UnsafeFPMath) {
6391 // Compute the reciprocal 1.0 / c2.
6392 APFloat N1APF = N1CFP->getValueAPF();
6393 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6394 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6395 // Only do the transform if the reciprocal is a legal fp immediate that
6396 // isn't too nasty (eg NaN, denormal, ...).
6397 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6398 (!LegalOperations ||
6399 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6400 // backend)... we should handle this gracefully after Legalize.
6401 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6402 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6403 TLI.isFPImmLegal(Recip, VT)))
6404 return DAG.getNode(ISD::FMUL, SDLoc(N), VT, N0,
6405 DAG.getConstantFP(Recip, VT));
6408 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6409 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6410 &DAG.getTarget().Options)) {
6411 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6412 &DAG.getTarget().Options)) {
6413 // Both can be negated for free, check to see if at least one is cheaper
6415 if (LHSNeg == 2 || RHSNeg == 2)
6416 return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
6417 GetNegatedExpression(N0, DAG, LegalOperations),
6418 GetNegatedExpression(N1, DAG, LegalOperations));
6425 SDValue DAGCombiner::visitFREM(SDNode *N) {
6426 SDValue N0 = N->getOperand(0);
6427 SDValue N1 = N->getOperand(1);
6428 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6429 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6430 EVT VT = N->getValueType(0);
6432 // fold (frem c1, c2) -> fmod(c1,c2)
6434 return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1);
6439 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6440 SDValue N0 = N->getOperand(0);
6441 SDValue N1 = N->getOperand(1);
6442 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6443 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6444 EVT VT = N->getValueType(0);
6446 if (N0CFP && N1CFP) // Constant fold
6447 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);
6450 const APFloat& V = N1CFP->getValueAPF();
6451 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6452 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6453 if (!V.isNegative()) {
6454 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6455 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6457 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6458 return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
6459 DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
6463 // copysign(fabs(x), y) -> copysign(x, y)
6464 // copysign(fneg(x), y) -> copysign(x, y)
6465 // copysign(copysign(x,z), y) -> copysign(x, y)
6466 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
6467 N0.getOpcode() == ISD::FCOPYSIGN)
6468 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6469 N0.getOperand(0), N1);
6471 // copysign(x, abs(y)) -> abs(x)
6472 if (N1.getOpcode() == ISD::FABS)
6473 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6475 // copysign(x, copysign(y,z)) -> copysign(x, z)
6476 if (N1.getOpcode() == ISD::FCOPYSIGN)
6477 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6478 N0, N1.getOperand(1));
6480 // copysign(x, fp_extend(y)) -> copysign(x, y)
6481 // copysign(x, fp_round(y)) -> copysign(x, y)
6482 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
6483 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6484 N0, N1.getOperand(0));
6489 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
6490 SDValue N0 = N->getOperand(0);
6491 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6492 EVT VT = N->getValueType(0);
6493 EVT OpVT = N0.getValueType();
6495 // fold (sint_to_fp c1) -> c1fp
6497 // ...but only if the target supports immediate floating-point values
6498 (!LegalOperations ||
6499 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6500 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
6502 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
6503 // but UINT_TO_FP is legal on this target, try to convert.
6504 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
6505 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
6506 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
6507 if (DAG.SignBitIsZero(N0))
6508 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
6511 // The next optimizations are desireable only if SELECT_CC can be lowered.
6512 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6513 // having to say they don't support SELECT_CC on every type the DAG knows
6514 // about, since there is no way to mark an opcode illegal at all value types
6515 // (See also visitSELECT)
6516 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6517 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6518 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
6520 (!LegalOperations ||
6521 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6523 { N0.getOperand(0), N0.getOperand(1),
6524 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
6526 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6529 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
6530 // (select_cc x, y, 1.0, 0.0,, cc)
6531 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
6532 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
6533 (!LegalOperations ||
6534 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6536 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
6537 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
6538 N0.getOperand(0).getOperand(2) };
6539 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6546 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
6547 SDValue N0 = N->getOperand(0);
6548 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6549 EVT VT = N->getValueType(0);
6550 EVT OpVT = N0.getValueType();
6552 // fold (uint_to_fp c1) -> c1fp
6554 // ...but only if the target supports immediate floating-point values
6555 (!LegalOperations ||
6556 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6557 return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
6559 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
6560 // but SINT_TO_FP is legal on this target, try to convert.
6561 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
6562 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
6563 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
6564 if (DAG.SignBitIsZero(N0))
6565 return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
6568 // The next optimizations are desireable only if SELECT_CC can be lowered.
6569 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6570 // having to say they don't support SELECT_CC on every type the DAG knows
6571 // about, since there is no way to mark an opcode illegal at all value types
6572 // (See also visitSELECT)
6573 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6574 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6576 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
6577 (!LegalOperations ||
6578 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6580 { N0.getOperand(0), N0.getOperand(1),
6581 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
6583 return DAG.getNode(ISD::SELECT_CC, SDLoc(N), VT, Ops, 5);
6590 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
6591 SDValue N0 = N->getOperand(0);
6592 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6593 EVT VT = N->getValueType(0);
6595 // fold (fp_to_sint c1fp) -> c1
6597 return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
6602 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
6603 SDValue N0 = N->getOperand(0);
6604 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6605 EVT VT = N->getValueType(0);
6607 // fold (fp_to_uint c1fp) -> c1
6609 return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);
6614 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
6615 SDValue N0 = N->getOperand(0);
6616 SDValue N1 = N->getOperand(1);
6617 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6618 EVT VT = N->getValueType(0);
6620 // fold (fp_round c1fp) -> c1fp
6622 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);
6624 // fold (fp_round (fp_extend x)) -> x
6625 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
6626 return N0.getOperand(0);
6628 // fold (fp_round (fp_round x)) -> (fp_round x)
6629 if (N0.getOpcode() == ISD::FP_ROUND) {
6630 // This is a value preserving truncation if both round's are.
6631 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
6632 N0.getNode()->getConstantOperandVal(1) == 1;
6633 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0.getOperand(0),
6634 DAG.getIntPtrConstant(IsTrunc));
6637 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
6638 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
6639 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
6640 N0.getOperand(0), N1);
6641 AddToWorkList(Tmp.getNode());
6642 return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
6643 Tmp, N0.getOperand(1));
6649 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
6650 SDValue N0 = N->getOperand(0);
6651 EVT VT = N->getValueType(0);
6652 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6653 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6655 // fold (fp_round_inreg c1fp) -> c1fp
6656 if (N0CFP && isTypeLegal(EVT)) {
6657 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
6658 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, Round);
6664 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
6665 SDValue N0 = N->getOperand(0);
6666 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6667 EVT VT = N->getValueType(0);
6669 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
6670 if (N->hasOneUse() &&
6671 N->use_begin()->getOpcode() == ISD::FP_ROUND)
6674 // fold (fp_extend c1fp) -> c1fp
6676 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);
6678 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
6680 if (N0.getOpcode() == ISD::FP_ROUND
6681 && N0.getNode()->getConstantOperandVal(1) == 1) {
6682 SDValue In = N0.getOperand(0);
6683 if (In.getValueType() == VT) return In;
6684 if (VT.bitsLT(In.getValueType()))
6685 return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
6686 In, N0.getOperand(1));
6687 return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
6690 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
6691 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
6692 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6693 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
6694 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6695 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
6697 LN0->getBasePtr(), LN0->getPointerInfo(),
6699 LN0->isVolatile(), LN0->isNonTemporal(),
6700 LN0->getAlignment());
6701 CombineTo(N, ExtLoad);
6702 CombineTo(N0.getNode(),
6703 DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
6704 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
6705 ExtLoad.getValue(1));
6706 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6712 SDValue DAGCombiner::visitFNEG(SDNode *N) {
6713 SDValue N0 = N->getOperand(0);
6714 EVT VT = N->getValueType(0);
6716 if (VT.isVector()) {
6717 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6718 if (FoldedVOp.getNode()) return FoldedVOp;
6721 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
6722 &DAG.getTarget().Options))
6723 return GetNegatedExpression(N0, DAG, LegalOperations);
6725 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
6726 // constant pool values.
6727 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
6729 N0.getNode()->hasOneUse() &&
6730 N0.getOperand(0).getValueType().isInteger()) {
6731 SDValue Int = N0.getOperand(0);
6732 EVT IntVT = Int.getValueType();
6733 if (IntVT.isInteger() && !IntVT.isVector()) {
6734 Int = DAG.getNode(ISD::XOR, SDLoc(N0), IntVT, Int,
6735 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6736 AddToWorkList(Int.getNode());
6737 return DAG.getNode(ISD::BITCAST, SDLoc(N),
6742 // (fneg (fmul c, x)) -> (fmul -c, x)
6743 if (N0.getOpcode() == ISD::FMUL) {
6744 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6746 return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
6748 DAG.getNode(ISD::FNEG, SDLoc(N), VT,
6755 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
6756 SDValue N0 = N->getOperand(0);
6757 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6758 EVT VT = N->getValueType(0);
6760 // fold (fceil c1) -> fceil(c1)
6762 return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);
6767 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
6768 SDValue N0 = N->getOperand(0);
6769 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6770 EVT VT = N->getValueType(0);
6772 // fold (ftrunc c1) -> ftrunc(c1)
6774 return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);
6779 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
6780 SDValue N0 = N->getOperand(0);
6781 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6782 EVT VT = N->getValueType(0);
6784 // fold (ffloor c1) -> ffloor(c1)
6786 return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);
6791 SDValue DAGCombiner::visitFABS(SDNode *N) {
6792 SDValue N0 = N->getOperand(0);
6793 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6794 EVT VT = N->getValueType(0);
6796 if (VT.isVector()) {
6797 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6798 if (FoldedVOp.getNode()) return FoldedVOp;
6801 // fold (fabs c1) -> fabs(c1)
6803 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
6804 // fold (fabs (fabs x)) -> (fabs x)
6805 if (N0.getOpcode() == ISD::FABS)
6806 return N->getOperand(0);
6807 // fold (fabs (fneg x)) -> (fabs x)
6808 // fold (fabs (fcopysign x, y)) -> (fabs x)
6809 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
6810 return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));
6812 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
6813 // constant pool values.
6814 if (!TLI.isFAbsFree(VT) &&
6815 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
6816 N0.getOperand(0).getValueType().isInteger() &&
6817 !N0.getOperand(0).getValueType().isVector()) {
6818 SDValue Int = N0.getOperand(0);
6819 EVT IntVT = Int.getValueType();
6820 if (IntVT.isInteger() && !IntVT.isVector()) {
6821 Int = DAG.getNode(ISD::AND, SDLoc(N0), IntVT, Int,
6822 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6823 AddToWorkList(Int.getNode());
6824 return DAG.getNode(ISD::BITCAST, SDLoc(N),
6825 N->getValueType(0), Int);
6832 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
6833 SDValue Chain = N->getOperand(0);
6834 SDValue N1 = N->getOperand(1);
6835 SDValue N2 = N->getOperand(2);
6837 // If N is a constant we could fold this into a fallthrough or unconditional
6838 // branch. However that doesn't happen very often in normal code, because
6839 // Instcombine/SimplifyCFG should have handled the available opportunities.
6840 // If we did this folding here, it would be necessary to update the
6841 // MachineBasicBlock CFG, which is awkward.
6843 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
6845 if (N1.getOpcode() == ISD::SETCC &&
6846 TLI.isOperationLegalOrCustom(ISD::BR_CC,
6847 N1.getOperand(0).getValueType())) {
6848 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
6849 Chain, N1.getOperand(2),
6850 N1.getOperand(0), N1.getOperand(1), N2);
6853 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
6854 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
6855 (N1.getOperand(0).hasOneUse() &&
6856 N1.getOperand(0).getOpcode() == ISD::SRL))) {
6858 if (N1.getOpcode() == ISD::TRUNCATE) {
6859 // Look pass the truncate.
6860 Trunc = N1.getNode();
6861 N1 = N1.getOperand(0);
6864 // Match this pattern so that we can generate simpler code:
6867 // %b = and i32 %a, 2
6868 // %c = srl i32 %b, 1
6869 // brcond i32 %c ...
6874 // %b = and i32 %a, 2
6875 // %c = setcc eq %b, 0
6878 // This applies only when the AND constant value has one bit set and the
6879 // SRL constant is equal to the log2 of the AND constant. The back-end is
6880 // smart enough to convert the result into a TEST/JMP sequence.
6881 SDValue Op0 = N1.getOperand(0);
6882 SDValue Op1 = N1.getOperand(1);
6884 if (Op0.getOpcode() == ISD::AND &&
6885 Op1.getOpcode() == ISD::Constant) {
6886 SDValue AndOp1 = Op0.getOperand(1);
6888 if (AndOp1.getOpcode() == ISD::Constant) {
6889 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
6891 if (AndConst.isPowerOf2() &&
6892 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
6894 DAG.getSetCC(SDLoc(N),
6895 getSetCCResultType(Op0.getValueType()),
6896 Op0, DAG.getConstant(0, Op0.getValueType()),
6899 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, SDLoc(N),
6900 MVT::Other, Chain, SetCC, N2);
6901 // Don't add the new BRCond into the worklist or else SimplifySelectCC
6902 // will convert it back to (X & C1) >> C2.
6903 CombineTo(N, NewBRCond, false);
6904 // Truncate is dead.
6906 removeFromWorkList(Trunc);
6907 DAG.DeleteNode(Trunc);
6909 // Replace the uses of SRL with SETCC
6910 WorkListRemover DeadNodes(*this);
6911 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6912 removeFromWorkList(N1.getNode());
6913 DAG.DeleteNode(N1.getNode());
6914 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6920 // Restore N1 if the above transformation doesn't match.
6921 N1 = N->getOperand(1);
6924 // Transform br(xor(x, y)) -> br(x != y)
6925 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
6926 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
6927 SDNode *TheXor = N1.getNode();
6928 SDValue Op0 = TheXor->getOperand(0);
6929 SDValue Op1 = TheXor->getOperand(1);
6930 if (Op0.getOpcode() == Op1.getOpcode()) {
6931 // Avoid missing important xor optimizations.
6932 SDValue Tmp = visitXOR(TheXor);
6933 if (Tmp.getNode()) {
6934 if (Tmp.getNode() != TheXor) {
6935 DEBUG(dbgs() << "\nReplacing.8 ";
6937 dbgs() << "\nWith: ";
6938 Tmp.getNode()->dump(&DAG);
6940 WorkListRemover DeadNodes(*this);
6941 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
6942 removeFromWorkList(TheXor);
6943 DAG.DeleteNode(TheXor);
6944 return DAG.getNode(ISD::BRCOND, SDLoc(N),
6945 MVT::Other, Chain, Tmp, N2);
6948 // visitXOR has changed XOR's operands or replaced the XOR completely,
6950 return SDValue(N, 0);
6954 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
6956 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
6957 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
6958 Op0.getOpcode() == ISD::XOR) {
6959 TheXor = Op0.getNode();
6963 EVT SetCCVT = N1.getValueType();
6965 SetCCVT = getSetCCResultType(SetCCVT);
6966 SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
6969 Equal ? ISD::SETEQ : ISD::SETNE);
6970 // Replace the uses of XOR with SETCC
6971 WorkListRemover DeadNodes(*this);
6972 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6973 removeFromWorkList(N1.getNode());
6974 DAG.DeleteNode(N1.getNode());
6975 return DAG.getNode(ISD::BRCOND, SDLoc(N),
6976 MVT::Other, Chain, SetCC, N2);
6983 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
6985 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
6986 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
6987 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
6989 // If N is a constant we could fold this into a fallthrough or unconditional
6990 // branch. However that doesn't happen very often in normal code, because
6991 // Instcombine/SimplifyCFG should have handled the available opportunities.
6992 // If we did this folding here, it would be necessary to update the
6993 // MachineBasicBlock CFG, which is awkward.
6995 // Use SimplifySetCC to simplify SETCC's.
6996 SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
6997 CondLHS, CondRHS, CC->get(), SDLoc(N),
6999 if (Simp.getNode()) AddToWorkList(Simp.getNode());
7001 // fold to a simpler setcc
7002 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
7003 return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
7004 N->getOperand(0), Simp.getOperand(2),
7005 Simp.getOperand(0), Simp.getOperand(1),
7011 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
7012 /// uses N as its base pointer and that N may be folded in the load / store
7013 /// addressing mode.
7014 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
7016 const TargetLowering &TLI) {
7018 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
7019 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
7021 VT = Use->getValueType(0);
7022 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
7023 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
7025 VT = ST->getValue().getValueType();
7029 TargetLowering::AddrMode AM;
7030 if (N->getOpcode() == ISD::ADD) {
7031 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
7034 AM.BaseOffs = Offset->getSExtValue();
7038 } else if (N->getOpcode() == ISD::SUB) {
7039 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
7042 AM.BaseOffs = -Offset->getSExtValue();
7049 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
7052 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
7053 /// pre-indexed load / store when the base pointer is an add or subtract
7054 /// and it has other uses besides the load / store. After the
7055 /// transformation, the new indexed load / store has effectively folded
7056 /// the add / subtract in and all of its other uses are redirected to the
7057 /// new load / store.
7058 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
7059 if (Level < AfterLegalizeDAG)
7065 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7066 if (LD->isIndexed())
7068 VT = LD->getMemoryVT();
7069 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
7070 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
7072 Ptr = LD->getBasePtr();
7073 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7074 if (ST->isIndexed())
7076 VT = ST->getMemoryVT();
7077 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
7078 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
7080 Ptr = ST->getBasePtr();
7086 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
7087 // out. There is no reason to make this a preinc/predec.
7088 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
7089 Ptr.getNode()->hasOneUse())
7092 // Ask the target to do addressing mode selection.
7095 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7096 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
7099 // Backends without true r+i pre-indexed forms may need to pass a
7100 // constant base with a variable offset so that constant coercion
7101 // will work with the patterns in canonical form.
7102 bool Swapped = false;
7103 if (isa<ConstantSDNode>(BasePtr)) {
7104 std::swap(BasePtr, Offset);
7108 // Don't create a indexed load / store with zero offset.
7109 if (isa<ConstantSDNode>(Offset) &&
7110 cast<ConstantSDNode>(Offset)->isNullValue())
7113 // Try turning it into a pre-indexed load / store except when:
7114 // 1) The new base ptr is a frame index.
7115 // 2) If N is a store and the new base ptr is either the same as or is a
7116 // predecessor of the value being stored.
7117 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
7118 // that would create a cycle.
7119 // 4) All uses are load / store ops that use it as old base ptr.
7121 // Check #1. Preinc'ing a frame index would require copying the stack pointer
7122 // (plus the implicit offset) to a register to preinc anyway.
7123 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7128 SDValue Val = cast<StoreSDNode>(N)->getValue();
7129 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
7133 // If the offset is a constant, there may be other adds of constants that
7134 // can be folded with this one. We should do this to avoid having to keep
7135 // a copy of the original base pointer.
7136 SmallVector<SDNode *, 16> OtherUses;
7137 if (isa<ConstantSDNode>(Offset))
7138 for (SDNode::use_iterator I = BasePtr.getNode()->use_begin(),
7139 E = BasePtr.getNode()->use_end(); I != E; ++I) {
7141 if (Use == Ptr.getNode())
7144 if (Use->isPredecessorOf(N))
7147 if (Use->getOpcode() != ISD::ADD && Use->getOpcode() != ISD::SUB) {
7152 SDValue Op0 = Use->getOperand(0), Op1 = Use->getOperand(1);
7153 if (Op1.getNode() == BasePtr.getNode())
7154 std::swap(Op0, Op1);
7155 assert(Op0.getNode() == BasePtr.getNode() &&
7156 "Use of ADD/SUB but not an operand");
7158 if (!isa<ConstantSDNode>(Op1)) {
7163 // FIXME: In some cases, we can be smarter about this.
7164 if (Op1.getValueType() != Offset.getValueType()) {
7169 OtherUses.push_back(Use);
7173 std::swap(BasePtr, Offset);
7175 // Now check for #3 and #4.
7176 bool RealUse = false;
7178 // Caches for hasPredecessorHelper
7179 SmallPtrSet<const SDNode *, 32> Visited;
7180 SmallVector<const SDNode *, 16> Worklist;
7182 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
7183 E = Ptr.getNode()->use_end(); I != E; ++I) {
7187 if (N->hasPredecessorHelper(Use, Visited, Worklist))
7190 // If Ptr may be folded in addressing mode of other use, then it's
7191 // not profitable to do this transformation.
7192 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
7201 Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7202 BasePtr, Offset, AM);
7204 Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7205 BasePtr, Offset, AM);
7208 DEBUG(dbgs() << "\nReplacing.4 ";
7210 dbgs() << "\nWith: ";
7211 Result.getNode()->dump(&DAG);
7213 WorkListRemover DeadNodes(*this);
7215 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7216 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7218 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7221 // Finally, since the node is now dead, remove it from the graph.
7225 std::swap(BasePtr, Offset);
7227 // Replace other uses of BasePtr that can be updated to use Ptr
7228 for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
7229 unsigned OffsetIdx = 1;
7230 if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
7232 assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==
7233 BasePtr.getNode() && "Expected BasePtr operand");
7235 // We need to replace ptr0 in the following expression:
7236 // x0 * offset0 + y0 * ptr0 = t0
7238 // x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
7240 // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
7241 // indexed load/store and the expresion that needs to be re-written.
7243 // Therefore, we have:
7244 // t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1
7246 ConstantSDNode *CN =
7247 cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
7249 APInt Offset0 = CN->getAPIntValue();
7250 APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();
7252 X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
7253 Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
7254 X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
7255 Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;
7257 unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;
7259 APInt CNV = Offset0;
7260 if (X0 < 0) CNV = -CNV;
7261 if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
7262 else CNV = CNV - Offset1;
7264 // We can now generate the new expression.
7265 SDValue NewOp1 = DAG.getConstant(CNV, CN->getValueType(0));
7266 SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);
7268 SDValue NewUse = DAG.getNode(Opcode,
7269 SDLoc(OtherUses[i]),
7270 OtherUses[i]->getValueType(0), NewOp1, NewOp2);
7271 DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
7272 removeFromWorkList(OtherUses[i]);
7273 DAG.DeleteNode(OtherUses[i]);
7276 // Replace the uses of Ptr with uses of the updated base value.
7277 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
7278 removeFromWorkList(Ptr.getNode());
7279 DAG.DeleteNode(Ptr.getNode());
7284 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
7285 /// add / sub of the base pointer node into a post-indexed load / store.
7286 /// The transformation folded the add / subtract into the new indexed
7287 /// load / store effectively and all of its uses are redirected to the
7288 /// new load / store.
7289 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
7290 if (Level < AfterLegalizeDAG)
7296 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7297 if (LD->isIndexed())
7299 VT = LD->getMemoryVT();
7300 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
7301 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
7303 Ptr = LD->getBasePtr();
7304 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7305 if (ST->isIndexed())
7307 VT = ST->getMemoryVT();
7308 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
7309 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
7311 Ptr = ST->getBasePtr();
7317 if (Ptr.getNode()->hasOneUse())
7320 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
7321 E = Ptr.getNode()->use_end(); I != E; ++I) {
7324 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
7329 ISD::MemIndexedMode AM = ISD::UNINDEXED;
7330 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
7331 // Don't create a indexed load / store with zero offset.
7332 if (isa<ConstantSDNode>(Offset) &&
7333 cast<ConstantSDNode>(Offset)->isNullValue())
7336 // Try turning it into a post-indexed load / store except when
7337 // 1) All uses are load / store ops that use it as base ptr (and
7338 // it may be folded as addressing mmode).
7339 // 2) Op must be independent of N, i.e. Op is neither a predecessor
7340 // nor a successor of N. Otherwise, if Op is folded that would
7343 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
7347 bool TryNext = false;
7348 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
7349 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
7351 if (Use == Ptr.getNode())
7354 // If all the uses are load / store addresses, then don't do the
7356 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
7357 bool RealUse = false;
7358 for (SDNode::use_iterator III = Use->use_begin(),
7359 EEE = Use->use_end(); III != EEE; ++III) {
7360 SDNode *UseUse = *III;
7361 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
7376 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
7377 SDValue Result = isLoad
7378 ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
7379 BasePtr, Offset, AM)
7380 : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
7381 BasePtr, Offset, AM);
7384 DEBUG(dbgs() << "\nReplacing.5 ";
7386 dbgs() << "\nWith: ";
7387 Result.getNode()->dump(&DAG);
7389 WorkListRemover DeadNodes(*this);
7391 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7392 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7394 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7397 // Finally, since the node is now dead, remove it from the graph.
7400 // Replace the uses of Use with uses of the updated base value.
7401 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
7402 Result.getValue(isLoad ? 1 : 0));
7403 removeFromWorkList(Op);
7413 SDValue DAGCombiner::visitLOAD(SDNode *N) {
7414 LoadSDNode *LD = cast<LoadSDNode>(N);
7415 SDValue Chain = LD->getChain();
7416 SDValue Ptr = LD->getBasePtr();
7418 // If load is not volatile and there are no uses of the loaded value (and
7419 // the updated indexed value in case of indexed loads), change uses of the
7420 // chain value into uses of the chain input (i.e. delete the dead load).
7421 if (!LD->isVolatile()) {
7422 if (N->getValueType(1) == MVT::Other) {
7424 if (!N->hasAnyUseOfValue(0)) {
7425 // It's not safe to use the two value CombineTo variant here. e.g.
7426 // v1, chain2 = load chain1, loc
7427 // v2, chain3 = load chain2, loc
7429 // Now we replace use of chain2 with chain1. This makes the second load
7430 // isomorphic to the one we are deleting, and thus makes this load live.
7431 DEBUG(dbgs() << "\nReplacing.6 ";
7433 dbgs() << "\nWith chain: ";
7434 Chain.getNode()->dump(&DAG);
7436 WorkListRemover DeadNodes(*this);
7437 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7439 if (N->use_empty()) {
7440 removeFromWorkList(N);
7444 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7448 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7449 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7450 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7451 DEBUG(dbgs() << "\nReplacing.7 ";
7453 dbgs() << "\nWith: ";
7454 Undef.getNode()->dump(&DAG);
7455 dbgs() << " and 2 other values\n");
7456 WorkListRemover DeadNodes(*this);
7457 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7458 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7459 DAG.getUNDEF(N->getValueType(1)));
7460 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7461 removeFromWorkList(N);
7463 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7468 // If this load is directly stored, replace the load value with the stored
7470 // TODO: Handle store large -> read small portion.
7471 // TODO: Handle TRUNCSTORE/LOADEXT
7472 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7473 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7474 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7475 if (PrevST->getBasePtr() == Ptr &&
7476 PrevST->getValue().getValueType() == N->getValueType(0))
7477 return CombineTo(N, Chain.getOperand(1), Chain);
7481 // Try to infer better alignment information than the load already has.
7482 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
7483 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7484 if (Align > LD->getMemOperand()->getBaseAlignment()) {
7486 DAG.getExtLoad(LD->getExtensionType(), SDLoc(N),
7487 LD->getValueType(0),
7488 Chain, Ptr, LD->getPointerInfo(),
7490 LD->isVolatile(), LD->isNonTemporal(), Align);
7491 return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
7496 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
7497 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
7499 // Walk up chain skipping non-aliasing memory nodes.
7500 SDValue BetterChain = FindBetterChain(N, Chain);
7502 // If there is a better chain.
7503 if (Chain != BetterChain) {
7506 // Replace the chain to void dependency.
7507 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
7508 ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
7509 BetterChain, Ptr, LD->getPointerInfo(),
7510 LD->isVolatile(), LD->isNonTemporal(),
7511 LD->isInvariant(), LD->getAlignment());
7513 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
7514 LD->getValueType(0),
7515 BetterChain, Ptr, LD->getPointerInfo(),
7518 LD->isNonTemporal(),
7519 LD->getAlignment());
7522 // Create token factor to keep old chain connected.
7523 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
7524 MVT::Other, Chain, ReplLoad.getValue(1));
7526 // Make sure the new and old chains are cleaned up.
7527 AddToWorkList(Token.getNode());
7529 // Replace uses with load result and token factor. Don't add users
7531 return CombineTo(N, ReplLoad.getValue(0), Token, false);
7535 // Try transforming N to an indexed load.
7536 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7537 return SDValue(N, 0);
7542 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
7543 /// load is having specific bytes cleared out. If so, return the byte size
7544 /// being masked out and the shift amount.
7545 static std::pair<unsigned, unsigned>
7546 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
7547 std::pair<unsigned, unsigned> Result(0, 0);
7549 // Check for the structure we're looking for.
7550 if (V->getOpcode() != ISD::AND ||
7551 !isa<ConstantSDNode>(V->getOperand(1)) ||
7552 !ISD::isNormalLoad(V->getOperand(0).getNode()))
7555 // Check the chain and pointer.
7556 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
7557 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
7559 // The store should be chained directly to the load or be an operand of a
7561 if (LD == Chain.getNode())
7563 else if (Chain->getOpcode() != ISD::TokenFactor)
7564 return Result; // Fail.
7567 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
7568 if (Chain->getOperand(i).getNode() == LD) {
7572 if (!isOk) return Result;
7575 // This only handles simple types.
7576 if (V.getValueType() != MVT::i16 &&
7577 V.getValueType() != MVT::i32 &&
7578 V.getValueType() != MVT::i64)
7581 // Check the constant mask. Invert it so that the bits being masked out are
7582 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
7583 // follow the sign bit for uniformity.
7584 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
7585 unsigned NotMaskLZ = countLeadingZeros(NotMask);
7586 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
7587 unsigned NotMaskTZ = countTrailingZeros(NotMask);
7588 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
7589 if (NotMaskLZ == 64) return Result; // All zero mask.
7591 // See if we have a continuous run of bits. If so, we have 0*1+0*
7592 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
7595 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
7596 if (V.getValueType() != MVT::i64 && NotMaskLZ)
7597 NotMaskLZ -= 64-V.getValueSizeInBits();
7599 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
7600 switch (MaskedBytes) {
7604 default: return Result; // All one mask, or 5-byte mask.
7607 // Verify that the first bit starts at a multiple of mask so that the access
7608 // is aligned the same as the access width.
7609 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
7611 Result.first = MaskedBytes;
7612 Result.second = NotMaskTZ/8;
7617 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
7618 /// provides a value as specified by MaskInfo. If so, replace the specified
7619 /// store with a narrower store of truncated IVal.
7621 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
7622 SDValue IVal, StoreSDNode *St,
7624 unsigned NumBytes = MaskInfo.first;
7625 unsigned ByteShift = MaskInfo.second;
7626 SelectionDAG &DAG = DC->getDAG();
7628 // Check to see if IVal is all zeros in the part being masked in by the 'or'
7629 // that uses this. If not, this is not a replacement.
7630 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
7631 ByteShift*8, (ByteShift+NumBytes)*8);
7632 if (!DAG.MaskedValueIsZero(IVal, Mask)) return 0;
7634 // Check that it is legal on the target to do this. It is legal if the new
7635 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
7637 MVT VT = MVT::getIntegerVT(NumBytes*8);
7638 if (!DC->isTypeLegal(VT))
7641 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
7642 // shifted by ByteShift and truncated down to NumBytes.
7644 IVal = DAG.getNode(ISD::SRL, SDLoc(IVal), IVal.getValueType(), IVal,
7645 DAG.getConstant(ByteShift*8,
7646 DC->getShiftAmountTy(IVal.getValueType())));
7648 // Figure out the offset for the store and the alignment of the access.
7650 unsigned NewAlign = St->getAlignment();
7652 if (DAG.getTargetLoweringInfo().isLittleEndian())
7653 StOffset = ByteShift;
7655 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
7657 SDValue Ptr = St->getBasePtr();
7659 Ptr = DAG.getNode(ISD::ADD, SDLoc(IVal), Ptr.getValueType(),
7660 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
7661 NewAlign = MinAlign(NewAlign, StOffset);
7664 // Truncate down to the new size.
7665 IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);
7668 return DAG.getStore(St->getChain(), SDLoc(St), IVal, Ptr,
7669 St->getPointerInfo().getWithOffset(StOffset),
7670 false, false, NewAlign).getNode();
7674 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
7675 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
7676 /// of the loaded bits, try narrowing the load and store if it would end up
7677 /// being a win for performance or code size.
7678 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
7679 StoreSDNode *ST = cast<StoreSDNode>(N);
7680 if (ST->isVolatile())
7683 SDValue Chain = ST->getChain();
7684 SDValue Value = ST->getValue();
7685 SDValue Ptr = ST->getBasePtr();
7686 EVT VT = Value.getValueType();
7688 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
7691 unsigned Opc = Value.getOpcode();
7693 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
7694 // is a byte mask indicating a consecutive number of bytes, check to see if
7695 // Y is known to provide just those bytes. If so, we try to replace the
7696 // load + replace + store sequence with a single (narrower) store, which makes
7698 if (Opc == ISD::OR) {
7699 std::pair<unsigned, unsigned> MaskedLoad;
7700 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
7701 if (MaskedLoad.first)
7702 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7703 Value.getOperand(1), ST,this))
7704 return SDValue(NewST, 0);
7706 // Or is commutative, so try swapping X and Y.
7707 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
7708 if (MaskedLoad.first)
7709 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7710 Value.getOperand(0), ST,this))
7711 return SDValue(NewST, 0);
7714 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
7715 Value.getOperand(1).getOpcode() != ISD::Constant)
7718 SDValue N0 = Value.getOperand(0);
7719 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7720 Chain == SDValue(N0.getNode(), 1)) {
7721 LoadSDNode *LD = cast<LoadSDNode>(N0);
7722 if (LD->getBasePtr() != Ptr ||
7723 LD->getPointerInfo().getAddrSpace() !=
7724 ST->getPointerInfo().getAddrSpace())
7727 // Find the type to narrow it the load / op / store to.
7728 SDValue N1 = Value.getOperand(1);
7729 unsigned BitWidth = N1.getValueSizeInBits();
7730 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
7731 if (Opc == ISD::AND)
7732 Imm ^= APInt::getAllOnesValue(BitWidth);
7733 if (Imm == 0 || Imm.isAllOnesValue())
7735 unsigned ShAmt = Imm.countTrailingZeros();
7736 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
7737 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
7738 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7739 while (NewBW < BitWidth &&
7740 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
7741 TLI.isNarrowingProfitable(VT, NewVT))) {
7742 NewBW = NextPowerOf2(NewBW);
7743 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7745 if (NewBW >= BitWidth)
7748 // If the lsb changed does not start at the type bitwidth boundary,
7749 // start at the previous one.
7751 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
7752 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
7753 std::min(BitWidth, ShAmt + NewBW));
7754 if ((Imm & Mask) == Imm) {
7755 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
7756 if (Opc == ISD::AND)
7757 NewImm ^= APInt::getAllOnesValue(NewBW);
7758 uint64_t PtrOff = ShAmt / 8;
7759 // For big endian targets, we need to adjust the offset to the pointer to
7760 // load the correct bytes.
7761 if (TLI.isBigEndian())
7762 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
7764 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
7765 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
7766 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
7769 SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
7770 Ptr.getValueType(), Ptr,
7771 DAG.getConstant(PtrOff, Ptr.getValueType()));
7772 SDValue NewLD = DAG.getLoad(NewVT, SDLoc(N0),
7773 LD->getChain(), NewPtr,
7774 LD->getPointerInfo().getWithOffset(PtrOff),
7775 LD->isVolatile(), LD->isNonTemporal(),
7776 LD->isInvariant(), NewAlign);
7777 SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
7778 DAG.getConstant(NewImm, NewVT));
7779 SDValue NewST = DAG.getStore(Chain, SDLoc(N),
7781 ST->getPointerInfo().getWithOffset(PtrOff),
7782 false, false, NewAlign);
7784 AddToWorkList(NewPtr.getNode());
7785 AddToWorkList(NewLD.getNode());
7786 AddToWorkList(NewVal.getNode());
7787 WorkListRemover DeadNodes(*this);
7788 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
7797 /// TransformFPLoadStorePair - For a given floating point load / store pair,
7798 /// if the load value isn't used by any other operations, then consider
7799 /// transforming the pair to integer load / store operations if the target
7800 /// deems the transformation profitable.
7801 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
7802 StoreSDNode *ST = cast<StoreSDNode>(N);
7803 SDValue Chain = ST->getChain();
7804 SDValue Value = ST->getValue();
7805 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
7806 Value.hasOneUse() &&
7807 Chain == SDValue(Value.getNode(), 1)) {
7808 LoadSDNode *LD = cast<LoadSDNode>(Value);
7809 EVT VT = LD->getMemoryVT();
7810 if (!VT.isFloatingPoint() ||
7811 VT != ST->getMemoryVT() ||
7812 LD->isNonTemporal() ||
7813 ST->isNonTemporal() ||
7814 LD->getPointerInfo().getAddrSpace() != 0 ||
7815 ST->getPointerInfo().getAddrSpace() != 0)
7818 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
7819 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
7820 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
7821 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
7822 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
7825 unsigned LDAlign = LD->getAlignment();
7826 unsigned STAlign = ST->getAlignment();
7827 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
7828 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
7829 if (LDAlign < ABIAlign || STAlign < ABIAlign)
7832 SDValue NewLD = DAG.getLoad(IntVT, SDLoc(Value),
7833 LD->getChain(), LD->getBasePtr(),
7834 LD->getPointerInfo(),
7835 false, false, false, LDAlign);
7837 SDValue NewST = DAG.getStore(NewLD.getValue(1), SDLoc(N),
7838 NewLD, ST->getBasePtr(),
7839 ST->getPointerInfo(),
7840 false, false, STAlign);
7842 AddToWorkList(NewLD.getNode());
7843 AddToWorkList(NewST.getNode());
7844 WorkListRemover DeadNodes(*this);
7845 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
7853 /// Helper struct to parse and store a memory address as base + index + offset.
7854 /// We ignore sign extensions when it is safe to do so.
7855 /// The following two expressions are not equivalent. To differentiate we need
7856 /// to store whether there was a sign extension involved in the index
7858 /// (load (i64 add (i64 copyfromreg %c)
7859 /// (i64 signextend (add (i8 load %index)
7863 /// (load (i64 add (i64 copyfromreg %c)
7864 /// (i64 signextend (i32 add (i32 signextend (i8 load %index))
7866 struct BaseIndexOffset {
7870 bool IsIndexSignExt;
7872 BaseIndexOffset() : Offset(0), IsIndexSignExt(false) {}
7874 BaseIndexOffset(SDValue Base, SDValue Index, int64_t Offset,
7875 bool IsIndexSignExt) :
7876 Base(Base), Index(Index), Offset(Offset), IsIndexSignExt(IsIndexSignExt) {}
7878 bool equalBaseIndex(const BaseIndexOffset &Other) {
7879 return Other.Base == Base && Other.Index == Index &&
7880 Other.IsIndexSignExt == IsIndexSignExt;
7883 /// Parses tree in Ptr for base, index, offset addresses.
7884 static BaseIndexOffset match(SDValue Ptr) {
7885 bool IsIndexSignExt = false;
7887 // We only can pattern match BASE + INDEX + OFFSET. If Ptr is not an ADD
7888 // instruction, then it could be just the BASE or everything else we don't
7889 // know how to handle. Just use Ptr as BASE and give up.
7890 if (Ptr->getOpcode() != ISD::ADD)
7891 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
7893 // We know that we have at least an ADD instruction. Try to pattern match
7894 // the simple case of BASE + OFFSET.
7895 if (isa<ConstantSDNode>(Ptr->getOperand(1))) {
7896 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
7897 return BaseIndexOffset(Ptr->getOperand(0), SDValue(), Offset,
7901 // Inside a loop the current BASE pointer is calculated using an ADD and a
7902 // MUL instruction. In this case Ptr is the actual BASE pointer.
7903 // (i64 add (i64 %array_ptr)
7904 // (i64 mul (i64 %induction_var)
7905 // (i64 %element_size)))
7906 if (Ptr->getOperand(1)->getOpcode() == ISD::MUL)
7907 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
7909 // Look at Base + Index + Offset cases.
7910 SDValue Base = Ptr->getOperand(0);
7911 SDValue IndexOffset = Ptr->getOperand(1);
7913 // Skip signextends.
7914 if (IndexOffset->getOpcode() == ISD::SIGN_EXTEND) {
7915 IndexOffset = IndexOffset->getOperand(0);
7916 IsIndexSignExt = true;
7919 // Either the case of Base + Index (no offset) or something else.
7920 if (IndexOffset->getOpcode() != ISD::ADD)
7921 return BaseIndexOffset(Base, IndexOffset, 0, IsIndexSignExt);
7923 // Now we have the case of Base + Index + offset.
7924 SDValue Index = IndexOffset->getOperand(0);
7925 SDValue Offset = IndexOffset->getOperand(1);
7927 if (!isa<ConstantSDNode>(Offset))
7928 return BaseIndexOffset(Ptr, SDValue(), 0, IsIndexSignExt);
7930 // Ignore signextends.
7931 if (Index->getOpcode() == ISD::SIGN_EXTEND) {
7932 Index = Index->getOperand(0);
7933 IsIndexSignExt = true;
7934 } else IsIndexSignExt = false;
7936 int64_t Off = cast<ConstantSDNode>(Offset)->getSExtValue();
7937 return BaseIndexOffset(Base, Index, Off, IsIndexSignExt);
7941 /// Holds a pointer to an LSBaseSDNode as well as information on where it
7942 /// is located in a sequence of memory operations connected by a chain.
7944 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
7945 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
7946 // Ptr to the mem node.
7947 LSBaseSDNode *MemNode;
7948 // Offset from the base ptr.
7949 int64_t OffsetFromBase;
7950 // What is the sequence number of this mem node.
7951 // Lowest mem operand in the DAG starts at zero.
7952 unsigned SequenceNum;
7955 /// Sorts store nodes in a link according to their offset from a shared
7957 struct ConsecutiveMemoryChainSorter {
7958 bool operator()(MemOpLink LHS, MemOpLink RHS) {
7959 return LHS.OffsetFromBase < RHS.OffsetFromBase;
7963 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
7964 EVT MemVT = St->getMemoryVT();
7965 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
7966 bool NoVectors = DAG.getMachineFunction().getFunction()->getAttributes().
7967 hasAttribute(AttributeSet::FunctionIndex, Attribute::NoImplicitFloat);
7969 // Don't merge vectors into wider inputs.
7970 if (MemVT.isVector() || !MemVT.isSimple())
7973 // Perform an early exit check. Do not bother looking at stored values that
7974 // are not constants or loads.
7975 SDValue StoredVal = St->getValue();
7976 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
7977 if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
7981 // Only look at ends of store sequences.
7982 SDValue Chain = SDValue(St, 1);
7983 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
7986 // This holds the base pointer, index, and the offset in bytes from the base
7988 BaseIndexOffset BasePtr = BaseIndexOffset::match(St->getBasePtr());
7990 // We must have a base and an offset.
7991 if (!BasePtr.Base.getNode())
7994 // Do not handle stores to undef base pointers.
7995 if (BasePtr.Base.getOpcode() == ISD::UNDEF)
7998 // Save the LoadSDNodes that we find in the chain.
7999 // We need to make sure that these nodes do not interfere with
8000 // any of the store nodes.
8001 SmallVector<LSBaseSDNode*, 8> AliasLoadNodes;
8003 // Save the StoreSDNodes that we find in the chain.
8004 SmallVector<MemOpLink, 8> StoreNodes;
8006 // Walk up the chain and look for nodes with offsets from the same
8007 // base pointer. Stop when reaching an instruction with a different kind
8008 // or instruction which has a different base pointer.
8010 StoreSDNode *Index = St;
8012 // If the chain has more than one use, then we can't reorder the mem ops.
8013 if (Index != St && !SDValue(Index, 1)->hasOneUse())
8016 // Find the base pointer and offset for this memory node.
8017 BaseIndexOffset Ptr = BaseIndexOffset::match(Index->getBasePtr());
8019 // Check that the base pointer is the same as the original one.
8020 if (!Ptr.equalBaseIndex(BasePtr))
8023 // Check that the alignment is the same.
8024 if (Index->getAlignment() != St->getAlignment())
8027 // The memory operands must not be volatile.
8028 if (Index->isVolatile() || Index->isIndexed())
8032 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
8033 if (St->isTruncatingStore())
8036 // The stored memory type must be the same.
8037 if (Index->getMemoryVT() != MemVT)
8040 // We do not allow unaligned stores because we want to prevent overriding
8042 if (Index->getAlignment()*8 != MemVT.getSizeInBits())
8045 // We found a potential memory operand to merge.
8046 StoreNodes.push_back(MemOpLink(Index, Ptr.Offset, Seq++));
8048 // Find the next memory operand in the chain. If the next operand in the
8049 // chain is a store then move up and continue the scan with the next
8050 // memory operand. If the next operand is a load save it and use alias
8051 // information to check if it interferes with anything.
8052 SDNode *NextInChain = Index->getChain().getNode();
8054 if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
8055 // We found a store node. Use it for the next iteration.
8058 } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
8059 // Save the load node for later. Continue the scan.
8060 AliasLoadNodes.push_back(Ldn);
8061 NextInChain = Ldn->getChain().getNode();
8070 // Check if there is anything to merge.
8071 if (StoreNodes.size() < 2)
8074 // Sort the memory operands according to their distance from the base pointer.
8075 std::sort(StoreNodes.begin(), StoreNodes.end(),
8076 ConsecutiveMemoryChainSorter());
8078 // Scan the memory operations on the chain and find the first non-consecutive
8079 // store memory address.
8080 unsigned LastConsecutiveStore = 0;
8081 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
8082 for (unsigned i = 0, e = StoreNodes.size(); i < e; ++i) {
8084 // Check that the addresses are consecutive starting from the second
8085 // element in the list of stores.
8087 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
8088 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
8093 // Check if this store interferes with any of the loads that we found.
8094 for (unsigned ld = 0, lde = AliasLoadNodes.size(); ld < lde; ++ld)
8095 if (isAlias(AliasLoadNodes[ld], StoreNodes[i].MemNode)) {
8099 // We found a load that alias with this store. Stop the sequence.
8103 // Mark this node as useful.
8104 LastConsecutiveStore = i;
8107 // The node with the lowest store address.
8108 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
8110 // Store the constants into memory as one consecutive store.
8112 unsigned LastLegalType = 0;
8113 unsigned LastLegalVectorType = 0;
8114 bool NonZero = false;
8115 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
8116 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8117 SDValue StoredVal = St->getValue();
8119 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
8120 NonZero |= !C->isNullValue();
8121 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
8122 NonZero |= !C->getConstantFPValue()->isNullValue();
8128 // Find a legal type for the constant store.
8129 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
8130 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8131 if (TLI.isTypeLegal(StoreTy))
8132 LastLegalType = i+1;
8133 // Or check whether a truncstore is legal.
8134 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
8135 TargetLowering::TypePromoteInteger) {
8136 EVT LegalizedStoredValueTy =
8137 TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
8138 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy))
8139 LastLegalType = i+1;
8142 // Find a legal type for the vector store.
8143 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
8144 if (TLI.isTypeLegal(Ty))
8145 LastLegalVectorType = i + 1;
8148 // We only use vectors if the constant is known to be zero and the
8149 // function is not marked with the noimplicitfloat attribute.
8150 if (NonZero || NoVectors)
8151 LastLegalVectorType = 0;
8153 // Check if we found a legal integer type to store.
8154 if (LastLegalType == 0 && LastLegalVectorType == 0)
8157 bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
8158 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
8160 // Make sure we have something to merge.
8164 unsigned EarliestNodeUsed = 0;
8165 for (unsigned i=0; i < NumElem; ++i) {
8166 // Find a chain for the new wide-store operand. Notice that some
8167 // of the store nodes that we found may not be selected for inclusion
8168 // in the wide store. The chain we use needs to be the chain of the
8169 // earliest store node which is *used* and replaced by the wide store.
8170 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
8171 EarliestNodeUsed = i;
8174 // The earliest Node in the DAG.
8175 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
8176 SDLoc DL(StoreNodes[0].MemNode);
8180 // Find a legal type for the vector store.
8181 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
8182 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
8183 StoredVal = DAG.getConstant(0, Ty);
8185 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
8186 APInt StoreInt(StoreBW, 0);
8188 // Construct a single integer constant which is made of the smaller
8190 bool IsLE = TLI.isLittleEndian();
8191 for (unsigned i = 0; i < NumElem ; ++i) {
8192 unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
8193 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
8194 SDValue Val = St->getValue();
8195 StoreInt<<=ElementSizeBytes*8;
8196 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
8197 StoreInt|=C->getAPIntValue().zext(StoreBW);
8198 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
8199 StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
8201 assert(false && "Invalid constant element type");
8205 // Create the new Load and Store operations.
8206 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8207 StoredVal = DAG.getConstant(StoreInt, StoreTy);
8210 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, StoredVal,
8211 FirstInChain->getBasePtr(),
8212 FirstInChain->getPointerInfo(),
8214 FirstInChain->getAlignment());
8216 // Replace the first store with the new store
8217 CombineTo(EarliestOp, NewStore);
8218 // Erase all other stores.
8219 for (unsigned i = 0; i < NumElem ; ++i) {
8220 if (StoreNodes[i].MemNode == EarliestOp)
8222 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8223 // ReplaceAllUsesWith will replace all uses that existed when it was
8224 // called, but graph optimizations may cause new ones to appear. For
8225 // example, the case in pr14333 looks like
8227 // St's chain -> St -> another store -> X
8229 // And the only difference from St to the other store is the chain.
8230 // When we change it's chain to be St's chain they become identical,
8231 // get CSEed and the net result is that X is now a use of St.
8232 // Since we know that St is redundant, just iterate.
8233 while (!St->use_empty())
8234 DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
8235 removeFromWorkList(St);
8242 // Below we handle the case of multiple consecutive stores that
8243 // come from multiple consecutive loads. We merge them into a single
8244 // wide load and a single wide store.
8246 // Look for load nodes which are used by the stored values.
8247 SmallVector<MemOpLink, 8> LoadNodes;
8249 // Find acceptable loads. Loads need to have the same chain (token factor),
8250 // must not be zext, volatile, indexed, and they must be consecutive.
8251 BaseIndexOffset LdBasePtr;
8252 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
8253 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8254 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
8257 // Loads must only have one use.
8258 if (!Ld->hasNUsesOfValue(1, 0))
8261 // Check that the alignment is the same as the stores.
8262 if (Ld->getAlignment() != St->getAlignment())
8265 // The memory operands must not be volatile.
8266 if (Ld->isVolatile() || Ld->isIndexed())
8269 // We do not accept ext loads.
8270 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
8273 // The stored memory type must be the same.
8274 if (Ld->getMemoryVT() != MemVT)
8277 BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld->getBasePtr());
8278 // If this is not the first ptr that we check.
8279 if (LdBasePtr.Base.getNode()) {
8280 // The base ptr must be the same.
8281 if (!LdPtr.equalBaseIndex(LdBasePtr))
8284 // Check that all other base pointers are the same as this one.
8288 // We found a potential memory operand to merge.
8289 LoadNodes.push_back(MemOpLink(Ld, LdPtr.Offset, 0));
8292 if (LoadNodes.size() < 2)
8295 // Scan the memory operations on the chain and find the first non-consecutive
8296 // load memory address. These variables hold the index in the store node
8298 unsigned LastConsecutiveLoad = 0;
8299 // This variable refers to the size and not index in the array.
8300 unsigned LastLegalVectorType = 0;
8301 unsigned LastLegalIntegerType = 0;
8302 StartAddress = LoadNodes[0].OffsetFromBase;
8303 SDValue FirstChain = LoadNodes[0].MemNode->getChain();
8304 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
8305 // All loads much share the same chain.
8306 if (LoadNodes[i].MemNode->getChain() != FirstChain)
8309 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
8310 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
8312 LastConsecutiveLoad = i;
8314 // Find a legal type for the vector store.
8315 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
8316 if (TLI.isTypeLegal(StoreTy))
8317 LastLegalVectorType = i + 1;
8319 // Find a legal type for the integer store.
8320 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
8321 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8322 if (TLI.isTypeLegal(StoreTy))
8323 LastLegalIntegerType = i + 1;
8324 // Or check whether a truncstore and extload is legal.
8325 else if (TLI.getTypeAction(*DAG.getContext(), StoreTy) ==
8326 TargetLowering::TypePromoteInteger) {
8327 EVT LegalizedStoredValueTy =
8328 TLI.getTypeToTransformTo(*DAG.getContext(), StoreTy);
8329 if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
8330 TLI.isLoadExtLegal(ISD::ZEXTLOAD, StoreTy) &&
8331 TLI.isLoadExtLegal(ISD::SEXTLOAD, StoreTy) &&
8332 TLI.isLoadExtLegal(ISD::EXTLOAD, StoreTy))
8333 LastLegalIntegerType = i+1;
8337 // Only use vector types if the vector type is larger than the integer type.
8338 // If they are the same, use integers.
8339 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
8340 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
8342 // We add +1 here because the LastXXX variables refer to location while
8343 // the NumElem refers to array/index size.
8344 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
8345 NumElem = std::min(LastLegalType, NumElem);
8350 // The earliest Node in the DAG.
8351 unsigned EarliestNodeUsed = 0;
8352 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
8353 for (unsigned i=1; i<NumElem; ++i) {
8354 // Find a chain for the new wide-store operand. Notice that some
8355 // of the store nodes that we found may not be selected for inclusion
8356 // in the wide store. The chain we use needs to be the chain of the
8357 // earliest store node which is *used* and replaced by the wide store.
8358 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
8359 EarliestNodeUsed = i;
8362 // Find if it is better to use vectors or integers to load and store
8366 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
8368 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
8369 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
8372 SDLoc LoadDL(LoadNodes[0].MemNode);
8373 SDLoc StoreDL(StoreNodes[0].MemNode);
8375 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
8376 SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
8377 FirstLoad->getChain(),
8378 FirstLoad->getBasePtr(),
8379 FirstLoad->getPointerInfo(),
8380 false, false, false,
8381 FirstLoad->getAlignment());
8383 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
8384 FirstInChain->getBasePtr(),
8385 FirstInChain->getPointerInfo(), false, false,
8386 FirstInChain->getAlignment());
8388 // Replace one of the loads with the new load.
8389 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
8390 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
8391 SDValue(NewLoad.getNode(), 1));
8393 // Remove the rest of the load chains.
8394 for (unsigned i = 1; i < NumElem ; ++i) {
8395 // Replace all chain users of the old load nodes with the chain of the new
8397 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
8398 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
8401 // Replace the first store with the new store.
8402 CombineTo(EarliestOp, NewStore);
8403 // Erase all other stores.
8404 for (unsigned i = 0; i < NumElem ; ++i) {
8405 // Remove all Store nodes.
8406 if (StoreNodes[i].MemNode == EarliestOp)
8408 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
8409 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
8410 removeFromWorkList(St);
8417 SDValue DAGCombiner::visitSTORE(SDNode *N) {
8418 StoreSDNode *ST = cast<StoreSDNode>(N);
8419 SDValue Chain = ST->getChain();
8420 SDValue Value = ST->getValue();
8421 SDValue Ptr = ST->getBasePtr();
8423 // If this is a store of a bit convert, store the input value if the
8424 // resultant store does not need a higher alignment than the original.
8425 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
8426 ST->isUnindexed()) {
8427 unsigned OrigAlign = ST->getAlignment();
8428 EVT SVT = Value.getOperand(0).getValueType();
8429 unsigned Align = TLI.getDataLayout()->
8430 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
8431 if (Align <= OrigAlign &&
8432 ((!LegalOperations && !ST->isVolatile()) ||
8433 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
8434 return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0),
8435 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8436 ST->isNonTemporal(), OrigAlign);
8439 // Turn 'store undef, Ptr' -> nothing.
8440 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
8443 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
8444 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
8445 // NOTE: If the original store is volatile, this transform must not increase
8446 // the number of stores. For example, on x86-32 an f64 can be stored in one
8447 // processor operation but an i64 (which is not legal) requires two. So the
8448 // transform should not be done in this case.
8449 if (Value.getOpcode() != ISD::TargetConstantFP) {
8451 switch (CFP->getSimpleValueType(0).SimpleTy) {
8452 default: llvm_unreachable("Unknown FP type");
8453 case MVT::f16: // We don't do this for these yet.
8459 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
8460 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
8461 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
8462 bitcastToAPInt().getZExtValue(), MVT::i32);
8463 return DAG.getStore(Chain, SDLoc(N), Tmp,
8464 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8465 ST->isNonTemporal(), ST->getAlignment());
8469 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
8470 !ST->isVolatile()) ||
8471 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
8472 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
8473 getZExtValue(), MVT::i64);
8474 return DAG.getStore(Chain, SDLoc(N), Tmp,
8475 Ptr, ST->getPointerInfo(), ST->isVolatile(),
8476 ST->isNonTemporal(), ST->getAlignment());
8479 if (!ST->isVolatile() &&
8480 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
8481 // Many FP stores are not made apparent until after legalize, e.g. for
8482 // argument passing. Since this is so common, custom legalize the
8483 // 64-bit integer store into two 32-bit stores.
8484 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
8485 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
8486 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
8487 if (TLI.isBigEndian()) std::swap(Lo, Hi);
8489 unsigned Alignment = ST->getAlignment();
8490 bool isVolatile = ST->isVolatile();
8491 bool isNonTemporal = ST->isNonTemporal();
8493 SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
8494 Ptr, ST->getPointerInfo(),
8495 isVolatile, isNonTemporal,
8496 ST->getAlignment());
8497 Ptr = DAG.getNode(ISD::ADD, SDLoc(N), Ptr.getValueType(), Ptr,
8498 DAG.getConstant(4, Ptr.getValueType()));
8499 Alignment = MinAlign(Alignment, 4U);
8500 SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
8501 Ptr, ST->getPointerInfo().getWithOffset(4),
8502 isVolatile, isNonTemporal,
8504 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
8513 // Try to infer better alignment information than the store already has.
8514 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
8515 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
8516 if (Align > ST->getAlignment())
8517 return DAG.getTruncStore(Chain, SDLoc(N), Value,
8518 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8519 ST->isVolatile(), ST->isNonTemporal(), Align);
8523 // Try transforming a pair floating point load / store ops to integer
8524 // load / store ops.
8525 SDValue NewST = TransformFPLoadStorePair(N);
8526 if (NewST.getNode())
8529 bool UseAA = CombinerAA.getNumOccurrences() > 0 ? CombinerAA :
8530 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
8532 // Walk up chain skipping non-aliasing memory nodes.
8533 SDValue BetterChain = FindBetterChain(N, Chain);
8535 // If there is a better chain.
8536 if (Chain != BetterChain) {
8539 // Replace the chain to avoid dependency.
8540 if (ST->isTruncatingStore()) {
8541 ReplStore = DAG.getTruncStore(BetterChain, SDLoc(N), Value, Ptr,
8542 ST->getPointerInfo(),
8543 ST->getMemoryVT(), ST->isVolatile(),
8544 ST->isNonTemporal(), ST->getAlignment());
8546 ReplStore = DAG.getStore(BetterChain, SDLoc(N), Value, Ptr,
8547 ST->getPointerInfo(),
8548 ST->isVolatile(), ST->isNonTemporal(),
8549 ST->getAlignment());
8552 // Create token to keep both nodes around.
8553 SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
8554 MVT::Other, Chain, ReplStore);
8556 // Make sure the new and old chains are cleaned up.
8557 AddToWorkList(Token.getNode());
8559 // Don't add users to work list.
8560 return CombineTo(N, Token, false);
8564 // Try transforming N to an indexed store.
8565 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
8566 return SDValue(N, 0);
8568 // FIXME: is there such a thing as a truncating indexed store?
8569 if (ST->isTruncatingStore() && ST->isUnindexed() &&
8570 Value.getValueType().isInteger()) {
8571 // See if we can simplify the input to this truncstore with knowledge that
8572 // only the low bits are being used. For example:
8573 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
8575 GetDemandedBits(Value,
8576 APInt::getLowBitsSet(
8577 Value.getValueType().getScalarType().getSizeInBits(),
8578 ST->getMemoryVT().getScalarType().getSizeInBits()));
8579 AddToWorkList(Value.getNode());
8580 if (Shorter.getNode())
8581 return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
8582 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8583 ST->isVolatile(), ST->isNonTemporal(),
8584 ST->getAlignment());
8586 // Otherwise, see if we can simplify the operation with
8587 // SimplifyDemandedBits, which only works if the value has a single use.
8588 if (SimplifyDemandedBits(Value,
8589 APInt::getLowBitsSet(
8590 Value.getValueType().getScalarType().getSizeInBits(),
8591 ST->getMemoryVT().getScalarType().getSizeInBits())))
8592 return SDValue(N, 0);
8595 // If this is a load followed by a store to the same location, then the store
8597 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
8598 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
8599 ST->isUnindexed() && !ST->isVolatile() &&
8600 // There can't be any side effects between the load and store, such as
8602 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
8603 // The store is dead, remove it.
8608 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
8609 // truncating store. We can do this even if this is already a truncstore.
8610 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
8611 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
8612 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
8613 ST->getMemoryVT())) {
8614 return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
8615 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8616 ST->isVolatile(), ST->isNonTemporal(),
8617 ST->getAlignment());
8620 // Only perform this optimization before the types are legal, because we
8621 // don't want to perform this optimization on every DAGCombine invocation.
8623 bool EverChanged = false;
8626 // There can be multiple store sequences on the same chain.
8627 // Keep trying to merge store sequences until we are unable to do so
8628 // or until we merge the last store on the chain.
8629 bool Changed = MergeConsecutiveStores(ST);
8630 EverChanged |= Changed;
8631 if (!Changed) break;
8632 } while (ST->getOpcode() != ISD::DELETED_NODE);
8635 return SDValue(N, 0);
8638 return ReduceLoadOpStoreWidth(N);
8641 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
8642 SDValue InVec = N->getOperand(0);
8643 SDValue InVal = N->getOperand(1);
8644 SDValue EltNo = N->getOperand(2);
8647 // If the inserted element is an UNDEF, just use the input vector.
8648 if (InVal.getOpcode() == ISD::UNDEF)
8651 EVT VT = InVec.getValueType();
8653 // If we can't generate a legal BUILD_VECTOR, exit
8654 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
8657 // Check that we know which element is being inserted
8658 if (!isa<ConstantSDNode>(EltNo))
8660 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8662 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
8663 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
8665 SmallVector<SDValue, 8> Ops;
8666 // Do not combine these two vectors if the output vector will not replace
8667 // the input vector.
8668 if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
8669 Ops.append(InVec.getNode()->op_begin(),
8670 InVec.getNode()->op_end());
8671 } else if (InVec.getOpcode() == ISD::UNDEF) {
8672 unsigned NElts = VT.getVectorNumElements();
8673 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
8678 // Insert the element
8679 if (Elt < Ops.size()) {
8680 // All the operands of BUILD_VECTOR must have the same type;
8681 // we enforce that here.
8682 EVT OpVT = Ops[0].getValueType();
8683 if (InVal.getValueType() != OpVT)
8684 InVal = OpVT.bitsGT(InVal.getValueType()) ?
8685 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
8686 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
8690 // Return the new vector
8691 return DAG.getNode(ISD::BUILD_VECTOR, dl,
8692 VT, &Ops[0], Ops.size());
8695 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
8696 // (vextract (scalar_to_vector val, 0) -> val
8697 SDValue InVec = N->getOperand(0);
8698 EVT VT = InVec.getValueType();
8699 EVT NVT = N->getValueType(0);
8701 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
8702 // Check if the result type doesn't match the inserted element type. A
8703 // SCALAR_TO_VECTOR may truncate the inserted element and the
8704 // EXTRACT_VECTOR_ELT may widen the extracted vector.
8705 SDValue InOp = InVec.getOperand(0);
8706 if (InOp.getValueType() != NVT) {
8707 assert(InOp.getValueType().isInteger() && NVT.isInteger());
8708 return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
8713 SDValue EltNo = N->getOperand(1);
8714 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
8716 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
8717 // We only perform this optimization before the op legalization phase because
8718 // we may introduce new vector instructions which are not backed by TD
8719 // patterns. For example on AVX, extracting elements from a wide vector
8720 // without using extract_subvector.
8721 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
8722 && ConstEltNo && !LegalOperations) {
8723 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8724 int NumElem = VT.getVectorNumElements();
8725 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
8726 // Find the new index to extract from.
8727 int OrigElt = SVOp->getMaskElt(Elt);
8729 // Extracting an undef index is undef.
8731 return DAG.getUNDEF(NVT);
8733 // Select the right vector half to extract from.
8734 if (OrigElt < NumElem) {
8735 InVec = InVec->getOperand(0);
8737 InVec = InVec->getOperand(1);
8741 EVT IndexTy = TLI.getVectorIdxTy();
8742 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT,
8743 InVec, DAG.getConstant(OrigElt, IndexTy));
8746 // Perform only after legalization to ensure build_vector / vector_shuffle
8747 // optimizations have already been done.
8748 if (!LegalOperations) return SDValue();
8750 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
8751 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
8752 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
8755 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8756 bool NewLoad = false;
8757 bool BCNumEltsChanged = false;
8758 EVT ExtVT = VT.getVectorElementType();
8761 // If the result of load has to be truncated, then it's not necessarily
8763 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
8766 if (InVec.getOpcode() == ISD::BITCAST) {
8767 // Don't duplicate a load with other uses.
8768 if (!InVec.hasOneUse())
8771 EVT BCVT = InVec.getOperand(0).getValueType();
8772 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
8774 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
8775 BCNumEltsChanged = true;
8776 InVec = InVec.getOperand(0);
8777 ExtVT = BCVT.getVectorElementType();
8781 LoadSDNode *LN0 = NULL;
8782 const ShuffleVectorSDNode *SVN = NULL;
8783 if (ISD::isNormalLoad(InVec.getNode())) {
8784 LN0 = cast<LoadSDNode>(InVec);
8785 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
8786 InVec.getOperand(0).getValueType() == ExtVT &&
8787 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
8788 // Don't duplicate a load with other uses.
8789 if (!InVec.hasOneUse())
8792 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
8793 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
8794 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
8796 // (load $addr+1*size)
8798 // Don't duplicate a load with other uses.
8799 if (!InVec.hasOneUse())
8802 // If the bit convert changed the number of elements, it is unsafe
8803 // to examine the mask.
8804 if (BCNumEltsChanged)
8807 // Select the input vector, guarding against out of range extract vector.
8808 unsigned NumElems = VT.getVectorNumElements();
8809 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
8810 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
8812 if (InVec.getOpcode() == ISD::BITCAST) {
8813 // Don't duplicate a load with other uses.
8814 if (!InVec.hasOneUse())
8817 InVec = InVec.getOperand(0);
8819 if (ISD::isNormalLoad(InVec.getNode())) {
8820 LN0 = cast<LoadSDNode>(InVec);
8821 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
8825 // Make sure we found a non-volatile load and the extractelement is
8827 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
8830 // If Idx was -1 above, Elt is going to be -1, so just return undef.
8832 return DAG.getUNDEF(LVT);
8834 unsigned Align = LN0->getAlignment();
8836 // Check the resultant load doesn't need a higher alignment than the
8840 ->getABITypeAlignment(LVT.getTypeForEVT(*DAG.getContext()));
8842 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
8848 SDValue NewPtr = LN0->getBasePtr();
8849 unsigned PtrOff = 0;
8852 PtrOff = LVT.getSizeInBits() * Elt / 8;
8853 EVT PtrType = NewPtr.getValueType();
8854 if (TLI.isBigEndian())
8855 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
8856 NewPtr = DAG.getNode(ISD::ADD, SDLoc(N), PtrType, NewPtr,
8857 DAG.getConstant(PtrOff, PtrType));
8860 // The replacement we need to do here is a little tricky: we need to
8861 // replace an extractelement of a load with a load.
8862 // Use ReplaceAllUsesOfValuesWith to do the replacement.
8863 // Note that this replacement assumes that the extractvalue is the only
8864 // use of the load; that's okay because we don't want to perform this
8865 // transformation in other cases anyway.
8868 if (NVT.bitsGT(LVT)) {
8869 // If the result type of vextract is wider than the load, then issue an
8870 // extending load instead.
8871 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, LVT)
8872 ? ISD::ZEXTLOAD : ISD::EXTLOAD;
8873 Load = DAG.getExtLoad(ExtType, SDLoc(N), NVT, LN0->getChain(),
8874 NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
8875 LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
8876 Chain = Load.getValue(1);
8878 Load = DAG.getLoad(LVT, SDLoc(N), LN0->getChain(), NewPtr,
8879 LN0->getPointerInfo().getWithOffset(PtrOff),
8880 LN0->isVolatile(), LN0->isNonTemporal(),
8881 LN0->isInvariant(), Align);
8882 Chain = Load.getValue(1);
8883 if (NVT.bitsLT(LVT))
8884 Load = DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, Load);
8886 Load = DAG.getNode(ISD::BITCAST, SDLoc(N), NVT, Load);
8888 WorkListRemover DeadNodes(*this);
8889 SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
8890 SDValue To[] = { Load, Chain };
8891 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
8892 // Since we're explcitly calling ReplaceAllUses, add the new node to the
8893 // worklist explicitly as well.
8894 AddToWorkList(Load.getNode());
8895 AddUsersToWorkList(Load.getNode()); // Add users too
8896 // Make sure to revisit this node to clean it up; it will usually be dead.
8898 return SDValue(N, 0);
8904 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
8905 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
8906 // We perform this optimization post type-legalization because
8907 // the type-legalizer often scalarizes integer-promoted vectors.
8908 // Performing this optimization before may create bit-casts which
8909 // will be type-legalized to complex code sequences.
8910 // We perform this optimization only before the operation legalizer because we
8911 // may introduce illegal operations.
8912 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
8915 unsigned NumInScalars = N->getNumOperands();
8917 EVT VT = N->getValueType(0);
8919 // Check to see if this is a BUILD_VECTOR of a bunch of values
8920 // which come from any_extend or zero_extend nodes. If so, we can create
8921 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
8922 // optimizations. We do not handle sign-extend because we can't fill the sign
8924 EVT SourceType = MVT::Other;
8925 bool AllAnyExt = true;
8927 for (unsigned i = 0; i != NumInScalars; ++i) {
8928 SDValue In = N->getOperand(i);
8929 // Ignore undef inputs.
8930 if (In.getOpcode() == ISD::UNDEF) continue;
8932 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
8933 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
8935 // Abort if the element is not an extension.
8936 if (!ZeroExt && !AnyExt) {
8937 SourceType = MVT::Other;
8941 // The input is a ZeroExt or AnyExt. Check the original type.
8942 EVT InTy = In.getOperand(0).getValueType();
8944 // Check that all of the widened source types are the same.
8945 if (SourceType == MVT::Other)
8948 else if (InTy != SourceType) {
8949 // Multiple income types. Abort.
8950 SourceType = MVT::Other;
8954 // Check if all of the extends are ANY_EXTENDs.
8955 AllAnyExt &= AnyExt;
8958 // In order to have valid types, all of the inputs must be extended from the
8959 // same source type and all of the inputs must be any or zero extend.
8960 // Scalar sizes must be a power of two.
8961 EVT OutScalarTy = VT.getScalarType();
8962 bool ValidTypes = SourceType != MVT::Other &&
8963 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
8964 isPowerOf2_32(SourceType.getSizeInBits());
8966 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
8967 // turn into a single shuffle instruction.
8971 bool isLE = TLI.isLittleEndian();
8972 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
8973 assert(ElemRatio > 1 && "Invalid element size ratio");
8974 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
8975 DAG.getConstant(0, SourceType);
8977 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
8978 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
8980 // Populate the new build_vector
8981 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
8982 SDValue Cast = N->getOperand(i);
8983 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
8984 Cast.getOpcode() == ISD::ZERO_EXTEND ||
8985 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
8987 if (Cast.getOpcode() == ISD::UNDEF)
8988 In = DAG.getUNDEF(SourceType);
8990 In = Cast->getOperand(0);
8991 unsigned Index = isLE ? (i * ElemRatio) :
8992 (i * ElemRatio + (ElemRatio - 1));
8994 assert(Index < Ops.size() && "Invalid index");
8998 // The type of the new BUILD_VECTOR node.
8999 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
9000 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
9001 "Invalid vector size");
9002 // Check if the new vector type is legal.
9003 if (!isTypeLegal(VecVT)) return SDValue();
9005 // Make the new BUILD_VECTOR.
9006 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, &Ops[0], Ops.size());
9008 // The new BUILD_VECTOR node has the potential to be further optimized.
9009 AddToWorkList(BV.getNode());
9010 // Bitcast to the desired type.
9011 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
9014 SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
9015 EVT VT = N->getValueType(0);
9017 unsigned NumInScalars = N->getNumOperands();
9020 EVT SrcVT = MVT::Other;
9021 unsigned Opcode = ISD::DELETED_NODE;
9022 unsigned NumDefs = 0;
9024 for (unsigned i = 0; i != NumInScalars; ++i) {
9025 SDValue In = N->getOperand(i);
9026 unsigned Opc = In.getOpcode();
9028 if (Opc == ISD::UNDEF)
9031 // If all scalar values are floats and converted from integers.
9032 if (Opcode == ISD::DELETED_NODE &&
9033 (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
9040 EVT InVT = In.getOperand(0).getValueType();
9042 // If all scalar values are typed differently, bail out. It's chosen to
9043 // simplify BUILD_VECTOR of integer types.
9044 if (SrcVT == MVT::Other)
9051 // If the vector has just one element defined, it's not worth to fold it into
9052 // a vectorized one.
9056 assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)
9057 && "Should only handle conversion from integer to float.");
9058 assert(SrcVT != MVT::Other && "Cannot determine source type!");
9060 EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);
9062 if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
9065 SmallVector<SDValue, 8> Opnds;
9066 for (unsigned i = 0; i != NumInScalars; ++i) {
9067 SDValue In = N->getOperand(i);
9069 if (In.getOpcode() == ISD::UNDEF)
9070 Opnds.push_back(DAG.getUNDEF(SrcVT));
9072 Opnds.push_back(In.getOperand(0));
9074 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
9075 &Opnds[0], Opnds.size());
9076 AddToWorkList(BV.getNode());
9078 return DAG.getNode(Opcode, dl, VT, BV);
9081 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
9082 unsigned NumInScalars = N->getNumOperands();
9084 EVT VT = N->getValueType(0);
9086 // A vector built entirely of undefs is undef.
9087 if (ISD::allOperandsUndef(N))
9088 return DAG.getUNDEF(VT);
9090 SDValue V = reduceBuildVecExtToExtBuildVec(N);
9094 V = reduceBuildVecConvertToConvertBuildVec(N);
9098 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
9099 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
9100 // at most two distinct vectors, turn this into a shuffle node.
9102 // May only combine to shuffle after legalize if shuffle is legal.
9103 if (LegalOperations &&
9104 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
9107 SDValue VecIn1, VecIn2;
9108 for (unsigned i = 0; i != NumInScalars; ++i) {
9109 // Ignore undef inputs.
9110 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
9112 // If this input is something other than a EXTRACT_VECTOR_ELT with a
9113 // constant index, bail out.
9114 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
9115 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
9116 VecIn1 = VecIn2 = SDValue(0, 0);
9120 // We allow up to two distinct input vectors.
9121 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
9122 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
9125 if (VecIn1.getNode() == 0) {
9126 VecIn1 = ExtractedFromVec;
9127 } else if (VecIn2.getNode() == 0) {
9128 VecIn2 = ExtractedFromVec;
9131 VecIn1 = VecIn2 = SDValue(0, 0);
9136 // If everything is good, we can make a shuffle operation.
9137 if (VecIn1.getNode()) {
9138 SmallVector<int, 8> Mask;
9139 for (unsigned i = 0; i != NumInScalars; ++i) {
9140 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
9145 // If extracting from the first vector, just use the index directly.
9146 SDValue Extract = N->getOperand(i);
9147 SDValue ExtVal = Extract.getOperand(1);
9148 if (Extract.getOperand(0) == VecIn1) {
9149 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
9150 if (ExtIndex > VT.getVectorNumElements())
9153 Mask.push_back(ExtIndex);
9157 // Otherwise, use InIdx + VecSize
9158 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
9159 Mask.push_back(Idx+NumInScalars);
9162 // We can't generate a shuffle node with mismatched input and output types.
9163 // Attempt to transform a single input vector to the correct type.
9164 if ((VT != VecIn1.getValueType())) {
9165 // We don't support shuffeling between TWO values of different types.
9166 if (VecIn2.getNode() != 0)
9169 // We only support widening of vectors which are half the size of the
9170 // output registers. For example XMM->YMM widening on X86 with AVX.
9171 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
9174 // If the input vector type has a different base type to the output
9175 // vector type, bail out.
9176 if (VecIn1.getValueType().getVectorElementType() !=
9177 VT.getVectorElementType())
9180 // Widen the input vector by adding undef values.
9181 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
9182 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
9185 // If VecIn2 is unused then change it to undef.
9186 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
9188 // Check that we were able to transform all incoming values to the same
9190 if (VecIn2.getValueType() != VecIn1.getValueType() ||
9191 VecIn1.getValueType() != VT)
9194 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
9195 if (!isTypeLegal(VT))
9198 // Return the new VECTOR_SHUFFLE node.
9202 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
9208 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
9209 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
9210 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
9211 // inputs come from at most two distinct vectors, turn this into a shuffle
9214 // If we only have one input vector, we don't need to do any concatenation.
9215 if (N->getNumOperands() == 1)
9216 return N->getOperand(0);
9218 // Check if all of the operands are undefs.
9219 if (ISD::allOperandsUndef(N))
9220 return DAG.getUNDEF(N->getValueType(0));
9222 // Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
9223 // nodes often generate nop CONCAT_VECTOR nodes.
9224 // Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
9225 // place the incoming vectors at the exact same location.
9226 SDValue SingleSource = SDValue();
9227 unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();
9229 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
9230 SDValue Op = N->getOperand(i);
9232 if (Op.getOpcode() == ISD::UNDEF)
9235 // Check if this is the identity extract:
9236 if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
9239 // Find the single incoming vector for the extract_subvector.
9240 if (SingleSource.getNode()) {
9241 if (Op.getOperand(0) != SingleSource)
9244 SingleSource = Op.getOperand(0);
9246 // Check the source type is the same as the type of the result.
9247 // If not, this concat may extend the vector, so we can not
9248 // optimize it away.
9249 if (SingleSource.getValueType() != N->getValueType(0))
9253 unsigned IdentityIndex = i * PartNumElem;
9254 ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
9255 // The extract index must be constant.
9259 // Check that we are reading from the identity index.
9260 if (CS->getZExtValue() != IdentityIndex)
9264 if (SingleSource.getNode())
9265 return SingleSource;
9270 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
9271 EVT NVT = N->getValueType(0);
9272 SDValue V = N->getOperand(0);
9274 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
9276 // (extract_subvec (concat V1, V2, ...), i)
9279 // Only operand 0 is checked as 'concat' assumes all inputs of the same type.
9280 if (V->getOperand(0).getValueType() != NVT)
9282 unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
9283 unsigned NumElems = NVT.getVectorNumElements();
9284 assert((Idx % NumElems) == 0 &&
9285 "IDX in concat is not a multiple of the result vector length.");
9286 return V->getOperand(Idx / NumElems);
9290 if (V->getOpcode() == ISD::BITCAST)
9291 V = V.getOperand(0);
9293 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
9295 // Handle only simple case where vector being inserted and vector
9296 // being extracted are of same type, and are half size of larger vectors.
9297 EVT BigVT = V->getOperand(0).getValueType();
9298 EVT SmallVT = V->getOperand(1).getValueType();
9299 if (!NVT.bitsEq(SmallVT) || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
9302 // Only handle cases where both indexes are constants with the same type.
9303 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
9304 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
9306 if (InsIdx && ExtIdx &&
9307 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
9308 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
9310 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
9312 // indices are equal or bit offsets are equal => V1
9313 // otherwise => (extract_subvec V1, ExtIdx)
9314 if (InsIdx->getZExtValue() * SmallVT.getScalarType().getSizeInBits() ==
9315 ExtIdx->getZExtValue() * NVT.getScalarType().getSizeInBits())
9316 return DAG.getNode(ISD::BITCAST, dl, NVT, V->getOperand(1));
9317 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT,
9318 DAG.getNode(ISD::BITCAST, dl,
9319 N->getOperand(0).getValueType(),
9320 V->getOperand(0)), N->getOperand(1));
9327 // Tries to turn a shuffle of two CONCAT_VECTORS into a single concat.
9328 static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
9329 EVT VT = N->getValueType(0);
9330 unsigned NumElts = VT.getVectorNumElements();
9332 SDValue N0 = N->getOperand(0);
9333 SDValue N1 = N->getOperand(1);
9334 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
9336 SmallVector<SDValue, 4> Ops;
9337 EVT ConcatVT = N0.getOperand(0).getValueType();
9338 unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
9339 unsigned NumConcats = NumElts / NumElemsPerConcat;
9341 // Look at every vector that's inserted. We're looking for exact
9342 // subvector-sized copies from a concatenated vector
9343 for (unsigned I = 0; I != NumConcats; ++I) {
9344 // Make sure we're dealing with a copy.
9345 unsigned Begin = I * NumElemsPerConcat;
9346 bool AllUndef = true, NoUndef = true;
9347 for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
9348 if (SVN->getMaskElt(J) >= 0)
9355 if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
9358 for (unsigned J = 1; J != NumElemsPerConcat; ++J)
9359 if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
9362 unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
9363 if (FirstElt < N0.getNumOperands())
9364 Ops.push_back(N0.getOperand(FirstElt));
9366 Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));
9368 } else if (AllUndef) {
9369 Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
9370 } else { // Mixed with general masks and undefs, can't do optimization.
9375 return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops.data(),
9379 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
9380 EVT VT = N->getValueType(0);
9381 unsigned NumElts = VT.getVectorNumElements();
9383 SDValue N0 = N->getOperand(0);
9384 SDValue N1 = N->getOperand(1);
9386 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
9388 // Canonicalize shuffle undef, undef -> undef
9389 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
9390 return DAG.getUNDEF(VT);
9392 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
9394 // Canonicalize shuffle v, v -> v, undef
9396 SmallVector<int, 8> NewMask;
9397 for (unsigned i = 0; i != NumElts; ++i) {
9398 int Idx = SVN->getMaskElt(i);
9399 if (Idx >= (int)NumElts) Idx -= NumElts;
9400 NewMask.push_back(Idx);
9402 return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT),
9406 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
9407 if (N0.getOpcode() == ISD::UNDEF) {
9408 SmallVector<int, 8> NewMask;
9409 for (unsigned i = 0; i != NumElts; ++i) {
9410 int Idx = SVN->getMaskElt(i);
9412 if (Idx >= (int)NumElts)
9415 Idx = -1; // remove reference to lhs
9417 NewMask.push_back(Idx);
9419 return DAG.getVectorShuffle(VT, SDLoc(N), N1, DAG.getUNDEF(VT),
9423 // Remove references to rhs if it is undef
9424 if (N1.getOpcode() == ISD::UNDEF) {
9425 bool Changed = false;
9426 SmallVector<int, 8> NewMask;
9427 for (unsigned i = 0; i != NumElts; ++i) {
9428 int Idx = SVN->getMaskElt(i);
9429 if (Idx >= (int)NumElts) {
9433 NewMask.push_back(Idx);
9436 return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, &NewMask[0]);
9439 // If it is a splat, check if the argument vector is another splat or a
9440 // build_vector with all scalar elements the same.
9441 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
9442 SDNode *V = N0.getNode();
9444 // If this is a bit convert that changes the element type of the vector but
9445 // not the number of vector elements, look through it. Be careful not to
9446 // look though conversions that change things like v4f32 to v2f64.
9447 if (V->getOpcode() == ISD::BITCAST) {
9448 SDValue ConvInput = V->getOperand(0);
9449 if (ConvInput.getValueType().isVector() &&
9450 ConvInput.getValueType().getVectorNumElements() == NumElts)
9451 V = ConvInput.getNode();
9454 if (V->getOpcode() == ISD::BUILD_VECTOR) {
9455 assert(V->getNumOperands() == NumElts &&
9456 "BUILD_VECTOR has wrong number of operands");
9458 bool AllSame = true;
9459 for (unsigned i = 0; i != NumElts; ++i) {
9460 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
9461 Base = V->getOperand(i);
9465 // Splat of <u, u, u, u>, return <u, u, u, u>
9466 if (!Base.getNode())
9468 for (unsigned i = 0; i != NumElts; ++i) {
9469 if (V->getOperand(i) != Base) {
9474 // Splat of <x, x, x, x>, return <x, x, x, x>
9480 if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
9481 Level < AfterLegalizeVectorOps &&
9482 (N1.getOpcode() == ISD::UNDEF ||
9483 (N1.getOpcode() == ISD::CONCAT_VECTORS &&
9484 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
9485 SDValue V = partitionShuffleOfConcats(N, DAG);
9491 // If this shuffle node is simply a swizzle of another shuffle node,
9492 // and it reverses the swizzle of the previous shuffle then we can
9493 // optimize shuffle(shuffle(x, undef), undef) -> x.
9494 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
9495 N1.getOpcode() == ISD::UNDEF) {
9497 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
9499 // Shuffle nodes can only reverse shuffles with a single non-undef value.
9500 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
9503 // The incoming shuffle must be of the same type as the result of the
9505 assert(OtherSV->getOperand(0).getValueType() == VT &&
9506 "Shuffle types don't match");
9508 for (unsigned i = 0; i != NumElts; ++i) {
9509 int Idx = SVN->getMaskElt(i);
9510 assert(Idx < (int)NumElts && "Index references undef operand");
9511 // Next, this index comes from the first value, which is the incoming
9512 // shuffle. Adopt the incoming index.
9514 Idx = OtherSV->getMaskElt(Idx);
9516 // The combined shuffle must map each index to itself.
9517 if (Idx >= 0 && (unsigned)Idx != i)
9521 return OtherSV->getOperand(0);
9527 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
9528 /// an AND to a vector_shuffle with the destination vector and a zero vector.
9529 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
9530 /// vector_shuffle V, Zero, <0, 4, 2, 4>
9531 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
9532 EVT VT = N->getValueType(0);
9534 SDValue LHS = N->getOperand(0);
9535 SDValue RHS = N->getOperand(1);
9536 if (N->getOpcode() == ISD::AND) {
9537 if (RHS.getOpcode() == ISD::BITCAST)
9538 RHS = RHS.getOperand(0);
9539 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
9540 SmallVector<int, 8> Indices;
9541 unsigned NumElts = RHS.getNumOperands();
9542 for (unsigned i = 0; i != NumElts; ++i) {
9543 SDValue Elt = RHS.getOperand(i);
9544 if (!isa<ConstantSDNode>(Elt))
9547 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
9548 Indices.push_back(i);
9549 else if (cast<ConstantSDNode>(Elt)->isNullValue())
9550 Indices.push_back(NumElts);
9555 // Let's see if the target supports this vector_shuffle.
9556 EVT RVT = RHS.getValueType();
9557 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
9560 // Return the new VECTOR_SHUFFLE node.
9561 EVT EltVT = RVT.getVectorElementType();
9562 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
9563 DAG.getConstant(0, EltVT));
9564 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9565 RVT, &ZeroOps[0], ZeroOps.size());
9566 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
9567 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
9568 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
9575 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
9576 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
9577 assert(N->getValueType(0).isVector() &&
9578 "SimplifyVBinOp only works on vectors!");
9580 SDValue LHS = N->getOperand(0);
9581 SDValue RHS = N->getOperand(1);
9582 SDValue Shuffle = XformToShuffleWithZero(N);
9583 if (Shuffle.getNode()) return Shuffle;
9585 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
9587 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
9588 RHS.getOpcode() == ISD::BUILD_VECTOR) {
9589 SmallVector<SDValue, 8> Ops;
9590 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
9591 SDValue LHSOp = LHS.getOperand(i);
9592 SDValue RHSOp = RHS.getOperand(i);
9593 // If these two elements can't be folded, bail out.
9594 if ((LHSOp.getOpcode() != ISD::UNDEF &&
9595 LHSOp.getOpcode() != ISD::Constant &&
9596 LHSOp.getOpcode() != ISD::ConstantFP) ||
9597 (RHSOp.getOpcode() != ISD::UNDEF &&
9598 RHSOp.getOpcode() != ISD::Constant &&
9599 RHSOp.getOpcode() != ISD::ConstantFP))
9602 // Can't fold divide by zero.
9603 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
9604 N->getOpcode() == ISD::FDIV) {
9605 if ((RHSOp.getOpcode() == ISD::Constant &&
9606 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
9607 (RHSOp.getOpcode() == ISD::ConstantFP &&
9608 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
9612 EVT VT = LHSOp.getValueType();
9613 EVT RVT = RHSOp.getValueType();
9615 // Integer BUILD_VECTOR operands may have types larger than the element
9616 // size (e.g., when the element type is not legal). Prior to type
9617 // legalization, the types may not match between the two BUILD_VECTORS.
9618 // Truncate one of the operands to make them match.
9619 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
9620 RHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, RHSOp);
9622 LHSOp = DAG.getNode(ISD::TRUNCATE, SDLoc(N), RVT, LHSOp);
9626 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(LHS), VT,
9628 if (FoldOp.getOpcode() != ISD::UNDEF &&
9629 FoldOp.getOpcode() != ISD::Constant &&
9630 FoldOp.getOpcode() != ISD::ConstantFP)
9632 Ops.push_back(FoldOp);
9633 AddToWorkList(FoldOp.getNode());
9636 if (Ops.size() == LHS.getNumOperands())
9637 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9638 LHS.getValueType(), &Ops[0], Ops.size());
9644 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
9645 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
9646 assert(N->getValueType(0).isVector() &&
9647 "SimplifyVUnaryOp only works on vectors!");
9649 SDValue N0 = N->getOperand(0);
9651 if (N0.getOpcode() != ISD::BUILD_VECTOR)
9654 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
9655 SmallVector<SDValue, 8> Ops;
9656 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
9657 SDValue Op = N0.getOperand(i);
9658 if (Op.getOpcode() != ISD::UNDEF &&
9659 Op.getOpcode() != ISD::ConstantFP)
9661 EVT EltVT = Op.getValueType();
9662 SDValue FoldOp = DAG.getNode(N->getOpcode(), SDLoc(N0), EltVT, Op);
9663 if (FoldOp.getOpcode() != ISD::UNDEF &&
9664 FoldOp.getOpcode() != ISD::ConstantFP)
9666 Ops.push_back(FoldOp);
9667 AddToWorkList(FoldOp.getNode());
9670 if (Ops.size() != N0.getNumOperands())
9673 return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N),
9674 N0.getValueType(), &Ops[0], Ops.size());
9677 SDValue DAGCombiner::SimplifySelect(SDLoc DL, SDValue N0,
9678 SDValue N1, SDValue N2){
9679 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
9681 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
9682 cast<CondCodeSDNode>(N0.getOperand(2))->get());
9684 // If we got a simplified select_cc node back from SimplifySelectCC, then
9685 // break it down into a new SETCC node, and a new SELECT node, and then return
9686 // the SELECT node, since we were called with a SELECT node.
9687 if (SCC.getNode()) {
9688 // Check to see if we got a select_cc back (to turn into setcc/select).
9689 // Otherwise, just return whatever node we got back, like fabs.
9690 if (SCC.getOpcode() == ISD::SELECT_CC) {
9691 SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
9693 SCC.getOperand(0), SCC.getOperand(1),
9695 AddToWorkList(SETCC.getNode());
9696 return DAG.getSelect(SDLoc(SCC), SCC.getValueType(),
9697 SCC.getOperand(2), SCC.getOperand(3), SETCC);
9705 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
9706 /// are the two values being selected between, see if we can simplify the
9707 /// select. Callers of this should assume that TheSelect is deleted if this
9708 /// returns true. As such, they should return the appropriate thing (e.g. the
9709 /// node) back to the top-level of the DAG combiner loop to avoid it being
9711 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
9714 // Cannot simplify select with vector condition
9715 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
9717 // If this is a select from two identical things, try to pull the operation
9718 // through the select.
9719 if (LHS.getOpcode() != RHS.getOpcode() ||
9720 !LHS.hasOneUse() || !RHS.hasOneUse())
9723 // If this is a load and the token chain is identical, replace the select
9724 // of two loads with a load through a select of the address to load from.
9725 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
9726 // constants have been dropped into the constant pool.
9727 if (LHS.getOpcode() == ISD::LOAD) {
9728 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
9729 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
9731 // Token chains must be identical.
9732 if (LHS.getOperand(0) != RHS.getOperand(0) ||
9733 // Do not let this transformation reduce the number of volatile loads.
9734 LLD->isVolatile() || RLD->isVolatile() ||
9735 // If this is an EXTLOAD, the VT's must match.
9736 LLD->getMemoryVT() != RLD->getMemoryVT() ||
9737 // If this is an EXTLOAD, the kind of extension must match.
9738 (LLD->getExtensionType() != RLD->getExtensionType() &&
9739 // The only exception is if one of the extensions is anyext.
9740 LLD->getExtensionType() != ISD::EXTLOAD &&
9741 RLD->getExtensionType() != ISD::EXTLOAD) ||
9742 // FIXME: this discards src value information. This is
9743 // over-conservative. It would be beneficial to be able to remember
9744 // both potential memory locations. Since we are discarding
9745 // src value info, don't do the transformation if the memory
9746 // locations are not in the default address space.
9747 LLD->getPointerInfo().getAddrSpace() != 0 ||
9748 RLD->getPointerInfo().getAddrSpace() != 0 ||
9749 !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
9750 LLD->getBasePtr().getValueType()))
9753 // Check that the select condition doesn't reach either load. If so,
9754 // folding this will induce a cycle into the DAG. If not, this is safe to
9755 // xform, so create a select of the addresses.
9757 if (TheSelect->getOpcode() == ISD::SELECT) {
9758 SDNode *CondNode = TheSelect->getOperand(0).getNode();
9759 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
9760 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
9762 // The loads must not depend on one another.
9763 if (LLD->isPredecessorOf(RLD) ||
9764 RLD->isPredecessorOf(LLD))
9766 Addr = DAG.getSelect(SDLoc(TheSelect),
9767 LLD->getBasePtr().getValueType(),
9768 TheSelect->getOperand(0), LLD->getBasePtr(),
9770 } else { // Otherwise SELECT_CC
9771 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
9772 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
9774 if ((LLD->hasAnyUseOfValue(1) &&
9775 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
9776 (RLD->hasAnyUseOfValue(1) &&
9777 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
9780 Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
9781 LLD->getBasePtr().getValueType(),
9782 TheSelect->getOperand(0),
9783 TheSelect->getOperand(1),
9784 LLD->getBasePtr(), RLD->getBasePtr(),
9785 TheSelect->getOperand(4));
9789 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
9790 Load = DAG.getLoad(TheSelect->getValueType(0),
9792 // FIXME: Discards pointer info.
9793 LLD->getChain(), Addr, MachinePointerInfo(),
9794 LLD->isVolatile(), LLD->isNonTemporal(),
9795 LLD->isInvariant(), LLD->getAlignment());
9797 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
9798 RLD->getExtensionType() : LLD->getExtensionType(),
9800 TheSelect->getValueType(0),
9801 // FIXME: Discards pointer info.
9802 LLD->getChain(), Addr, MachinePointerInfo(),
9803 LLD->getMemoryVT(), LLD->isVolatile(),
9804 LLD->isNonTemporal(), LLD->getAlignment());
9807 // Users of the select now use the result of the load.
9808 CombineTo(TheSelect, Load);
9810 // Users of the old loads now use the new load's chain. We know the
9811 // old-load value is dead now.
9812 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
9813 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
9820 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
9821 /// where 'cond' is the comparison specified by CC.
9822 SDValue DAGCombiner::SimplifySelectCC(SDLoc DL, SDValue N0, SDValue N1,
9823 SDValue N2, SDValue N3,
9824 ISD::CondCode CC, bool NotExtCompare) {
9825 // (x ? y : y) -> y.
9826 if (N2 == N3) return N2;
9828 EVT VT = N2.getValueType();
9829 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
9830 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
9831 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
9833 // Determine if the condition we're dealing with is constant
9834 SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
9835 N0, N1, CC, DL, false);
9836 if (SCC.getNode()) AddToWorkList(SCC.getNode());
9837 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
9839 // fold select_cc true, x, y -> x
9840 if (SCCC && !SCCC->isNullValue())
9842 // fold select_cc false, x, y -> y
9843 if (SCCC && SCCC->isNullValue())
9846 // Check to see if we can simplify the select into an fabs node
9847 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
9848 // Allow either -0.0 or 0.0
9849 if (CFP->getValueAPF().isZero()) {
9850 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
9851 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
9852 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
9853 N2 == N3.getOperand(0))
9854 return DAG.getNode(ISD::FABS, DL, VT, N0);
9856 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
9857 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
9858 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
9859 N2.getOperand(0) == N3)
9860 return DAG.getNode(ISD::FABS, DL, VT, N3);
9864 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
9865 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
9866 // in it. This is a win when the constant is not otherwise available because
9867 // it replaces two constant pool loads with one. We only do this if the FP
9868 // type is known to be legal, because if it isn't, then we are before legalize
9869 // types an we want the other legalization to happen first (e.g. to avoid
9870 // messing with soft float) and if the ConstantFP is not legal, because if
9871 // it is legal, we may not need to store the FP constant in a constant pool.
9872 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
9873 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
9874 if (TLI.isTypeLegal(N2.getValueType()) &&
9875 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
9876 TargetLowering::Legal) &&
9877 // If both constants have multiple uses, then we won't need to do an
9878 // extra load, they are likely around in registers for other users.
9879 (TV->hasOneUse() || FV->hasOneUse())) {
9880 Constant *Elts[] = {
9881 const_cast<ConstantFP*>(FV->getConstantFPValue()),
9882 const_cast<ConstantFP*>(TV->getConstantFPValue())
9884 Type *FPTy = Elts[0]->getType();
9885 const DataLayout &TD = *TLI.getDataLayout();
9887 // Create a ConstantArray of the two constants.
9888 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
9889 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
9890 TD.getPrefTypeAlignment(FPTy));
9891 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
9893 // Get the offsets to the 0 and 1 element of the array so that we can
9894 // select between them.
9895 SDValue Zero = DAG.getIntPtrConstant(0);
9896 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
9897 SDValue One = DAG.getIntPtrConstant(EltSize);
9899 SDValue Cond = DAG.getSetCC(DL,
9900 getSetCCResultType(N0.getValueType()),
9902 AddToWorkList(Cond.getNode());
9903 SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
9905 AddToWorkList(CstOffset.getNode());
9906 CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
9908 AddToWorkList(CPIdx.getNode());
9909 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
9910 MachinePointerInfo::getConstantPool(), false,
9911 false, false, Alignment);
9916 // Check to see if we can perform the "gzip trick", transforming
9917 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
9918 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
9919 (N1C->isNullValue() || // (a < 0) ? b : 0
9920 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
9921 EVT XType = N0.getValueType();
9922 EVT AType = N2.getValueType();
9923 if (XType.bitsGE(AType)) {
9924 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
9925 // single-bit constant.
9926 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
9927 unsigned ShCtV = N2C->getAPIntValue().logBase2();
9928 ShCtV = XType.getSizeInBits()-ShCtV-1;
9929 SDValue ShCt = DAG.getConstant(ShCtV,
9930 getShiftAmountTy(N0.getValueType()));
9931 SDValue Shift = DAG.getNode(ISD::SRL, SDLoc(N0),
9933 AddToWorkList(Shift.getNode());
9935 if (XType.bitsGT(AType)) {
9936 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9937 AddToWorkList(Shift.getNode());
9940 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9943 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0),
9945 DAG.getConstant(XType.getSizeInBits()-1,
9946 getShiftAmountTy(N0.getValueType())));
9947 AddToWorkList(Shift.getNode());
9949 if (XType.bitsGT(AType)) {
9950 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9951 AddToWorkList(Shift.getNode());
9954 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9958 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
9959 // where y is has a single bit set.
9960 // A plaintext description would be, we can turn the SELECT_CC into an AND
9961 // when the condition can be materialized as an all-ones register. Any
9962 // single bit-test can be materialized as an all-ones register with
9963 // shift-left and shift-right-arith.
9964 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
9965 N0->getValueType(0) == VT &&
9966 N1C && N1C->isNullValue() &&
9967 N2C && N2C->isNullValue()) {
9968 SDValue AndLHS = N0->getOperand(0);
9969 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
9970 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
9971 // Shift the tested bit over the sign bit.
9972 APInt AndMask = ConstAndRHS->getAPIntValue();
9974 DAG.getConstant(AndMask.countLeadingZeros(),
9975 getShiftAmountTy(AndLHS.getValueType()));
9976 SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);
9978 // Now arithmetic right shift it all the way over, so the result is either
9979 // all-ones, or zero.
9981 DAG.getConstant(AndMask.getBitWidth()-1,
9982 getShiftAmountTy(Shl.getValueType()));
9983 SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);
9985 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
9989 // fold select C, 16, 0 -> shl C, 4
9990 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
9991 TLI.getBooleanContents(N0.getValueType().isVector()) ==
9992 TargetLowering::ZeroOrOneBooleanContent) {
9994 // If the caller doesn't want us to simplify this into a zext of a compare,
9996 if (NotExtCompare && N2C->getAPIntValue() == 1)
9999 // Get a SetCC of the condition
10000 // NOTE: Don't create a SETCC if it's not legal on this target.
10001 if (!LegalOperations ||
10002 TLI.isOperationLegal(ISD::SETCC,
10003 LegalTypes ? getSetCCResultType(N0.getValueType()) : MVT::i1)) {
10005 // cast from setcc result type to select result type
10007 SCC = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
10009 if (N2.getValueType().bitsLT(SCC.getValueType()))
10010 Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
10011 N2.getValueType());
10013 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
10014 N2.getValueType(), SCC);
10016 SCC = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
10017 Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
10018 N2.getValueType(), SCC);
10021 AddToWorkList(SCC.getNode());
10022 AddToWorkList(Temp.getNode());
10024 if (N2C->getAPIntValue() == 1)
10027 // shl setcc result by log2 n2c
10028 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
10029 DAG.getConstant(N2C->getAPIntValue().logBase2(),
10030 getShiftAmountTy(Temp.getValueType())));
10034 // Check to see if this is the equivalent of setcc
10035 // FIXME: Turn all of these into setcc if setcc if setcc is legal
10036 // otherwise, go ahead with the folds.
10037 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
10038 EVT XType = N0.getValueType();
10039 if (!LegalOperations ||
10040 TLI.isOperationLegal(ISD::SETCC, getSetCCResultType(XType))) {
10041 SDValue Res = DAG.getSetCC(DL, getSetCCResultType(XType), N0, N1, CC);
10042 if (Res.getValueType() != VT)
10043 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
10047 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
10048 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
10049 (!LegalOperations ||
10050 TLI.isOperationLegal(ISD::CTLZ, XType))) {
10051 SDValue Ctlz = DAG.getNode(ISD::CTLZ, SDLoc(N0), XType, N0);
10052 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
10053 DAG.getConstant(Log2_32(XType.getSizeInBits()),
10054 getShiftAmountTy(Ctlz.getValueType())));
10056 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
10057 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
10058 SDValue NegN0 = DAG.getNode(ISD::SUB, SDLoc(N0),
10059 XType, DAG.getConstant(0, XType), N0);
10060 SDValue NotN0 = DAG.getNOT(SDLoc(N0), N0, XType);
10061 return DAG.getNode(ISD::SRL, DL, XType,
10062 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
10063 DAG.getConstant(XType.getSizeInBits()-1,
10064 getShiftAmountTy(XType)));
10066 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
10067 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
10068 SDValue Sign = DAG.getNode(ISD::SRL, SDLoc(N0), XType, N0,
10069 DAG.getConstant(XType.getSizeInBits()-1,
10070 getShiftAmountTy(N0.getValueType())));
10071 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
10075 // Check to see if this is an integer abs.
10076 // select_cc setg[te] X, 0, X, -X ->
10077 // select_cc setgt X, -1, X, -X ->
10078 // select_cc setl[te] X, 0, -X, X ->
10079 // select_cc setlt X, 1, -X, X ->
10080 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
10082 ConstantSDNode *SubC = NULL;
10083 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
10084 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
10085 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
10086 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
10087 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
10088 (N1C->isOne() && CC == ISD::SETLT)) &&
10089 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
10090 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
10092 EVT XType = N0.getValueType();
10093 if (SubC && SubC->isNullValue() && XType.isInteger()) {
10094 SDValue Shift = DAG.getNode(ISD::SRA, SDLoc(N0), XType,
10096 DAG.getConstant(XType.getSizeInBits()-1,
10097 getShiftAmountTy(N0.getValueType())));
10098 SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N0),
10100 AddToWorkList(Shift.getNode());
10101 AddToWorkList(Add.getNode());
10102 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
10109 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
10110 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
10111 SDValue N1, ISD::CondCode Cond,
10112 SDLoc DL, bool foldBooleans) {
10113 TargetLowering::DAGCombinerInfo
10114 DagCombineInfo(DAG, Level, false, this);
10115 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
10118 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
10119 /// return a DAG expression to select that will generate the same value by
10120 /// multiplying by a magic number. See:
10121 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
10122 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
10123 std::vector<SDNode*> Built;
10124 SDValue S = TLI.BuildSDIV(N, DAG, LegalOperations, &Built);
10126 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
10128 AddToWorkList(*ii);
10132 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
10133 /// return a DAG expression to select that will generate the same value by
10134 /// multiplying by a magic number. See:
10135 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
10136 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
10137 std::vector<SDNode*> Built;
10138 SDValue S = TLI.BuildUDIV(N, DAG, LegalOperations, &Built);
10140 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
10142 AddToWorkList(*ii);
10146 /// FindBaseOffset - Return true if base is a frame index, which is known not
10147 // to alias with anything but itself. Provides base object and offset as
10149 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
10150 const GlobalValue *&GV, const void *&CV) {
10151 // Assume it is a primitive operation.
10152 Base = Ptr; Offset = 0; GV = 0; CV = 0;
10154 // If it's an adding a simple constant then integrate the offset.
10155 if (Base.getOpcode() == ISD::ADD) {
10156 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
10157 Base = Base.getOperand(0);
10158 Offset += C->getZExtValue();
10162 // Return the underlying GlobalValue, and update the Offset. Return false
10163 // for GlobalAddressSDNode since the same GlobalAddress may be represented
10164 // by multiple nodes with different offsets.
10165 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
10166 GV = G->getGlobal();
10167 Offset += G->getOffset();
10171 // Return the underlying Constant value, and update the Offset. Return false
10172 // for ConstantSDNodes since the same constant pool entry may be represented
10173 // by multiple nodes with different offsets.
10174 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
10175 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
10176 : (const void *)C->getConstVal();
10177 Offset += C->getOffset();
10180 // If it's any of the following then it can't alias with anything but itself.
10181 return isa<FrameIndexSDNode>(Base);
10184 /// isAlias - Return true if there is any possibility that the two addresses
10186 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
10187 const Value *SrcValue1, int SrcValueOffset1,
10188 unsigned SrcValueAlign1,
10189 const MDNode *TBAAInfo1,
10190 SDValue Ptr2, int64_t Size2,
10191 const Value *SrcValue2, int SrcValueOffset2,
10192 unsigned SrcValueAlign2,
10193 const MDNode *TBAAInfo2) const {
10194 // If they are the same then they must be aliases.
10195 if (Ptr1 == Ptr2) return true;
10197 // Gather base node and offset information.
10198 SDValue Base1, Base2;
10199 int64_t Offset1, Offset2;
10200 const GlobalValue *GV1, *GV2;
10201 const void *CV1, *CV2;
10202 bool isFrameIndex1 = FindBaseOffset(Ptr1, Base1, Offset1, GV1, CV1);
10203 bool isFrameIndex2 = FindBaseOffset(Ptr2, Base2, Offset2, GV2, CV2);
10205 // If they have a same base address then check to see if they overlap.
10206 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
10207 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
10209 // It is possible for different frame indices to alias each other, mostly
10210 // when tail call optimization reuses return address slots for arguments.
10211 // To catch this case, look up the actual index of frame indices to compute
10212 // the real alias relationship.
10213 if (isFrameIndex1 && isFrameIndex2) {
10214 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
10215 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
10216 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
10217 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
10220 // Otherwise, if we know what the bases are, and they aren't identical, then
10221 // we know they cannot alias.
10222 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
10225 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
10226 // compared to the size and offset of the access, we may be able to prove they
10227 // do not alias. This check is conservative for now to catch cases created by
10228 // splitting vector types.
10229 if ((SrcValueAlign1 == SrcValueAlign2) &&
10230 (SrcValueOffset1 != SrcValueOffset2) &&
10231 (Size1 == Size2) && (SrcValueAlign1 > Size1)) {
10232 int64_t OffAlign1 = SrcValueOffset1 % SrcValueAlign1;
10233 int64_t OffAlign2 = SrcValueOffset2 % SrcValueAlign1;
10235 // There is no overlap between these relatively aligned accesses of similar
10236 // size, return no alias.
10237 if ((OffAlign1 + Size1) <= OffAlign2 || (OffAlign2 + Size2) <= OffAlign1)
10241 bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0 ? CombinerGlobalAA :
10242 TLI.getTargetMachine().getSubtarget<TargetSubtargetInfo>().useAA();
10243 if (UseAA && SrcValue1 && SrcValue2) {
10244 // Use alias analysis information.
10245 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
10246 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
10247 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
10248 AliasAnalysis::AliasResult AAResult =
10249 AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
10250 AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
10251 if (AAResult == AliasAnalysis::NoAlias)
10255 // Otherwise we have to assume they alias.
10259 bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) {
10260 SDValue Ptr0, Ptr1;
10261 int64_t Size0, Size1;
10262 const Value *SrcValue0, *SrcValue1;
10263 int SrcValueOffset0, SrcValueOffset1;
10264 unsigned SrcValueAlign0, SrcValueAlign1;
10265 const MDNode *SrcTBAAInfo0, *SrcTBAAInfo1;
10266 FindAliasInfo(Op0, Ptr0, Size0, SrcValue0, SrcValueOffset0,
10267 SrcValueAlign0, SrcTBAAInfo0);
10268 FindAliasInfo(Op1, Ptr1, Size1, SrcValue1, SrcValueOffset1,
10269 SrcValueAlign1, SrcTBAAInfo1);
10270 return isAlias(Ptr0, Size0, SrcValue0, SrcValueOffset0,
10271 SrcValueAlign0, SrcTBAAInfo0,
10272 Ptr1, Size1, SrcValue1, SrcValueOffset1,
10273 SrcValueAlign1, SrcTBAAInfo1);
10276 /// FindAliasInfo - Extracts the relevant alias information from the memory
10277 /// node. Returns true if the operand was a load.
10278 bool DAGCombiner::FindAliasInfo(SDNode *N,
10279 SDValue &Ptr, int64_t &Size,
10280 const Value *&SrcValue,
10281 int &SrcValueOffset,
10282 unsigned &SrcValueAlign,
10283 const MDNode *&TBAAInfo) const {
10284 LSBaseSDNode *LS = cast<LSBaseSDNode>(N);
10286 Ptr = LS->getBasePtr();
10287 Size = LS->getMemoryVT().getSizeInBits() >> 3;
10288 SrcValue = LS->getSrcValue();
10289 SrcValueOffset = LS->getSrcValueOffset();
10290 SrcValueAlign = LS->getOriginalAlignment();
10291 TBAAInfo = LS->getTBAAInfo();
10292 return isa<LoadSDNode>(LS);
10295 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
10296 /// looking for aliasing nodes and adding them to the Aliases vector.
10297 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
10298 SmallVectorImpl<SDValue> &Aliases) {
10299 SmallVector<SDValue, 8> Chains; // List of chains to visit.
10300 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
10302 // Get alias information for node.
10305 const Value *SrcValue;
10306 int SrcValueOffset;
10307 unsigned SrcValueAlign;
10308 const MDNode *SrcTBAAInfo;
10309 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
10310 SrcValueAlign, SrcTBAAInfo);
10313 Chains.push_back(OriginalChain);
10314 unsigned Depth = 0;
10316 // Look at each chain and determine if it is an alias. If so, add it to the
10317 // aliases list. If not, then continue up the chain looking for the next
10319 while (!Chains.empty()) {
10320 SDValue Chain = Chains.back();
10323 // For TokenFactor nodes, look at each operand and only continue up the
10324 // chain until we find two aliases. If we've seen two aliases, assume we'll
10325 // find more and revert to original chain since the xform is unlikely to be
10328 // FIXME: The depth check could be made to return the last non-aliasing
10329 // chain we found before we hit a tokenfactor rather than the original
10331 if (Depth > 6 || Aliases.size() == 2) {
10333 Aliases.push_back(OriginalChain);
10337 // Don't bother if we've been before.
10338 if (!Visited.insert(Chain.getNode()))
10341 switch (Chain.getOpcode()) {
10342 case ISD::EntryToken:
10343 // Entry token is ideal chain operand, but handled in FindBetterChain.
10348 // Get alias information for Chain.
10351 const Value *OpSrcValue;
10352 int OpSrcValueOffset;
10353 unsigned OpSrcValueAlign;
10354 const MDNode *OpSrcTBAAInfo;
10355 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
10356 OpSrcValue, OpSrcValueOffset,
10360 // If chain is alias then stop here.
10361 if (!(IsLoad && IsOpLoad) &&
10362 isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
10364 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
10365 OpSrcValueAlign, OpSrcTBAAInfo)) {
10366 Aliases.push_back(Chain);
10368 // Look further up the chain.
10369 Chains.push_back(Chain.getOperand(0));
10375 case ISD::TokenFactor:
10376 // We have to check each of the operands of the token factor for "small"
10377 // token factors, so we queue them up. Adding the operands to the queue
10378 // (stack) in reverse order maintains the original order and increases the
10379 // likelihood that getNode will find a matching token factor (CSE.)
10380 if (Chain.getNumOperands() > 16) {
10381 Aliases.push_back(Chain);
10384 for (unsigned n = Chain.getNumOperands(); n;)
10385 Chains.push_back(Chain.getOperand(--n));
10390 // For all other instructions we will just have to take what we can get.
10391 Aliases.push_back(Chain);
10397 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
10398 /// for a better chain (aliasing node.)
10399 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
10400 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
10402 // Accumulate all the aliases to this node.
10403 GatherAllAliases(N, OldChain, Aliases);
10405 // If no operands then chain to entry token.
10406 if (Aliases.size() == 0)
10407 return DAG.getEntryNode();
10409 // If a single operand then chain to it. We don't need to revisit it.
10410 if (Aliases.size() == 1)
10413 // Construct a custom tailored token factor.
10414 return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other,
10415 &Aliases[0], Aliases.size());
10418 // SelectionDAG::Combine - This is the entry point for the file.
10420 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
10421 CodeGenOpt::Level OptLevel) {
10422 /// run - This is the main entry point to this class.
10424 DAGCombiner(*this, AA, OptLevel).Run(Level);