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/DerivedTypes.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/Analysis/AliasAnalysis.h"
26 #include "llvm/DataLayout.h"
27 #include "llvm/Target/TargetLowering.h"
28 #include "llvm/Target/TargetMachine.h"
29 #include "llvm/Target/TargetOptions.h"
30 #include "llvm/ADT/SmallPtrSet.h"
31 #include "llvm/ADT/Statistic.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/raw_ostream.h"
40 STATISTIC(NodesCombined , "Number of dag nodes combined");
41 STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
42 STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
43 STATISTIC(OpsNarrowed , "Number of load/op/store narrowed");
44 STATISTIC(LdStFP2Int , "Number of fp load/store pairs transformed to int");
48 CombinerAA("combiner-alias-analysis", cl::Hidden,
49 cl::desc("Turn on alias analysis during testing"));
52 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
53 cl::desc("Include global information in alias analysis"));
55 //------------------------------ DAGCombiner ---------------------------------//
59 const TargetLowering &TLI;
61 CodeGenOpt::Level OptLevel;
65 // Worklist of all of the nodes that need to be simplified.
67 // This has the semantics that when adding to the worklist,
68 // the item added must be next to be processed. It should
69 // also only appear once. The naive approach to this takes
72 // To reduce the insert/remove time to logarithmic, we use
73 // a set and a vector to maintain our worklist.
75 // The set contains the items on the worklist, but does not
76 // maintain the order they should be visited.
78 // The vector maintains the order nodes should be visited, but may
79 // contain duplicate or removed nodes. When choosing a node to
80 // visit, we pop off the order stack until we find an item that is
81 // also in the contents set. All operations are O(log N).
82 SmallPtrSet<SDNode*, 64> WorkListContents;
83 SmallVector<SDNode*, 64> WorkListOrder;
85 // AA - Used for DAG load/store alias analysis.
88 /// AddUsersToWorkList - When an instruction is simplified, add all users of
89 /// the instruction to the work lists because they might get more simplified
92 void AddUsersToWorkList(SDNode *N) {
93 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
98 /// visit - call the node-specific routine that knows how to fold each
99 /// particular type of node.
100 SDValue visit(SDNode *N);
103 /// AddToWorkList - Add to the work list making sure its instance is at the
104 /// back (next to be processed.)
105 void AddToWorkList(SDNode *N) {
106 WorkListContents.insert(N);
107 WorkListOrder.push_back(N);
110 /// removeFromWorkList - remove all instances of N from the worklist.
112 void removeFromWorkList(SDNode *N) {
113 WorkListContents.erase(N);
116 SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
119 SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
120 return CombineTo(N, &Res, 1, AddTo);
123 SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
125 SDValue To[] = { Res0, Res1 };
126 return CombineTo(N, To, 2, AddTo);
129 void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);
133 /// SimplifyDemandedBits - Check the specified integer node value to see if
134 /// it can be simplified or if things it uses can be simplified by bit
135 /// propagation. If so, return true.
136 bool SimplifyDemandedBits(SDValue Op) {
137 unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
138 APInt Demanded = APInt::getAllOnesValue(BitWidth);
139 return SimplifyDemandedBits(Op, Demanded);
142 bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);
144 bool CombineToPreIndexedLoadStore(SDNode *N);
145 bool CombineToPostIndexedLoadStore(SDNode *N);
147 void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
148 SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
149 SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
150 SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
151 SDValue PromoteIntBinOp(SDValue Op);
152 SDValue PromoteIntShiftOp(SDValue Op);
153 SDValue PromoteExtend(SDValue Op);
154 bool PromoteLoad(SDValue Op);
156 void ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
157 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
158 ISD::NodeType ExtType);
160 /// combine - call the node-specific routine that knows how to fold each
161 /// particular type of node. If that doesn't do anything, try the
162 /// target-specific DAG combines.
163 SDValue combine(SDNode *N);
165 // Visitation implementation - Implement dag node combining for different
166 // node types. The semantics are as follows:
168 // SDValue.getNode() == 0 - No change was made
169 // SDValue.getNode() == N - N was replaced, is dead and has been handled.
170 // otherwise - N should be replaced by the returned Operand.
172 SDValue visitTokenFactor(SDNode *N);
173 SDValue visitMERGE_VALUES(SDNode *N);
174 SDValue visitADD(SDNode *N);
175 SDValue visitSUB(SDNode *N);
176 SDValue visitADDC(SDNode *N);
177 SDValue visitSUBC(SDNode *N);
178 SDValue visitADDE(SDNode *N);
179 SDValue visitSUBE(SDNode *N);
180 SDValue visitMUL(SDNode *N);
181 SDValue visitSDIV(SDNode *N);
182 SDValue visitUDIV(SDNode *N);
183 SDValue visitSREM(SDNode *N);
184 SDValue visitUREM(SDNode *N);
185 SDValue visitMULHU(SDNode *N);
186 SDValue visitMULHS(SDNode *N);
187 SDValue visitSMUL_LOHI(SDNode *N);
188 SDValue visitUMUL_LOHI(SDNode *N);
189 SDValue visitSMULO(SDNode *N);
190 SDValue visitUMULO(SDNode *N);
191 SDValue visitSDIVREM(SDNode *N);
192 SDValue visitUDIVREM(SDNode *N);
193 SDValue visitAND(SDNode *N);
194 SDValue visitOR(SDNode *N);
195 SDValue visitXOR(SDNode *N);
196 SDValue SimplifyVBinOp(SDNode *N);
197 SDValue SimplifyVUnaryOp(SDNode *N);
198 SDValue visitSHL(SDNode *N);
199 SDValue visitSRA(SDNode *N);
200 SDValue visitSRL(SDNode *N);
201 SDValue visitCTLZ(SDNode *N);
202 SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
203 SDValue visitCTTZ(SDNode *N);
204 SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
205 SDValue visitCTPOP(SDNode *N);
206 SDValue visitSELECT(SDNode *N);
207 SDValue visitSELECT_CC(SDNode *N);
208 SDValue visitSETCC(SDNode *N);
209 SDValue visitSIGN_EXTEND(SDNode *N);
210 SDValue visitZERO_EXTEND(SDNode *N);
211 SDValue visitANY_EXTEND(SDNode *N);
212 SDValue visitSIGN_EXTEND_INREG(SDNode *N);
213 SDValue visitTRUNCATE(SDNode *N);
214 SDValue visitBITCAST(SDNode *N);
215 SDValue visitBUILD_PAIR(SDNode *N);
216 SDValue visitFADD(SDNode *N);
217 SDValue visitFSUB(SDNode *N);
218 SDValue visitFMUL(SDNode *N);
219 SDValue visitFMA(SDNode *N);
220 SDValue visitFDIV(SDNode *N);
221 SDValue visitFREM(SDNode *N);
222 SDValue visitFCOPYSIGN(SDNode *N);
223 SDValue visitSINT_TO_FP(SDNode *N);
224 SDValue visitUINT_TO_FP(SDNode *N);
225 SDValue visitFP_TO_SINT(SDNode *N);
226 SDValue visitFP_TO_UINT(SDNode *N);
227 SDValue visitFP_ROUND(SDNode *N);
228 SDValue visitFP_ROUND_INREG(SDNode *N);
229 SDValue visitFP_EXTEND(SDNode *N);
230 SDValue visitFNEG(SDNode *N);
231 SDValue visitFABS(SDNode *N);
232 SDValue visitFCEIL(SDNode *N);
233 SDValue visitFTRUNC(SDNode *N);
234 SDValue visitFFLOOR(SDNode *N);
235 SDValue visitBRCOND(SDNode *N);
236 SDValue visitBR_CC(SDNode *N);
237 SDValue visitLOAD(SDNode *N);
238 SDValue visitSTORE(SDNode *N);
239 SDValue visitINSERT_VECTOR_ELT(SDNode *N);
240 SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
241 SDValue visitBUILD_VECTOR(SDNode *N);
242 SDValue visitCONCAT_VECTORS(SDNode *N);
243 SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
244 SDValue visitVECTOR_SHUFFLE(SDNode *N);
245 SDValue visitMEMBARRIER(SDNode *N);
247 SDValue XformToShuffleWithZero(SDNode *N);
248 SDValue ReassociateOps(unsigned Opc, DebugLoc DL, SDValue LHS, SDValue RHS);
250 SDValue visitShiftByConstant(SDNode *N, unsigned Amt);
252 bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
253 SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
254 SDValue SimplifySelect(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2);
255 SDValue SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1, SDValue N2,
256 SDValue N3, ISD::CondCode CC,
257 bool NotExtCompare = false);
258 SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
259 DebugLoc DL, bool foldBooleans = true);
260 SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
262 SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
263 SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
264 SDValue BuildSDIV(SDNode *N);
265 SDValue BuildUDIV(SDNode *N);
266 SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
267 bool DemandHighBits = true);
268 SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
269 SDNode *MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL);
270 SDValue ReduceLoadWidth(SDNode *N);
271 SDValue ReduceLoadOpStoreWidth(SDNode *N);
272 SDValue TransformFPLoadStorePair(SDNode *N);
273 SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
275 SDValue GetDemandedBits(SDValue V, const APInt &Mask);
277 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
278 /// looking for aliasing nodes and adding them to the Aliases vector.
279 void GatherAllAliases(SDNode *N, SDValue OriginalChain,
280 SmallVector<SDValue, 8> &Aliases);
282 /// isAlias - Return true if there is any possibility that the two addresses
284 bool isAlias(SDValue Ptr1, int64_t Size1,
285 const Value *SrcValue1, int SrcValueOffset1,
286 unsigned SrcValueAlign1,
287 const MDNode *TBAAInfo1,
288 SDValue Ptr2, int64_t Size2,
289 const Value *SrcValue2, int SrcValueOffset2,
290 unsigned SrcValueAlign2,
291 const MDNode *TBAAInfo2) const;
293 /// FindAliasInfo - Extracts the relevant alias information from the memory
294 /// node. Returns true if the operand was a load.
295 bool FindAliasInfo(SDNode *N,
296 SDValue &Ptr, int64_t &Size,
297 const Value *&SrcValue, int &SrcValueOffset,
298 unsigned &SrcValueAlignment,
299 const MDNode *&TBAAInfo) const;
301 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
302 /// looking for a better chain (aliasing node.)
303 SDValue FindBetterChain(SDNode *N, SDValue Chain);
305 /// Merge consecutive store operations into a wide store.
306 /// This optimization uses wide integers or vectors when possible.
307 /// \return True if some memory operations were changed.
308 bool MergeConsecutiveStores(StoreSDNode *N);
311 DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
312 : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
313 OptLevel(OL), LegalOperations(false), LegalTypes(false), AA(A) {}
315 /// Run - runs the dag combiner on all nodes in the work list
316 void Run(CombineLevel AtLevel);
318 SelectionDAG &getDAG() const { return DAG; }
320 /// getShiftAmountTy - Returns a type large enough to hold any valid
321 /// shift amount - before type legalization these can be huge.
322 EVT getShiftAmountTy(EVT LHSTy) {
323 return LegalTypes ? TLI.getShiftAmountTy(LHSTy) : TLI.getPointerTy();
326 /// isTypeLegal - This method returns true if we are running before type
327 /// legalization or if the specified VT is legal.
328 bool isTypeLegal(const EVT &VT) {
329 if (!LegalTypes) return true;
330 return TLI.isTypeLegal(VT);
337 /// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
338 /// nodes from the worklist.
339 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
342 explicit WorkListRemover(DAGCombiner &dc)
343 : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
345 virtual void NodeDeleted(SDNode *N, SDNode *E) {
346 DC.removeFromWorkList(N);
351 //===----------------------------------------------------------------------===//
352 // TargetLowering::DAGCombinerInfo implementation
353 //===----------------------------------------------------------------------===//
355 void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
356 ((DAGCombiner*)DC)->AddToWorkList(N);
359 void TargetLowering::DAGCombinerInfo::RemoveFromWorklist(SDNode *N) {
360 ((DAGCombiner*)DC)->removeFromWorkList(N);
363 SDValue TargetLowering::DAGCombinerInfo::
364 CombineTo(SDNode *N, const std::vector<SDValue> &To, bool AddTo) {
365 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
368 SDValue TargetLowering::DAGCombinerInfo::
369 CombineTo(SDNode *N, SDValue Res, bool AddTo) {
370 return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
374 SDValue TargetLowering::DAGCombinerInfo::
375 CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
376 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
379 void TargetLowering::DAGCombinerInfo::
380 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
381 return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
384 //===----------------------------------------------------------------------===//
386 //===----------------------------------------------------------------------===//
388 /// isNegatibleForFree - Return 1 if we can compute the negated form of the
389 /// specified expression for the same cost as the expression itself, or 2 if we
390 /// can compute the negated form more cheaply than the expression itself.
391 static char isNegatibleForFree(SDValue Op, bool LegalOperations,
392 const TargetLowering &TLI,
393 const TargetOptions *Options,
394 unsigned Depth = 0) {
395 // No compile time optimizations on this type.
396 if (Op.getValueType() == MVT::ppcf128)
399 // fneg is removable even if it has multiple uses.
400 if (Op.getOpcode() == ISD::FNEG) return 2;
402 // Don't allow anything with multiple uses.
403 if (!Op.hasOneUse()) return 0;
405 // Don't recurse exponentially.
406 if (Depth > 6) return 0;
408 switch (Op.getOpcode()) {
409 default: return false;
410 case ISD::ConstantFP:
411 // Don't invert constant FP values after legalize. The negated constant
412 // isn't necessarily legal.
413 return LegalOperations ? 0 : 1;
415 // FIXME: determine better conditions for this xform.
416 if (!Options->UnsafeFPMath) return 0;
418 // After operation legalization, it might not be legal to create new FSUBs.
419 if (LegalOperations &&
420 !TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType()))
423 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
424 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
427 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
428 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
431 // We can't turn -(A-B) into B-A when we honor signed zeros.
432 if (!Options->UnsafeFPMath) return 0;
434 // fold (fneg (fsub A, B)) -> (fsub B, A)
439 if (Options->HonorSignDependentRoundingFPMath()) return 0;
441 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
442 if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
446 return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
452 return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
457 /// GetNegatedExpression - If isNegatibleForFree returns true, this function
458 /// returns the newly negated expression.
459 static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
460 bool LegalOperations, unsigned Depth = 0) {
461 // fneg is removable even if it has multiple uses.
462 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
464 // Don't allow anything with multiple uses.
465 assert(Op.hasOneUse() && "Unknown reuse!");
467 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
468 switch (Op.getOpcode()) {
469 default: llvm_unreachable("Unknown code");
470 case ISD::ConstantFP: {
471 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
473 return DAG.getConstantFP(V, Op.getValueType());
476 // FIXME: determine better conditions for this xform.
477 assert(DAG.getTarget().Options.UnsafeFPMath);
479 // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
480 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
481 DAG.getTargetLoweringInfo(),
482 &DAG.getTarget().Options, Depth+1))
483 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
484 GetNegatedExpression(Op.getOperand(0), DAG,
485 LegalOperations, Depth+1),
487 // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
488 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
489 GetNegatedExpression(Op.getOperand(1), DAG,
490 LegalOperations, Depth+1),
493 // We can't turn -(A-B) into B-A when we honor signed zeros.
494 assert(DAG.getTarget().Options.UnsafeFPMath);
496 // fold (fneg (fsub 0, B)) -> B
497 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
498 if (N0CFP->getValueAPF().isZero())
499 return Op.getOperand(1);
501 // fold (fneg (fsub A, B)) -> (fsub B, A)
502 return DAG.getNode(ISD::FSUB, Op.getDebugLoc(), Op.getValueType(),
503 Op.getOperand(1), Op.getOperand(0));
507 assert(!DAG.getTarget().Options.HonorSignDependentRoundingFPMath());
509 // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
510 if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
511 DAG.getTargetLoweringInfo(),
512 &DAG.getTarget().Options, Depth+1))
513 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
514 GetNegatedExpression(Op.getOperand(0), DAG,
515 LegalOperations, Depth+1),
518 // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
519 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
521 GetNegatedExpression(Op.getOperand(1), DAG,
522 LegalOperations, Depth+1));
526 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), Op.getValueType(),
527 GetNegatedExpression(Op.getOperand(0), DAG,
528 LegalOperations, Depth+1));
530 return DAG.getNode(ISD::FP_ROUND, Op.getDebugLoc(), Op.getValueType(),
531 GetNegatedExpression(Op.getOperand(0), DAG,
532 LegalOperations, Depth+1),
538 // isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
539 // that selects between the values 1 and 0, making it equivalent to a setcc.
540 // Also, set the incoming LHS, RHS, and CC references to the appropriate
541 // nodes based on the type of node we are checking. This simplifies life a
542 // bit for the callers.
543 static bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
545 if (N.getOpcode() == ISD::SETCC) {
546 LHS = N.getOperand(0);
547 RHS = N.getOperand(1);
548 CC = N.getOperand(2);
551 if (N.getOpcode() == ISD::SELECT_CC &&
552 N.getOperand(2).getOpcode() == ISD::Constant &&
553 N.getOperand(3).getOpcode() == ISD::Constant &&
554 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
555 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
556 LHS = N.getOperand(0);
557 RHS = N.getOperand(1);
558 CC = N.getOperand(4);
564 // isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
565 // one use. If this is true, it allows the users to invert the operation for
566 // free when it is profitable to do so.
567 static bool isOneUseSetCC(SDValue N) {
569 if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
574 SDValue DAGCombiner::ReassociateOps(unsigned Opc, DebugLoc DL,
575 SDValue N0, SDValue N1) {
576 EVT VT = N0.getValueType();
577 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
578 if (isa<ConstantSDNode>(N1)) {
579 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
581 DAG.FoldConstantArithmetic(Opc, VT,
582 cast<ConstantSDNode>(N0.getOperand(1)),
583 cast<ConstantSDNode>(N1));
584 return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
586 if (N0.hasOneUse()) {
587 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
588 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
589 N0.getOperand(0), N1);
590 AddToWorkList(OpNode.getNode());
591 return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
595 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
596 if (isa<ConstantSDNode>(N0)) {
597 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
599 DAG.FoldConstantArithmetic(Opc, VT,
600 cast<ConstantSDNode>(N1.getOperand(1)),
601 cast<ConstantSDNode>(N0));
602 return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
604 if (N1.hasOneUse()) {
605 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
606 SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
607 N1.getOperand(0), N0);
608 AddToWorkList(OpNode.getNode());
609 return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
616 SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
618 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
620 DEBUG(dbgs() << "\nReplacing.1 ";
622 dbgs() << "\nWith: ";
623 To[0].getNode()->dump(&DAG);
624 dbgs() << " and " << NumTo-1 << " other values\n";
625 for (unsigned i = 0, e = NumTo; i != e; ++i)
626 assert((!To[i].getNode() ||
627 N->getValueType(i) == To[i].getValueType()) &&
628 "Cannot combine value to value of different type!"));
629 WorkListRemover DeadNodes(*this);
630 DAG.ReplaceAllUsesWith(N, To);
632 // Push the new nodes and any users onto the worklist
633 for (unsigned i = 0, e = NumTo; i != e; ++i) {
634 if (To[i].getNode()) {
635 AddToWorkList(To[i].getNode());
636 AddUsersToWorkList(To[i].getNode());
641 // Finally, if the node is now dead, remove it from the graph. The node
642 // may not be dead if the replacement process recursively simplified to
643 // something else needing this node.
644 if (N->use_empty()) {
645 // Nodes can be reintroduced into the worklist. Make sure we do not
646 // process a node that has been replaced.
647 removeFromWorkList(N);
649 // Finally, since the node is now dead, remove it from the graph.
652 return SDValue(N, 0);
656 CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
657 // Replace all uses. If any nodes become isomorphic to other nodes and
658 // are deleted, make sure to remove them from our worklist.
659 WorkListRemover DeadNodes(*this);
660 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
662 // Push the new node and any (possibly new) users onto the worklist.
663 AddToWorkList(TLO.New.getNode());
664 AddUsersToWorkList(TLO.New.getNode());
666 // Finally, if the node is now dead, remove it from the graph. The node
667 // may not be dead if the replacement process recursively simplified to
668 // something else needing this node.
669 if (TLO.Old.getNode()->use_empty()) {
670 removeFromWorkList(TLO.Old.getNode());
672 // If the operands of this node are only used by the node, they will now
673 // be dead. Make sure to visit them first to delete dead nodes early.
674 for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
675 if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
676 AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
678 DAG.DeleteNode(TLO.Old.getNode());
682 /// SimplifyDemandedBits - Check the specified integer node value to see if
683 /// it can be simplified or if things it uses can be simplified by bit
684 /// propagation. If so, return true.
685 bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
686 TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
687 APInt KnownZero, KnownOne;
688 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
692 AddToWorkList(Op.getNode());
694 // Replace the old value with the new one.
696 DEBUG(dbgs() << "\nReplacing.2 ";
697 TLO.Old.getNode()->dump(&DAG);
698 dbgs() << "\nWith: ";
699 TLO.New.getNode()->dump(&DAG);
702 CommitTargetLoweringOpt(TLO);
706 void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
707 DebugLoc dl = Load->getDebugLoc();
708 EVT VT = Load->getValueType(0);
709 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, VT, SDValue(ExtLoad, 0));
711 DEBUG(dbgs() << "\nReplacing.9 ";
713 dbgs() << "\nWith: ";
714 Trunc.getNode()->dump(&DAG);
716 WorkListRemover DeadNodes(*this);
717 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
718 DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
719 removeFromWorkList(Load);
720 DAG.DeleteNode(Load);
721 AddToWorkList(Trunc.getNode());
724 SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
726 DebugLoc dl = Op.getDebugLoc();
727 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) {
728 EVT MemVT = LD->getMemoryVT();
729 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
730 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
732 : LD->getExtensionType();
734 return DAG.getExtLoad(ExtType, dl, PVT,
735 LD->getChain(), LD->getBasePtr(),
736 LD->getPointerInfo(),
737 MemVT, LD->isVolatile(),
738 LD->isNonTemporal(), LD->getAlignment());
741 unsigned Opc = Op.getOpcode();
744 case ISD::AssertSext:
745 return DAG.getNode(ISD::AssertSext, dl, PVT,
746 SExtPromoteOperand(Op.getOperand(0), PVT),
748 case ISD::AssertZext:
749 return DAG.getNode(ISD::AssertZext, dl, PVT,
750 ZExtPromoteOperand(Op.getOperand(0), PVT),
752 case ISD::Constant: {
754 Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
755 return DAG.getNode(ExtOpc, dl, PVT, Op);
759 if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
761 return DAG.getNode(ISD::ANY_EXTEND, dl, PVT, Op);
764 SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
765 if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
767 EVT OldVT = Op.getValueType();
768 DebugLoc dl = Op.getDebugLoc();
769 bool Replace = false;
770 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
771 if (NewOp.getNode() == 0)
773 AddToWorkList(NewOp.getNode());
776 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
777 return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, NewOp.getValueType(), NewOp,
778 DAG.getValueType(OldVT));
781 SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
782 EVT OldVT = Op.getValueType();
783 DebugLoc dl = Op.getDebugLoc();
784 bool Replace = false;
785 SDValue NewOp = PromoteOperand(Op, PVT, Replace);
786 if (NewOp.getNode() == 0)
788 AddToWorkList(NewOp.getNode());
791 ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
792 return DAG.getZeroExtendInReg(NewOp, dl, OldVT);
795 /// PromoteIntBinOp - Promote the specified integer binary operation if the
796 /// target indicates it is beneficial. e.g. On x86, it's usually better to
797 /// promote i16 operations to i32 since i16 instructions are longer.
798 SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
799 if (!LegalOperations)
802 EVT VT = Op.getValueType();
803 if (VT.isVector() || !VT.isInteger())
806 // If operation type is 'undesirable', e.g. i16 on x86, consider
808 unsigned Opc = Op.getOpcode();
809 if (TLI.isTypeDesirableForOp(Opc, VT))
813 // Consult target whether it is a good idea to promote this operation and
814 // what's the right type to promote it to.
815 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
816 assert(PVT != VT && "Don't know what type to promote to!");
818 bool Replace0 = false;
819 SDValue N0 = Op.getOperand(0);
820 SDValue NN0 = PromoteOperand(N0, PVT, Replace0);
821 if (NN0.getNode() == 0)
824 bool Replace1 = false;
825 SDValue N1 = Op.getOperand(1);
830 NN1 = PromoteOperand(N1, PVT, Replace1);
831 if (NN1.getNode() == 0)
835 AddToWorkList(NN0.getNode());
837 AddToWorkList(NN1.getNode());
840 ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
842 ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
844 DEBUG(dbgs() << "\nPromoting ";
845 Op.getNode()->dump(&DAG));
846 DebugLoc dl = Op.getDebugLoc();
847 return DAG.getNode(ISD::TRUNCATE, dl, VT,
848 DAG.getNode(Opc, dl, PVT, NN0, NN1));
853 /// PromoteIntShiftOp - Promote the specified integer shift operation if the
854 /// target indicates it is beneficial. e.g. On x86, it's usually better to
855 /// promote i16 operations to i32 since i16 instructions are longer.
856 SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
857 if (!LegalOperations)
860 EVT VT = Op.getValueType();
861 if (VT.isVector() || !VT.isInteger())
864 // If operation type is 'undesirable', e.g. i16 on x86, consider
866 unsigned Opc = Op.getOpcode();
867 if (TLI.isTypeDesirableForOp(Opc, VT))
871 // Consult target whether it is a good idea to promote this operation and
872 // what's the right type to promote it to.
873 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
874 assert(PVT != VT && "Don't know what type to promote to!");
876 bool Replace = false;
877 SDValue N0 = Op.getOperand(0);
879 N0 = SExtPromoteOperand(Op.getOperand(0), PVT);
880 else if (Opc == ISD::SRL)
881 N0 = ZExtPromoteOperand(Op.getOperand(0), PVT);
883 N0 = PromoteOperand(N0, PVT, Replace);
884 if (N0.getNode() == 0)
887 AddToWorkList(N0.getNode());
889 ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());
891 DEBUG(dbgs() << "\nPromoting ";
892 Op.getNode()->dump(&DAG));
893 DebugLoc dl = Op.getDebugLoc();
894 return DAG.getNode(ISD::TRUNCATE, dl, VT,
895 DAG.getNode(Opc, dl, PVT, N0, Op.getOperand(1)));
900 SDValue DAGCombiner::PromoteExtend(SDValue Op) {
901 if (!LegalOperations)
904 EVT VT = Op.getValueType();
905 if (VT.isVector() || !VT.isInteger())
908 // If operation type is 'undesirable', e.g. i16 on x86, consider
910 unsigned Opc = Op.getOpcode();
911 if (TLI.isTypeDesirableForOp(Opc, VT))
915 // Consult target whether it is a good idea to promote this operation and
916 // what's the right type to promote it to.
917 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
918 assert(PVT != VT && "Don't know what type to promote to!");
919 // fold (aext (aext x)) -> (aext x)
920 // fold (aext (zext x)) -> (zext x)
921 // fold (aext (sext x)) -> (sext x)
922 DEBUG(dbgs() << "\nPromoting ";
923 Op.getNode()->dump(&DAG));
924 return DAG.getNode(Op.getOpcode(), Op.getDebugLoc(), VT, Op.getOperand(0));
929 bool DAGCombiner::PromoteLoad(SDValue Op) {
930 if (!LegalOperations)
933 EVT VT = Op.getValueType();
934 if (VT.isVector() || !VT.isInteger())
937 // If operation type is 'undesirable', e.g. i16 on x86, consider
939 unsigned Opc = Op.getOpcode();
940 if (TLI.isTypeDesirableForOp(Opc, VT))
944 // Consult target whether it is a good idea to promote this operation and
945 // what's the right type to promote it to.
946 if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
947 assert(PVT != VT && "Don't know what type to promote to!");
949 DebugLoc dl = Op.getDebugLoc();
950 SDNode *N = Op.getNode();
951 LoadSDNode *LD = cast<LoadSDNode>(N);
952 EVT MemVT = LD->getMemoryVT();
953 ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
954 ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT) ? ISD::ZEXTLOAD
956 : LD->getExtensionType();
957 SDValue NewLD = DAG.getExtLoad(ExtType, dl, PVT,
958 LD->getChain(), LD->getBasePtr(),
959 LD->getPointerInfo(),
960 MemVT, LD->isVolatile(),
961 LD->isNonTemporal(), LD->getAlignment());
962 SDValue Result = DAG.getNode(ISD::TRUNCATE, dl, VT, NewLD);
964 DEBUG(dbgs() << "\nPromoting ";
967 Result.getNode()->dump(&DAG);
969 WorkListRemover DeadNodes(*this);
970 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
971 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
972 removeFromWorkList(N);
974 AddToWorkList(Result.getNode());
981 //===----------------------------------------------------------------------===//
982 // Main DAG Combiner implementation
983 //===----------------------------------------------------------------------===//
985 void DAGCombiner::Run(CombineLevel AtLevel) {
986 // set the instance variables, so that the various visit routines may use it.
988 LegalOperations = Level >= AfterLegalizeVectorOps;
989 LegalTypes = Level >= AfterLegalizeTypes;
991 // Add all the dag nodes to the worklist.
992 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
993 E = DAG.allnodes_end(); I != E; ++I)
996 // Create a dummy node (which is not added to allnodes), that adds a reference
997 // to the root node, preventing it from being deleted, and tracking any
998 // changes of the root.
999 HandleSDNode Dummy(DAG.getRoot());
1001 // The root of the dag may dangle to deleted nodes until the dag combiner is
1002 // done. Set it to null to avoid confusion.
1003 DAG.setRoot(SDValue());
1005 // while the worklist isn't empty, find a node and
1006 // try and combine it.
1007 while (!WorkListContents.empty()) {
1009 // The WorkListOrder holds the SDNodes in order, but it may contain duplicates.
1010 // In order to avoid a linear scan, we use a set (O(log N)) to hold what the
1011 // worklist *should* contain, and check the node we want to visit is should
1012 // actually be visited.
1014 N = WorkListOrder.pop_back_val();
1015 } while (!WorkListContents.erase(N));
1017 // If N has no uses, it is dead. Make sure to revisit all N's operands once
1018 // N is deleted from the DAG, since they too may now be dead or may have a
1019 // reduced number of uses, allowing other xforms.
1020 if (N->use_empty() && N != &Dummy) {
1021 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1022 AddToWorkList(N->getOperand(i).getNode());
1028 SDValue RV = combine(N);
1030 if (RV.getNode() == 0)
1035 // If we get back the same node we passed in, rather than a new node or
1036 // zero, we know that the node must have defined multiple values and
1037 // CombineTo was used. Since CombineTo takes care of the worklist
1038 // mechanics for us, we have no work to do in this case.
1039 if (RV.getNode() == N)
1042 assert(N->getOpcode() != ISD::DELETED_NODE &&
1043 RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
1044 "Node was deleted but visit returned new node!");
1046 DEBUG(dbgs() << "\nReplacing.3 ";
1048 dbgs() << "\nWith: ";
1049 RV.getNode()->dump(&DAG);
1052 // Transfer debug value.
1053 DAG.TransferDbgValues(SDValue(N, 0), RV);
1054 WorkListRemover DeadNodes(*this);
1055 if (N->getNumValues() == RV.getNode()->getNumValues())
1056 DAG.ReplaceAllUsesWith(N, RV.getNode());
1058 assert(N->getValueType(0) == RV.getValueType() &&
1059 N->getNumValues() == 1 && "Type mismatch");
1061 DAG.ReplaceAllUsesWith(N, &OpV);
1064 // Push the new node and any users onto the worklist
1065 AddToWorkList(RV.getNode());
1066 AddUsersToWorkList(RV.getNode());
1068 // Add any uses of the old node to the worklist in case this node is the
1069 // last one that uses them. They may become dead after this node is
1071 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1072 AddToWorkList(N->getOperand(i).getNode());
1074 // Finally, if the node is now dead, remove it from the graph. The node
1075 // may not be dead if the replacement process recursively simplified to
1076 // something else needing this node.
1077 if (N->use_empty()) {
1078 // Nodes can be reintroduced into the worklist. Make sure we do not
1079 // process a node that has been replaced.
1080 removeFromWorkList(N);
1082 // Finally, since the node is now dead, remove it from the graph.
1087 // If the root changed (e.g. it was a dead load, update the root).
1088 DAG.setRoot(Dummy.getValue());
1089 DAG.RemoveDeadNodes();
1092 SDValue DAGCombiner::visit(SDNode *N) {
1093 switch (N->getOpcode()) {
1095 case ISD::TokenFactor: return visitTokenFactor(N);
1096 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
1097 case ISD::ADD: return visitADD(N);
1098 case ISD::SUB: return visitSUB(N);
1099 case ISD::ADDC: return visitADDC(N);
1100 case ISD::SUBC: return visitSUBC(N);
1101 case ISD::ADDE: return visitADDE(N);
1102 case ISD::SUBE: return visitSUBE(N);
1103 case ISD::MUL: return visitMUL(N);
1104 case ISD::SDIV: return visitSDIV(N);
1105 case ISD::UDIV: return visitUDIV(N);
1106 case ISD::SREM: return visitSREM(N);
1107 case ISD::UREM: return visitUREM(N);
1108 case ISD::MULHU: return visitMULHU(N);
1109 case ISD::MULHS: return visitMULHS(N);
1110 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
1111 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
1112 case ISD::SMULO: return visitSMULO(N);
1113 case ISD::UMULO: return visitUMULO(N);
1114 case ISD::SDIVREM: return visitSDIVREM(N);
1115 case ISD::UDIVREM: return visitUDIVREM(N);
1116 case ISD::AND: return visitAND(N);
1117 case ISD::OR: return visitOR(N);
1118 case ISD::XOR: return visitXOR(N);
1119 case ISD::SHL: return visitSHL(N);
1120 case ISD::SRA: return visitSRA(N);
1121 case ISD::SRL: return visitSRL(N);
1122 case ISD::CTLZ: return visitCTLZ(N);
1123 case ISD::CTLZ_ZERO_UNDEF: return visitCTLZ_ZERO_UNDEF(N);
1124 case ISD::CTTZ: return visitCTTZ(N);
1125 case ISD::CTTZ_ZERO_UNDEF: return visitCTTZ_ZERO_UNDEF(N);
1126 case ISD::CTPOP: return visitCTPOP(N);
1127 case ISD::SELECT: return visitSELECT(N);
1128 case ISD::SELECT_CC: return visitSELECT_CC(N);
1129 case ISD::SETCC: return visitSETCC(N);
1130 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
1131 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
1132 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
1133 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
1134 case ISD::TRUNCATE: return visitTRUNCATE(N);
1135 case ISD::BITCAST: return visitBITCAST(N);
1136 case ISD::BUILD_PAIR: return visitBUILD_PAIR(N);
1137 case ISD::FADD: return visitFADD(N);
1138 case ISD::FSUB: return visitFSUB(N);
1139 case ISD::FMUL: return visitFMUL(N);
1140 case ISD::FMA: return visitFMA(N);
1141 case ISD::FDIV: return visitFDIV(N);
1142 case ISD::FREM: return visitFREM(N);
1143 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
1144 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
1145 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
1146 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
1147 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
1148 case ISD::FP_ROUND: return visitFP_ROUND(N);
1149 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
1150 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
1151 case ISD::FNEG: return visitFNEG(N);
1152 case ISD::FABS: return visitFABS(N);
1153 case ISD::FFLOOR: return visitFFLOOR(N);
1154 case ISD::FCEIL: return visitFCEIL(N);
1155 case ISD::FTRUNC: return visitFTRUNC(N);
1156 case ISD::BRCOND: return visitBRCOND(N);
1157 case ISD::BR_CC: return visitBR_CC(N);
1158 case ISD::LOAD: return visitLOAD(N);
1159 case ISD::STORE: return visitSTORE(N);
1160 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
1161 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
1162 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
1163 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
1164 case ISD::EXTRACT_SUBVECTOR: return visitEXTRACT_SUBVECTOR(N);
1165 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
1166 case ISD::MEMBARRIER: return visitMEMBARRIER(N);
1171 SDValue DAGCombiner::combine(SDNode *N) {
1172 SDValue RV = visit(N);
1174 // If nothing happened, try a target-specific DAG combine.
1175 if (RV.getNode() == 0) {
1176 assert(N->getOpcode() != ISD::DELETED_NODE &&
1177 "Node was deleted but visit returned NULL!");
1179 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
1180 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
1182 // Expose the DAG combiner to the target combiner impls.
1183 TargetLowering::DAGCombinerInfo
1184 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
1186 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
1190 // If nothing happened still, try promoting the operation.
1191 if (RV.getNode() == 0) {
1192 switch (N->getOpcode()) {
1200 RV = PromoteIntBinOp(SDValue(N, 0));
1205 RV = PromoteIntShiftOp(SDValue(N, 0));
1207 case ISD::SIGN_EXTEND:
1208 case ISD::ZERO_EXTEND:
1209 case ISD::ANY_EXTEND:
1210 RV = PromoteExtend(SDValue(N, 0));
1213 if (PromoteLoad(SDValue(N, 0)))
1219 // If N is a commutative binary node, try commuting it to enable more
1221 if (RV.getNode() == 0 &&
1222 SelectionDAG::isCommutativeBinOp(N->getOpcode()) &&
1223 N->getNumValues() == 1) {
1224 SDValue N0 = N->getOperand(0);
1225 SDValue N1 = N->getOperand(1);
1227 // Constant operands are canonicalized to RHS.
1228 if (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1)) {
1229 SDValue Ops[] = { N1, N0 };
1230 SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(),
1233 return SDValue(CSENode, 0);
1240 /// getInputChainForNode - Given a node, return its input chain if it has one,
1241 /// otherwise return a null sd operand.
1242 static SDValue getInputChainForNode(SDNode *N) {
1243 if (unsigned NumOps = N->getNumOperands()) {
1244 if (N->getOperand(0).getValueType() == MVT::Other)
1245 return N->getOperand(0);
1246 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
1247 return N->getOperand(NumOps-1);
1248 for (unsigned i = 1; i < NumOps-1; ++i)
1249 if (N->getOperand(i).getValueType() == MVT::Other)
1250 return N->getOperand(i);
1255 SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
1256 // If N has two operands, where one has an input chain equal to the other,
1257 // the 'other' chain is redundant.
1258 if (N->getNumOperands() == 2) {
1259 if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
1260 return N->getOperand(0);
1261 if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
1262 return N->getOperand(1);
1265 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
1266 SmallVector<SDValue, 8> Ops; // Ops for replacing token factor.
1267 SmallPtrSet<SDNode*, 16> SeenOps;
1268 bool Changed = false; // If we should replace this token factor.
1270 // Start out with this token factor.
1273 // Iterate through token factors. The TFs grows when new token factors are
1275 for (unsigned i = 0; i < TFs.size(); ++i) {
1276 SDNode *TF = TFs[i];
1278 // Check each of the operands.
1279 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
1280 SDValue Op = TF->getOperand(i);
1282 switch (Op.getOpcode()) {
1283 case ISD::EntryToken:
1284 // Entry tokens don't need to be added to the list. They are
1289 case ISD::TokenFactor:
1290 if (Op.hasOneUse() &&
1291 std::find(TFs.begin(), TFs.end(), Op.getNode()) == TFs.end()) {
1292 // Queue up for processing.
1293 TFs.push_back(Op.getNode());
1294 // Clean up in case the token factor is removed.
1295 AddToWorkList(Op.getNode());
1302 // Only add if it isn't already in the list.
1303 if (SeenOps.insert(Op.getNode()))
1314 // If we've change things around then replace token factor.
1317 // The entry token is the only possible outcome.
1318 Result = DAG.getEntryNode();
1320 // New and improved token factor.
1321 Result = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
1322 MVT::Other, &Ops[0], Ops.size());
1325 // Don't add users to work list.
1326 return CombineTo(N, Result, false);
1332 /// MERGE_VALUES can always be eliminated.
1333 SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
1334 WorkListRemover DeadNodes(*this);
1335 // Replacing results may cause a different MERGE_VALUES to suddenly
1336 // be CSE'd with N, and carry its uses with it. Iterate until no
1337 // uses remain, to ensure that the node can be safely deleted.
1338 // First add the users of this node to the work list so that they
1339 // can be tried again once they have new operands.
1340 AddUsersToWorkList(N);
1342 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
1343 DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
1344 } while (!N->use_empty());
1345 removeFromWorkList(N);
1347 return SDValue(N, 0); // Return N so it doesn't get rechecked!
1351 SDValue combineShlAddConstant(DebugLoc DL, SDValue N0, SDValue N1,
1352 SelectionDAG &DAG) {
1353 EVT VT = N0.getValueType();
1354 SDValue N00 = N0.getOperand(0);
1355 SDValue N01 = N0.getOperand(1);
1356 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
1358 if (N01C && N00.getOpcode() == ISD::ADD && N00.getNode()->hasOneUse() &&
1359 isa<ConstantSDNode>(N00.getOperand(1))) {
1360 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1361 N0 = DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
1362 DAG.getNode(ISD::SHL, N00.getDebugLoc(), VT,
1363 N00.getOperand(0), N01),
1364 DAG.getNode(ISD::SHL, N01.getDebugLoc(), VT,
1365 N00.getOperand(1), N01));
1366 return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
1372 SDValue DAGCombiner::visitADD(SDNode *N) {
1373 SDValue N0 = N->getOperand(0);
1374 SDValue N1 = N->getOperand(1);
1375 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1376 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1377 EVT VT = N0.getValueType();
1380 if (VT.isVector()) {
1381 SDValue FoldedVOp = SimplifyVBinOp(N);
1382 if (FoldedVOp.getNode()) return FoldedVOp;
1385 // fold (add x, undef) -> undef
1386 if (N0.getOpcode() == ISD::UNDEF)
1388 if (N1.getOpcode() == ISD::UNDEF)
1390 // fold (add c1, c2) -> c1+c2
1392 return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
1393 // canonicalize constant to RHS
1395 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0);
1396 // fold (add x, 0) -> x
1397 if (N1C && N1C->isNullValue())
1399 // fold (add Sym, c) -> Sym+c
1400 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1401 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA) && N1C &&
1402 GA->getOpcode() == ISD::GlobalAddress)
1403 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1405 (uint64_t)N1C->getSExtValue());
1406 // fold ((c1-A)+c2) -> (c1+c2)-A
1407 if (N1C && N0.getOpcode() == ISD::SUB)
1408 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
1409 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1410 DAG.getConstant(N1C->getAPIntValue()+
1411 N0C->getAPIntValue(), VT),
1414 SDValue RADD = ReassociateOps(ISD::ADD, N->getDebugLoc(), N0, N1);
1415 if (RADD.getNode() != 0)
1417 // fold ((0-A) + B) -> B-A
1418 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
1419 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
1420 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1, N0.getOperand(1));
1421 // fold (A + (0-B)) -> A-B
1422 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
1423 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
1424 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1.getOperand(1));
1425 // fold (A+(B-A)) -> B
1426 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
1427 return N1.getOperand(0);
1428 // fold ((B-A)+A) -> B
1429 if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
1430 return N0.getOperand(0);
1431 // fold (A+(B-(A+C))) to (B-C)
1432 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1433 N0 == N1.getOperand(1).getOperand(0))
1434 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1435 N1.getOperand(1).getOperand(1));
1436 // fold (A+(B-(C+A))) to (B-C)
1437 if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
1438 N0 == N1.getOperand(1).getOperand(1))
1439 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1.getOperand(0),
1440 N1.getOperand(1).getOperand(0));
1441 // fold (A+((B-A)+or-C)) to (B+or-C)
1442 if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
1443 N1.getOperand(0).getOpcode() == ISD::SUB &&
1444 N0 == N1.getOperand(0).getOperand(1))
1445 return DAG.getNode(N1.getOpcode(), N->getDebugLoc(), VT,
1446 N1.getOperand(0).getOperand(0), N1.getOperand(1));
1448 // fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
1449 if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
1450 SDValue N00 = N0.getOperand(0);
1451 SDValue N01 = N0.getOperand(1);
1452 SDValue N10 = N1.getOperand(0);
1453 SDValue N11 = N1.getOperand(1);
1455 if (isa<ConstantSDNode>(N00) || isa<ConstantSDNode>(N10))
1456 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1457 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT, N00, N10),
1458 DAG.getNode(ISD::ADD, N1.getDebugLoc(), VT, N01, N11));
1461 if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
1462 return SDValue(N, 0);
1464 // fold (a+b) -> (a|b) iff a and b share no bits.
1465 if (VT.isInteger() && !VT.isVector()) {
1466 APInt LHSZero, LHSOne;
1467 APInt RHSZero, RHSOne;
1468 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1470 if (LHSZero.getBoolValue()) {
1471 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1473 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1474 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1475 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1476 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1);
1480 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1481 if (N0.getOpcode() == ISD::SHL && N0.getNode()->hasOneUse()) {
1482 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N0, N1, DAG);
1483 if (Result.getNode()) return Result;
1485 if (N1.getOpcode() == ISD::SHL && N1.getNode()->hasOneUse()) {
1486 SDValue Result = combineShlAddConstant(N->getDebugLoc(), N1, N0, DAG);
1487 if (Result.getNode()) return Result;
1490 // fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
1491 if (N1.getOpcode() == ISD::SHL &&
1492 N1.getOperand(0).getOpcode() == ISD::SUB)
1493 if (ConstantSDNode *C =
1494 dyn_cast<ConstantSDNode>(N1.getOperand(0).getOperand(0)))
1495 if (C->getAPIntValue() == 0)
1496 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0,
1497 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1498 N1.getOperand(0).getOperand(1),
1500 if (N0.getOpcode() == ISD::SHL &&
1501 N0.getOperand(0).getOpcode() == ISD::SUB)
1502 if (ConstantSDNode *C =
1503 dyn_cast<ConstantSDNode>(N0.getOperand(0).getOperand(0)))
1504 if (C->getAPIntValue() == 0)
1505 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N1,
1506 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1507 N0.getOperand(0).getOperand(1),
1510 if (N1.getOpcode() == ISD::AND) {
1511 SDValue AndOp0 = N1.getOperand(0);
1512 ConstantSDNode *AndOp1 = dyn_cast<ConstantSDNode>(N1->getOperand(1));
1513 unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
1514 unsigned DestBits = VT.getScalarType().getSizeInBits();
1516 // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
1517 // and similar xforms where the inner op is either ~0 or 0.
1518 if (NumSignBits == DestBits && AndOp1 && AndOp1->isOne()) {
1519 DebugLoc DL = N->getDebugLoc();
1520 return DAG.getNode(ISD::SUB, DL, VT, N->getOperand(0), AndOp0);
1524 // add (sext i1), X -> sub X, (zext i1)
1525 if (N0.getOpcode() == ISD::SIGN_EXTEND &&
1526 N0.getOperand(0).getValueType() == MVT::i1 &&
1527 !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
1528 DebugLoc DL = N->getDebugLoc();
1529 SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
1530 return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
1536 SDValue DAGCombiner::visitADDC(SDNode *N) {
1537 SDValue N0 = N->getOperand(0);
1538 SDValue N1 = N->getOperand(1);
1539 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1540 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1541 EVT VT = N0.getValueType();
1543 // If the flag result is dead, turn this into an ADD.
1544 if (!N->hasAnyUseOfValue(1))
1545 return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, N1),
1546 DAG.getNode(ISD::CARRY_FALSE,
1547 N->getDebugLoc(), MVT::Glue));
1549 // canonicalize constant to RHS.
1551 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
1553 // fold (addc x, 0) -> x + no carry out
1554 if (N1C && N1C->isNullValue())
1555 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
1556 N->getDebugLoc(), MVT::Glue));
1558 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
1559 APInt LHSZero, LHSOne;
1560 APInt RHSZero, RHSOne;
1561 DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
1563 if (LHSZero.getBoolValue()) {
1564 DAG.ComputeMaskedBits(N1, RHSZero, RHSOne);
1566 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1567 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1568 if ((RHSZero & ~LHSZero) == ~LHSZero || (LHSZero & ~RHSZero) == ~RHSZero)
1569 return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
1570 DAG.getNode(ISD::CARRY_FALSE,
1571 N->getDebugLoc(), MVT::Glue));
1577 SDValue DAGCombiner::visitADDE(SDNode *N) {
1578 SDValue N0 = N->getOperand(0);
1579 SDValue N1 = N->getOperand(1);
1580 SDValue CarryIn = N->getOperand(2);
1581 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1582 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1584 // canonicalize constant to RHS
1586 return DAG.getNode(ISD::ADDE, N->getDebugLoc(), N->getVTList(),
1589 // fold (adde x, y, false) -> (addc x, y)
1590 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1591 return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N0, N1);
1596 // Since it may not be valid to emit a fold to zero for vector initializers
1597 // check if we can before folding.
1598 static SDValue tryFoldToZero(DebugLoc DL, const TargetLowering &TLI, EVT VT,
1599 SelectionDAG &DAG, bool LegalOperations) {
1600 if (!VT.isVector()) {
1601 return DAG.getConstant(0, VT);
1603 if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
1604 // Produce a vector of zeros.
1605 SDValue El = DAG.getConstant(0, VT.getVectorElementType());
1606 std::vector<SDValue> Ops(VT.getVectorNumElements(), El);
1607 return DAG.getNode(ISD::BUILD_VECTOR, DL, VT,
1608 &Ops[0], Ops.size());
1613 SDValue DAGCombiner::visitSUB(SDNode *N) {
1614 SDValue N0 = N->getOperand(0);
1615 SDValue N1 = N->getOperand(1);
1616 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1617 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1618 ConstantSDNode *N1C1 = N1.getOpcode() != ISD::ADD ? 0 :
1619 dyn_cast<ConstantSDNode>(N1.getOperand(1).getNode());
1620 EVT VT = N0.getValueType();
1623 if (VT.isVector()) {
1624 SDValue FoldedVOp = SimplifyVBinOp(N);
1625 if (FoldedVOp.getNode()) return FoldedVOp;
1628 // fold (sub x, x) -> 0
1629 // FIXME: Refactor this and xor and other similar operations together.
1631 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
1632 // fold (sub c1, c2) -> c1-c2
1634 return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
1635 // fold (sub x, c) -> (add x, -c)
1637 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0,
1638 DAG.getConstant(-N1C->getAPIntValue(), VT));
1639 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
1640 if (N0C && N0C->isAllOnesValue())
1641 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
1642 // fold A-(A-B) -> B
1643 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
1644 return N1.getOperand(1);
1645 // fold (A+B)-A -> B
1646 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
1647 return N0.getOperand(1);
1648 // fold (A+B)-B -> A
1649 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
1650 return N0.getOperand(0);
1651 // fold C2-(A+C1) -> (C2-C1)-A
1652 if (N1.getOpcode() == ISD::ADD && N0C && N1C1) {
1653 SDValue NewC = DAG.getConstant(N0C->getAPIntValue() - N1C1->getAPIntValue(),
1655 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, NewC,
1658 // fold ((A+(B+or-C))-B) -> A+or-C
1659 if (N0.getOpcode() == ISD::ADD &&
1660 (N0.getOperand(1).getOpcode() == ISD::SUB ||
1661 N0.getOperand(1).getOpcode() == ISD::ADD) &&
1662 N0.getOperand(1).getOperand(0) == N1)
1663 return DAG.getNode(N0.getOperand(1).getOpcode(), N->getDebugLoc(), VT,
1664 N0.getOperand(0), N0.getOperand(1).getOperand(1));
1665 // fold ((A+(C+B))-B) -> A+C
1666 if (N0.getOpcode() == ISD::ADD &&
1667 N0.getOperand(1).getOpcode() == ISD::ADD &&
1668 N0.getOperand(1).getOperand(1) == N1)
1669 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1670 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1671 // fold ((A-(B-C))-C) -> A-B
1672 if (N0.getOpcode() == ISD::SUB &&
1673 N0.getOperand(1).getOpcode() == ISD::SUB &&
1674 N0.getOperand(1).getOperand(1) == N1)
1675 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1676 N0.getOperand(0), N0.getOperand(1).getOperand(0));
1678 // If either operand of a sub is undef, the result is undef
1679 if (N0.getOpcode() == ISD::UNDEF)
1681 if (N1.getOpcode() == ISD::UNDEF)
1684 // If the relocation model supports it, consider symbol offsets.
1685 if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
1686 if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
1687 // fold (sub Sym, c) -> Sym-c
1688 if (N1C && GA->getOpcode() == ISD::GlobalAddress)
1689 return DAG.getGlobalAddress(GA->getGlobal(), N1C->getDebugLoc(), VT,
1691 (uint64_t)N1C->getSExtValue());
1692 // fold (sub Sym+c1, Sym+c2) -> c1-c2
1693 if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
1694 if (GA->getGlobal() == GB->getGlobal())
1695 return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
1702 SDValue DAGCombiner::visitSUBC(SDNode *N) {
1703 SDValue N0 = N->getOperand(0);
1704 SDValue N1 = N->getOperand(1);
1705 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1706 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1707 EVT VT = N0.getValueType();
1709 // If the flag result is dead, turn this into an SUB.
1710 if (!N->hasAnyUseOfValue(1))
1711 return CombineTo(N, DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, N1),
1712 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1715 // fold (subc x, x) -> 0 + no borrow
1717 return CombineTo(N, DAG.getConstant(0, VT),
1718 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1721 // fold (subc x, 0) -> x + no borrow
1722 if (N1C && N1C->isNullValue())
1723 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1726 // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
1727 if (N0C && N0C->isAllOnesValue())
1728 return CombineTo(N, DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0),
1729 DAG.getNode(ISD::CARRY_FALSE, N->getDebugLoc(),
1735 SDValue DAGCombiner::visitSUBE(SDNode *N) {
1736 SDValue N0 = N->getOperand(0);
1737 SDValue N1 = N->getOperand(1);
1738 SDValue CarryIn = N->getOperand(2);
1740 // fold (sube x, y, false) -> (subc x, y)
1741 if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
1742 return DAG.getNode(ISD::SUBC, N->getDebugLoc(), N->getVTList(), N0, N1);
1747 SDValue DAGCombiner::visitMUL(SDNode *N) {
1748 SDValue N0 = N->getOperand(0);
1749 SDValue N1 = N->getOperand(1);
1750 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1751 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1752 EVT VT = N0.getValueType();
1755 if (VT.isVector()) {
1756 SDValue FoldedVOp = SimplifyVBinOp(N);
1757 if (FoldedVOp.getNode()) return FoldedVOp;
1760 // fold (mul x, undef) -> 0
1761 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
1762 return DAG.getConstant(0, VT);
1763 // fold (mul c1, c2) -> c1*c2
1765 return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0C, N1C);
1766 // canonicalize constant to RHS
1768 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT, N1, N0);
1769 // fold (mul x, 0) -> 0
1770 if (N1C && N1C->isNullValue())
1772 // fold (mul x, -1) -> 0-x
1773 if (N1C && N1C->isAllOnesValue())
1774 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1775 DAG.getConstant(0, VT), N0);
1776 // fold (mul x, (1 << c)) -> x << c
1777 if (N1C && N1C->getAPIntValue().isPowerOf2())
1778 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1779 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1780 getShiftAmountTy(N0.getValueType())));
1781 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1782 if (N1C && (-N1C->getAPIntValue()).isPowerOf2()) {
1783 unsigned Log2Val = (-N1C->getAPIntValue()).logBase2();
1784 // FIXME: If the input is something that is easily negated (e.g. a
1785 // single-use add), we should put the negate there.
1786 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1787 DAG.getConstant(0, VT),
1788 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
1789 DAG.getConstant(Log2Val,
1790 getShiftAmountTy(N0.getValueType()))));
1792 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1793 if (N1C && N0.getOpcode() == ISD::SHL &&
1794 isa<ConstantSDNode>(N0.getOperand(1))) {
1795 SDValue C3 = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1796 N1, N0.getOperand(1));
1797 AddToWorkList(C3.getNode());
1798 return DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1799 N0.getOperand(0), C3);
1802 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1805 SDValue Sh(0,0), Y(0,0);
1806 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1807 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1808 N0.getNode()->hasOneUse()) {
1810 } else if (N1.getOpcode() == ISD::SHL &&
1811 isa<ConstantSDNode>(N1.getOperand(1)) &&
1812 N1.getNode()->hasOneUse()) {
1817 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
1818 Sh.getOperand(0), Y);
1819 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT,
1820 Mul, Sh.getOperand(1));
1824 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1825 if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
1826 isa<ConstantSDNode>(N0.getOperand(1)))
1827 return DAG.getNode(ISD::ADD, N->getDebugLoc(), VT,
1828 DAG.getNode(ISD::MUL, N0.getDebugLoc(), VT,
1829 N0.getOperand(0), N1),
1830 DAG.getNode(ISD::MUL, N1.getDebugLoc(), VT,
1831 N0.getOperand(1), N1));
1834 SDValue RMUL = ReassociateOps(ISD::MUL, N->getDebugLoc(), N0, N1);
1835 if (RMUL.getNode() != 0)
1841 SDValue DAGCombiner::visitSDIV(SDNode *N) {
1842 SDValue N0 = N->getOperand(0);
1843 SDValue N1 = N->getOperand(1);
1844 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1845 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1846 EVT VT = N->getValueType(0);
1849 if (VT.isVector()) {
1850 SDValue FoldedVOp = SimplifyVBinOp(N);
1851 if (FoldedVOp.getNode()) return FoldedVOp;
1854 // fold (sdiv c1, c2) -> c1/c2
1855 if (N0C && N1C && !N1C->isNullValue())
1856 return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
1857 // fold (sdiv X, 1) -> X
1858 if (N1C && N1C->getAPIntValue() == 1LL)
1860 // fold (sdiv X, -1) -> 0-X
1861 if (N1C && N1C->isAllOnesValue())
1862 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1863 DAG.getConstant(0, VT), N0);
1864 // If we know the sign bits of both operands are zero, strength reduce to a
1865 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
1866 if (!VT.isVector()) {
1867 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1868 return DAG.getNode(ISD::UDIV, N->getDebugLoc(), N1.getValueType(),
1871 // fold (sdiv X, pow2) -> simple ops after legalize
1872 if (N1C && !N1C->isNullValue() &&
1873 (N1C->getAPIntValue().isPowerOf2() ||
1874 (-N1C->getAPIntValue()).isPowerOf2())) {
1875 // If dividing by powers of two is cheap, then don't perform the following
1877 if (TLI.isPow2DivCheap())
1880 unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();
1882 // Splat the sign bit into the register
1883 SDValue SGN = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
1884 DAG.getConstant(VT.getSizeInBits()-1,
1885 getShiftAmountTy(N0.getValueType())));
1886 AddToWorkList(SGN.getNode());
1888 // Add (N0 < 0) ? abs2 - 1 : 0;
1889 SDValue SRL = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, SGN,
1890 DAG.getConstant(VT.getSizeInBits() - lg2,
1891 getShiftAmountTy(SGN.getValueType())));
1892 SDValue ADD = DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N0, SRL);
1893 AddToWorkList(SRL.getNode());
1894 AddToWorkList(ADD.getNode()); // Divide by pow2
1895 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, ADD,
1896 DAG.getConstant(lg2, getShiftAmountTy(ADD.getValueType())));
1898 // If we're dividing by a positive value, we're done. Otherwise, we must
1899 // negate the result.
1900 if (N1C->getAPIntValue().isNonNegative())
1903 AddToWorkList(SRA.getNode());
1904 return DAG.getNode(ISD::SUB, N->getDebugLoc(), VT,
1905 DAG.getConstant(0, VT), SRA);
1908 // if integer divide is expensive and we satisfy the requirements, emit an
1909 // alternate sequence.
1910 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1911 SDValue Op = BuildSDIV(N);
1912 if (Op.getNode()) return Op;
1916 if (N0.getOpcode() == ISD::UNDEF)
1917 return DAG.getConstant(0, VT);
1918 // X / undef -> undef
1919 if (N1.getOpcode() == ISD::UNDEF)
1925 SDValue DAGCombiner::visitUDIV(SDNode *N) {
1926 SDValue N0 = N->getOperand(0);
1927 SDValue N1 = N->getOperand(1);
1928 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getNode());
1929 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
1930 EVT VT = N->getValueType(0);
1933 if (VT.isVector()) {
1934 SDValue FoldedVOp = SimplifyVBinOp(N);
1935 if (FoldedVOp.getNode()) return FoldedVOp;
1938 // fold (udiv c1, c2) -> c1/c2
1939 if (N0C && N1C && !N1C->isNullValue())
1940 return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
1941 // fold (udiv x, (1 << c)) -> x >>u c
1942 if (N1C && N1C->getAPIntValue().isPowerOf2())
1943 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
1944 DAG.getConstant(N1C->getAPIntValue().logBase2(),
1945 getShiftAmountTy(N0.getValueType())));
1946 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1947 if (N1.getOpcode() == ISD::SHL) {
1948 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
1949 if (SHC->getAPIntValue().isPowerOf2()) {
1950 EVT ADDVT = N1.getOperand(1).getValueType();
1951 SDValue Add = DAG.getNode(ISD::ADD, N->getDebugLoc(), ADDVT,
1953 DAG.getConstant(SHC->getAPIntValue()
1956 AddToWorkList(Add.getNode());
1957 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, Add);
1961 // fold (udiv x, c) -> alternate
1962 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
1963 SDValue Op = BuildUDIV(N);
1964 if (Op.getNode()) return Op;
1968 if (N0.getOpcode() == ISD::UNDEF)
1969 return DAG.getConstant(0, VT);
1970 // X / undef -> undef
1971 if (N1.getOpcode() == ISD::UNDEF)
1977 SDValue DAGCombiner::visitSREM(SDNode *N) {
1978 SDValue N0 = N->getOperand(0);
1979 SDValue N1 = N->getOperand(1);
1980 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1981 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1982 EVT VT = N->getValueType(0);
1984 // fold (srem c1, c2) -> c1%c2
1985 if (N0C && N1C && !N1C->isNullValue())
1986 return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
1987 // If we know the sign bits of both operands are zero, strength reduce to a
1988 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
1989 if (!VT.isVector()) {
1990 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
1991 return DAG.getNode(ISD::UREM, N->getDebugLoc(), VT, N0, N1);
1994 // If X/C can be simplified by the division-by-constant logic, lower
1995 // X%C to the equivalent of X-X/C*C.
1996 if (N1C && !N1C->isNullValue()) {
1997 SDValue Div = DAG.getNode(ISD::SDIV, N->getDebugLoc(), VT, N0, N1);
1998 AddToWorkList(Div.getNode());
1999 SDValue OptimizedDiv = combine(Div.getNode());
2000 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2001 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
2003 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
2004 AddToWorkList(Mul.getNode());
2010 if (N0.getOpcode() == ISD::UNDEF)
2011 return DAG.getConstant(0, VT);
2012 // X % undef -> undef
2013 if (N1.getOpcode() == ISD::UNDEF)
2019 SDValue DAGCombiner::visitUREM(SDNode *N) {
2020 SDValue N0 = N->getOperand(0);
2021 SDValue N1 = N->getOperand(1);
2022 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2023 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2024 EVT VT = N->getValueType(0);
2026 // fold (urem c1, c2) -> c1%c2
2027 if (N0C && N1C && !N1C->isNullValue())
2028 return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
2029 // fold (urem x, pow2) -> (and x, pow2-1)
2030 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
2031 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0,
2032 DAG.getConstant(N1C->getAPIntValue()-1,VT));
2033 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
2034 if (N1.getOpcode() == ISD::SHL) {
2035 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
2036 if (SHC->getAPIntValue().isPowerOf2()) {
2038 DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1,
2039 DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()),
2041 AddToWorkList(Add.getNode());
2042 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, Add);
2047 // If X/C can be simplified by the division-by-constant logic, lower
2048 // X%C to the equivalent of X-X/C*C.
2049 if (N1C && !N1C->isNullValue()) {
2050 SDValue Div = DAG.getNode(ISD::UDIV, N->getDebugLoc(), VT, N0, N1);
2051 AddToWorkList(Div.getNode());
2052 SDValue OptimizedDiv = combine(Div.getNode());
2053 if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
2054 SDValue Mul = DAG.getNode(ISD::MUL, N->getDebugLoc(), VT,
2056 SDValue Sub = DAG.getNode(ISD::SUB, N->getDebugLoc(), VT, N0, Mul);
2057 AddToWorkList(Mul.getNode());
2063 if (N0.getOpcode() == ISD::UNDEF)
2064 return DAG.getConstant(0, VT);
2065 // X % undef -> undef
2066 if (N1.getOpcode() == ISD::UNDEF)
2072 SDValue DAGCombiner::visitMULHS(SDNode *N) {
2073 SDValue N0 = N->getOperand(0);
2074 SDValue N1 = N->getOperand(1);
2075 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2076 EVT VT = N->getValueType(0);
2077 DebugLoc DL = N->getDebugLoc();
2079 // fold (mulhs x, 0) -> 0
2080 if (N1C && N1C->isNullValue())
2082 // fold (mulhs x, 1) -> (sra x, size(x)-1)
2083 if (N1C && N1C->getAPIntValue() == 1)
2084 return DAG.getNode(ISD::SRA, N->getDebugLoc(), N0.getValueType(), N0,
2085 DAG.getConstant(N0.getValueType().getSizeInBits() - 1,
2086 getShiftAmountTy(N0.getValueType())));
2087 // fold (mulhs x, undef) -> 0
2088 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2089 return DAG.getConstant(0, VT);
2091 // If the type twice as wide is legal, transform the mulhs to a wider multiply
2093 if (VT.isSimple() && !VT.isVector()) {
2094 MVT Simple = VT.getSimpleVT();
2095 unsigned SimpleSize = Simple.getSizeInBits();
2096 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2097 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2098 N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
2099 N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
2100 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2101 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2102 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2103 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2110 SDValue DAGCombiner::visitMULHU(SDNode *N) {
2111 SDValue N0 = N->getOperand(0);
2112 SDValue N1 = N->getOperand(1);
2113 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2114 EVT VT = N->getValueType(0);
2115 DebugLoc DL = N->getDebugLoc();
2117 // fold (mulhu x, 0) -> 0
2118 if (N1C && N1C->isNullValue())
2120 // fold (mulhu x, 1) -> 0
2121 if (N1C && N1C->getAPIntValue() == 1)
2122 return DAG.getConstant(0, N0.getValueType());
2123 // fold (mulhu x, undef) -> 0
2124 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2125 return DAG.getConstant(0, VT);
2127 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2129 if (VT.isSimple() && !VT.isVector()) {
2130 MVT Simple = VT.getSimpleVT();
2131 unsigned SimpleSize = Simple.getSizeInBits();
2132 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2133 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2134 N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
2135 N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
2136 N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
2137 N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
2138 DAG.getConstant(SimpleSize, getShiftAmountTy(N1.getValueType())));
2139 return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
2146 /// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
2147 /// compute two values. LoOp and HiOp give the opcodes for the two computations
2148 /// that are being performed. Return true if a simplification was made.
2150 SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
2152 // If the high half is not needed, just compute the low half.
2153 bool HiExists = N->hasAnyUseOfValue(1);
2155 (!LegalOperations ||
2156 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
2157 SDValue Res = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2158 N->op_begin(), N->getNumOperands());
2159 return CombineTo(N, Res, Res);
2162 // If the low half is not needed, just compute the high half.
2163 bool LoExists = N->hasAnyUseOfValue(0);
2165 (!LegalOperations ||
2166 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
2167 SDValue Res = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2168 N->op_begin(), N->getNumOperands());
2169 return CombineTo(N, Res, Res);
2172 // If both halves are used, return as it is.
2173 if (LoExists && HiExists)
2176 // If the two computed results can be simplified separately, separate them.
2178 SDValue Lo = DAG.getNode(LoOp, N->getDebugLoc(), N->getValueType(0),
2179 N->op_begin(), N->getNumOperands());
2180 AddToWorkList(Lo.getNode());
2181 SDValue LoOpt = combine(Lo.getNode());
2182 if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
2183 (!LegalOperations ||
2184 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
2185 return CombineTo(N, LoOpt, LoOpt);
2189 SDValue Hi = DAG.getNode(HiOp, N->getDebugLoc(), N->getValueType(1),
2190 N->op_begin(), N->getNumOperands());
2191 AddToWorkList(Hi.getNode());
2192 SDValue HiOpt = combine(Hi.getNode());
2193 if (HiOpt.getNode() && HiOpt != Hi &&
2194 (!LegalOperations ||
2195 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
2196 return CombineTo(N, HiOpt, HiOpt);
2202 SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
2203 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
2204 if (Res.getNode()) return Res;
2206 EVT VT = N->getValueType(0);
2207 DebugLoc DL = N->getDebugLoc();
2209 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2211 if (VT.isSimple() && !VT.isVector()) {
2212 MVT Simple = VT.getSimpleVT();
2213 unsigned SimpleSize = Simple.getSizeInBits();
2214 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2215 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2216 SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
2217 SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
2218 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2219 // Compute the high part as N1.
2220 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2221 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2222 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2223 // Compute the low part as N0.
2224 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2225 return CombineTo(N, Lo, Hi);
2232 SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
2233 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
2234 if (Res.getNode()) return Res;
2236 EVT VT = N->getValueType(0);
2237 DebugLoc DL = N->getDebugLoc();
2239 // If the type twice as wide is legal, transform the mulhu to a wider multiply
2241 if (VT.isSimple() && !VT.isVector()) {
2242 MVT Simple = VT.getSimpleVT();
2243 unsigned SimpleSize = Simple.getSizeInBits();
2244 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
2245 if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
2246 SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
2247 SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
2248 Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
2249 // Compute the high part as N1.
2250 Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
2251 DAG.getConstant(SimpleSize, getShiftAmountTy(Lo.getValueType())));
2252 Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
2253 // Compute the low part as N0.
2254 Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
2255 return CombineTo(N, Lo, Hi);
2262 SDValue DAGCombiner::visitSMULO(SDNode *N) {
2263 // (smulo x, 2) -> (saddo x, x)
2264 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2265 if (C2->getAPIntValue() == 2)
2266 return DAG.getNode(ISD::SADDO, N->getDebugLoc(), N->getVTList(),
2267 N->getOperand(0), N->getOperand(0));
2272 SDValue DAGCombiner::visitUMULO(SDNode *N) {
2273 // (umulo x, 2) -> (uaddo x, x)
2274 if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
2275 if (C2->getAPIntValue() == 2)
2276 return DAG.getNode(ISD::UADDO, N->getDebugLoc(), N->getVTList(),
2277 N->getOperand(0), N->getOperand(0));
2282 SDValue DAGCombiner::visitSDIVREM(SDNode *N) {
2283 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
2284 if (Res.getNode()) return Res;
2289 SDValue DAGCombiner::visitUDIVREM(SDNode *N) {
2290 SDValue Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
2291 if (Res.getNode()) return Res;
2296 /// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
2297 /// two operands of the same opcode, try to simplify it.
2298 SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
2299 SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
2300 EVT VT = N0.getValueType();
2301 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
2303 // Bail early if none of these transforms apply.
2304 if (N0.getNode()->getNumOperands() == 0) return SDValue();
2306 // For each of OP in AND/OR/XOR:
2307 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
2308 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
2309 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
2310 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
2312 // do not sink logical op inside of a vector extend, since it may combine
2314 EVT Op0VT = N0.getOperand(0).getValueType();
2315 if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
2316 N0.getOpcode() == ISD::SIGN_EXTEND ||
2317 // Avoid infinite looping with PromoteIntBinOp.
2318 (N0.getOpcode() == ISD::ANY_EXTEND &&
2319 (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
2320 (N0.getOpcode() == ISD::TRUNCATE &&
2321 (!TLI.isZExtFree(VT, Op0VT) ||
2322 !TLI.isTruncateFree(Op0VT, VT)) &&
2323 TLI.isTypeLegal(Op0VT))) &&
2325 Op0VT == N1.getOperand(0).getValueType() &&
2326 (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
2327 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2328 N0.getOperand(0).getValueType(),
2329 N0.getOperand(0), N1.getOperand(0));
2330 AddToWorkList(ORNode.getNode());
2331 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, ORNode);
2334 // For each of OP in SHL/SRL/SRA/AND...
2335 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
2336 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
2337 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
2338 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
2339 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
2340 N0.getOperand(1) == N1.getOperand(1)) {
2341 SDValue ORNode = DAG.getNode(N->getOpcode(), N0.getDebugLoc(),
2342 N0.getOperand(0).getValueType(),
2343 N0.getOperand(0), N1.getOperand(0));
2344 AddToWorkList(ORNode.getNode());
2345 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
2346 ORNode, N0.getOperand(1));
2349 // Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
2350 // Only perform this optimization after type legalization and before
2351 // LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
2352 // adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
2353 // we don't want to undo this promotion.
2354 // We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
2356 if ((N0.getOpcode() == ISD::BITCAST ||
2357 N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
2358 Level == AfterLegalizeTypes) {
2359 SDValue In0 = N0.getOperand(0);
2360 SDValue In1 = N1.getOperand(0);
2361 EVT In0Ty = In0.getValueType();
2362 EVT In1Ty = In1.getValueType();
2363 DebugLoc DL = N->getDebugLoc();
2364 // If both incoming values are integers, and the original types are the
2366 if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
2367 SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
2368 SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
2369 AddToWorkList(Op.getNode());
2374 // Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
2375 // Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
2376 // If both shuffles use the same mask, and both shuffle within a single
2377 // vector, then it is worthwhile to move the swizzle after the operation.
2378 // The type-legalizer generates this pattern when loading illegal
2379 // vector types from memory. In many cases this allows additional shuffle
2381 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
2382 N0.getOperand(1).getOpcode() == ISD::UNDEF &&
2383 N1.getOperand(1).getOpcode() == ISD::UNDEF) {
2384 ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
2385 ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);
2387 assert(N0.getOperand(0).getValueType() == N1.getOperand(1).getValueType() &&
2388 "Inputs to shuffles are not the same type");
2390 unsigned NumElts = VT.getVectorNumElements();
2392 // Check that both shuffles use the same mask. The masks are known to be of
2393 // the same length because the result vector type is the same.
2394 bool SameMask = true;
2395 for (unsigned i = 0; i != NumElts; ++i) {
2396 int Idx0 = SVN0->getMaskElt(i);
2397 int Idx1 = SVN1->getMaskElt(i);
2405 SDValue Op = DAG.getNode(N->getOpcode(), N->getDebugLoc(), VT,
2406 N0.getOperand(0), N1.getOperand(0));
2407 AddToWorkList(Op.getNode());
2408 return DAG.getVectorShuffle(VT, N->getDebugLoc(), Op,
2409 DAG.getUNDEF(VT), &SVN0->getMask()[0]);
2416 SDValue DAGCombiner::visitAND(SDNode *N) {
2417 SDValue N0 = N->getOperand(0);
2418 SDValue N1 = N->getOperand(1);
2419 SDValue LL, LR, RL, RR, CC0, CC1;
2420 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2421 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2422 EVT VT = N1.getValueType();
2423 unsigned BitWidth = VT.getScalarType().getSizeInBits();
2426 if (VT.isVector()) {
2427 SDValue FoldedVOp = SimplifyVBinOp(N);
2428 if (FoldedVOp.getNode()) return FoldedVOp;
2431 // fold (and x, undef) -> 0
2432 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
2433 return DAG.getConstant(0, VT);
2434 // fold (and c1, c2) -> c1&c2
2436 return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
2437 // canonicalize constant to RHS
2439 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N1, N0);
2440 // fold (and x, -1) -> x
2441 if (N1C && N1C->isAllOnesValue())
2443 // if (and x, c) is known to be zero, return 0
2444 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
2445 APInt::getAllOnesValue(BitWidth)))
2446 return DAG.getConstant(0, VT);
2448 SDValue RAND = ReassociateOps(ISD::AND, N->getDebugLoc(), N0, N1);
2449 if (RAND.getNode() != 0)
2451 // fold (and (or x, C), D) -> D if (C & D) == D
2452 if (N1C && N0.getOpcode() == ISD::OR)
2453 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
2454 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
2456 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
2457 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2458 SDValue N0Op0 = N0.getOperand(0);
2459 APInt Mask = ~N1C->getAPIntValue();
2460 Mask = Mask.trunc(N0Op0.getValueSizeInBits());
2461 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
2462 SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(),
2463 N0.getValueType(), N0Op0);
2465 // Replace uses of the AND with uses of the Zero extend node.
2468 // We actually want to replace all uses of the any_extend with the
2469 // zero_extend, to avoid duplicating things. This will later cause this
2470 // AND to be folded.
2471 CombineTo(N0.getNode(), Zext);
2472 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2475 // similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
2476 // (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
2477 // already be zero by virtue of the width of the base type of the load.
2479 // the 'X' node here can either be nothing or an extract_vector_elt to catch
2481 if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
2482 N0.getOperand(0).getOpcode() == ISD::LOAD) ||
2483 N0.getOpcode() == ISD::LOAD) {
2484 LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
2485 N0 : N0.getOperand(0) );
2487 // Get the constant (if applicable) the zero'th operand is being ANDed with.
2488 // This can be a pure constant or a vector splat, in which case we treat the
2489 // vector as a scalar and use the splat value.
2490 APInt Constant = APInt::getNullValue(1);
2491 if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
2492 Constant = C->getAPIntValue();
2493 } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
2494 APInt SplatValue, SplatUndef;
2495 unsigned SplatBitSize;
2497 bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
2498 SplatBitSize, HasAnyUndefs);
2500 // Undef bits can contribute to a possible optimisation if set, so
2502 SplatValue |= SplatUndef;
2504 // The splat value may be something like "0x00FFFFFF", which means 0 for
2505 // the first vector value and FF for the rest, repeating. We need a mask
2506 // that will apply equally to all members of the vector, so AND all the
2507 // lanes of the constant together.
2508 EVT VT = Vector->getValueType(0);
2509 unsigned BitWidth = VT.getVectorElementType().getSizeInBits();
2511 // If the splat value has been compressed to a bitlength lower
2512 // than the size of the vector lane, we need to re-expand it to
2514 if (BitWidth > SplatBitSize)
2515 for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
2516 SplatBitSize < BitWidth;
2517 SplatBitSize = SplatBitSize * 2)
2518 SplatValue |= SplatValue.shl(SplatBitSize);
2520 Constant = APInt::getAllOnesValue(BitWidth);
2521 for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
2522 Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
2526 // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
2527 // actually legal and isn't going to get expanded, else this is a false
2529 bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
2530 Load->getMemoryVT());
2532 // Resize the constant to the same size as the original memory access before
2533 // extension. If it is still the AllOnesValue then this AND is completely
2536 Constant.zextOrTrunc(Load->getMemoryVT().getScalarType().getSizeInBits());
2539 switch (Load->getExtensionType()) {
2540 default: B = false; break;
2541 case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
2543 case ISD::NON_EXTLOAD: B = true; break;
2546 if (B && Constant.isAllOnesValue()) {
2547 // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
2548 // preserve semantics once we get rid of the AND.
2549 SDValue NewLoad(Load, 0);
2550 if (Load->getExtensionType() == ISD::EXTLOAD) {
2551 NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
2552 Load->getValueType(0), Load->getDebugLoc(),
2553 Load->getChain(), Load->getBasePtr(),
2554 Load->getOffset(), Load->getMemoryVT(),
2555 Load->getMemOperand());
2556 // Replace uses of the EXTLOAD with the new ZEXTLOAD.
2557 if (Load->getNumValues() == 3) {
2558 // PRE/POST_INC loads have 3 values.
2559 SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
2560 NewLoad.getValue(2) };
2561 CombineTo(Load, To, 3, true);
2563 CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
2567 // Fold the AND away, taking care not to fold to the old load node if we
2569 CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);
2571 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2574 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
2575 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
2576 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
2577 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
2579 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
2580 LL.getValueType().isInteger()) {
2581 // fold (and (seteq X, 0), (seteq Y, 0)) -> (seteq (or X, Y), 0)
2582 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
2583 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2584 LR.getValueType(), LL, RL);
2585 AddToWorkList(ORNode.getNode());
2586 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2588 // fold (and (seteq X, -1), (seteq Y, -1)) -> (seteq (and X, Y), -1)
2589 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
2590 SDValue ANDNode = DAG.getNode(ISD::AND, N0.getDebugLoc(),
2591 LR.getValueType(), LL, RL);
2592 AddToWorkList(ANDNode.getNode());
2593 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
2595 // fold (and (setgt X, -1), (setgt Y, -1)) -> (setgt (or X, Y), -1)
2596 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
2597 SDValue ORNode = DAG.getNode(ISD::OR, N0.getDebugLoc(),
2598 LR.getValueType(), LL, RL);
2599 AddToWorkList(ORNode.getNode());
2600 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
2603 // canonicalize equivalent to ll == rl
2604 if (LL == RR && LR == RL) {
2605 Op1 = ISD::getSetCCSwappedOperands(Op1);
2608 if (LL == RL && LR == RR) {
2609 bool isInteger = LL.getValueType().isInteger();
2610 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
2611 if (Result != ISD::SETCC_INVALID &&
2612 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
2613 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
2618 // Simplify: (and (op x...), (op y...)) -> (op (and x, y))
2619 if (N0.getOpcode() == N1.getOpcode()) {
2620 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2621 if (Tmp.getNode()) return Tmp;
2624 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
2625 // fold (and (sra)) -> (and (srl)) when possible.
2626 if (!VT.isVector() &&
2627 SimplifyDemandedBits(SDValue(N, 0)))
2628 return SDValue(N, 0);
2630 // fold (zext_inreg (extload x)) -> (zextload x)
2631 if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
2632 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2633 EVT MemVT = LN0->getMemoryVT();
2634 // If we zero all the possible extended bits, then we can turn this into
2635 // a zextload if we are running before legalize or the operation is legal.
2636 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2637 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2638 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2639 ((!LegalOperations && !LN0->isVolatile()) ||
2640 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2641 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2642 LN0->getChain(), LN0->getBasePtr(),
2643 LN0->getPointerInfo(), MemVT,
2644 LN0->isVolatile(), LN0->isNonTemporal(),
2645 LN0->getAlignment());
2647 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2648 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2651 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
2652 if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
2654 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2655 EVT MemVT = LN0->getMemoryVT();
2656 // If we zero all the possible extended bits, then we can turn this into
2657 // a zextload if we are running before legalize or the operation is legal.
2658 unsigned BitWidth = N1.getValueType().getScalarType().getSizeInBits();
2659 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
2660 BitWidth - MemVT.getScalarType().getSizeInBits())) &&
2661 ((!LegalOperations && !LN0->isVolatile()) ||
2662 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT))) {
2663 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N0.getDebugLoc(), VT,
2665 LN0->getBasePtr(), LN0->getPointerInfo(),
2667 LN0->isVolatile(), LN0->isNonTemporal(),
2668 LN0->getAlignment());
2670 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
2671 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2675 // fold (and (load x), 255) -> (zextload x, i8)
2676 // fold (and (extload x, i16), 255) -> (zextload x, i8)
2677 // fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
2678 if (N1C && (N0.getOpcode() == ISD::LOAD ||
2679 (N0.getOpcode() == ISD::ANY_EXTEND &&
2680 N0.getOperand(0).getOpcode() == ISD::LOAD))) {
2681 bool HasAnyExt = N0.getOpcode() == ISD::ANY_EXTEND;
2682 LoadSDNode *LN0 = HasAnyExt
2683 ? cast<LoadSDNode>(N0.getOperand(0))
2684 : cast<LoadSDNode>(N0);
2685 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
2686 LN0->isUnindexed() && N0.hasOneUse() && LN0->hasOneUse()) {
2687 uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
2688 if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
2689 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
2690 EVT LoadedVT = LN0->getMemoryVT();
2692 if (ExtVT == LoadedVT &&
2693 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2694 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2697 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2698 LN0->getChain(), LN0->getBasePtr(),
2699 LN0->getPointerInfo(),
2700 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2701 LN0->getAlignment());
2703 CombineTo(LN0, NewLoad, NewLoad.getValue(1));
2704 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2707 // Do not change the width of a volatile load.
2708 // Do not generate loads of non-round integer types since these can
2709 // be expensive (and would be wrong if the type is not byte sized).
2710 if (!LN0->isVolatile() && LoadedVT.bitsGT(ExtVT) && ExtVT.isRound() &&
2711 (!LegalOperations || TLI.isLoadExtLegal(ISD::ZEXTLOAD, ExtVT))) {
2712 EVT PtrType = LN0->getOperand(1).getValueType();
2714 unsigned Alignment = LN0->getAlignment();
2715 SDValue NewPtr = LN0->getBasePtr();
2717 // For big endian targets, we need to add an offset to the pointer
2718 // to load the correct bytes. For little endian systems, we merely
2719 // need to read fewer bytes from the same pointer.
2720 if (TLI.isBigEndian()) {
2721 unsigned LVTStoreBytes = LoadedVT.getStoreSize();
2722 unsigned EVTStoreBytes = ExtVT.getStoreSize();
2723 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
2724 NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(), PtrType,
2725 NewPtr, DAG.getConstant(PtrOff, PtrType));
2726 Alignment = MinAlign(Alignment, PtrOff);
2729 AddToWorkList(NewPtr.getNode());
2731 EVT LoadResultTy = HasAnyExt ? LN0->getValueType(0) : VT;
2733 DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), LoadResultTy,
2734 LN0->getChain(), NewPtr,
2735 LN0->getPointerInfo(),
2736 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
2739 CombineTo(LN0, Load, Load.getValue(1));
2740 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2746 if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
2747 VT.getSizeInBits() <= 64) {
2748 if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2749 APInt ADDC = ADDI->getAPIntValue();
2750 if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2751 // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
2752 // immediate for an add, but it is legal if its top c2 bits are set,
2753 // transform the ADD so the immediate doesn't need to be materialized
2755 if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
2756 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
2757 SRLI->getZExtValue());
2758 if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
2760 if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
2762 DAG.getNode(ISD::ADD, N0.getDebugLoc(), VT,
2763 N0.getOperand(0), DAG.getConstant(ADDC, VT));
2764 CombineTo(N0.getNode(), NewAdd);
2765 return SDValue(N, 0); // Return N so it doesn't get rechecked!
2777 /// MatchBSwapHWord - Match (a >> 8) | (a << 8) as (bswap a) >> 16
2779 SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
2780 bool DemandHighBits) {
2781 if (!LegalOperations)
2784 EVT VT = N->getValueType(0);
2785 if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
2787 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2790 // Recognize (and (shl a, 8), 0xff), (and (srl a, 8), 0xff00)
2791 bool LookPassAnd0 = false;
2792 bool LookPassAnd1 = false;
2793 if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
2795 if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
2797 if (N0.getOpcode() == ISD::AND) {
2798 if (!N0.getNode()->hasOneUse())
2800 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2801 if (!N01C || N01C->getZExtValue() != 0xFF00)
2803 N0 = N0.getOperand(0);
2804 LookPassAnd0 = true;
2807 if (N1.getOpcode() == ISD::AND) {
2808 if (!N1.getNode()->hasOneUse())
2810 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2811 if (!N11C || N11C->getZExtValue() != 0xFF)
2813 N1 = N1.getOperand(0);
2814 LookPassAnd1 = true;
2817 if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
2819 if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
2821 if (!N0.getNode()->hasOneUse() ||
2822 !N1.getNode()->hasOneUse())
2825 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2826 ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
2829 if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
2832 // Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
2833 SDValue N00 = N0->getOperand(0);
2834 if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
2835 if (!N00.getNode()->hasOneUse())
2837 ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
2838 if (!N001C || N001C->getZExtValue() != 0xFF)
2840 N00 = N00.getOperand(0);
2841 LookPassAnd0 = true;
2844 SDValue N10 = N1->getOperand(0);
2845 if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
2846 if (!N10.getNode()->hasOneUse())
2848 ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
2849 if (!N101C || N101C->getZExtValue() != 0xFF00)
2851 N10 = N10.getOperand(0);
2852 LookPassAnd1 = true;
2858 // Make sure everything beyond the low halfword is zero since the SRL 16
2859 // will clear the top bits.
2860 unsigned OpSizeInBits = VT.getSizeInBits();
2861 if (DemandHighBits && OpSizeInBits > 16 &&
2862 (!LookPassAnd0 || !LookPassAnd1) &&
2863 !DAG.MaskedValueIsZero(N10, APInt::getHighBitsSet(OpSizeInBits, 16)))
2866 SDValue Res = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT, N00);
2867 if (OpSizeInBits > 16)
2868 Res = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Res,
2869 DAG.getConstant(OpSizeInBits-16, getShiftAmountTy(VT)));
2873 /// isBSwapHWordElement - Return true if the specified node is an element
2874 /// that makes up a 32-bit packed halfword byteswap. i.e.
2875 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2876 static bool isBSwapHWordElement(SDValue N, SmallVector<SDNode*,4> &Parts) {
2877 if (!N.getNode()->hasOneUse())
2880 unsigned Opc = N.getOpcode();
2881 if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
2884 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2889 switch (N1C->getZExtValue()) {
2892 case 0xFF: Num = 0; break;
2893 case 0xFF00: Num = 1; break;
2894 case 0xFF0000: Num = 2; break;
2895 case 0xFF000000: Num = 3; break;
2898 // Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
2899 SDValue N0 = N.getOperand(0);
2900 if (Opc == ISD::AND) {
2901 if (Num == 0 || Num == 2) {
2903 // (x >> 8) & 0xff0000
2904 if (N0.getOpcode() != ISD::SRL)
2906 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2907 if (!C || C->getZExtValue() != 8)
2910 // (x << 8) & 0xff00
2911 // (x << 8) & 0xff000000
2912 if (N0.getOpcode() != ISD::SHL)
2914 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2915 if (!C || C->getZExtValue() != 8)
2918 } else if (Opc == ISD::SHL) {
2920 // (x & 0xff0000) << 8
2921 if (Num != 0 && Num != 2)
2923 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2924 if (!C || C->getZExtValue() != 8)
2926 } else { // Opc == ISD::SRL
2927 // (x & 0xff00) >> 8
2928 // (x & 0xff000000) >> 8
2929 if (Num != 1 && Num != 3)
2931 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
2932 if (!C || C->getZExtValue() != 8)
2939 Parts[Num] = N0.getOperand(0).getNode();
2943 /// MatchBSwapHWord - Match a 32-bit packed halfword bswap. That is
2944 /// ((x&0xff)<<8)|((x&0xff00)>>8)|((x&0x00ff0000)<<8)|((x&0xff000000)>>8)
2945 /// => (rotl (bswap x), 16)
2946 SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
2947 if (!LegalOperations)
2950 EVT VT = N->getValueType(0);
2953 if (!TLI.isOperationLegal(ISD::BSWAP, VT))
2956 SmallVector<SDNode*,4> Parts(4, (SDNode*)0);
2958 // (or (or (and), (and)), (or (and), (and)))
2959 // (or (or (or (and), (and)), (and)), (and))
2960 if (N0.getOpcode() != ISD::OR)
2962 SDValue N00 = N0.getOperand(0);
2963 SDValue N01 = N0.getOperand(1);
2965 if (N1.getOpcode() == ISD::OR) {
2966 // (or (or (and), (and)), (or (and), (and)))
2967 SDValue N000 = N00.getOperand(0);
2968 if (!isBSwapHWordElement(N000, Parts))
2971 SDValue N001 = N00.getOperand(1);
2972 if (!isBSwapHWordElement(N001, Parts))
2974 SDValue N010 = N01.getOperand(0);
2975 if (!isBSwapHWordElement(N010, Parts))
2977 SDValue N011 = N01.getOperand(1);
2978 if (!isBSwapHWordElement(N011, Parts))
2981 // (or (or (or (and), (and)), (and)), (and))
2982 if (!isBSwapHWordElement(N1, Parts))
2984 if (!isBSwapHWordElement(N01, Parts))
2986 if (N00.getOpcode() != ISD::OR)
2988 SDValue N000 = N00.getOperand(0);
2989 if (!isBSwapHWordElement(N000, Parts))
2991 SDValue N001 = N00.getOperand(1);
2992 if (!isBSwapHWordElement(N001, Parts))
2996 // Make sure the parts are all coming from the same node.
2997 if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
3000 SDValue BSwap = DAG.getNode(ISD::BSWAP, N->getDebugLoc(), VT,
3001 SDValue(Parts[0],0));
3003 // Result of the bswap should be rotated by 16. If it's not legal, than
3004 // do (x << 16) | (x >> 16).
3005 SDValue ShAmt = DAG.getConstant(16, getShiftAmountTy(VT));
3006 if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
3007 return DAG.getNode(ISD::ROTL, N->getDebugLoc(), VT, BSwap, ShAmt);
3008 if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
3009 return DAG.getNode(ISD::ROTR, N->getDebugLoc(), VT, BSwap, ShAmt);
3010 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT,
3011 DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, BSwap, ShAmt),
3012 DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, BSwap, ShAmt));
3015 SDValue DAGCombiner::visitOR(SDNode *N) {
3016 SDValue N0 = N->getOperand(0);
3017 SDValue N1 = N->getOperand(1);
3018 SDValue LL, LR, RL, RR, CC0, CC1;
3019 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3020 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3021 EVT VT = N1.getValueType();
3024 if (VT.isVector()) {
3025 SDValue FoldedVOp = SimplifyVBinOp(N);
3026 if (FoldedVOp.getNode()) return FoldedVOp;
3029 // fold (or x, undef) -> -1
3030 if (!LegalOperations &&
3031 (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)) {
3032 EVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
3033 return DAG.getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), VT);
3035 // fold (or c1, c2) -> c1|c2
3037 return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
3038 // canonicalize constant to RHS
3040 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N1, N0);
3041 // fold (or x, 0) -> x
3042 if (N1C && N1C->isNullValue())
3044 // fold (or x, -1) -> -1
3045 if (N1C && N1C->isAllOnesValue())
3047 // fold (or x, c) -> c iff (x & ~c) == 0
3048 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
3051 // Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
3052 SDValue BSwap = MatchBSwapHWord(N, N0, N1);
3053 if (BSwap.getNode() != 0)
3055 BSwap = MatchBSwapHWordLow(N, N0, N1);
3056 if (BSwap.getNode() != 0)
3060 SDValue ROR = ReassociateOps(ISD::OR, N->getDebugLoc(), N0, N1);
3061 if (ROR.getNode() != 0)
3063 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
3064 // iff (c1 & c2) == 0.
3065 if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
3066 isa<ConstantSDNode>(N0.getOperand(1))) {
3067 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
3068 if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
3069 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
3070 DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3071 N0.getOperand(0), N1),
3072 DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
3074 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
3075 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
3076 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
3077 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
3079 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
3080 LL.getValueType().isInteger()) {
3081 // fold (or (setne X, 0), (setne Y, 0)) -> (setne (or X, Y), 0)
3082 // fold (or (setlt X, 0), (setlt Y, 0)) -> (setne (or X, Y), 0)
3083 if (cast<ConstantSDNode>(LR)->isNullValue() &&
3084 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
3085 SDValue ORNode = DAG.getNode(ISD::OR, LR.getDebugLoc(),
3086 LR.getValueType(), LL, RL);
3087 AddToWorkList(ORNode.getNode());
3088 return DAG.getSetCC(N->getDebugLoc(), VT, ORNode, LR, Op1);
3090 // fold (or (setne X, -1), (setne Y, -1)) -> (setne (and X, Y), -1)
3091 // fold (or (setgt X, -1), (setgt Y -1)) -> (setgt (and X, Y), -1)
3092 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
3093 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
3094 SDValue ANDNode = DAG.getNode(ISD::AND, LR.getDebugLoc(),
3095 LR.getValueType(), LL, RL);
3096 AddToWorkList(ANDNode.getNode());
3097 return DAG.getSetCC(N->getDebugLoc(), VT, ANDNode, LR, Op1);
3100 // canonicalize equivalent to ll == rl
3101 if (LL == RR && LR == RL) {
3102 Op1 = ISD::getSetCCSwappedOperands(Op1);
3105 if (LL == RL && LR == RR) {
3106 bool isInteger = LL.getValueType().isInteger();
3107 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
3108 if (Result != ISD::SETCC_INVALID &&
3109 (!LegalOperations || TLI.isCondCodeLegal(Result, LL.getValueType())))
3110 return DAG.getSetCC(N->getDebugLoc(), N0.getValueType(),
3115 // Simplify: (or (op x...), (op y...)) -> (op (or x, y))
3116 if (N0.getOpcode() == N1.getOpcode()) {
3117 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3118 if (Tmp.getNode()) return Tmp;
3121 // (or (and X, C1), (and Y, C2)) -> (and (or X, Y), C3) if possible.
3122 if (N0.getOpcode() == ISD::AND &&
3123 N1.getOpcode() == ISD::AND &&
3124 N0.getOperand(1).getOpcode() == ISD::Constant &&
3125 N1.getOperand(1).getOpcode() == ISD::Constant &&
3126 // Don't increase # computations.
3127 (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
3128 // We can only do this xform if we know that bits from X that are set in C2
3129 // but not in C1 are already zero. Likewise for Y.
3130 const APInt &LHSMask =
3131 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3132 const APInt &RHSMask =
3133 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
3135 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
3136 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
3137 SDValue X = DAG.getNode(ISD::OR, N0.getDebugLoc(), VT,
3138 N0.getOperand(0), N1.getOperand(0));
3139 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, X,
3140 DAG.getConstant(LHSMask | RHSMask, VT));
3144 // See if this is some rotate idiom.
3145 if (SDNode *Rot = MatchRotate(N0, N1, N->getDebugLoc()))
3146 return SDValue(Rot, 0);
3148 // Simplify the operands using demanded-bits information.
3149 if (!VT.isVector() &&
3150 SimplifyDemandedBits(SDValue(N, 0)))
3151 return SDValue(N, 0);
3156 /// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
3157 static bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
3158 if (Op.getOpcode() == ISD::AND) {
3159 if (isa<ConstantSDNode>(Op.getOperand(1))) {
3160 Mask = Op.getOperand(1);
3161 Op = Op.getOperand(0);
3167 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
3175 // MatchRotate - Handle an 'or' of two operands. If this is one of the many
3176 // idioms for rotate, and if the target supports rotation instructions, generate
3178 SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, DebugLoc DL) {
3179 // Must be a legal type. Expanded 'n promoted things won't work with rotates.
3180 EVT VT = LHS.getValueType();
3181 if (!TLI.isTypeLegal(VT)) return 0;
3183 // The target must have at least one rotate flavor.
3184 bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
3185 bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
3186 if (!HasROTL && !HasROTR) return 0;
3188 // Match "(X shl/srl V1) & V2" where V2 may not be present.
3189 SDValue LHSShift; // The shift.
3190 SDValue LHSMask; // AND value if any.
3191 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
3192 return 0; // Not part of a rotate.
3194 SDValue RHSShift; // The shift.
3195 SDValue RHSMask; // AND value if any.
3196 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
3197 return 0; // Not part of a rotate.
3199 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
3200 return 0; // Not shifting the same value.
3202 if (LHSShift.getOpcode() == RHSShift.getOpcode())
3203 return 0; // Shifts must disagree.
3205 // Canonicalize shl to left side in a shl/srl pair.
3206 if (RHSShift.getOpcode() == ISD::SHL) {
3207 std::swap(LHS, RHS);
3208 std::swap(LHSShift, RHSShift);
3209 std::swap(LHSMask , RHSMask );
3212 unsigned OpSizeInBits = VT.getSizeInBits();
3213 SDValue LHSShiftArg = LHSShift.getOperand(0);
3214 SDValue LHSShiftAmt = LHSShift.getOperand(1);
3215 SDValue RHSShiftAmt = RHSShift.getOperand(1);
3217 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
3218 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
3219 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
3220 RHSShiftAmt.getOpcode() == ISD::Constant) {
3221 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getZExtValue();
3222 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getZExtValue();
3223 if ((LShVal + RShVal) != OpSizeInBits)
3226 SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3227 LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);
3229 // If there is an AND of either shifted operand, apply it to the result.
3230 if (LHSMask.getNode() || RHSMask.getNode()) {
3231 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
3233 if (LHSMask.getNode()) {
3234 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
3235 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
3237 if (RHSMask.getNode()) {
3238 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
3239 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
3242 Rot = DAG.getNode(ISD::AND, DL, VT, Rot, DAG.getConstant(Mask, VT));
3245 return Rot.getNode();
3248 // If there is a mask here, and we have a variable shift, we can't be sure
3249 // that we're masking out the right stuff.
3250 if (LHSMask.getNode() || RHSMask.getNode())
3253 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
3254 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
3255 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
3256 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
3257 if (ConstantSDNode *SUBC =
3258 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
3259 if (SUBC->getAPIntValue() == OpSizeInBits) {
3260 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT, LHSShiftArg,
3261 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3266 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
3267 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
3268 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
3269 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
3270 if (ConstantSDNode *SUBC =
3271 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
3272 if (SUBC->getAPIntValue() == OpSizeInBits) {
3273 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT, LHSShiftArg,
3274 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3279 // Look for sign/zext/any-extended or truncate cases:
3280 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3281 LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3282 LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3283 LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
3284 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
3285 RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
3286 RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
3287 RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
3288 SDValue LExtOp0 = LHSShiftAmt.getOperand(0);
3289 SDValue RExtOp0 = RHSShiftAmt.getOperand(0);
3290 if (RExtOp0.getOpcode() == ISD::SUB &&
3291 RExtOp0.getOperand(1) == LExtOp0) {
3292 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3294 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
3295 // (rotr x, (sub 32, y))
3296 if (ConstantSDNode *SUBC =
3297 dyn_cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
3298 if (SUBC->getAPIntValue() == OpSizeInBits) {
3299 return DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
3301 HasROTL ? LHSShiftAmt : RHSShiftAmt).getNode();
3304 } else if (LExtOp0.getOpcode() == ISD::SUB &&
3305 RExtOp0 == LExtOp0.getOperand(1)) {
3306 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3308 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext y))) ->
3309 // (rotl x, (sub 32, y))
3310 if (ConstantSDNode *SUBC =
3311 dyn_cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
3312 if (SUBC->getAPIntValue() == OpSizeInBits) {
3313 return DAG.getNode(HasROTR ? ISD::ROTR : ISD::ROTL, DL, VT,
3315 HasROTR ? RHSShiftAmt : LHSShiftAmt).getNode();
3324 SDValue DAGCombiner::visitXOR(SDNode *N) {
3325 SDValue N0 = N->getOperand(0);
3326 SDValue N1 = N->getOperand(1);
3327 SDValue LHS, RHS, CC;
3328 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3329 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3330 EVT VT = N0.getValueType();
3333 if (VT.isVector()) {
3334 SDValue FoldedVOp = SimplifyVBinOp(N);
3335 if (FoldedVOp.getNode()) return FoldedVOp;
3338 // fold (xor undef, undef) -> 0. This is a common idiom (misuse).
3339 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
3340 return DAG.getConstant(0, VT);
3341 // fold (xor x, undef) -> undef
3342 if (N0.getOpcode() == ISD::UNDEF)
3344 if (N1.getOpcode() == ISD::UNDEF)
3346 // fold (xor c1, c2) -> c1^c2
3348 return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
3349 // canonicalize constant to RHS
3351 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N1, N0);
3352 // fold (xor x, 0) -> x
3353 if (N1C && N1C->isNullValue())
3356 SDValue RXOR = ReassociateOps(ISD::XOR, N->getDebugLoc(), N0, N1);
3357 if (RXOR.getNode() != 0)
3360 // fold !(x cc y) -> (x !cc y)
3361 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
3362 bool isInt = LHS.getValueType().isInteger();
3363 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3366 if (!LegalOperations || TLI.isCondCodeLegal(NotCC, LHS.getValueType())) {
3367 switch (N0.getOpcode()) {
3369 llvm_unreachable("Unhandled SetCC Equivalent!");
3371 return DAG.getSetCC(N->getDebugLoc(), VT, LHS, RHS, NotCC);
3372 case ISD::SELECT_CC:
3373 return DAG.getSelectCC(N->getDebugLoc(), LHS, RHS, N0.getOperand(2),
3374 N0.getOperand(3), NotCC);
3379 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
3380 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
3381 N0.getNode()->hasOneUse() &&
3382 isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
3383 SDValue V = N0.getOperand(0);
3384 V = DAG.getNode(ISD::XOR, N0.getDebugLoc(), V.getValueType(), V,
3385 DAG.getConstant(1, V.getValueType()));
3386 AddToWorkList(V.getNode());
3387 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, V);
3390 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
3391 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
3392 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3393 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3394 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
3395 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3396 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3397 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3398 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3399 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3402 // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
3403 if (N1C && N1C->isAllOnesValue() &&
3404 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
3405 SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
3406 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
3407 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
3408 LHS = DAG.getNode(ISD::XOR, LHS.getDebugLoc(), VT, LHS, N1); // LHS = ~LHS
3409 RHS = DAG.getNode(ISD::XOR, RHS.getDebugLoc(), VT, RHS, N1); // RHS = ~RHS
3410 AddToWorkList(LHS.getNode()); AddToWorkList(RHS.getNode());
3411 return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
3414 // fold (xor (xor x, c1), c2) -> (xor x, (xor c1, c2))
3415 if (N1C && N0.getOpcode() == ISD::XOR) {
3416 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
3417 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3419 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(1),
3420 DAG.getConstant(N1C->getAPIntValue() ^
3421 N00C->getAPIntValue(), VT));
3423 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT, N0.getOperand(0),
3424 DAG.getConstant(N1C->getAPIntValue() ^
3425 N01C->getAPIntValue(), VT));
3427 // fold (xor x, x) -> 0
3429 return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations);
3431 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
3432 if (N0.getOpcode() == N1.getOpcode()) {
3433 SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N);
3434 if (Tmp.getNode()) return Tmp;
3437 // Simplify the expression using non-local knowledge.
3438 if (!VT.isVector() &&
3439 SimplifyDemandedBits(SDValue(N, 0)))
3440 return SDValue(N, 0);
3445 /// visitShiftByConstant - Handle transforms common to the three shifts, when
3446 /// the shift amount is a constant.
3447 SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
3448 SDNode *LHS = N->getOperand(0).getNode();
3449 if (!LHS->hasOneUse()) return SDValue();
3451 // We want to pull some binops through shifts, so that we have (and (shift))
3452 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
3453 // thing happens with address calculations, so it's important to canonicalize
3455 bool HighBitSet = false; // Can we transform this if the high bit is set?
3457 switch (LHS->getOpcode()) {
3458 default: return SDValue();
3461 HighBitSet = false; // We can only transform sra if the high bit is clear.
3464 HighBitSet = true; // We can only transform sra if the high bit is set.
3467 if (N->getOpcode() != ISD::SHL)
3468 return SDValue(); // only shl(add) not sr[al](add).
3469 HighBitSet = false; // We can only transform sra if the high bit is clear.
3473 // We require the RHS of the binop to be a constant as well.
3474 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
3475 if (!BinOpCst) return SDValue();
3477 // FIXME: disable this unless the input to the binop is a shift by a constant.
3478 // If it is not a shift, it pessimizes some common cases like:
3480 // void foo(int *X, int i) { X[i & 1235] = 1; }
3481 // int bar(int *X, int i) { return X[i & 255]; }
3482 SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
3483 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
3484 BinOpLHSVal->getOpcode() != ISD::SRA &&
3485 BinOpLHSVal->getOpcode() != ISD::SRL) ||
3486 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
3489 EVT VT = N->getValueType(0);
3491 // If this is a signed shift right, and the high bit is modified by the
3492 // logical operation, do not perform the transformation. The highBitSet
3493 // boolean indicates the value of the high bit of the constant which would
3494 // cause it to be modified for this operation.
3495 if (N->getOpcode() == ISD::SRA) {
3496 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
3497 if (BinOpRHSSignSet != HighBitSet)
3501 // Fold the constants, shifting the binop RHS by the shift amount.
3502 SDValue NewRHS = DAG.getNode(N->getOpcode(), LHS->getOperand(1).getDebugLoc(),
3504 LHS->getOperand(1), N->getOperand(1));
3506 // Create the new shift.
3507 SDValue NewShift = DAG.getNode(N->getOpcode(),
3508 LHS->getOperand(0).getDebugLoc(),
3509 VT, LHS->getOperand(0), N->getOperand(1));
3511 // Create the new binop.
3512 return DAG.getNode(LHS->getOpcode(), N->getDebugLoc(), VT, NewShift, NewRHS);
3515 SDValue DAGCombiner::visitSHL(SDNode *N) {
3516 SDValue N0 = N->getOperand(0);
3517 SDValue N1 = N->getOperand(1);
3518 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3519 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3520 EVT VT = N0.getValueType();
3521 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3523 // fold (shl c1, c2) -> c1<<c2
3525 return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
3526 // fold (shl 0, x) -> 0
3527 if (N0C && N0C->isNullValue())
3529 // fold (shl x, c >= size(x)) -> undef
3530 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3531 return DAG.getUNDEF(VT);
3532 // fold (shl x, 0) -> x
3533 if (N1C && N1C->isNullValue())
3535 // fold (shl undef, x) -> 0
3536 if (N0.getOpcode() == ISD::UNDEF)
3537 return DAG.getConstant(0, VT);
3538 // if (shl x, c) is known to be zero, return 0
3539 if (DAG.MaskedValueIsZero(SDValue(N, 0),
3540 APInt::getAllOnesValue(OpSizeInBits)))
3541 return DAG.getConstant(0, VT);
3542 // fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
3543 if (N1.getOpcode() == ISD::TRUNCATE &&
3544 N1.getOperand(0).getOpcode() == ISD::AND &&
3545 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3546 SDValue N101 = N1.getOperand(0).getOperand(1);
3547 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3548 EVT TruncVT = N1.getValueType();
3549 SDValue N100 = N1.getOperand(0).getOperand(0);
3550 APInt TruncC = N101C->getAPIntValue();
3551 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3552 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
3553 DAG.getNode(ISD::AND, N->getDebugLoc(), TruncVT,
3554 DAG.getNode(ISD::TRUNCATE,
3557 DAG.getConstant(TruncC, TruncVT)));
3561 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3562 return SDValue(N, 0);
3564 // fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
3565 if (N1C && N0.getOpcode() == ISD::SHL &&
3566 N0.getOperand(1).getOpcode() == ISD::Constant) {
3567 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3568 uint64_t c2 = N1C->getZExtValue();
3569 if (c1 + c2 >= OpSizeInBits)
3570 return DAG.getConstant(0, VT);
3571 return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3572 DAG.getConstant(c1 + c2, N1.getValueType()));
3575 // fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
3576 // For this to be valid, the second form must not preserve any of the bits
3577 // that are shifted out by the inner shift in the first form. This means
3578 // the outer shift size must be >= the number of bits added by the ext.
3579 // As a corollary, we don't care what kind of ext it is.
3580 if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
3581 N0.getOpcode() == ISD::ANY_EXTEND ||
3582 N0.getOpcode() == ISD::SIGN_EXTEND) &&
3583 N0.getOperand(0).getOpcode() == ISD::SHL &&
3584 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3586 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3587 uint64_t c2 = N1C->getZExtValue();
3588 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3589 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3590 if (c2 >= OpSizeInBits - InnerShiftSize) {
3591 if (c1 + c2 >= OpSizeInBits)
3592 return DAG.getConstant(0, VT);
3593 return DAG.getNode(ISD::SHL, N0->getDebugLoc(), VT,
3594 DAG.getNode(N0.getOpcode(), N0->getDebugLoc(), VT,
3595 N0.getOperand(0)->getOperand(0)),
3596 DAG.getConstant(c1 + c2, N1.getValueType()));
3600 // fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
3601 // (and (srl x, (sub c1, c2), MASK)
3602 // Only fold this if the inner shift has no other uses -- if it does, folding
3603 // this will increase the total number of instructions.
3604 if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse() &&
3605 N0.getOperand(1).getOpcode() == ISD::Constant) {
3606 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3607 if (c1 < VT.getSizeInBits()) {
3608 uint64_t c2 = N1C->getZExtValue();
3609 APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
3610 VT.getSizeInBits() - c1);
3613 Mask = Mask.shl(c2-c1);
3614 Shift = DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
3615 DAG.getConstant(c2-c1, N1.getValueType()));
3617 Mask = Mask.lshr(c1-c2);
3618 Shift = DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3619 DAG.getConstant(c1-c2, N1.getValueType()));
3621 return DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, Shift,
3622 DAG.getConstant(Mask, VT));
3625 // fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
3626 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1)) {
3627 SDValue HiBitsMask =
3628 DAG.getConstant(APInt::getHighBitsSet(VT.getSizeInBits(),
3629 VT.getSizeInBits() -
3630 N1C->getZExtValue()),
3632 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3637 SDValue NewSHL = visitShiftByConstant(N, N1C->getZExtValue());
3638 if (NewSHL.getNode())
3645 SDValue DAGCombiner::visitSRA(SDNode *N) {
3646 SDValue N0 = N->getOperand(0);
3647 SDValue N1 = N->getOperand(1);
3648 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3649 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3650 EVT VT = N0.getValueType();
3651 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3653 // fold (sra c1, c2) -> (sra c1, c2)
3655 return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
3656 // fold (sra 0, x) -> 0
3657 if (N0C && N0C->isNullValue())
3659 // fold (sra -1, x) -> -1
3660 if (N0C && N0C->isAllOnesValue())
3662 // fold (sra x, (setge c, size(x))) -> undef
3663 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3664 return DAG.getUNDEF(VT);
3665 // fold (sra x, 0) -> x
3666 if (N1C && N1C->isNullValue())
3668 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
3670 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
3671 unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
3672 EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
3674 ExtVT = EVT::getVectorVT(*DAG.getContext(),
3675 ExtVT, VT.getVectorNumElements());
3676 if ((!LegalOperations ||
3677 TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
3678 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
3679 N0.getOperand(0), DAG.getValueType(ExtVT));
3682 // fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
3683 if (N1C && N0.getOpcode() == ISD::SRA) {
3684 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3685 unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
3686 if (Sum >= OpSizeInBits) Sum = OpSizeInBits-1;
3687 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0.getOperand(0),
3688 DAG.getConstant(Sum, N1C->getValueType(0)));
3692 // fold (sra (shl X, m), (sub result_size, n))
3693 // -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
3694 // result_size - n != m.
3695 // If truncate is free for the target sext(shl) is likely to result in better
3697 if (N0.getOpcode() == ISD::SHL) {
3698 // Get the two constanst of the shifts, CN0 = m, CN = n.
3699 const ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
3701 // Determine what the truncate's result bitsize and type would be.
3703 EVT::getIntegerVT(*DAG.getContext(),
3704 OpSizeInBits - N1C->getZExtValue());
3705 // Determine the residual right-shift amount.
3706 signed ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();
3708 // If the shift is not a no-op (in which case this should be just a sign
3709 // extend already), the truncated to type is legal, sign_extend is legal
3710 // on that type, and the truncate to that type is both legal and free,
3711 // perform the transform.
3712 if ((ShiftAmt > 0) &&
3713 TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
3714 TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
3715 TLI.isTruncateFree(VT, TruncVT)) {
3717 SDValue Amt = DAG.getConstant(ShiftAmt,
3718 getShiftAmountTy(N0.getOperand(0).getValueType()));
3719 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT,
3720 N0.getOperand(0), Amt);
3721 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), TruncVT,
3723 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
3724 N->getValueType(0), Trunc);
3729 // fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
3730 if (N1.getOpcode() == ISD::TRUNCATE &&
3731 N1.getOperand(0).getOpcode() == ISD::AND &&
3732 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3733 SDValue N101 = N1.getOperand(0).getOperand(1);
3734 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3735 EVT TruncVT = N1.getValueType();
3736 SDValue N100 = N1.getOperand(0).getOperand(0);
3737 APInt TruncC = N101C->getAPIntValue();
3738 TruncC = TruncC.trunc(TruncVT.getScalarType().getSizeInBits());
3739 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
3740 DAG.getNode(ISD::AND, N->getDebugLoc(),
3742 DAG.getNode(ISD::TRUNCATE,
3745 DAG.getConstant(TruncC, TruncVT)));
3749 // fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, c1+c2))
3750 // if c1 is equal to the number of bits the trunc removes
3751 if (N0.getOpcode() == ISD::TRUNCATE &&
3752 (N0.getOperand(0).getOpcode() == ISD::SRL ||
3753 N0.getOperand(0).getOpcode() == ISD::SRA) &&
3754 N0.getOperand(0).hasOneUse() &&
3755 N0.getOperand(0).getOperand(1).hasOneUse() &&
3756 N1C && isa<ConstantSDNode>(N0.getOperand(0).getOperand(1))) {
3757 EVT LargeVT = N0.getOperand(0).getValueType();
3758 ConstantSDNode *LargeShiftAmt =
3759 cast<ConstantSDNode>(N0.getOperand(0).getOperand(1));
3761 if (LargeVT.getScalarType().getSizeInBits() - OpSizeInBits ==
3762 LargeShiftAmt->getZExtValue()) {
3764 DAG.getConstant(LargeShiftAmt->getZExtValue() + N1C->getZExtValue(),
3765 getShiftAmountTy(N0.getOperand(0).getOperand(0).getValueType()));
3766 SDValue SRA = DAG.getNode(ISD::SRA, N->getDebugLoc(), LargeVT,
3767 N0.getOperand(0).getOperand(0), Amt);
3768 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, SRA);
3772 // Simplify, based on bits shifted out of the LHS.
3773 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3774 return SDValue(N, 0);
3777 // If the sign bit is known to be zero, switch this to a SRL.
3778 if (DAG.SignBitIsZero(N0))
3779 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, N1);
3782 SDValue NewSRA = visitShiftByConstant(N, N1C->getZExtValue());
3783 if (NewSRA.getNode())
3790 SDValue DAGCombiner::visitSRL(SDNode *N) {
3791 SDValue N0 = N->getOperand(0);
3792 SDValue N1 = N->getOperand(1);
3793 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
3794 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3795 EVT VT = N0.getValueType();
3796 unsigned OpSizeInBits = VT.getScalarType().getSizeInBits();
3798 // fold (srl c1, c2) -> c1 >>u c2
3800 return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
3801 // fold (srl 0, x) -> 0
3802 if (N0C && N0C->isNullValue())
3804 // fold (srl x, c >= size(x)) -> undef
3805 if (N1C && N1C->getZExtValue() >= OpSizeInBits)
3806 return DAG.getUNDEF(VT);
3807 // fold (srl x, 0) -> x
3808 if (N1C && N1C->isNullValue())
3810 // if (srl x, c) is known to be zero, return 0
3811 if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
3812 APInt::getAllOnesValue(OpSizeInBits)))
3813 return DAG.getConstant(0, VT);
3815 // fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
3816 if (N1C && N0.getOpcode() == ISD::SRL &&
3817 N0.getOperand(1).getOpcode() == ISD::Constant) {
3818 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
3819 uint64_t c2 = N1C->getZExtValue();
3820 if (c1 + c2 >= OpSizeInBits)
3821 return DAG.getConstant(0, VT);
3822 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
3823 DAG.getConstant(c1 + c2, N1.getValueType()));
3826 // fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
3827 if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
3828 N0.getOperand(0).getOpcode() == ISD::SRL &&
3829 isa<ConstantSDNode>(N0.getOperand(0)->getOperand(1))) {
3831 cast<ConstantSDNode>(N0.getOperand(0)->getOperand(1))->getZExtValue();
3832 uint64_t c2 = N1C->getZExtValue();
3833 EVT InnerShiftVT = N0.getOperand(0).getValueType();
3834 EVT ShiftCountVT = N0.getOperand(0)->getOperand(1).getValueType();
3835 uint64_t InnerShiftSize = InnerShiftVT.getScalarType().getSizeInBits();
3836 // This is only valid if the OpSizeInBits + c1 = size of inner shift.
3837 if (c1 + OpSizeInBits == InnerShiftSize) {
3838 if (c1 + c2 >= InnerShiftSize)
3839 return DAG.getConstant(0, VT);
3840 return DAG.getNode(ISD::TRUNCATE, N0->getDebugLoc(), VT,
3841 DAG.getNode(ISD::SRL, N0->getDebugLoc(), InnerShiftVT,
3842 N0.getOperand(0)->getOperand(0),
3843 DAG.getConstant(c1 + c2, ShiftCountVT)));
3847 // fold (srl (shl x, c), c) -> (and x, cst2)
3848 if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
3849 N0.getValueSizeInBits() <= 64) {
3850 uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
3851 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
3852 DAG.getConstant(~0ULL >> ShAmt, VT));
3856 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
3857 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
3858 // Shifting in all undef bits?
3859 EVT SmallVT = N0.getOperand(0).getValueType();
3860 if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
3861 return DAG.getUNDEF(VT);
3863 if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
3864 uint64_t ShiftAmt = N1C->getZExtValue();
3865 SDValue SmallShift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), SmallVT,
3867 DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
3868 AddToWorkList(SmallShift.getNode());
3869 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, SmallShift);
3873 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
3874 // bit, which is unmodified by sra.
3875 if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
3876 if (N0.getOpcode() == ISD::SRA)
3877 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
3880 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
3881 if (N1C && N0.getOpcode() == ISD::CTLZ &&
3882 N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
3883 APInt KnownZero, KnownOne;
3884 DAG.ComputeMaskedBits(N0.getOperand(0), KnownZero, KnownOne);
3886 // If any of the input bits are KnownOne, then the input couldn't be all
3887 // zeros, thus the result of the srl will always be zero.
3888 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
3890 // If all of the bits input the to ctlz node are known to be zero, then
3891 // the result of the ctlz is "32" and the result of the shift is one.
3892 APInt UnknownBits = ~KnownZero;
3893 if (UnknownBits == 0) return DAG.getConstant(1, VT);
3895 // Otherwise, check to see if there is exactly one bit input to the ctlz.
3896 if ((UnknownBits & (UnknownBits - 1)) == 0) {
3897 // Okay, we know that only that the single bit specified by UnknownBits
3898 // could be set on input to the CTLZ node. If this bit is set, the SRL
3899 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
3900 // to an SRL/XOR pair, which is likely to simplify more.
3901 unsigned ShAmt = UnknownBits.countTrailingZeros();
3902 SDValue Op = N0.getOperand(0);
3905 Op = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT, Op,
3906 DAG.getConstant(ShAmt, getShiftAmountTy(Op.getValueType())));
3907 AddToWorkList(Op.getNode());
3910 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
3911 Op, DAG.getConstant(1, VT));
3915 // fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
3916 if (N1.getOpcode() == ISD::TRUNCATE &&
3917 N1.getOperand(0).getOpcode() == ISD::AND &&
3918 N1.hasOneUse() && N1.getOperand(0).hasOneUse()) {
3919 SDValue N101 = N1.getOperand(0).getOperand(1);
3920 if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
3921 EVT TruncVT = N1.getValueType();
3922 SDValue N100 = N1.getOperand(0).getOperand(0);
3923 APInt TruncC = N101C->getAPIntValue();
3924 TruncC = TruncC.trunc(TruncVT.getSizeInBits());
3925 return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
3926 DAG.getNode(ISD::AND, N->getDebugLoc(),
3928 DAG.getNode(ISD::TRUNCATE,
3931 DAG.getConstant(TruncC, TruncVT)));
3935 // fold operands of srl based on knowledge that the low bits are not
3937 if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
3938 return SDValue(N, 0);
3941 SDValue NewSRL = visitShiftByConstant(N, N1C->getZExtValue());
3942 if (NewSRL.getNode())
3946 // Attempt to convert a srl of a load into a narrower zero-extending load.
3947 SDValue NarrowLoad = ReduceLoadWidth(N);
3948 if (NarrowLoad.getNode())
3951 // Here is a common situation. We want to optimize:
3954 // %b = and i32 %a, 2
3955 // %c = srl i32 %b, 1
3956 // brcond i32 %c ...
3962 // %c = setcc eq %b, 0
3965 // However when after the source operand of SRL is optimized into AND, the SRL
3966 // itself may not be optimized further. Look for it and add the BRCOND into
3968 if (N->hasOneUse()) {
3969 SDNode *Use = *N->use_begin();
3970 if (Use->getOpcode() == ISD::BRCOND)
3972 else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
3973 // Also look pass the truncate.
3974 Use = *Use->use_begin();
3975 if (Use->getOpcode() == ISD::BRCOND)
3983 SDValue DAGCombiner::visitCTLZ(SDNode *N) {
3984 SDValue N0 = N->getOperand(0);
3985 EVT VT = N->getValueType(0);
3987 // fold (ctlz c1) -> c2
3988 if (isa<ConstantSDNode>(N0))
3989 return DAG.getNode(ISD::CTLZ, N->getDebugLoc(), VT, N0);
3993 SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
3994 SDValue N0 = N->getOperand(0);
3995 EVT VT = N->getValueType(0);
3997 // fold (ctlz_zero_undef c1) -> c2
3998 if (isa<ConstantSDNode>(N0))
3999 return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
4003 SDValue DAGCombiner::visitCTTZ(SDNode *N) {
4004 SDValue N0 = N->getOperand(0);
4005 EVT VT = N->getValueType(0);
4007 // fold (cttz c1) -> c2
4008 if (isa<ConstantSDNode>(N0))
4009 return DAG.getNode(ISD::CTTZ, N->getDebugLoc(), VT, N0);
4013 SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
4014 SDValue N0 = N->getOperand(0);
4015 EVT VT = N->getValueType(0);
4017 // fold (cttz_zero_undef c1) -> c2
4018 if (isa<ConstantSDNode>(N0))
4019 return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, N->getDebugLoc(), VT, N0);
4023 SDValue DAGCombiner::visitCTPOP(SDNode *N) {
4024 SDValue N0 = N->getOperand(0);
4025 EVT VT = N->getValueType(0);
4027 // fold (ctpop c1) -> c2
4028 if (isa<ConstantSDNode>(N0))
4029 return DAG.getNode(ISD::CTPOP, N->getDebugLoc(), VT, N0);
4033 SDValue DAGCombiner::visitSELECT(SDNode *N) {
4034 SDValue N0 = N->getOperand(0);
4035 SDValue N1 = N->getOperand(1);
4036 SDValue N2 = N->getOperand(2);
4037 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
4038 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
4039 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
4040 EVT VT = N->getValueType(0);
4041 EVT VT0 = N0.getValueType();
4043 // fold (select C, X, X) -> X
4046 // fold (select true, X, Y) -> X
4047 if (N0C && !N0C->isNullValue())
4049 // fold (select false, X, Y) -> Y
4050 if (N0C && N0C->isNullValue())
4052 // fold (select C, 1, X) -> (or C, X)
4053 if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
4054 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4055 // fold (select C, 0, 1) -> (xor C, 1)
4056 if (VT.isInteger() &&
4059 TLI.getBooleanContents(false) ==
4060 TargetLowering::ZeroOrOneBooleanContent)) &&
4061 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
4064 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT0,
4065 N0, DAG.getConstant(1, VT0));
4066 XORNode = DAG.getNode(ISD::XOR, N0.getDebugLoc(), VT0,
4067 N0, DAG.getConstant(1, VT0));
4068 AddToWorkList(XORNode.getNode());
4070 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, XORNode);
4071 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, XORNode);
4073 // fold (select C, 0, X) -> (and (not C), X)
4074 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
4075 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4076 AddToWorkList(NOTNode.getNode());
4077 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, NOTNode, N2);
4079 // fold (select C, X, 1) -> (or (not C), X)
4080 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
4081 SDValue NOTNode = DAG.getNOT(N0.getDebugLoc(), N0, VT);
4082 AddToWorkList(NOTNode.getNode());
4083 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, NOTNode, N1);
4085 // fold (select C, X, 0) -> (and C, X)
4086 if (VT == MVT::i1 && N2C && N2C->isNullValue())
4087 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4088 // fold (select X, X, Y) -> (or X, Y)
4089 // fold (select X, 1, Y) -> (or X, Y)
4090 if (VT == MVT::i1 && (N0 == N1 || (N1C && N1C->getAPIntValue() == 1)))
4091 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N2);
4092 // fold (select X, Y, X) -> (and X, Y)
4093 // fold (select X, Y, 0) -> (and X, Y)
4094 if (VT == MVT::i1 && (N0 == N2 || (N2C && N2C->getAPIntValue() == 0)))
4095 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0, N1);
4097 // If we can fold this based on the true/false value, do so.
4098 if (SimplifySelectOps(N, N1, N2))
4099 return SDValue(N, 0); // Don't revisit N.
4101 // fold selects based on a setcc into other things, such as min/max/abs
4102 if (N0.getOpcode() == ISD::SETCC) {
4104 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
4105 // having to say they don't support SELECT_CC on every type the DAG knows
4106 // about, since there is no way to mark an opcode illegal at all value types
4107 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other) &&
4108 TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT))
4109 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT,
4110 N0.getOperand(0), N0.getOperand(1),
4111 N1, N2, N0.getOperand(2));
4112 return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
4118 SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
4119 SDValue N0 = N->getOperand(0);
4120 SDValue N1 = N->getOperand(1);
4121 SDValue N2 = N->getOperand(2);
4122 SDValue N3 = N->getOperand(3);
4123 SDValue N4 = N->getOperand(4);
4124 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
4126 // fold select_cc lhs, rhs, x, x, cc -> x
4130 // Determine if the condition we're dealing with is constant
4131 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
4132 N0, N1, CC, N->getDebugLoc(), false);
4133 if (SCC.getNode()) AddToWorkList(SCC.getNode());
4135 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
4136 if (!SCCC->isNullValue())
4137 return N2; // cond always true -> true val
4139 return N3; // cond always false -> false val
4142 // Fold to a simpler select_cc
4143 if (SCC.getNode() && SCC.getOpcode() == ISD::SETCC)
4144 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), N2.getValueType(),
4145 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
4148 // If we can fold this based on the true/false value, do so.
4149 if (SimplifySelectOps(N, N2, N3))
4150 return SDValue(N, 0); // Don't revisit N.
4152 // fold select_cc into other things, such as min/max/abs
4153 return SimplifySelectCC(N->getDebugLoc(), N0, N1, N2, N3, CC);
4156 SDValue DAGCombiner::visitSETCC(SDNode *N) {
4157 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
4158 cast<CondCodeSDNode>(N->getOperand(2))->get(),
4162 // ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
4163 // "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
4164 // transformation. Returns true if extension are possible and the above
4165 // mentioned transformation is profitable.
4166 static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
4168 SmallVector<SDNode*, 4> &ExtendNodes,
4169 const TargetLowering &TLI) {
4170 bool HasCopyToRegUses = false;
4171 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
4172 for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
4173 UE = N0.getNode()->use_end();
4178 if (UI.getUse().getResNo() != N0.getResNo())
4180 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
4181 if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
4182 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
4183 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
4184 // Sign bits will be lost after a zext.
4187 for (unsigned i = 0; i != 2; ++i) {
4188 SDValue UseOp = User->getOperand(i);
4191 if (!isa<ConstantSDNode>(UseOp))
4196 ExtendNodes.push_back(User);
4199 // If truncates aren't free and there are users we can't
4200 // extend, it isn't worthwhile.
4203 // Remember if this value is live-out.
4204 if (User->getOpcode() == ISD::CopyToReg)
4205 HasCopyToRegUses = true;
4208 if (HasCopyToRegUses) {
4209 bool BothLiveOut = false;
4210 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
4212 SDUse &Use = UI.getUse();
4213 if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
4219 // Both unextended and extended values are live out. There had better be
4220 // a good reason for the transformation.
4221 return ExtendNodes.size();
4226 void DAGCombiner::ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
4227 SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
4228 ISD::NodeType ExtType) {
4229 // Extend SetCC uses if necessary.
4230 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
4231 SDNode *SetCC = SetCCs[i];
4232 SmallVector<SDValue, 4> Ops;
4234 for (unsigned j = 0; j != 2; ++j) {
4235 SDValue SOp = SetCC->getOperand(j);
4237 Ops.push_back(ExtLoad);
4239 Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
4242 Ops.push_back(SetCC->getOperand(2));
4243 CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
4244 &Ops[0], Ops.size()));
4248 SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
4249 SDValue N0 = N->getOperand(0);
4250 EVT VT = N->getValueType(0);
4252 // fold (sext c1) -> c1
4253 if (isa<ConstantSDNode>(N0))
4254 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N0);
4256 // fold (sext (sext x)) -> (sext x)
4257 // fold (sext (aext x)) -> (sext x)
4258 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4259 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT,
4262 if (N0.getOpcode() == ISD::TRUNCATE) {
4263 // fold (sext (truncate (load x))) -> (sext (smaller load x))
4264 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
4265 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4266 if (NarrowLoad.getNode()) {
4267 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4268 if (NarrowLoad.getNode() != N0.getNode()) {
4269 CombineTo(N0.getNode(), NarrowLoad);
4270 // CombineTo deleted the truncate, if needed, but not what's under it.
4273 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4276 // See if the value being truncated is already sign extended. If so, just
4277 // eliminate the trunc/sext pair.
4278 SDValue Op = N0.getOperand(0);
4279 unsigned OpBits = Op.getValueType().getScalarType().getSizeInBits();
4280 unsigned MidBits = N0.getValueType().getScalarType().getSizeInBits();
4281 unsigned DestBits = VT.getScalarType().getSizeInBits();
4282 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
4284 if (OpBits == DestBits) {
4285 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
4286 // bits, it is already ready.
4287 if (NumSignBits > DestBits-MidBits)
4289 } else if (OpBits < DestBits) {
4290 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
4291 // bits, just sext from i32.
4292 if (NumSignBits > OpBits-MidBits)
4293 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, Op);
4295 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
4296 // bits, just truncate to i32.
4297 if (NumSignBits > OpBits-MidBits)
4298 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4301 // fold (sext (truncate x)) -> (sextinreg x).
4302 if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
4303 N0.getValueType())) {
4304 if (OpBits < DestBits)
4305 Op = DAG.getNode(ISD::ANY_EXTEND, N0.getDebugLoc(), VT, Op);
4306 else if (OpBits > DestBits)
4307 Op = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), VT, Op);
4308 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, Op,
4309 DAG.getValueType(N0.getValueType()));
4313 // fold (sext (load x)) -> (sext (truncate (sextload x)))
4314 // None of the supported targets knows how to perform load and sign extend
4315 // on vectors in one instruction. We only perform this transformation on
4317 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4318 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4319 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()))) {
4320 bool DoXform = true;
4321 SmallVector<SDNode*, 4> SetCCs;
4322 if (!N0.hasOneUse())
4323 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
4325 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4326 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4328 LN0->getBasePtr(), LN0->getPointerInfo(),
4330 LN0->isVolatile(), LN0->isNonTemporal(),
4331 LN0->getAlignment());
4332 CombineTo(N, ExtLoad);
4333 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4334 N0.getValueType(), ExtLoad);
4335 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4336 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4338 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4342 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
4343 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
4344 if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4345 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4346 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4347 EVT MemVT = LN0->getMemoryVT();
4348 if ((!LegalOperations && !LN0->isVolatile()) ||
4349 TLI.isLoadExtLegal(ISD::SEXTLOAD, MemVT)) {
4350 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
4352 LN0->getBasePtr(), LN0->getPointerInfo(),
4354 LN0->isVolatile(), LN0->isNonTemporal(),
4355 LN0->getAlignment());
4356 CombineTo(N, ExtLoad);
4357 CombineTo(N0.getNode(),
4358 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4359 N0.getValueType(), ExtLoad),
4360 ExtLoad.getValue(1));
4361 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4365 // fold (sext (and/or/xor (load x), cst)) ->
4366 // (and/or/xor (sextload x), (sext cst))
4367 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4368 N0.getOpcode() == ISD::XOR) &&
4369 isa<LoadSDNode>(N0.getOperand(0)) &&
4370 N0.getOperand(1).getOpcode() == ISD::Constant &&
4371 TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
4372 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4373 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4374 if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
4375 bool DoXform = true;
4376 SmallVector<SDNode*, 4> SetCCs;
4377 if (!N0.hasOneUse())
4378 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
4381 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, LN0->getDebugLoc(), VT,
4382 LN0->getChain(), LN0->getBasePtr(),
4383 LN0->getPointerInfo(),
4386 LN0->isNonTemporal(),
4387 LN0->getAlignment());
4388 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4389 Mask = Mask.sext(VT.getSizeInBits());
4390 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4391 ExtLoad, DAG.getConstant(Mask, VT));
4392 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4393 N0.getOperand(0).getDebugLoc(),
4394 N0.getOperand(0).getValueType(), ExtLoad);
4396 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4397 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4399 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4404 if (N0.getOpcode() == ISD::SETCC) {
4405 // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
4406 // Only do this before legalize for now.
4407 if (VT.isVector() && !LegalOperations) {
4408 EVT N0VT = N0.getOperand(0).getValueType();
4409 // On some architectures (such as SSE/NEON/etc) the SETCC result type is
4410 // of the same size as the compared operands. Only optimize sext(setcc())
4411 // if this is the case.
4412 EVT SVT = TLI.getSetCCResultType(N0VT);
4414 // We know that the # elements of the results is the same as the
4415 // # elements of the compare (and the # elements of the compare result
4416 // for that matter). Check to see that they are the same size. If so,
4417 // we know that the element size of the sext'd result matches the
4418 // element size of the compare operands.
4419 if (VT.getSizeInBits() == SVT.getSizeInBits())
4420 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4422 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4423 // If the desired elements are smaller or larger than the source
4424 // elements we can use a matching integer vector type and then
4425 // truncate/sign extend
4426 EVT MatchingElementType =
4427 EVT::getIntegerVT(*DAG.getContext(),
4428 N0VT.getScalarType().getSizeInBits());
4429 EVT MatchingVectorType =
4430 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4431 N0VT.getVectorNumElements());
4433 if (SVT == MatchingVectorType) {
4434 SDValue VsetCC = DAG.getSetCC(N->getDebugLoc(), MatchingVectorType,
4435 N0.getOperand(0), N0.getOperand(1),
4436 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4437 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4441 // sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
4442 unsigned ElementWidth = VT.getScalarType().getSizeInBits();
4444 DAG.getConstant(APInt::getAllOnesValue(ElementWidth), VT);
4446 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4447 NegOne, DAG.getConstant(0, VT),
4448 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4449 if (SCC.getNode()) return SCC;
4450 if (!LegalOperations ||
4451 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(VT)))
4452 return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
4453 DAG.getSetCC(N->getDebugLoc(),
4454 TLI.getSetCCResultType(VT),
4455 N0.getOperand(0), N0.getOperand(1),
4456 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4457 NegOne, DAG.getConstant(0, VT));
4460 // fold (sext x) -> (zext x) if the sign bit is known zero.
4461 if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
4462 DAG.SignBitIsZero(N0))
4463 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4468 // isTruncateOf - If N is a truncate of some other value, return true, record
4469 // the value being truncated in Op and which of Op's bits are zero in KnownZero.
4470 // This function computes KnownZero to avoid a duplicated call to
4471 // ComputeMaskedBits in the caller.
4472 static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
4475 if (N->getOpcode() == ISD::TRUNCATE) {
4476 Op = N->getOperand(0);
4477 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4481 if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
4482 cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
4485 SDValue Op0 = N->getOperand(0);
4486 SDValue Op1 = N->getOperand(1);
4487 assert(Op0.getValueType() == Op1.getValueType());
4489 ConstantSDNode *COp0 = dyn_cast<ConstantSDNode>(Op0);
4490 ConstantSDNode *COp1 = dyn_cast<ConstantSDNode>(Op1);
4491 if (COp0 && COp0->isNullValue())
4493 else if (COp1 && COp1->isNullValue())
4498 DAG.ComputeMaskedBits(Op, KnownZero, KnownOne);
4500 if (!(KnownZero | APInt(Op.getValueSizeInBits(), 1)).isAllOnesValue())
4506 SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
4507 SDValue N0 = N->getOperand(0);
4508 EVT VT = N->getValueType(0);
4510 // fold (zext c1) -> c1
4511 if (isa<ConstantSDNode>(N0))
4512 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, N0);
4513 // fold (zext (zext x)) -> (zext x)
4514 // fold (zext (aext x)) -> (zext x)
4515 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
4516 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
4519 // fold (zext (truncate x)) -> (zext x) or
4520 // (zext (truncate x)) -> (truncate x)
4521 // This is valid when the truncated bits of x are already zero.
4522 // FIXME: We should extend this to work for vectors too.
4525 if (!VT.isVector() && isTruncateOf(DAG, N0, Op, KnownZero)) {
4526 APInt TruncatedBits =
4527 (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
4528 APInt(Op.getValueSizeInBits(), 0) :
4529 APInt::getBitsSet(Op.getValueSizeInBits(),
4530 N0.getValueSizeInBits(),
4531 std::min(Op.getValueSizeInBits(),
4532 VT.getSizeInBits()));
4533 if (TruncatedBits == (KnownZero & TruncatedBits)) {
4534 if (VT.bitsGT(Op.getValueType()))
4535 return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, Op);
4536 if (VT.bitsLT(Op.getValueType()))
4537 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4543 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4544 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
4545 if (N0.getOpcode() == ISD::TRUNCATE) {
4546 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4547 if (NarrowLoad.getNode()) {
4548 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4549 if (NarrowLoad.getNode() != N0.getNode()) {
4550 CombineTo(N0.getNode(), NarrowLoad);
4551 // CombineTo deleted the truncate, if needed, but not what's under it.
4554 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4558 // fold (zext (truncate x)) -> (and x, mask)
4559 if (N0.getOpcode() == ISD::TRUNCATE &&
4560 (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT))) {
4562 // fold (zext (truncate (load x))) -> (zext (smaller load x))
4563 // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
4564 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4565 if (NarrowLoad.getNode()) {
4566 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4567 if (NarrowLoad.getNode() != N0.getNode()) {
4568 CombineTo(N0.getNode(), NarrowLoad);
4569 // CombineTo deleted the truncate, if needed, but not what's under it.
4572 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4575 SDValue Op = N0.getOperand(0);
4576 if (Op.getValueType().bitsLT(VT)) {
4577 Op = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, Op);
4578 AddToWorkList(Op.getNode());
4579 } else if (Op.getValueType().bitsGT(VT)) {
4580 Op = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Op);
4581 AddToWorkList(Op.getNode());
4583 return DAG.getZeroExtendInReg(Op, N->getDebugLoc(),
4584 N0.getValueType().getScalarType());
4587 // Fold (zext (and (trunc x), cst)) -> (and x, cst),
4588 // if either of the casts is not free.
4589 if (N0.getOpcode() == ISD::AND &&
4590 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4591 N0.getOperand(1).getOpcode() == ISD::Constant &&
4592 (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4593 N0.getValueType()) ||
4594 !TLI.isZExtFree(N0.getValueType(), VT))) {
4595 SDValue X = N0.getOperand(0).getOperand(0);
4596 if (X.getValueType().bitsLT(VT)) {
4597 X = DAG.getNode(ISD::ANY_EXTEND, X.getDebugLoc(), VT, X);
4598 } else if (X.getValueType().bitsGT(VT)) {
4599 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
4601 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4602 Mask = Mask.zext(VT.getSizeInBits());
4603 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4604 X, DAG.getConstant(Mask, VT));
4607 // fold (zext (load x)) -> (zext (truncate (zextload x)))
4608 // None of the supported targets knows how to perform load and vector_zext
4609 // on vectors in one instruction. We only perform this transformation on
4611 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4612 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4613 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
4614 bool DoXform = true;
4615 SmallVector<SDNode*, 4> SetCCs;
4616 if (!N0.hasOneUse())
4617 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
4619 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4620 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4622 LN0->getBasePtr(), LN0->getPointerInfo(),
4624 LN0->isVolatile(), LN0->isNonTemporal(),
4625 LN0->getAlignment());
4626 CombineTo(N, ExtLoad);
4627 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4628 N0.getValueType(), ExtLoad);
4629 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4631 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4633 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4637 // fold (zext (and/or/xor (load x), cst)) ->
4638 // (and/or/xor (zextload x), (zext cst))
4639 if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
4640 N0.getOpcode() == ISD::XOR) &&
4641 isa<LoadSDNode>(N0.getOperand(0)) &&
4642 N0.getOperand(1).getOpcode() == ISD::Constant &&
4643 TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
4644 (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
4645 LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
4646 if (LN0->getExtensionType() != ISD::SEXTLOAD) {
4647 bool DoXform = true;
4648 SmallVector<SDNode*, 4> SetCCs;
4649 if (!N0.hasOneUse())
4650 DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
4653 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), VT,
4654 LN0->getChain(), LN0->getBasePtr(),
4655 LN0->getPointerInfo(),
4658 LN0->isNonTemporal(),
4659 LN0->getAlignment());
4660 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4661 Mask = Mask.zext(VT.getSizeInBits());
4662 SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
4663 ExtLoad, DAG.getConstant(Mask, VT));
4664 SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
4665 N0.getOperand(0).getDebugLoc(),
4666 N0.getOperand(0).getValueType(), ExtLoad);
4668 CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
4669 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4671 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4676 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
4677 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
4678 if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
4679 ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
4680 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4681 EVT MemVT = LN0->getMemoryVT();
4682 if ((!LegalOperations && !LN0->isVolatile()) ||
4683 TLI.isLoadExtLegal(ISD::ZEXTLOAD, MemVT)) {
4684 SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, N->getDebugLoc(), VT,
4686 LN0->getBasePtr(), LN0->getPointerInfo(),
4688 LN0->isVolatile(), LN0->isNonTemporal(),
4689 LN0->getAlignment());
4690 CombineTo(N, ExtLoad);
4691 CombineTo(N0.getNode(),
4692 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), N0.getValueType(),
4694 ExtLoad.getValue(1));
4695 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4699 if (N0.getOpcode() == ISD::SETCC) {
4700 if (!LegalOperations && VT.isVector()) {
4701 // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
4702 // Only do this before legalize for now.
4703 EVT N0VT = N0.getOperand(0).getValueType();
4704 EVT EltVT = VT.getVectorElementType();
4705 SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
4706 DAG.getConstant(1, EltVT));
4707 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4708 // We know that the # elements of the results is the same as the
4709 // # elements of the compare (and the # elements of the compare result
4710 // for that matter). Check to see that they are the same size. If so,
4711 // we know that the element size of the sext'd result matches the
4712 // element size of the compare operands.
4713 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4714 DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4716 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
4717 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4718 &OneOps[0], OneOps.size()));
4720 // If the desired elements are smaller or larger than the source
4721 // elements we can use a matching integer vector type and then
4722 // truncate/sign extend
4723 EVT MatchingElementType =
4724 EVT::getIntegerVT(*DAG.getContext(),
4725 N0VT.getScalarType().getSizeInBits());
4726 EVT MatchingVectorType =
4727 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4728 N0VT.getVectorNumElements());
4730 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4732 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4733 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4734 DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT),
4735 DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
4736 &OneOps[0], OneOps.size()));
4739 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4741 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4742 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4743 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4744 if (SCC.getNode()) return SCC;
4747 // (zext (shl (zext x), cst)) -> (shl (zext x), cst)
4748 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
4749 isa<ConstantSDNode>(N0.getOperand(1)) &&
4750 N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
4752 SDValue ShAmt = N0.getOperand(1);
4753 unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
4754 if (N0.getOpcode() == ISD::SHL) {
4755 SDValue InnerZExt = N0.getOperand(0);
4756 // If the original shl may be shifting out bits, do not perform this
4758 unsigned KnownZeroBits = InnerZExt.getValueType().getSizeInBits() -
4759 InnerZExt.getOperand(0).getValueType().getSizeInBits();
4760 if (ShAmtVal > KnownZeroBits)
4764 DebugLoc DL = N->getDebugLoc();
4766 // Ensure that the shift amount is wide enough for the shifted value.
4767 if (VT.getSizeInBits() >= 256)
4768 ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);
4770 return DAG.getNode(N0.getOpcode(), DL, VT,
4771 DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
4778 SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
4779 SDValue N0 = N->getOperand(0);
4780 EVT VT = N->getValueType(0);
4782 // fold (aext c1) -> c1
4783 if (isa<ConstantSDNode>(N0))
4784 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, N0);
4785 // fold (aext (aext x)) -> (aext x)
4786 // fold (aext (zext x)) -> (zext x)
4787 // fold (aext (sext x)) -> (sext x)
4788 if (N0.getOpcode() == ISD::ANY_EXTEND ||
4789 N0.getOpcode() == ISD::ZERO_EXTEND ||
4790 N0.getOpcode() == ISD::SIGN_EXTEND)
4791 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, N0.getOperand(0));
4793 // fold (aext (truncate (load x))) -> (aext (smaller load x))
4794 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
4795 if (N0.getOpcode() == ISD::TRUNCATE) {
4796 SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
4797 if (NarrowLoad.getNode()) {
4798 SDNode* oye = N0.getNode()->getOperand(0).getNode();
4799 if (NarrowLoad.getNode() != N0.getNode()) {
4800 CombineTo(N0.getNode(), NarrowLoad);
4801 // CombineTo deleted the truncate, if needed, but not what's under it.
4804 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4808 // fold (aext (truncate x))
4809 if (N0.getOpcode() == ISD::TRUNCATE) {
4810 SDValue TruncOp = N0.getOperand(0);
4811 if (TruncOp.getValueType() == VT)
4812 return TruncOp; // x iff x size == zext size.
4813 if (TruncOp.getValueType().bitsGT(VT))
4814 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, TruncOp);
4815 return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, TruncOp);
4818 // Fold (aext (and (trunc x), cst)) -> (and x, cst)
4819 // if the trunc is not free.
4820 if (N0.getOpcode() == ISD::AND &&
4821 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
4822 N0.getOperand(1).getOpcode() == ISD::Constant &&
4823 !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
4824 N0.getValueType())) {
4825 SDValue X = N0.getOperand(0).getOperand(0);
4826 if (X.getValueType().bitsLT(VT)) {
4827 X = DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, X);
4828 } else if (X.getValueType().bitsGT(VT)) {
4829 X = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, X);
4831 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
4832 Mask = Mask.zext(VT.getSizeInBits());
4833 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
4834 X, DAG.getConstant(Mask, VT));
4837 // fold (aext (load x)) -> (aext (truncate (extload x)))
4838 // None of the supported targets knows how to perform load and any_ext
4839 // on vectors in one instruction. We only perform this transformation on
4841 if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
4842 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
4843 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
4844 bool DoXform = true;
4845 SmallVector<SDNode*, 4> SetCCs;
4846 if (!N0.hasOneUse())
4847 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
4849 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4850 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
4852 LN0->getBasePtr(), LN0->getPointerInfo(),
4854 LN0->isVolatile(), LN0->isNonTemporal(),
4855 LN0->getAlignment());
4856 CombineTo(N, ExtLoad);
4857 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4858 N0.getValueType(), ExtLoad);
4859 CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
4860 ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
4862 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4866 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
4867 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
4868 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
4869 if (N0.getOpcode() == ISD::LOAD &&
4870 !ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
4872 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
4873 EVT MemVT = LN0->getMemoryVT();
4874 SDValue ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), N->getDebugLoc(),
4875 VT, LN0->getChain(), LN0->getBasePtr(),
4876 LN0->getPointerInfo(), MemVT,
4877 LN0->isVolatile(), LN0->isNonTemporal(),
4878 LN0->getAlignment());
4879 CombineTo(N, ExtLoad);
4880 CombineTo(N0.getNode(),
4881 DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
4882 N0.getValueType(), ExtLoad),
4883 ExtLoad.getValue(1));
4884 return SDValue(N, 0); // Return N so it doesn't get rechecked!
4887 if (N0.getOpcode() == ISD::SETCC) {
4888 // aext(setcc) -> sext_in_reg(vsetcc) for vectors.
4889 // Only do this before legalize for now.
4890 if (VT.isVector() && !LegalOperations) {
4891 EVT N0VT = N0.getOperand(0).getValueType();
4892 // We know that the # elements of the results is the same as the
4893 // # elements of the compare (and the # elements of the compare result
4894 // for that matter). Check to see that they are the same size. If so,
4895 // we know that the element size of the sext'd result matches the
4896 // element size of the compare operands.
4897 if (VT.getSizeInBits() == N0VT.getSizeInBits())
4898 return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
4900 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4901 // If the desired elements are smaller or larger than the source
4902 // elements we can use a matching integer vector type and then
4903 // truncate/sign extend
4905 EVT MatchingElementType =
4906 EVT::getIntegerVT(*DAG.getContext(),
4907 N0VT.getScalarType().getSizeInBits());
4908 EVT MatchingVectorType =
4909 EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
4910 N0VT.getVectorNumElements());
4912 DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
4914 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4915 return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
4919 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
4921 SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
4922 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
4923 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
4931 /// GetDemandedBits - See if the specified operand can be simplified with the
4932 /// knowledge that only the bits specified by Mask are used. If so, return the
4933 /// simpler operand, otherwise return a null SDValue.
4934 SDValue DAGCombiner::GetDemandedBits(SDValue V, const APInt &Mask) {
4935 switch (V.getOpcode()) {
4937 case ISD::Constant: {
4938 const ConstantSDNode *CV = cast<ConstantSDNode>(V.getNode());
4939 assert(CV != 0 && "Const value should be ConstSDNode.");
4940 const APInt &CVal = CV->getAPIntValue();
4941 APInt NewVal = CVal & Mask;
4942 if (NewVal != CVal) {
4943 return DAG.getConstant(NewVal, V.getValueType());
4949 // If the LHS or RHS don't contribute bits to the or, drop them.
4950 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
4951 return V.getOperand(1);
4952 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
4953 return V.getOperand(0);
4956 // Only look at single-use SRLs.
4957 if (!V.getNode()->hasOneUse())
4959 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
4960 // See if we can recursively simplify the LHS.
4961 unsigned Amt = RHSC->getZExtValue();
4963 // Watch out for shift count overflow though.
4964 if (Amt >= Mask.getBitWidth()) break;
4965 APInt NewMask = Mask << Amt;
4966 SDValue SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
4967 if (SimplifyLHS.getNode())
4968 return DAG.getNode(ISD::SRL, V.getDebugLoc(), V.getValueType(),
4969 SimplifyLHS, V.getOperand(1));
4975 /// ReduceLoadWidth - If the result of a wider load is shifted to right of N
4976 /// bits and then truncated to a narrower type and where N is a multiple
4977 /// of number of bits of the narrower type, transform it to a narrower load
4978 /// from address + N / num of bits of new type. If the result is to be
4979 /// extended, also fold the extension to form a extending load.
4980 SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
4981 unsigned Opc = N->getOpcode();
4983 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
4984 SDValue N0 = N->getOperand(0);
4985 EVT VT = N->getValueType(0);
4988 // This transformation isn't valid for vector loads.
4992 // Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
4994 if (Opc == ISD::SIGN_EXTEND_INREG) {
4995 ExtType = ISD::SEXTLOAD;
4996 ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
4997 } else if (Opc == ISD::SRL) {
4998 // Another special-case: SRL is basically zero-extending a narrower value.
4999 ExtType = ISD::ZEXTLOAD;
5001 ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
5002 if (!N01) return SDValue();
5003 ExtVT = EVT::getIntegerVT(*DAG.getContext(),
5004 VT.getSizeInBits() - N01->getZExtValue());
5006 if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
5009 unsigned EVTBits = ExtVT.getSizeInBits();
5011 // Do not generate loads of non-round integer types since these can
5012 // be expensive (and would be wrong if the type is not byte sized).
5013 if (!ExtVT.isRound())
5017 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
5018 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5019 ShAmt = N01->getZExtValue();
5020 // Is the shift amount a multiple of size of VT?
5021 if ((ShAmt & (EVTBits-1)) == 0) {
5022 N0 = N0.getOperand(0);
5023 // Is the load width a multiple of size of VT?
5024 if ((N0.getValueType().getSizeInBits() & (EVTBits-1)) != 0)
5028 // At this point, we must have a load or else we can't do the transform.
5029 if (!isa<LoadSDNode>(N0)) return SDValue();
5031 // If the shift amount is larger than the input type then we're not
5032 // accessing any of the loaded bytes. If the load was a zextload/extload
5033 // then the result of the shift+trunc is zero/undef (handled elsewhere).
5034 // If the load was a sextload then the result is a splat of the sign bit
5035 // of the extended byte. This is not worth optimizing for.
5036 if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
5041 // If the load is shifted left (and the result isn't shifted back right),
5042 // we can fold the truncate through the shift.
5043 unsigned ShLeftAmt = 0;
5044 if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
5045 ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
5046 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
5047 ShLeftAmt = N01->getZExtValue();
5048 N0 = N0.getOperand(0);
5052 // If we haven't found a load, we can't narrow it. Don't transform one with
5053 // multiple uses, this would require adding a new load.
5054 if (!isa<LoadSDNode>(N0) || !N0.hasOneUse() ||
5055 // Don't change the width of a volatile load.
5056 cast<LoadSDNode>(N0)->isVolatile())
5059 // Verify that we are actually reducing a load width here.
5060 if (cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() < EVTBits)
5063 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5064 EVT PtrType = N0.getOperand(1).getValueType();
5066 if (PtrType == MVT::Untyped || PtrType.isExtended())
5067 // It's not possible to generate a constant of extended or untyped type.
5070 // For big endian targets, we need to adjust the offset to the pointer to
5071 // load the correct bytes.
5072 if (TLI.isBigEndian()) {
5073 unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
5074 unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
5075 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
5078 uint64_t PtrOff = ShAmt / 8;
5079 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
5080 SDValue NewPtr = DAG.getNode(ISD::ADD, LN0->getDebugLoc(),
5081 PtrType, LN0->getBasePtr(),
5082 DAG.getConstant(PtrOff, PtrType));
5083 AddToWorkList(NewPtr.getNode());
5086 if (ExtType == ISD::NON_EXTLOAD)
5087 Load = DAG.getLoad(VT, N0.getDebugLoc(), LN0->getChain(), NewPtr,
5088 LN0->getPointerInfo().getWithOffset(PtrOff),
5089 LN0->isVolatile(), LN0->isNonTemporal(),
5090 LN0->isInvariant(), NewAlign);
5092 Load = DAG.getExtLoad(ExtType, N0.getDebugLoc(), VT, LN0->getChain(),NewPtr,
5093 LN0->getPointerInfo().getWithOffset(PtrOff),
5094 ExtVT, LN0->isVolatile(), LN0->isNonTemporal(),
5097 // Replace the old load's chain with the new load's chain.
5098 WorkListRemover DeadNodes(*this);
5099 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
5101 // Shift the result left, if we've swallowed a left shift.
5102 SDValue Result = Load;
5103 if (ShLeftAmt != 0) {
5104 EVT ShImmTy = getShiftAmountTy(Result.getValueType());
5105 if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
5107 Result = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT,
5108 Result, DAG.getConstant(ShLeftAmt, ShImmTy));
5111 // Return the new loaded value.
5115 SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
5116 SDValue N0 = N->getOperand(0);
5117 SDValue N1 = N->getOperand(1);
5118 EVT VT = N->getValueType(0);
5119 EVT EVT = cast<VTSDNode>(N1)->getVT();
5120 unsigned VTBits = VT.getScalarType().getSizeInBits();
5121 unsigned EVTBits = EVT.getScalarType().getSizeInBits();
5123 // fold (sext_in_reg c1) -> c1
5124 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
5125 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT, N0, N1);
5127 // If the input is already sign extended, just drop the extension.
5128 if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
5131 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
5132 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
5133 EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT())) {
5134 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5135 N0.getOperand(0), N1);
5138 // fold (sext_in_reg (sext x)) -> (sext x)
5139 // fold (sext_in_reg (aext x)) -> (sext x)
5140 // if x is small enough.
5141 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
5142 SDValue N00 = N0.getOperand(0);
5143 if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
5144 (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
5145 return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N00, N1);
5148 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
5149 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
5150 return DAG.getZeroExtendInReg(N0, N->getDebugLoc(), EVT);
5152 // fold operands of sext_in_reg based on knowledge that the top bits are not
5154 if (SimplifyDemandedBits(SDValue(N, 0)))
5155 return SDValue(N, 0);
5157 // fold (sext_in_reg (load x)) -> (smaller sextload x)
5158 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
5159 SDValue NarrowLoad = ReduceLoadWidth(N);
5160 if (NarrowLoad.getNode())
5163 // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
5164 // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
5165 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
5166 if (N0.getOpcode() == ISD::SRL) {
5167 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
5168 if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
5169 // We can turn this into an SRA iff the input to the SRL is already sign
5171 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
5172 if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
5173 return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT,
5174 N0.getOperand(0), N0.getOperand(1));
5178 // fold (sext_inreg (extload x)) -> (sextload x)
5179 if (ISD::isEXTLoad(N0.getNode()) &&
5180 ISD::isUNINDEXEDLoad(N0.getNode()) &&
5181 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5182 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5183 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5184 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5185 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5187 LN0->getBasePtr(), LN0->getPointerInfo(),
5189 LN0->isVolatile(), LN0->isNonTemporal(),
5190 LN0->getAlignment());
5191 CombineTo(N, ExtLoad);
5192 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5193 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5195 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
5196 if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
5198 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
5199 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
5200 TLI.isLoadExtLegal(ISD::SEXTLOAD, EVT))) {
5201 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5202 SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, N->getDebugLoc(), VT,
5204 LN0->getBasePtr(), LN0->getPointerInfo(),
5206 LN0->isVolatile(), LN0->isNonTemporal(),
5207 LN0->getAlignment());
5208 CombineTo(N, ExtLoad);
5209 CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
5210 return SDValue(N, 0); // Return N so it doesn't get rechecked!
5213 // Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
5214 if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
5215 SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
5216 N0.getOperand(1), false);
5217 if (BSwap.getNode() != 0)
5218 return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
5225 SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
5226 SDValue N0 = N->getOperand(0);
5227 EVT VT = N->getValueType(0);
5228 bool isLE = TLI.isLittleEndian();
5231 if (N0.getValueType() == N->getValueType(0))
5233 // fold (truncate c1) -> c1
5234 if (isa<ConstantSDNode>(N0))
5235 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0);
5236 // fold (truncate (truncate x)) -> (truncate x)
5237 if (N0.getOpcode() == ISD::TRUNCATE)
5238 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5239 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
5240 if (N0.getOpcode() == ISD::ZERO_EXTEND ||
5241 N0.getOpcode() == ISD::SIGN_EXTEND ||
5242 N0.getOpcode() == ISD::ANY_EXTEND) {
5243 if (N0.getOperand(0).getValueType().bitsLT(VT))
5244 // if the source is smaller than the dest, we still need an extend
5245 return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
5247 if (N0.getOperand(0).getValueType().bitsGT(VT))
5248 // if the source is larger than the dest, than we just need the truncate
5249 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, N0.getOperand(0));
5250 // if the source and dest are the same type, we can drop both the extend
5251 // and the truncate.
5252 return N0.getOperand(0);
5255 // Fold extract-and-trunc into a narrow extract. For example:
5256 // i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
5257 // i32 y = TRUNCATE(i64 x)
5259 // v16i8 b = BITCAST (v2i64 val)
5260 // i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
5262 // Note: We only run this optimization after type legalization (which often
5263 // creates this pattern) and before operation legalization after which
5264 // we need to be more careful about the vector instructions that we generate.
5265 if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
5266 LegalTypes && !LegalOperations && N0->hasOneUse()) {
5268 EVT VecTy = N0.getOperand(0).getValueType();
5269 EVT ExTy = N0.getValueType();
5270 EVT TrTy = N->getValueType(0);
5272 unsigned NumElem = VecTy.getVectorNumElements();
5273 unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();
5275 EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
5276 assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size");
5278 SDValue EltNo = N0->getOperand(1);
5279 if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
5280 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
5281 EVT IndexTy = N0->getOperand(1).getValueType();
5282 int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
5284 SDValue V = DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
5285 NVT, N0.getOperand(0));
5287 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
5288 N->getDebugLoc(), TrTy, V,
5289 DAG.getConstant(Index, IndexTy));
5293 // See if we can simplify the input to this truncate through knowledge that
5294 // only the low bits are being used.
5295 // For example "trunc (or (shl x, 8), y)" // -> trunc y
5296 // Currently we only perform this optimization on scalars because vectors
5297 // may have different active low bits.
5298 if (!VT.isVector()) {
5300 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
5301 VT.getSizeInBits()));
5302 if (Shorter.getNode())
5303 return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, Shorter);
5305 // fold (truncate (load x)) -> (smaller load x)
5306 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
5307 if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
5308 SDValue Reduced = ReduceLoadWidth(N);
5309 if (Reduced.getNode())
5312 // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
5313 // where ... are all 'undef'.
5314 if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
5315 SmallVector<EVT, 8> VTs;
5318 unsigned NumDefs = 0;
5320 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
5321 SDValue X = N0.getOperand(i);
5322 if (X.getOpcode() != ISD::UNDEF) {
5327 // Stop if more than one members are non-undef.
5330 VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
5331 VT.getVectorElementType(),
5332 X.getValueType().getVectorNumElements()));
5336 return DAG.getUNDEF(VT);
5339 assert(V.getNode() && "The single defined operand is empty!");
5340 SmallVector<SDValue, 8> Opnds;
5341 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
5343 Opnds.push_back(DAG.getUNDEF(VTs[i]));
5346 SDValue NV = DAG.getNode(ISD::TRUNCATE, V.getDebugLoc(), VTs[i], V);
5347 AddToWorkList(NV.getNode());
5348 Opnds.push_back(NV);
5350 return DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
5351 &Opnds[0], Opnds.size());
5355 // Simplify the operands using demanded-bits information.
5356 if (!VT.isVector() &&
5357 SimplifyDemandedBits(SDValue(N, 0)))
5358 return SDValue(N, 0);
5363 static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
5364 SDValue Elt = N->getOperand(i);
5365 if (Elt.getOpcode() != ISD::MERGE_VALUES)
5366 return Elt.getNode();
5367 return Elt.getOperand(Elt.getResNo()).getNode();
5370 /// CombineConsecutiveLoads - build_pair (load, load) -> load
5371 /// if load locations are consecutive.
5372 SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
5373 assert(N->getOpcode() == ISD::BUILD_PAIR);
5375 LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
5376 LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));
5377 if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
5378 LD1->getPointerInfo().getAddrSpace() !=
5379 LD2->getPointerInfo().getAddrSpace())
5381 EVT LD1VT = LD1->getValueType(0);
5383 if (ISD::isNON_EXTLoad(LD2) &&
5385 // If both are volatile this would reduce the number of volatile loads.
5386 // If one is volatile it might be ok, but play conservative and bail out.
5387 !LD1->isVolatile() &&
5388 !LD2->isVolatile() &&
5389 DAG.isConsecutiveLoad(LD2, LD1, LD1VT.getSizeInBits()/8, 1)) {
5390 unsigned Align = LD1->getAlignment();
5391 unsigned NewAlign = TLI.getDataLayout()->
5392 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5394 if (NewAlign <= Align &&
5395 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
5396 return DAG.getLoad(VT, N->getDebugLoc(), LD1->getChain(),
5397 LD1->getBasePtr(), LD1->getPointerInfo(),
5398 false, false, false, Align);
5404 SDValue DAGCombiner::visitBITCAST(SDNode *N) {
5405 SDValue N0 = N->getOperand(0);
5406 EVT VT = N->getValueType(0);
5408 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
5409 // Only do this before legalize, since afterward the target may be depending
5410 // on the bitconvert.
5411 // First check to see if this is all constant.
5413 N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
5415 bool isSimple = true;
5416 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
5417 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
5418 N0.getOperand(i).getOpcode() != ISD::Constant &&
5419 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
5424 EVT DestEltVT = N->getValueType(0).getVectorElementType();
5425 assert(!DestEltVT.isVector() &&
5426 "Element type of vector ValueType must not be vector!");
5428 return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
5431 // If the input is a constant, let getNode fold it.
5432 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
5433 SDValue Res = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT, N0);
5434 if (Res.getNode() != N) {
5435 if (!LegalOperations ||
5436 TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
5439 // Folding it resulted in an illegal node, and it's too late to
5440 // do that. Clean up the old node and forego the transformation.
5441 // Ideally this won't happen very often, because instcombine
5442 // and the earlier dagcombine runs (where illegal nodes are
5443 // permitted) should have folded most of them already.
5444 DAG.DeleteNode(Res.getNode());
5448 // (conv (conv x, t1), t2) -> (conv x, t2)
5449 if (N0.getOpcode() == ISD::BITCAST)
5450 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT,
5453 // fold (conv (load x)) -> (load (conv*)x)
5454 // If the resultant load doesn't need a higher alignment than the original!
5455 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
5456 // Do not change the width of a volatile load.
5457 !cast<LoadSDNode>(N0)->isVolatile() &&
5458 (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT))) {
5459 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
5460 unsigned Align = TLI.getDataLayout()->
5461 getABITypeAlignment(VT.getTypeForEVT(*DAG.getContext()));
5462 unsigned OrigAlign = LN0->getAlignment();
5464 if (Align <= OrigAlign) {
5465 SDValue Load = DAG.getLoad(VT, N->getDebugLoc(), LN0->getChain(),
5466 LN0->getBasePtr(), LN0->getPointerInfo(),
5467 LN0->isVolatile(), LN0->isNonTemporal(),
5468 LN0->isInvariant(), OrigAlign);
5470 CombineTo(N0.getNode(),
5471 DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5472 N0.getValueType(), Load),
5478 // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
5479 // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
5480 // This often reduces constant pool loads.
5481 if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(VT)) ||
5482 (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(VT))) &&
5483 N0.getNode()->hasOneUse() && VT.isInteger() &&
5484 !VT.isVector() && !N0.getValueType().isVector()) {
5485 SDValue NewConv = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(), VT,
5487 AddToWorkList(NewConv.getNode());
5489 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5490 if (N0.getOpcode() == ISD::FNEG)
5491 return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
5492 NewConv, DAG.getConstant(SignBit, VT));
5493 assert(N0.getOpcode() == ISD::FABS);
5494 return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
5495 NewConv, DAG.getConstant(~SignBit, VT));
5498 // fold (bitconvert (fcopysign cst, x)) ->
5499 // (or (and (bitconvert x), sign), (and cst, (not sign)))
5500 // Note that we don't handle (copysign x, cst) because this can always be
5501 // folded to an fneg or fabs.
5502 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
5503 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
5504 VT.isInteger() && !VT.isVector()) {
5505 unsigned OrigXWidth = N0.getOperand(1).getValueType().getSizeInBits();
5506 EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
5507 if (isTypeLegal(IntXVT)) {
5508 SDValue X = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5509 IntXVT, N0.getOperand(1));
5510 AddToWorkList(X.getNode());
5512 // If X has a different width than the result/lhs, sext it or truncate it.
5513 unsigned VTWidth = VT.getSizeInBits();
5514 if (OrigXWidth < VTWidth) {
5515 X = DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, X);
5516 AddToWorkList(X.getNode());
5517 } else if (OrigXWidth > VTWidth) {
5518 // To get the sign bit in the right place, we have to shift it right
5519 // before truncating.
5520 X = DAG.getNode(ISD::SRL, X.getDebugLoc(),
5521 X.getValueType(), X,
5522 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
5523 AddToWorkList(X.getNode());
5524 X = DAG.getNode(ISD::TRUNCATE, X.getDebugLoc(), VT, X);
5525 AddToWorkList(X.getNode());
5528 APInt SignBit = APInt::getSignBit(VT.getSizeInBits());
5529 X = DAG.getNode(ISD::AND, X.getDebugLoc(), VT,
5530 X, DAG.getConstant(SignBit, VT));
5531 AddToWorkList(X.getNode());
5533 SDValue Cst = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(),
5534 VT, N0.getOperand(0));
5535 Cst = DAG.getNode(ISD::AND, Cst.getDebugLoc(), VT,
5536 Cst, DAG.getConstant(~SignBit, VT));
5537 AddToWorkList(Cst.getNode());
5539 return DAG.getNode(ISD::OR, N->getDebugLoc(), VT, X, Cst);
5543 // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
5544 if (N0.getOpcode() == ISD::BUILD_PAIR) {
5545 SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
5546 if (CombineLD.getNode())
5553 SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
5554 EVT VT = N->getValueType(0);
5555 return CombineConsecutiveLoads(N, VT);
5558 /// ConstantFoldBITCASTofBUILD_VECTOR - We know that BV is a build_vector
5559 /// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
5560 /// destination element value type.
5561 SDValue DAGCombiner::
5562 ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
5563 EVT SrcEltVT = BV->getValueType(0).getVectorElementType();
5565 // If this is already the right type, we're done.
5566 if (SrcEltVT == DstEltVT) return SDValue(BV, 0);
5568 unsigned SrcBitSize = SrcEltVT.getSizeInBits();
5569 unsigned DstBitSize = DstEltVT.getSizeInBits();
5571 // If this is a conversion of N elements of one type to N elements of another
5572 // type, convert each element. This handles FP<->INT cases.
5573 if (SrcBitSize == DstBitSize) {
5574 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5575 BV->getValueType(0).getVectorNumElements());
5577 // Due to the FP element handling below calling this routine recursively,
5578 // we can end up with a scalar-to-vector node here.
5579 if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
5580 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5581 DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5582 DstEltVT, BV->getOperand(0)));
5584 SmallVector<SDValue, 8> Ops;
5585 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5586 SDValue Op = BV->getOperand(i);
5587 // If the vector element type is not legal, the BUILD_VECTOR operands
5588 // are promoted and implicitly truncated. Make that explicit here.
5589 if (Op.getValueType() != SrcEltVT)
5590 Op = DAG.getNode(ISD::TRUNCATE, BV->getDebugLoc(), SrcEltVT, Op);
5591 Ops.push_back(DAG.getNode(ISD::BITCAST, BV->getDebugLoc(),
5593 AddToWorkList(Ops.back().getNode());
5595 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5596 &Ops[0], Ops.size());
5599 // Otherwise, we're growing or shrinking the elements. To avoid having to
5600 // handle annoying details of growing/shrinking FP values, we convert them to
5602 if (SrcEltVT.isFloatingPoint()) {
5603 // Convert the input float vector to a int vector where the elements are the
5605 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
5606 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
5607 BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
5611 // Now we know the input is an integer vector. If the output is a FP type,
5612 // convert to integer first, then to FP of the right size.
5613 if (DstEltVT.isFloatingPoint()) {
5614 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
5615 EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
5616 SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();
5618 // Next, convert to FP elements of the same size.
5619 return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
5622 // Okay, we know the src/dst types are both integers of differing types.
5623 // Handling growing first.
5624 assert(SrcEltVT.isInteger() && DstEltVT.isInteger());
5625 if (SrcBitSize < DstBitSize) {
5626 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
5628 SmallVector<SDValue, 8> Ops;
5629 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
5630 i += NumInputsPerOutput) {
5631 bool isLE = TLI.isLittleEndian();
5632 APInt NewBits = APInt(DstBitSize, 0);
5633 bool EltIsUndef = true;
5634 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
5635 // Shift the previously computed bits over.
5636 NewBits <<= SrcBitSize;
5637 SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
5638 if (Op.getOpcode() == ISD::UNDEF) continue;
5641 NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
5642 zextOrTrunc(SrcBitSize).zext(DstBitSize);
5646 Ops.push_back(DAG.getUNDEF(DstEltVT));
5648 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
5651 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
5652 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5653 &Ops[0], Ops.size());
5656 // Finally, this must be the case where we are shrinking elements: each input
5657 // turns into multiple outputs.
5658 bool isS2V = ISD::isScalarToVector(BV);
5659 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
5660 EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
5661 NumOutputsPerInput*BV->getNumOperands());
5662 SmallVector<SDValue, 8> Ops;
5664 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
5665 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
5666 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
5667 Ops.push_back(DAG.getUNDEF(DstEltVT));
5671 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->
5672 getAPIntValue().zextOrTrunc(SrcBitSize);
5674 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
5675 APInt ThisVal = OpVal.trunc(DstBitSize);
5676 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
5677 if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
5678 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
5679 return DAG.getNode(ISD::SCALAR_TO_VECTOR, BV->getDebugLoc(), VT,
5681 OpVal = OpVal.lshr(DstBitSize);
5684 // For big endian targets, swap the order of the pieces of each element.
5685 if (TLI.isBigEndian())
5686 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
5689 return DAG.getNode(ISD::BUILD_VECTOR, BV->getDebugLoc(), VT,
5690 &Ops[0], Ops.size());
5693 SDValue DAGCombiner::visitFADD(SDNode *N) {
5694 SDValue N0 = N->getOperand(0);
5695 SDValue N1 = N->getOperand(1);
5696 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5697 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5698 EVT VT = N->getValueType(0);
5701 if (VT.isVector()) {
5702 SDValue FoldedVOp = SimplifyVBinOp(N);
5703 if (FoldedVOp.getNode()) return FoldedVOp;
5706 // fold (fadd c1, c2) -> c1 + c2
5707 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5708 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N1);
5709 // canonicalize constant to RHS
5710 if (N0CFP && !N1CFP)
5711 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N0);
5712 // fold (fadd A, 0) -> A
5713 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5714 N1CFP->getValueAPF().isZero())
5716 // fold (fadd A, (fneg B)) -> (fsub A, B)
5717 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5718 isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5719 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0,
5720 GetNegatedExpression(N1, DAG, LegalOperations));
5721 // fold (fadd (fneg A), B) -> (fsub B, A)
5722 if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
5723 isNegatibleForFree(N0, LegalOperations, TLI, &DAG.getTarget().Options) == 2)
5724 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N1,
5725 GetNegatedExpression(N0, DAG, LegalOperations));
5727 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
5728 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
5729 N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
5730 isa<ConstantFPSDNode>(N0.getOperand(1)))
5731 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0.getOperand(0),
5732 DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5733 N0.getOperand(1), N1));
5735 // In unsafe math mode, we can fold chains of FADD's of the same value
5736 // into multiplications. This transform is not safe in general because
5737 // we are reducing the number of rounding steps.
5738 if (DAG.getTarget().Options.UnsafeFPMath &&
5739 TLI.isOperationLegalOrCustom(ISD::FMUL, VT) &&
5741 if (N0.getOpcode() == ISD::FMUL) {
5742 ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
5743 ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
5745 // (fadd (fmul c, x), x) -> (fmul c+1, x)
5746 if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
5747 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5749 DAG.getConstantFP(1.0, VT));
5750 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5754 // (fadd (fmul x, c), x) -> (fmul c+1, x)
5755 if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
5756 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5758 DAG.getConstantFP(1.0, VT));
5759 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5763 // (fadd (fadd x, x), x) -> (fmul 3.0, x)
5764 if (!CFP00 && !CFP01 && N0.getOperand(0) == N0.getOperand(1) &&
5765 N0.getOperand(0) == N1) {
5766 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5767 N1, DAG.getConstantFP(3.0, VT));
5770 // (fadd (fmul c, x), (fadd x, x)) -> (fmul c+2, x)
5771 if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
5772 N1.getOperand(0) == N1.getOperand(1) &&
5773 N0.getOperand(1) == N1.getOperand(0)) {
5774 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5776 DAG.getConstantFP(2.0, VT));
5777 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5778 N0.getOperand(1), NewCFP);
5781 // (fadd (fmul x, c), (fadd x, x)) -> (fmul c+2, x)
5782 if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
5783 N1.getOperand(0) == N1.getOperand(1) &&
5784 N0.getOperand(0) == N1.getOperand(0)) {
5785 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5787 DAG.getConstantFP(2.0, VT));
5788 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5789 N0.getOperand(0), NewCFP);
5793 if (N1.getOpcode() == ISD::FMUL) {
5794 ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
5795 ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
5797 // (fadd x, (fmul c, x)) -> (fmul c+1, x)
5798 if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
5799 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5801 DAG.getConstantFP(1.0, VT));
5802 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5806 // (fadd x, (fmul x, c)) -> (fmul c+1, x)
5807 if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
5808 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5810 DAG.getConstantFP(1.0, VT));
5811 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5815 // (fadd x, (fadd x, x)) -> (fmul 3.0, x)
5816 if (!CFP10 && !CFP11 && N1.getOperand(0) == N1.getOperand(1) &&
5817 N1.getOperand(0) == N0) {
5818 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5819 N0, DAG.getConstantFP(3.0, VT));
5822 // (fadd (fadd x, x), (fmul c, x)) -> (fmul c+2, x)
5823 if (CFP10 && !CFP11 && N1.getOpcode() == ISD::FADD &&
5824 N1.getOperand(0) == N1.getOperand(1) &&
5825 N0.getOperand(1) == N1.getOperand(0)) {
5826 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5828 DAG.getConstantFP(2.0, VT));
5829 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5830 N0.getOperand(1), NewCFP);
5833 // (fadd (fadd x, x), (fmul x, c)) -> (fmul c+2, x)
5834 if (CFP11 && !CFP10 && N1.getOpcode() == ISD::FADD &&
5835 N1.getOperand(0) == N1.getOperand(1) &&
5836 N0.getOperand(0) == N1.getOperand(0)) {
5837 SDValue NewCFP = DAG.getNode(ISD::FADD, N->getDebugLoc(), VT,
5839 DAG.getConstantFP(2.0, VT));
5840 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5841 N0.getOperand(0), NewCFP);
5845 // (fadd (fadd x, x), (fadd x, x)) -> (fmul 4.0, x)
5846 if (N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
5847 N0.getOperand(0) == N0.getOperand(1) &&
5848 N1.getOperand(0) == N1.getOperand(1) &&
5849 N0.getOperand(0) == N1.getOperand(0)) {
5850 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
5852 DAG.getConstantFP(4.0, VT));
5856 // FADD -> FMA combines:
5857 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5858 DAG.getTarget().Options.UnsafeFPMath) &&
5859 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5860 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5862 // fold (fadd (fmul x, y), z) -> (fma x, y, z)
5863 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5864 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5865 N0.getOperand(0), N0.getOperand(1), N1);
5868 // fold (fadd x, (fmul y, z)) -> (fma y, z, x)
5869 // Note: Commutes FADD operands.
5870 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5871 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT,
5872 N1.getOperand(0), N1.getOperand(1), N0);
5879 SDValue DAGCombiner::visitFSUB(SDNode *N) {
5880 SDValue N0 = N->getOperand(0);
5881 SDValue N1 = N->getOperand(1);
5882 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5883 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5884 EVT VT = N->getValueType(0);
5885 DebugLoc dl = N->getDebugLoc();
5888 if (VT.isVector()) {
5889 SDValue FoldedVOp = SimplifyVBinOp(N);
5890 if (FoldedVOp.getNode()) return FoldedVOp;
5893 // fold (fsub c1, c2) -> c1-c2
5894 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5895 return DAG.getNode(ISD::FSUB, N->getDebugLoc(), VT, N0, N1);
5896 // fold (fsub A, 0) -> A
5897 if (DAG.getTarget().Options.UnsafeFPMath &&
5898 N1CFP && N1CFP->getValueAPF().isZero())
5900 // fold (fsub 0, B) -> -B
5901 if (DAG.getTarget().Options.UnsafeFPMath &&
5902 N0CFP && N0CFP->getValueAPF().isZero()) {
5903 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5904 return GetNegatedExpression(N1, DAG, LegalOperations);
5905 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
5906 return DAG.getNode(ISD::FNEG, dl, VT, N1);
5908 // fold (fsub A, (fneg B)) -> (fadd A, B)
5909 if (isNegatibleForFree(N1, LegalOperations, TLI, &DAG.getTarget().Options))
5910 return DAG.getNode(ISD::FADD, dl, VT, N0,
5911 GetNegatedExpression(N1, DAG, LegalOperations));
5913 // If 'unsafe math' is enabled, fold
5914 // (fsub x, x) -> 0.0 &
5915 // (fsub x, (fadd x, y)) -> (fneg y) &
5916 // (fsub x, (fadd y, x)) -> (fneg y)
5917 if (DAG.getTarget().Options.UnsafeFPMath) {
5919 return DAG.getConstantFP(0.0f, VT);
5921 if (N1.getOpcode() == ISD::FADD) {
5922 SDValue N10 = N1->getOperand(0);
5923 SDValue N11 = N1->getOperand(1);
5925 if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI,
5926 &DAG.getTarget().Options))
5927 return GetNegatedExpression(N11, DAG, LegalOperations);
5928 else if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI,
5929 &DAG.getTarget().Options))
5930 return GetNegatedExpression(N10, DAG, LegalOperations);
5934 // FSUB -> FMA combines:
5935 if ((DAG.getTarget().Options.AllowFPOpFusion == FPOpFusion::Fast ||
5936 DAG.getTarget().Options.UnsafeFPMath) &&
5937 DAG.getTarget().getTargetLowering()->isFMAFasterThanMulAndAdd(VT) &&
5938 TLI.isOperationLegalOrCustom(ISD::FMA, VT)) {
5940 // fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
5941 if (N0.getOpcode() == ISD::FMUL && N0->hasOneUse()) {
5942 return DAG.getNode(ISD::FMA, dl, VT,
5943 N0.getOperand(0), N0.getOperand(1),
5944 DAG.getNode(ISD::FNEG, dl, VT, N1));
5947 // fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
5948 // Note: Commutes FSUB operands.
5949 if (N1.getOpcode() == ISD::FMUL && N1->hasOneUse()) {
5950 return DAG.getNode(ISD::FMA, dl, VT,
5951 DAG.getNode(ISD::FNEG, dl, VT,
5953 N1.getOperand(1), N0);
5956 // fold (fsub (-(fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
5957 if (N0.getOpcode() == ISD::FNEG &&
5958 N0.getOperand(0).getOpcode() == ISD::FMUL &&
5959 N0->hasOneUse() && N0.getOperand(0).hasOneUse()) {
5960 SDValue N00 = N0.getOperand(0).getOperand(0);
5961 SDValue N01 = N0.getOperand(0).getOperand(1);
5962 return DAG.getNode(ISD::FMA, dl, VT,
5963 DAG.getNode(ISD::FNEG, dl, VT, N00), N01,
5964 DAG.getNode(ISD::FNEG, dl, VT, N1));
5971 SDValue DAGCombiner::visitFMUL(SDNode *N) {
5972 SDValue N0 = N->getOperand(0);
5973 SDValue N1 = N->getOperand(1);
5974 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
5975 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
5976 EVT VT = N->getValueType(0);
5977 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
5980 if (VT.isVector()) {
5981 SDValue FoldedVOp = SimplifyVBinOp(N);
5982 if (FoldedVOp.getNode()) return FoldedVOp;
5985 // fold (fmul c1, c2) -> c1*c2
5986 if (N0CFP && N1CFP && VT != MVT::ppcf128)
5987 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0, N1);
5988 // canonicalize constant to RHS
5989 if (N0CFP && !N1CFP)
5990 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N1, N0);
5991 // fold (fmul A, 0) -> 0
5992 if (DAG.getTarget().Options.UnsafeFPMath &&
5993 N1CFP && N1CFP->getValueAPF().isZero())
5995 // fold (fmul A, 0) -> 0, vector edition.
5996 if (DAG.getTarget().Options.UnsafeFPMath &&
5997 ISD::isBuildVectorAllZeros(N1.getNode()))
5999 // fold (fmul A, 1.0) -> A
6000 if (N1CFP && N1CFP->isExactlyValue(1.0))
6002 // fold (fmul X, 2.0) -> (fadd X, X)
6003 if (N1CFP && N1CFP->isExactlyValue(+2.0))
6004 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N0);
6005 // fold (fmul X, -1.0) -> (fneg X)
6006 if (N1CFP && N1CFP->isExactlyValue(-1.0))
6007 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6008 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT, N0);
6010 // fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
6011 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6012 &DAG.getTarget().Options)) {
6013 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6014 &DAG.getTarget().Options)) {
6015 // Both can be negated for free, check to see if at least one is cheaper
6017 if (LHSNeg == 2 || RHSNeg == 2)
6018 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6019 GetNegatedExpression(N0, DAG, LegalOperations),
6020 GetNegatedExpression(N1, DAG, LegalOperations));
6024 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
6025 if (DAG.getTarget().Options.UnsafeFPMath &&
6026 N1CFP && N0.getOpcode() == ISD::FMUL &&
6027 N0.getNode()->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
6028 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0.getOperand(0),
6029 DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6030 N0.getOperand(1), N1));
6035 SDValue DAGCombiner::visitFMA(SDNode *N) {
6036 SDValue N0 = N->getOperand(0);
6037 SDValue N1 = N->getOperand(1);
6038 SDValue N2 = N->getOperand(2);
6039 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6040 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6041 EVT VT = N->getValueType(0);
6042 DebugLoc dl = N->getDebugLoc();
6044 if (N0CFP && N0CFP->isExactlyValue(1.0))
6045 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N2);
6046 if (N1CFP && N1CFP->isExactlyValue(1.0))
6047 return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N2);
6049 // Canonicalize (fma c, x, y) -> (fma x, c, y)
6050 if (N0CFP && !N1CFP)
6051 return DAG.getNode(ISD::FMA, N->getDebugLoc(), VT, N1, N0, N2);
6053 // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
6054 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6055 N2.getOpcode() == ISD::FMUL &&
6056 N0 == N2.getOperand(0) &&
6057 N2.getOperand(1).getOpcode() == ISD::ConstantFP) {
6058 return DAG.getNode(ISD::FMUL, dl, VT, N0,
6059 DAG.getNode(ISD::FADD, dl, VT, N1, N2.getOperand(1)));
6063 // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
6064 if (DAG.getTarget().Options.UnsafeFPMath &&
6065 N0.getOpcode() == ISD::FMUL && N1CFP &&
6066 N0.getOperand(1).getOpcode() == ISD::ConstantFP) {
6067 return DAG.getNode(ISD::FMA, dl, VT,
6069 DAG.getNode(ISD::FMUL, dl, VT, N1, N0.getOperand(1)),
6073 // (fma x, 1, y) -> (fadd x, y)
6074 // (fma x, -1, y) -> (fadd (fneg x), y)
6076 if (N1CFP->isExactlyValue(1.0))
6077 return DAG.getNode(ISD::FADD, dl, VT, N0, N2);
6079 if (N1CFP->isExactlyValue(-1.0) &&
6080 (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
6081 SDValue RHSNeg = DAG.getNode(ISD::FNEG, dl, VT, N0);
6082 AddToWorkList(RHSNeg.getNode());
6083 return DAG.getNode(ISD::FADD, dl, VT, N2, RHSNeg);
6087 // (fma x, c, x) -> (fmul x, (c+1))
6088 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP && N0 == N2) {
6089 return DAG.getNode(ISD::FMUL, dl, VT,
6091 DAG.getNode(ISD::FADD, dl, VT,
6092 N1, DAG.getConstantFP(1.0, VT)));
6095 // (fma x, c, (fneg x)) -> (fmul x, (c-1))
6096 if (DAG.getTarget().Options.UnsafeFPMath && N1CFP &&
6097 N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0) {
6098 return DAG.getNode(ISD::FMUL, dl, VT,
6100 DAG.getNode(ISD::FADD, dl, VT,
6101 N1, DAG.getConstantFP(-1.0, VT)));
6108 SDValue DAGCombiner::visitFDIV(SDNode *N) {
6109 SDValue N0 = N->getOperand(0);
6110 SDValue N1 = N->getOperand(1);
6111 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6112 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6113 EVT VT = N->getValueType(0);
6114 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6117 if (VT.isVector()) {
6118 SDValue FoldedVOp = SimplifyVBinOp(N);
6119 if (FoldedVOp.getNode()) return FoldedVOp;
6122 // fold (fdiv c1, c2) -> c1/c2
6123 if (N0CFP && N1CFP && VT != MVT::ppcf128)
6124 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT, N0, N1);
6126 // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
6127 if (N1CFP && VT != MVT::ppcf128 && DAG.getTarget().Options.UnsafeFPMath) {
6128 // Compute the reciprocal 1.0 / c2.
6129 APFloat N1APF = N1CFP->getValueAPF();
6130 APFloat Recip(N1APF.getSemantics(), 1); // 1.0
6131 APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
6132 // Only do the transform if the reciprocal is a legal fp immediate that
6133 // isn't too nasty (eg NaN, denormal, ...).
6134 if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
6135 (!LegalOperations ||
6136 // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
6137 // backend)... we should handle this gracefully after Legalize.
6138 // TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT) ||
6139 TLI.isOperationLegal(llvm::ISD::ConstantFP, VT) ||
6140 TLI.isFPImmLegal(Recip, VT)))
6141 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT, N0,
6142 DAG.getConstantFP(Recip, VT));
6145 // (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
6146 if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI,
6147 &DAG.getTarget().Options)) {
6148 if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI,
6149 &DAG.getTarget().Options)) {
6150 // Both can be negated for free, check to see if at least one is cheaper
6152 if (LHSNeg == 2 || RHSNeg == 2)
6153 return DAG.getNode(ISD::FDIV, N->getDebugLoc(), VT,
6154 GetNegatedExpression(N0, DAG, LegalOperations),
6155 GetNegatedExpression(N1, DAG, LegalOperations));
6162 SDValue DAGCombiner::visitFREM(SDNode *N) {
6163 SDValue N0 = N->getOperand(0);
6164 SDValue N1 = N->getOperand(1);
6165 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6166 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6167 EVT VT = N->getValueType(0);
6169 // fold (frem c1, c2) -> fmod(c1,c2)
6170 if (N0CFP && N1CFP && VT != MVT::ppcf128)
6171 return DAG.getNode(ISD::FREM, N->getDebugLoc(), VT, N0, N1);
6176 SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
6177 SDValue N0 = N->getOperand(0);
6178 SDValue N1 = N->getOperand(1);
6179 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6180 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
6181 EVT VT = N->getValueType(0);
6183 if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
6184 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT, N0, N1);
6187 const APFloat& V = N1CFP->getValueAPF();
6188 // copysign(x, c1) -> fabs(x) iff ispos(c1)
6189 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
6190 if (!V.isNegative()) {
6191 if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
6192 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6194 if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
6195 return DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6196 DAG.getNode(ISD::FABS, N0.getDebugLoc(), VT, N0));
6200 // copysign(fabs(x), y) -> copysign(x, y)
6201 // copysign(fneg(x), y) -> copysign(x, y)
6202 // copysign(copysign(x,z), y) -> copysign(x, y)
6203 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
6204 N0.getOpcode() == ISD::FCOPYSIGN)
6205 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6206 N0.getOperand(0), N1);
6208 // copysign(x, abs(y)) -> abs(x)
6209 if (N1.getOpcode() == ISD::FABS)
6210 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6212 // copysign(x, copysign(y,z)) -> copysign(x, z)
6213 if (N1.getOpcode() == ISD::FCOPYSIGN)
6214 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6215 N0, N1.getOperand(1));
6217 // copysign(x, fp_extend(y)) -> copysign(x, y)
6218 // copysign(x, fp_round(y)) -> copysign(x, y)
6219 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
6220 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6221 N0, N1.getOperand(0));
6226 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
6227 SDValue N0 = N->getOperand(0);
6228 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6229 EVT VT = N->getValueType(0);
6230 EVT OpVT = N0.getValueType();
6232 // fold (sint_to_fp c1) -> c1fp
6233 if (N0C && OpVT != MVT::ppcf128 &&
6234 // ...but only if the target supports immediate floating-point values
6235 (!LegalOperations ||
6236 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6237 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6239 // If the input is a legal type, and SINT_TO_FP is not legal on this target,
6240 // but UINT_TO_FP is legal on this target, try to convert.
6241 if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
6242 TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
6243 // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
6244 if (DAG.SignBitIsZero(N0))
6245 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6248 // The next optimizations are desireable only if SELECT_CC can be lowered.
6249 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6250 // having to say they don't support SELECT_CC on every type the DAG knows
6251 // about, since there is no way to mark an opcode illegal at all value types
6252 // (See also visitSELECT)
6253 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6254 // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6255 if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
6257 (!LegalOperations ||
6258 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6260 { N0.getOperand(0), N0.getOperand(1),
6261 DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
6263 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6266 // fold (sint_to_fp (zext (setcc x, y, cc))) ->
6267 // (select_cc x, y, 1.0, 0.0,, cc)
6268 if (N0.getOpcode() == ISD::ZERO_EXTEND &&
6269 N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
6270 (!LegalOperations ||
6271 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6273 { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
6274 DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
6275 N0.getOperand(0).getOperand(2) };
6276 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6283 SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
6284 SDValue N0 = N->getOperand(0);
6285 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
6286 EVT VT = N->getValueType(0);
6287 EVT OpVT = N0.getValueType();
6289 // fold (uint_to_fp c1) -> c1fp
6290 if (N0C && OpVT != MVT::ppcf128 &&
6291 // ...but only if the target supports immediate floating-point values
6292 (!LegalOperations ||
6293 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT)))
6294 return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
6296 // If the input is a legal type, and UINT_TO_FP is not legal on this target,
6297 // but SINT_TO_FP is legal on this target, try to convert.
6298 if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
6299 TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
6300 // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
6301 if (DAG.SignBitIsZero(N0))
6302 return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
6305 // The next optimizations are desireable only if SELECT_CC can be lowered.
6306 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
6307 // having to say they don't support SELECT_CC on every type the DAG knows
6308 // about, since there is no way to mark an opcode illegal at all value types
6309 // (See also visitSELECT)
6310 if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
6311 // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
6313 if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
6314 (!LegalOperations ||
6315 TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
6317 { N0.getOperand(0), N0.getOperand(1),
6318 DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
6320 return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
6327 SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
6328 SDValue N0 = N->getOperand(0);
6329 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6330 EVT VT = N->getValueType(0);
6332 // fold (fp_to_sint c1fp) -> c1
6334 return DAG.getNode(ISD::FP_TO_SINT, N->getDebugLoc(), VT, N0);
6339 SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
6340 SDValue N0 = N->getOperand(0);
6341 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6342 EVT VT = N->getValueType(0);
6344 // fold (fp_to_uint c1fp) -> c1
6345 if (N0CFP && VT != MVT::ppcf128)
6346 return DAG.getNode(ISD::FP_TO_UINT, N->getDebugLoc(), VT, N0);
6351 SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
6352 SDValue N0 = N->getOperand(0);
6353 SDValue N1 = N->getOperand(1);
6354 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6355 EVT VT = N->getValueType(0);
6357 // fold (fp_round c1fp) -> c1fp
6358 if (N0CFP && N0.getValueType() != MVT::ppcf128)
6359 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0, N1);
6361 // fold (fp_round (fp_extend x)) -> x
6362 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
6363 return N0.getOperand(0);
6365 // fold (fp_round (fp_round x)) -> (fp_round x)
6366 if (N0.getOpcode() == ISD::FP_ROUND) {
6367 // This is a value preserving truncation if both round's are.
6368 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
6369 N0.getNode()->getConstantOperandVal(1) == 1;
6370 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT, N0.getOperand(0),
6371 DAG.getIntPtrConstant(IsTrunc));
6374 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
6375 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
6376 SDValue Tmp = DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(), VT,
6377 N0.getOperand(0), N1);
6378 AddToWorkList(Tmp.getNode());
6379 return DAG.getNode(ISD::FCOPYSIGN, N->getDebugLoc(), VT,
6380 Tmp, N0.getOperand(1));
6386 SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
6387 SDValue N0 = N->getOperand(0);
6388 EVT VT = N->getValueType(0);
6389 EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
6390 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6392 // fold (fp_round_inreg c1fp) -> c1fp
6393 if (N0CFP && isTypeLegal(EVT)) {
6394 SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), EVT);
6395 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, Round);
6401 SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
6402 SDValue N0 = N->getOperand(0);
6403 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6404 EVT VT = N->getValueType(0);
6406 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
6407 if (N->hasOneUse() &&
6408 N->use_begin()->getOpcode() == ISD::FP_ROUND)
6411 // fold (fp_extend c1fp) -> c1fp
6412 if (N0CFP && VT != MVT::ppcf128)
6413 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, N0);
6415 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
6417 if (N0.getOpcode() == ISD::FP_ROUND
6418 && N0.getNode()->getConstantOperandVal(1) == 1) {
6419 SDValue In = N0.getOperand(0);
6420 if (In.getValueType() == VT) return In;
6421 if (VT.bitsLT(In.getValueType()))
6422 return DAG.getNode(ISD::FP_ROUND, N->getDebugLoc(), VT,
6423 In, N0.getOperand(1));
6424 return DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), VT, In);
6427 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
6428 if (ISD::isNON_EXTLoad(N0.getNode()) && N0.hasOneUse() &&
6429 ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
6430 TLI.isLoadExtLegal(ISD::EXTLOAD, N0.getValueType()))) {
6431 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6432 SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, N->getDebugLoc(), VT,
6434 LN0->getBasePtr(), LN0->getPointerInfo(),
6436 LN0->isVolatile(), LN0->isNonTemporal(),
6437 LN0->getAlignment());
6438 CombineTo(N, ExtLoad);
6439 CombineTo(N0.getNode(),
6440 DAG.getNode(ISD::FP_ROUND, N0.getDebugLoc(),
6441 N0.getValueType(), ExtLoad, DAG.getIntPtrConstant(1)),
6442 ExtLoad.getValue(1));
6443 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6449 SDValue DAGCombiner::visitFNEG(SDNode *N) {
6450 SDValue N0 = N->getOperand(0);
6451 EVT VT = N->getValueType(0);
6453 if (VT.isVector()) {
6454 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6455 if (FoldedVOp.getNode()) return FoldedVOp;
6458 if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
6459 &DAG.getTarget().Options))
6460 return GetNegatedExpression(N0, DAG, LegalOperations);
6462 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
6463 // constant pool values.
6464 if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST &&
6466 N0.getNode()->hasOneUse() &&
6467 N0.getOperand(0).getValueType().isInteger()) {
6468 SDValue Int = N0.getOperand(0);
6469 EVT IntVT = Int.getValueType();
6470 if (IntVT.isInteger() && !IntVT.isVector()) {
6471 Int = DAG.getNode(ISD::XOR, N0.getDebugLoc(), IntVT, Int,
6472 DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6473 AddToWorkList(Int.getNode());
6474 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6479 // (fneg (fmul c, x)) -> (fmul -c, x)
6480 if (N0.getOpcode() == ISD::FMUL) {
6481 ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
6483 return DAG.getNode(ISD::FMUL, N->getDebugLoc(), VT,
6485 DAG.getNode(ISD::FNEG, N->getDebugLoc(), VT,
6493 SDValue DAGCombiner::visitFCEIL(SDNode *N) {
6494 SDValue N0 = N->getOperand(0);
6495 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6496 EVT VT = N->getValueType(0);
6498 // fold (fceil c1) -> fceil(c1)
6499 if (N0CFP && VT != MVT::ppcf128)
6500 return DAG.getNode(ISD::FCEIL, N->getDebugLoc(), VT, N0);
6505 SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
6506 SDValue N0 = N->getOperand(0);
6507 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6508 EVT VT = N->getValueType(0);
6510 // fold (ftrunc c1) -> ftrunc(c1)
6511 if (N0CFP && VT != MVT::ppcf128)
6512 return DAG.getNode(ISD::FTRUNC, N->getDebugLoc(), VT, N0);
6517 SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
6518 SDValue N0 = N->getOperand(0);
6519 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6520 EVT VT = N->getValueType(0);
6522 // fold (ffloor c1) -> ffloor(c1)
6523 if (N0CFP && VT != MVT::ppcf128)
6524 return DAG.getNode(ISD::FFLOOR, N->getDebugLoc(), VT, N0);
6529 SDValue DAGCombiner::visitFABS(SDNode *N) {
6530 SDValue N0 = N->getOperand(0);
6531 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
6532 EVT VT = N->getValueType(0);
6534 if (VT.isVector()) {
6535 SDValue FoldedVOp = SimplifyVUnaryOp(N);
6536 if (FoldedVOp.getNode()) return FoldedVOp;
6539 // fold (fabs c1) -> fabs(c1)
6540 if (N0CFP && VT != MVT::ppcf128)
6541 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
6542 // fold (fabs (fabs x)) -> (fabs x)
6543 if (N0.getOpcode() == ISD::FABS)
6544 return N->getOperand(0);
6545 // fold (fabs (fneg x)) -> (fabs x)
6546 // fold (fabs (fcopysign x, y)) -> (fabs x)
6547 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
6548 return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0.getOperand(0));
6550 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
6551 // constant pool values.
6552 if (!TLI.isFAbsFree(VT) &&
6553 N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() &&
6554 N0.getOperand(0).getValueType().isInteger() &&
6555 !N0.getOperand(0).getValueType().isVector()) {
6556 SDValue Int = N0.getOperand(0);
6557 EVT IntVT = Int.getValueType();
6558 if (IntVT.isInteger() && !IntVT.isVector()) {
6559 Int = DAG.getNode(ISD::AND, N0.getDebugLoc(), IntVT, Int,
6560 DAG.getConstant(~APInt::getSignBit(IntVT.getSizeInBits()), IntVT));
6561 AddToWorkList(Int.getNode());
6562 return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
6563 N->getValueType(0), Int);
6570 SDValue DAGCombiner::visitBRCOND(SDNode *N) {
6571 SDValue Chain = N->getOperand(0);
6572 SDValue N1 = N->getOperand(1);
6573 SDValue N2 = N->getOperand(2);
6575 // If N is a constant we could fold this into a fallthrough or unconditional
6576 // branch. However that doesn't happen very often in normal code, because
6577 // Instcombine/SimplifyCFG should have handled the available opportunities.
6578 // If we did this folding here, it would be necessary to update the
6579 // MachineBasicBlock CFG, which is awkward.
6581 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
6583 if (N1.getOpcode() == ISD::SETCC &&
6584 TLI.isOperationLegalOrCustom(ISD::BR_CC, MVT::Other)) {
6585 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6586 Chain, N1.getOperand(2),
6587 N1.getOperand(0), N1.getOperand(1), N2);
6590 if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
6591 ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
6592 (N1.getOperand(0).hasOneUse() &&
6593 N1.getOperand(0).getOpcode() == ISD::SRL))) {
6595 if (N1.getOpcode() == ISD::TRUNCATE) {
6596 // Look pass the truncate.
6597 Trunc = N1.getNode();
6598 N1 = N1.getOperand(0);
6601 // Match this pattern so that we can generate simpler code:
6604 // %b = and i32 %a, 2
6605 // %c = srl i32 %b, 1
6606 // brcond i32 %c ...
6611 // %b = and i32 %a, 2
6612 // %c = setcc eq %b, 0
6615 // This applies only when the AND constant value has one bit set and the
6616 // SRL constant is equal to the log2 of the AND constant. The back-end is
6617 // smart enough to convert the result into a TEST/JMP sequence.
6618 SDValue Op0 = N1.getOperand(0);
6619 SDValue Op1 = N1.getOperand(1);
6621 if (Op0.getOpcode() == ISD::AND &&
6622 Op1.getOpcode() == ISD::Constant) {
6623 SDValue AndOp1 = Op0.getOperand(1);
6625 if (AndOp1.getOpcode() == ISD::Constant) {
6626 const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();
6628 if (AndConst.isPowerOf2() &&
6629 cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
6631 DAG.getSetCC(N->getDebugLoc(),
6632 TLI.getSetCCResultType(Op0.getValueType()),
6633 Op0, DAG.getConstant(0, Op0.getValueType()),
6636 SDValue NewBRCond = DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6637 MVT::Other, Chain, SetCC, N2);
6638 // Don't add the new BRCond into the worklist or else SimplifySelectCC
6639 // will convert it back to (X & C1) >> C2.
6640 CombineTo(N, NewBRCond, false);
6641 // Truncate is dead.
6643 removeFromWorkList(Trunc);
6644 DAG.DeleteNode(Trunc);
6646 // Replace the uses of SRL with SETCC
6647 WorkListRemover DeadNodes(*this);
6648 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6649 removeFromWorkList(N1.getNode());
6650 DAG.DeleteNode(N1.getNode());
6651 return SDValue(N, 0); // Return N so it doesn't get rechecked!
6657 // Restore N1 if the above transformation doesn't match.
6658 N1 = N->getOperand(1);
6661 // Transform br(xor(x, y)) -> br(x != y)
6662 // Transform br(xor(xor(x,y), 1)) -> br (x == y)
6663 if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
6664 SDNode *TheXor = N1.getNode();
6665 SDValue Op0 = TheXor->getOperand(0);
6666 SDValue Op1 = TheXor->getOperand(1);
6667 if (Op0.getOpcode() == Op1.getOpcode()) {
6668 // Avoid missing important xor optimizations.
6669 SDValue Tmp = visitXOR(TheXor);
6670 if (Tmp.getNode() && Tmp.getNode() != TheXor) {
6671 DEBUG(dbgs() << "\nReplacing.8 ";
6673 dbgs() << "\nWith: ";
6674 Tmp.getNode()->dump(&DAG);
6676 WorkListRemover DeadNodes(*this);
6677 DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
6678 removeFromWorkList(TheXor);
6679 DAG.DeleteNode(TheXor);
6680 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6681 MVT::Other, Chain, Tmp, N2);
6685 if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
6687 if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
6688 if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
6689 Op0.getOpcode() == ISD::XOR) {
6690 TheXor = Op0.getNode();
6694 EVT SetCCVT = N1.getValueType();
6696 SetCCVT = TLI.getSetCCResultType(SetCCVT);
6697 SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
6700 Equal ? ISD::SETEQ : ISD::SETNE);
6701 // Replace the uses of XOR with SETCC
6702 WorkListRemover DeadNodes(*this);
6703 DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
6704 removeFromWorkList(N1.getNode());
6705 DAG.DeleteNode(N1.getNode());
6706 return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
6707 MVT::Other, Chain, SetCC, N2);
6714 // Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
6716 SDValue DAGCombiner::visitBR_CC(SDNode *N) {
6717 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
6718 SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
6720 // If N is a constant we could fold this into a fallthrough or unconditional
6721 // branch. However that doesn't happen very often in normal code, because
6722 // Instcombine/SimplifyCFG should have handled the available opportunities.
6723 // If we did this folding here, it would be necessary to update the
6724 // MachineBasicBlock CFG, which is awkward.
6726 // Use SimplifySetCC to simplify SETCC's.
6727 SDValue Simp = SimplifySetCC(TLI.getSetCCResultType(CondLHS.getValueType()),
6728 CondLHS, CondRHS, CC->get(), N->getDebugLoc(),
6730 if (Simp.getNode()) AddToWorkList(Simp.getNode());
6732 // fold to a simpler setcc
6733 if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
6734 return DAG.getNode(ISD::BR_CC, N->getDebugLoc(), MVT::Other,
6735 N->getOperand(0), Simp.getOperand(2),
6736 Simp.getOperand(0), Simp.getOperand(1),
6742 /// canFoldInAddressingMode - Return true if 'Use' is a load or a store that
6743 /// uses N as its base pointer and that N may be folded in the load / store
6744 /// addressing mode.
6745 static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
6747 const TargetLowering &TLI) {
6749 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Use)) {
6750 if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
6752 VT = Use->getValueType(0);
6753 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(Use)) {
6754 if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
6756 VT = ST->getValue().getValueType();
6761 if (N->getOpcode() == ISD::ADD) {
6762 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6765 AM.BaseOffs = Offset->getSExtValue();
6769 } else if (N->getOpcode() == ISD::SUB) {
6770 ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
6773 AM.BaseOffs = -Offset->getSExtValue();
6780 return TLI.isLegalAddressingMode(AM, VT.getTypeForEVT(*DAG.getContext()));
6783 /// CombineToPreIndexedLoadStore - Try turning a load / store into a
6784 /// pre-indexed load / store when the base pointer is an add or subtract
6785 /// and it has other uses besides the load / store. After the
6786 /// transformation, the new indexed load / store has effectively folded
6787 /// the add / subtract in and all of its other uses are redirected to the
6788 /// new load / store.
6789 bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
6790 if (Level < AfterLegalizeDAG)
6796 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6797 if (LD->isIndexed())
6799 VT = LD->getMemoryVT();
6800 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
6801 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
6803 Ptr = LD->getBasePtr();
6804 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6805 if (ST->isIndexed())
6807 VT = ST->getMemoryVT();
6808 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
6809 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
6811 Ptr = ST->getBasePtr();
6817 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
6818 // out. There is no reason to make this a preinc/predec.
6819 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
6820 Ptr.getNode()->hasOneUse())
6823 // Ask the target to do addressing mode selection.
6826 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6827 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
6829 // Don't create a indexed load / store with zero offset.
6830 if (isa<ConstantSDNode>(Offset) &&
6831 cast<ConstantSDNode>(Offset)->isNullValue())
6834 // Try turning it into a pre-indexed load / store except when:
6835 // 1) The new base ptr is a frame index.
6836 // 2) If N is a store and the new base ptr is either the same as or is a
6837 // predecessor of the value being stored.
6838 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
6839 // that would create a cycle.
6840 // 4) All uses are load / store ops that use it as old base ptr.
6842 // Check #1. Preinc'ing a frame index would require copying the stack pointer
6843 // (plus the implicit offset) to a register to preinc anyway.
6844 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6849 SDValue Val = cast<StoreSDNode>(N)->getValue();
6850 if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
6854 // Now check for #3 and #4.
6855 bool RealUse = false;
6857 // Caches for hasPredecessorHelper
6858 SmallPtrSet<const SDNode *, 32> Visited;
6859 SmallVector<const SDNode *, 16> Worklist;
6861 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6862 E = Ptr.getNode()->use_end(); I != E; ++I) {
6866 if (N->hasPredecessorHelper(Use, Visited, Worklist))
6869 // If Ptr may be folded in addressing mode of other use, then it's
6870 // not profitable to do this transformation.
6871 if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
6880 Result = DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
6881 BasePtr, Offset, AM);
6883 Result = DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
6884 BasePtr, Offset, AM);
6887 DEBUG(dbgs() << "\nReplacing.4 ";
6889 dbgs() << "\nWith: ";
6890 Result.getNode()->dump(&DAG);
6892 WorkListRemover DeadNodes(*this);
6894 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
6895 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
6897 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
6900 // Finally, since the node is now dead, remove it from the graph.
6903 // Replace the uses of Ptr with uses of the updated base value.
6904 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
6905 removeFromWorkList(Ptr.getNode());
6906 DAG.DeleteNode(Ptr.getNode());
6911 /// CombineToPostIndexedLoadStore - Try to combine a load / store with a
6912 /// add / sub of the base pointer node into a post-indexed load / store.
6913 /// The transformation folded the add / subtract into the new indexed
6914 /// load / store effectively and all of its uses are redirected to the
6915 /// new load / store.
6916 bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
6917 if (Level < AfterLegalizeDAG)
6923 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
6924 if (LD->isIndexed())
6926 VT = LD->getMemoryVT();
6927 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
6928 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
6930 Ptr = LD->getBasePtr();
6931 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
6932 if (ST->isIndexed())
6934 VT = ST->getMemoryVT();
6935 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
6936 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
6938 Ptr = ST->getBasePtr();
6944 if (Ptr.getNode()->hasOneUse())
6947 for (SDNode::use_iterator I = Ptr.getNode()->use_begin(),
6948 E = Ptr.getNode()->use_end(); I != E; ++I) {
6951 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
6956 ISD::MemIndexedMode AM = ISD::UNINDEXED;
6957 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
6958 // Don't create a indexed load / store with zero offset.
6959 if (isa<ConstantSDNode>(Offset) &&
6960 cast<ConstantSDNode>(Offset)->isNullValue())
6963 // Try turning it into a post-indexed load / store except when
6964 // 1) All uses are load / store ops that use it as base ptr (and
6965 // it may be folded as addressing mmode).
6966 // 2) Op must be independent of N, i.e. Op is neither a predecessor
6967 // nor a successor of N. Otherwise, if Op is folded that would
6970 if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
6974 bool TryNext = false;
6975 for (SDNode::use_iterator II = BasePtr.getNode()->use_begin(),
6976 EE = BasePtr.getNode()->use_end(); II != EE; ++II) {
6978 if (Use == Ptr.getNode())
6981 // If all the uses are load / store addresses, then don't do the
6983 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
6984 bool RealUse = false;
6985 for (SDNode::use_iterator III = Use->use_begin(),
6986 EEE = Use->use_end(); III != EEE; ++III) {
6987 SDNode *UseUse = *III;
6988 if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
7003 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
7004 SDValue Result = isLoad
7005 ? DAG.getIndexedLoad(SDValue(N,0), N->getDebugLoc(),
7006 BasePtr, Offset, AM)
7007 : DAG.getIndexedStore(SDValue(N,0), N->getDebugLoc(),
7008 BasePtr, Offset, AM);
7011 DEBUG(dbgs() << "\nReplacing.5 ";
7013 dbgs() << "\nWith: ";
7014 Result.getNode()->dump(&DAG);
7016 WorkListRemover DeadNodes(*this);
7018 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
7019 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
7021 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
7024 // Finally, since the node is now dead, remove it from the graph.
7027 // Replace the uses of Use with uses of the updated base value.
7028 DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
7029 Result.getValue(isLoad ? 1 : 0));
7030 removeFromWorkList(Op);
7040 SDValue DAGCombiner::visitLOAD(SDNode *N) {
7041 LoadSDNode *LD = cast<LoadSDNode>(N);
7042 SDValue Chain = LD->getChain();
7043 SDValue Ptr = LD->getBasePtr();
7045 // If load is not volatile and there are no uses of the loaded value (and
7046 // the updated indexed value in case of indexed loads), change uses of the
7047 // chain value into uses of the chain input (i.e. delete the dead load).
7048 if (!LD->isVolatile()) {
7049 if (N->getValueType(1) == MVT::Other) {
7051 if (!N->hasAnyUseOfValue(0)) {
7052 // It's not safe to use the two value CombineTo variant here. e.g.
7053 // v1, chain2 = load chain1, loc
7054 // v2, chain3 = load chain2, loc
7056 // Now we replace use of chain2 with chain1. This makes the second load
7057 // isomorphic to the one we are deleting, and thus makes this load live.
7058 DEBUG(dbgs() << "\nReplacing.6 ";
7060 dbgs() << "\nWith chain: ";
7061 Chain.getNode()->dump(&DAG);
7063 WorkListRemover DeadNodes(*this);
7064 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
7066 if (N->use_empty()) {
7067 removeFromWorkList(N);
7071 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7075 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
7076 if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
7077 SDValue Undef = DAG.getUNDEF(N->getValueType(0));
7078 DEBUG(dbgs() << "\nReplacing.7 ";
7080 dbgs() << "\nWith: ";
7081 Undef.getNode()->dump(&DAG);
7082 dbgs() << " and 2 other values\n");
7083 WorkListRemover DeadNodes(*this);
7084 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
7085 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
7086 DAG.getUNDEF(N->getValueType(1)));
7087 DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
7088 removeFromWorkList(N);
7090 return SDValue(N, 0); // Return N so it doesn't get rechecked!
7095 // If this load is directly stored, replace the load value with the stored
7097 // TODO: Handle store large -> read small portion.
7098 // TODO: Handle TRUNCSTORE/LOADEXT
7099 if (ISD::isNormalLoad(N) && !LD->isVolatile()) {
7100 if (ISD::isNON_TRUNCStore(Chain.getNode())) {
7101 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
7102 if (PrevST->getBasePtr() == Ptr &&
7103 PrevST->getValue().getValueType() == N->getValueType(0))
7104 return CombineTo(N, Chain.getOperand(1), Chain);
7108 // Try to infer better alignment information than the load already has.
7109 if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
7110 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7111 if (Align > LD->getAlignment())
7112 return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
7113 LD->getValueType(0),
7114 Chain, Ptr, LD->getPointerInfo(),
7116 LD->isVolatile(), LD->isNonTemporal(), Align);
7121 // Walk up chain skipping non-aliasing memory nodes.
7122 SDValue BetterChain = FindBetterChain(N, Chain);
7124 // If there is a better chain.
7125 if (Chain != BetterChain) {
7128 // Replace the chain to void dependency.
7129 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
7130 ReplLoad = DAG.getLoad(N->getValueType(0), LD->getDebugLoc(),
7131 BetterChain, Ptr, LD->getPointerInfo(),
7132 LD->isVolatile(), LD->isNonTemporal(),
7133 LD->isInvariant(), LD->getAlignment());
7135 ReplLoad = DAG.getExtLoad(LD->getExtensionType(), LD->getDebugLoc(),
7136 LD->getValueType(0),
7137 BetterChain, Ptr, LD->getPointerInfo(),
7140 LD->isNonTemporal(),
7141 LD->getAlignment());
7144 // Create token factor to keep old chain connected.
7145 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
7146 MVT::Other, Chain, ReplLoad.getValue(1));
7148 // Make sure the new and old chains are cleaned up.
7149 AddToWorkList(Token.getNode());
7151 // Replace uses with load result and token factor. Don't add users
7153 return CombineTo(N, ReplLoad.getValue(0), Token, false);
7157 // Try transforming N to an indexed load.
7158 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
7159 return SDValue(N, 0);
7164 /// CheckForMaskedLoad - Check to see if V is (and load (ptr), imm), where the
7165 /// load is having specific bytes cleared out. If so, return the byte size
7166 /// being masked out and the shift amount.
7167 static std::pair<unsigned, unsigned>
7168 CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
7169 std::pair<unsigned, unsigned> Result(0, 0);
7171 // Check for the structure we're looking for.
7172 if (V->getOpcode() != ISD::AND ||
7173 !isa<ConstantSDNode>(V->getOperand(1)) ||
7174 !ISD::isNormalLoad(V->getOperand(0).getNode()))
7177 // Check the chain and pointer.
7178 LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
7179 if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
7181 // The store should be chained directly to the load or be an operand of a
7183 if (LD == Chain.getNode())
7185 else if (Chain->getOpcode() != ISD::TokenFactor)
7186 return Result; // Fail.
7189 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
7190 if (Chain->getOperand(i).getNode() == LD) {
7194 if (!isOk) return Result;
7197 // This only handles simple types.
7198 if (V.getValueType() != MVT::i16 &&
7199 V.getValueType() != MVT::i32 &&
7200 V.getValueType() != MVT::i64)
7203 // Check the constant mask. Invert it so that the bits being masked out are
7204 // 0 and the bits being kept are 1. Use getSExtValue so that leading bits
7205 // follow the sign bit for uniformity.
7206 uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
7207 unsigned NotMaskLZ = CountLeadingZeros_64(NotMask);
7208 if (NotMaskLZ & 7) return Result; // Must be multiple of a byte.
7209 unsigned NotMaskTZ = CountTrailingZeros_64(NotMask);
7210 if (NotMaskTZ & 7) return Result; // Must be multiple of a byte.
7211 if (NotMaskLZ == 64) return Result; // All zero mask.
7213 // See if we have a continuous run of bits. If so, we have 0*1+0*
7214 if (CountTrailingOnes_64(NotMask >> NotMaskTZ)+NotMaskTZ+NotMaskLZ != 64)
7217 // Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
7218 if (V.getValueType() != MVT::i64 && NotMaskLZ)
7219 NotMaskLZ -= 64-V.getValueSizeInBits();
7221 unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
7222 switch (MaskedBytes) {
7226 default: return Result; // All one mask, or 5-byte mask.
7229 // Verify that the first bit starts at a multiple of mask so that the access
7230 // is aligned the same as the access width.
7231 if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;
7233 Result.first = MaskedBytes;
7234 Result.second = NotMaskTZ/8;
7239 /// ShrinkLoadReplaceStoreWithStore - Check to see if IVal is something that
7240 /// provides a value as specified by MaskInfo. If so, replace the specified
7241 /// store with a narrower store of truncated IVal.
7243 ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
7244 SDValue IVal, StoreSDNode *St,
7246 unsigned NumBytes = MaskInfo.first;
7247 unsigned ByteShift = MaskInfo.second;
7248 SelectionDAG &DAG = DC->getDAG();
7250 // Check to see if IVal is all zeros in the part being masked in by the 'or'
7251 // that uses this. If not, this is not a replacement.
7252 APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
7253 ByteShift*8, (ByteShift+NumBytes)*8);
7254 if (!DAG.MaskedValueIsZero(IVal, Mask)) return 0;
7256 // Check that it is legal on the target to do this. It is legal if the new
7257 // VT we're shrinking to (i8/i16/i32) is legal or we're still before type
7259 MVT VT = MVT::getIntegerVT(NumBytes*8);
7260 if (!DC->isTypeLegal(VT))
7263 // Okay, we can do this! Replace the 'St' store with a store of IVal that is
7264 // shifted by ByteShift and truncated down to NumBytes.
7266 IVal = DAG.getNode(ISD::SRL, IVal->getDebugLoc(), IVal.getValueType(), IVal,
7267 DAG.getConstant(ByteShift*8,
7268 DC->getShiftAmountTy(IVal.getValueType())));
7270 // Figure out the offset for the store and the alignment of the access.
7272 unsigned NewAlign = St->getAlignment();
7274 if (DAG.getTargetLoweringInfo().isLittleEndian())
7275 StOffset = ByteShift;
7277 StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;
7279 SDValue Ptr = St->getBasePtr();
7281 Ptr = DAG.getNode(ISD::ADD, IVal->getDebugLoc(), Ptr.getValueType(),
7282 Ptr, DAG.getConstant(StOffset, Ptr.getValueType()));
7283 NewAlign = MinAlign(NewAlign, StOffset);
7286 // Truncate down to the new size.
7287 IVal = DAG.getNode(ISD::TRUNCATE, IVal->getDebugLoc(), VT, IVal);
7290 return DAG.getStore(St->getChain(), St->getDebugLoc(), IVal, Ptr,
7291 St->getPointerInfo().getWithOffset(StOffset),
7292 false, false, NewAlign).getNode();
7296 /// ReduceLoadOpStoreWidth - Look for sequence of load / op / store where op is
7297 /// one of 'or', 'xor', and 'and' of immediates. If 'op' is only touching some
7298 /// of the loaded bits, try narrowing the load and store if it would end up
7299 /// being a win for performance or code size.
7300 SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
7301 StoreSDNode *ST = cast<StoreSDNode>(N);
7302 if (ST->isVolatile())
7305 SDValue Chain = ST->getChain();
7306 SDValue Value = ST->getValue();
7307 SDValue Ptr = ST->getBasePtr();
7308 EVT VT = Value.getValueType();
7310 if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
7313 unsigned Opc = Value.getOpcode();
7315 // If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
7316 // is a byte mask indicating a consecutive number of bytes, check to see if
7317 // Y is known to provide just those bytes. If so, we try to replace the
7318 // load + replace + store sequence with a single (narrower) store, which makes
7320 if (Opc == ISD::OR) {
7321 std::pair<unsigned, unsigned> MaskedLoad;
7322 MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
7323 if (MaskedLoad.first)
7324 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7325 Value.getOperand(1), ST,this))
7326 return SDValue(NewST, 0);
7328 // Or is commutative, so try swapping X and Y.
7329 MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
7330 if (MaskedLoad.first)
7331 if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
7332 Value.getOperand(0), ST,this))
7333 return SDValue(NewST, 0);
7336 if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
7337 Value.getOperand(1).getOpcode() != ISD::Constant)
7340 SDValue N0 = Value.getOperand(0);
7341 if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
7342 Chain == SDValue(N0.getNode(), 1)) {
7343 LoadSDNode *LD = cast<LoadSDNode>(N0);
7344 if (LD->getBasePtr() != Ptr ||
7345 LD->getPointerInfo().getAddrSpace() !=
7346 ST->getPointerInfo().getAddrSpace())
7349 // Find the type to narrow it the load / op / store to.
7350 SDValue N1 = Value.getOperand(1);
7351 unsigned BitWidth = N1.getValueSizeInBits();
7352 APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
7353 if (Opc == ISD::AND)
7354 Imm ^= APInt::getAllOnesValue(BitWidth);
7355 if (Imm == 0 || Imm.isAllOnesValue())
7357 unsigned ShAmt = Imm.countTrailingZeros();
7358 unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
7359 unsigned NewBW = NextPowerOf2(MSB - ShAmt);
7360 EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7361 while (NewBW < BitWidth &&
7362 !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
7363 TLI.isNarrowingProfitable(VT, NewVT))) {
7364 NewBW = NextPowerOf2(NewBW);
7365 NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
7367 if (NewBW >= BitWidth)
7370 // If the lsb changed does not start at the type bitwidth boundary,
7371 // start at the previous one.
7373 ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
7374 APInt Mask = APInt::getBitsSet(BitWidth, ShAmt, ShAmt + NewBW);
7375 if ((Imm & Mask) == Imm) {
7376 APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
7377 if (Opc == ISD::AND)
7378 NewImm ^= APInt::getAllOnesValue(NewBW);
7379 uint64_t PtrOff = ShAmt / 8;
7380 // For big endian targets, we need to adjust the offset to the pointer to
7381 // load the correct bytes.
7382 if (TLI.isBigEndian())
7383 PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;
7385 unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
7386 Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
7387 if (NewAlign < TLI.getDataLayout()->getABITypeAlignment(NewVTTy))
7390 SDValue NewPtr = DAG.getNode(ISD::ADD, LD->getDebugLoc(),
7391 Ptr.getValueType(), Ptr,
7392 DAG.getConstant(PtrOff, Ptr.getValueType()));
7393 SDValue NewLD = DAG.getLoad(NewVT, N0.getDebugLoc(),
7394 LD->getChain(), NewPtr,
7395 LD->getPointerInfo().getWithOffset(PtrOff),
7396 LD->isVolatile(), LD->isNonTemporal(),
7397 LD->isInvariant(), NewAlign);
7398 SDValue NewVal = DAG.getNode(Opc, Value.getDebugLoc(), NewVT, NewLD,
7399 DAG.getConstant(NewImm, NewVT));
7400 SDValue NewST = DAG.getStore(Chain, N->getDebugLoc(),
7402 ST->getPointerInfo().getWithOffset(PtrOff),
7403 false, false, NewAlign);
7405 AddToWorkList(NewPtr.getNode());
7406 AddToWorkList(NewLD.getNode());
7407 AddToWorkList(NewVal.getNode());
7408 WorkListRemover DeadNodes(*this);
7409 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
7418 /// TransformFPLoadStorePair - For a given floating point load / store pair,
7419 /// if the load value isn't used by any other operations, then consider
7420 /// transforming the pair to integer load / store operations if the target
7421 /// deems the transformation profitable.
7422 SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
7423 StoreSDNode *ST = cast<StoreSDNode>(N);
7424 SDValue Chain = ST->getChain();
7425 SDValue Value = ST->getValue();
7426 if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
7427 Value.hasOneUse() &&
7428 Chain == SDValue(Value.getNode(), 1)) {
7429 LoadSDNode *LD = cast<LoadSDNode>(Value);
7430 EVT VT = LD->getMemoryVT();
7431 if (!VT.isFloatingPoint() ||
7432 VT != ST->getMemoryVT() ||
7433 LD->isNonTemporal() ||
7434 ST->isNonTemporal() ||
7435 LD->getPointerInfo().getAddrSpace() != 0 ||
7436 ST->getPointerInfo().getAddrSpace() != 0)
7439 EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
7440 if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
7441 !TLI.isOperationLegal(ISD::STORE, IntVT) ||
7442 !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
7443 !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
7446 unsigned LDAlign = LD->getAlignment();
7447 unsigned STAlign = ST->getAlignment();
7448 Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
7449 unsigned ABIAlign = TLI.getDataLayout()->getABITypeAlignment(IntVTTy);
7450 if (LDAlign < ABIAlign || STAlign < ABIAlign)
7453 SDValue NewLD = DAG.getLoad(IntVT, Value.getDebugLoc(),
7454 LD->getChain(), LD->getBasePtr(),
7455 LD->getPointerInfo(),
7456 false, false, false, LDAlign);
7458 SDValue NewST = DAG.getStore(NewLD.getValue(1), N->getDebugLoc(),
7459 NewLD, ST->getBasePtr(),
7460 ST->getPointerInfo(),
7461 false, false, STAlign);
7463 AddToWorkList(NewLD.getNode());
7464 AddToWorkList(NewST.getNode());
7465 WorkListRemover DeadNodes(*this);
7466 DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
7474 /// Returns the base pointer and an integer offset from that object.
7475 static std::pair<SDValue, int64_t> GetPointerBaseAndOffset(SDValue Ptr) {
7476 if (Ptr->getOpcode() == ISD::ADD && isa<ConstantSDNode>(Ptr->getOperand(1))) {
7477 int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
7478 SDValue Base = Ptr->getOperand(0);
7479 return std::make_pair(Base, Offset);
7482 return std::make_pair(Ptr, 0);
7485 /// Holds a pointer to an LSBaseSDNode as well as information on where it
7486 /// is located in a sequence of memory operations connected by a chain.
7488 MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
7489 MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
7490 // Ptr to the mem node.
7491 LSBaseSDNode *MemNode;
7492 // Offset from the base ptr.
7493 int64_t OffsetFromBase;
7494 // What is the sequence number of this mem node.
7495 // Lowest mem operand in the DAG starts at zero.
7496 unsigned SequenceNum;
7499 /// Sorts store nodes in a link according to their offset from a shared
7501 struct ConsecutiveMemoryChainSorter {
7502 bool operator()(MemOpLink LHS, MemOpLink RHS) {
7503 return LHS.OffsetFromBase < RHS.OffsetFromBase;
7507 bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
7508 EVT MemVT = St->getMemoryVT();
7509 int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
7511 // Don't merge vectors into wider inputs.
7512 if (MemVT.isVector() || !MemVT.isSimple())
7515 // Perform an early exit check. Do not bother looking at stored values that
7516 // are not constants or loads.
7517 SDValue StoredVal = St->getValue();
7518 bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
7519 if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
7523 // Only look at ends of store sequences.
7524 SDValue Chain = SDValue(St, 1);
7525 if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
7528 // This holds the base pointer and the offset in bytes from the base pointer.
7529 std::pair<SDValue, int64_t> BasePtr =
7530 GetPointerBaseAndOffset(St->getBasePtr());
7532 // We must have a base and an offset.
7533 if (!BasePtr.first.getNode())
7536 // Do not handle stores to undef base pointers.
7537 if (BasePtr.first.getOpcode() == ISD::UNDEF)
7540 SmallVector<MemOpLink, 8> StoreNodes;
7541 // Walk up the chain and look for nodes with offsets from the same
7542 // base pointer. Stop when reaching an instruction with a different kind
7543 // or instruction which has a different base pointer.
7545 StoreSDNode *Index = St;
7547 // If the chain has more than one use, then we can't reorder the mem ops.
7548 if (Index != St && !SDValue(Index, 1)->hasOneUse())
7551 // Find the base pointer and offset for this memory node.
7552 std::pair<SDValue, int64_t> Ptr =
7553 GetPointerBaseAndOffset(Index->getBasePtr());
7555 // Check that the base pointer is the same as the original one.
7556 if (Ptr.first.getNode() != BasePtr.first.getNode())
7559 // Check that the alignment is the same.
7560 if (Index->getAlignment() != St->getAlignment())
7563 // The memory operands must not be volatile.
7564 if (Index->isVolatile() || Index->isIndexed())
7568 if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
7569 if (St->isTruncatingStore())
7572 // The stored memory type must be the same.
7573 if (Index->getMemoryVT() != MemVT)
7576 // We do not allow unaligned stores because we want to prevent overriding
7578 if (Index->getAlignment()*8 != MemVT.getSizeInBits())
7581 // We found a potential memory operand to merge.
7582 StoreNodes.push_back(MemOpLink(Index, Ptr.second, Seq++));
7584 // Move up the chain to the next memory operation.
7585 Index = dyn_cast<StoreSDNode>(Index->getChain().getNode());
7588 // Check if there is anything to merge.
7589 if (StoreNodes.size() < 2)
7592 // Sort the memory operands according to their distance from the base pointer.
7593 std::sort(StoreNodes.begin(), StoreNodes.end(),
7594 ConsecutiveMemoryChainSorter());
7596 // Scan the memory operations on the chain and find the first non-consecutive
7597 // store memory address.
7598 unsigned LastConsecutiveStore = 0;
7599 int64_t StartAddress = StoreNodes[0].OffsetFromBase;
7600 for (unsigned i=1; i<StoreNodes.size(); ++i) {
7601 int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
7602 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
7605 // Mark this node as useful.
7606 LastConsecutiveStore = i;
7609 // The node with the lowest store address.
7610 LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
7612 // Store the constants into memory as one consecutive store.
7614 unsigned LastLegalType = 0;
7615 unsigned LastLegalVectorType = 0;
7616 bool NonZero = false;
7617 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
7618 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7619 SDValue StoredVal = St->getValue();
7621 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal)) {
7622 NonZero |= !C->isNullValue();
7623 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal)) {
7624 NonZero |= !C->getConstantFPValue()->isNullValue();
7630 // Find a legal type for the constant store.
7631 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
7632 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7633 if (TLI.isTypeLegal(StoreTy))
7634 LastLegalType = i+1;
7636 // Find a legal type for the vector store.
7637 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
7638 if (TLI.isTypeLegal(Ty))
7639 LastLegalVectorType = i + 1;
7642 // We only use vectors if the constant is known to be zero.
7644 LastLegalVectorType = 0;
7646 // Check if we found a legal integer type to store.
7647 if (LastLegalType == 0 && LastLegalVectorType == 0)
7650 bool UseVector = LastLegalVectorType > LastLegalType;
7651 unsigned NumElem = UseVector ? LastLegalVectorType : LastLegalType;
7653 // Make sure we have something to merge.
7657 unsigned EarliestNodeUsed = 0;
7658 for (unsigned i=0; i < NumElem; ++i) {
7659 // Find a chain for the new wide-store operand. Notice that some
7660 // of the store nodes that we found may not be selected for inclusion
7661 // in the wide store. The chain we use needs to be the chain of the
7662 // earliest store node which is *used* and replaced by the wide store.
7663 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
7664 EarliestNodeUsed = i;
7667 // The earliest Node in the DAG.
7668 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
7669 DebugLoc DL = StoreNodes[0].MemNode->getDebugLoc();
7673 // Find a legal type for the vector store.
7674 EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
7675 assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
7676 StoredVal = DAG.getConstant(0, Ty);
7678 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
7679 APInt StoreInt(StoreBW, 0);
7681 // Construct a single integer constant which is made of the smaller
7683 bool IsLE = TLI.isLittleEndian();
7684 for (unsigned i = 0; i < NumElem ; ++i) {
7685 unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
7686 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
7687 SDValue Val = St->getValue();
7688 StoreInt<<=ElementSizeBytes*8;
7689 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
7690 StoreInt|=C->getAPIntValue().zext(StoreBW);
7691 } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
7692 StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
7694 assert(false && "Invalid constant element type");
7698 // Create the new Load and Store operations.
7699 EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7700 StoredVal = DAG.getConstant(StoreInt, StoreTy);
7703 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, StoredVal,
7704 FirstInChain->getBasePtr(),
7705 FirstInChain->getPointerInfo(),
7707 FirstInChain->getAlignment());
7709 // Replace the first store with the new store
7710 CombineTo(EarliestOp, NewStore);
7711 // Erase all other stores.
7712 for (unsigned i = 0; i < NumElem ; ++i) {
7713 if (StoreNodes[i].MemNode == EarliestOp)
7715 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7716 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
7717 removeFromWorkList(St);
7724 // Below we handle the case of multiple consecutive stores that
7725 // come from multiple consecutive loads. We merge them into a single
7726 // wide load and a single wide store.
7728 // Look for load nodes which are used by the stored values.
7729 SmallVector<MemOpLink, 8> LoadNodes;
7731 // Find acceptable loads. Loads need to have the same chain (token factor),
7732 // must not be zext, volatile, indexed, and they must be consecutive.
7734 for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
7735 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7736 LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
7739 // Loads must only have one use.
7740 if (!Ld->hasNUsesOfValue(1, 0))
7743 // Check that the alignment is the same as the stores.
7744 if (Ld->getAlignment() != St->getAlignment())
7747 // The memory operands must not be volatile.
7748 if (Ld->isVolatile() || Ld->isIndexed())
7751 // We do not accept ext loads.
7752 if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
7755 // The stored memory type must be the same.
7756 if (Ld->getMemoryVT() != MemVT)
7759 std::pair<SDValue, int64_t> LdPtr =
7760 GetPointerBaseAndOffset(Ld->getBasePtr());
7762 // If this is not the first ptr that we check.
7763 if (LdBasePtr.getNode()) {
7764 // The base ptr must be the same.
7765 if (LdPtr.first != LdBasePtr)
7768 // Check that all other base pointers are the same as this one.
7769 LdBasePtr = LdPtr.first;
7772 // We found a potential memory operand to merge.
7773 LoadNodes.push_back(MemOpLink(Ld, LdPtr.second, 0));
7776 if (LoadNodes.size() < 2)
7779 // Scan the memory operations on the chain and find the first non-consecutive
7780 // load memory address. These variables hold the index in the store node
7782 unsigned LastConsecutiveLoad = 0;
7783 // This variable refers to the size and not index in the array.
7784 unsigned LastLegalVectorType = 0;
7785 unsigned LastLegalIntegerType = 0;
7786 StartAddress = LoadNodes[0].OffsetFromBase;
7787 SDValue FirstChain = LoadNodes[0].MemNode->getChain();
7788 for (unsigned i = 1; i < LoadNodes.size(); ++i) {
7789 // All loads much share the same chain.
7790 if (LoadNodes[i].MemNode->getChain() != FirstChain)
7793 int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
7794 if (CurrAddress - StartAddress != (ElementSizeBytes * i))
7796 LastConsecutiveLoad = i;
7798 // Find a legal type for the vector store.
7799 EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
7800 if (TLI.isTypeLegal(StoreTy))
7801 LastLegalVectorType = i + 1;
7803 // Find a legal type for the integer store.
7804 unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
7805 StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7806 if (TLI.isTypeLegal(StoreTy))
7807 LastLegalIntegerType = i + 1;
7810 // Only use vector types if the vector type is larger than the integer type.
7811 // If they are the same, use integers.
7812 bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType;
7813 unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
7815 // We add +1 here because the LastXXX variables refer to location while
7816 // the NumElem refers to array/index size.
7817 unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
7818 NumElem = std::min(LastLegalType, NumElem);
7823 // The earliest Node in the DAG.
7824 unsigned EarliestNodeUsed = 0;
7825 LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
7826 for (unsigned i=1; i<NumElem; ++i) {
7827 // Find a chain for the new wide-store operand. Notice that some
7828 // of the store nodes that we found may not be selected for inclusion
7829 // in the wide store. The chain we use needs to be the chain of the
7830 // earliest store node which is *used* and replaced by the wide store.
7831 if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
7832 EarliestNodeUsed = i;
7835 // Find if it is better to use vectors or integers to load and store
7839 JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
7841 unsigned StoreBW = NumElem * ElementSizeBytes * 8;
7842 JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
7845 DebugLoc LoadDL = LoadNodes[0].MemNode->getDebugLoc();
7846 DebugLoc StoreDL = StoreNodes[0].MemNode->getDebugLoc();
7848 LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
7849 SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
7850 FirstLoad->getChain(),
7851 FirstLoad->getBasePtr(),
7852 FirstLoad->getPointerInfo(),
7853 false, false, false,
7854 FirstLoad->getAlignment());
7856 SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
7857 FirstInChain->getBasePtr(),
7858 FirstInChain->getPointerInfo(), false, false,
7859 FirstInChain->getAlignment());
7861 // Replace one of the loads with the new load.
7862 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[0].MemNode);
7863 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
7864 SDValue(NewLoad.getNode(), 1));
7866 // Remove the rest of the load chains.
7867 for (unsigned i = 1; i < NumElem ; ++i) {
7868 // Replace all chain users of the old load nodes with the chain of the new
7870 LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
7871 DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1), Ld->getChain());
7874 // Replace the first store with the new store.
7875 CombineTo(EarliestOp, NewStore);
7876 // Erase all other stores.
7877 for (unsigned i = 0; i < NumElem ; ++i) {
7878 // Remove all Store nodes.
7879 if (StoreNodes[i].MemNode == EarliestOp)
7881 StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
7882 DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
7883 removeFromWorkList(St);
7890 SDValue DAGCombiner::visitSTORE(SDNode *N) {
7891 StoreSDNode *ST = cast<StoreSDNode>(N);
7892 SDValue Chain = ST->getChain();
7893 SDValue Value = ST->getValue();
7894 SDValue Ptr = ST->getBasePtr();
7896 // If this is a store of a bit convert, store the input value if the
7897 // resultant store does not need a higher alignment than the original.
7898 if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
7899 ST->isUnindexed()) {
7900 unsigned OrigAlign = ST->getAlignment();
7901 EVT SVT = Value.getOperand(0).getValueType();
7902 unsigned Align = TLI.getDataLayout()->
7903 getABITypeAlignment(SVT.getTypeForEVT(*DAG.getContext()));
7904 if (Align <= OrigAlign &&
7905 ((!LegalOperations && !ST->isVolatile()) ||
7906 TLI.isOperationLegalOrCustom(ISD::STORE, SVT)))
7907 return DAG.getStore(Chain, N->getDebugLoc(), Value.getOperand(0),
7908 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7909 ST->isNonTemporal(), OrigAlign);
7912 // Turn 'store undef, Ptr' -> nothing.
7913 if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
7916 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
7917 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
7918 // NOTE: If the original store is volatile, this transform must not increase
7919 // the number of stores. For example, on x86-32 an f64 can be stored in one
7920 // processor operation but an i64 (which is not legal) requires two. So the
7921 // transform should not be done in this case.
7922 if (Value.getOpcode() != ISD::TargetConstantFP) {
7924 switch (CFP->getValueType(0).getSimpleVT().SimpleTy) {
7925 default: llvm_unreachable("Unknown FP type");
7926 case MVT::f16: // We don't do this for these yet.
7932 if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
7933 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7934 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
7935 bitcastToAPInt().getZExtValue(), MVT::i32);
7936 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7937 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7938 ST->isNonTemporal(), ST->getAlignment());
7942 if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
7943 !ST->isVolatile()) ||
7944 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
7945 Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
7946 getZExtValue(), MVT::i64);
7947 return DAG.getStore(Chain, N->getDebugLoc(), Tmp,
7948 Ptr, ST->getPointerInfo(), ST->isVolatile(),
7949 ST->isNonTemporal(), ST->getAlignment());
7952 if (!ST->isVolatile() &&
7953 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
7954 // Many FP stores are not made apparent until after legalize, e.g. for
7955 // argument passing. Since this is so common, custom legalize the
7956 // 64-bit integer store into two 32-bit stores.
7957 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
7958 SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
7959 SDValue Hi = DAG.getConstant(Val >> 32, MVT::i32);
7960 if (TLI.isBigEndian()) std::swap(Lo, Hi);
7962 unsigned Alignment = ST->getAlignment();
7963 bool isVolatile = ST->isVolatile();
7964 bool isNonTemporal = ST->isNonTemporal();
7966 SDValue St0 = DAG.getStore(Chain, ST->getDebugLoc(), Lo,
7967 Ptr, ST->getPointerInfo(),
7968 isVolatile, isNonTemporal,
7969 ST->getAlignment());
7970 Ptr = DAG.getNode(ISD::ADD, N->getDebugLoc(), Ptr.getValueType(), Ptr,
7971 DAG.getConstant(4, Ptr.getValueType()));
7972 Alignment = MinAlign(Alignment, 4U);
7973 SDValue St1 = DAG.getStore(Chain, ST->getDebugLoc(), Hi,
7974 Ptr, ST->getPointerInfo().getWithOffset(4),
7975 isVolatile, isNonTemporal,
7977 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
7986 // Try to infer better alignment information than the store already has.
7987 if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
7988 if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
7989 if (Align > ST->getAlignment())
7990 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
7991 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
7992 ST->isVolatile(), ST->isNonTemporal(), Align);
7996 // Try transforming a pair floating point load / store ops to integer
7997 // load / store ops.
7998 SDValue NewST = TransformFPLoadStorePair(N);
7999 if (NewST.getNode())
8003 // Walk up chain skipping non-aliasing memory nodes.
8004 SDValue BetterChain = FindBetterChain(N, Chain);
8006 // If there is a better chain.
8007 if (Chain != BetterChain) {
8010 // Replace the chain to avoid dependency.
8011 if (ST->isTruncatingStore()) {
8012 ReplStore = DAG.getTruncStore(BetterChain, N->getDebugLoc(), Value, Ptr,
8013 ST->getPointerInfo(),
8014 ST->getMemoryVT(), ST->isVolatile(),
8015 ST->isNonTemporal(), ST->getAlignment());
8017 ReplStore = DAG.getStore(BetterChain, N->getDebugLoc(), Value, Ptr,
8018 ST->getPointerInfo(),
8019 ST->isVolatile(), ST->isNonTemporal(),
8020 ST->getAlignment());
8023 // Create token to keep both nodes around.
8024 SDValue Token = DAG.getNode(ISD::TokenFactor, N->getDebugLoc(),
8025 MVT::Other, Chain, ReplStore);
8027 // Make sure the new and old chains are cleaned up.
8028 AddToWorkList(Token.getNode());
8030 // Don't add users to work list.
8031 return CombineTo(N, Token, false);
8035 // Try transforming N to an indexed store.
8036 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
8037 return SDValue(N, 0);
8039 // FIXME: is there such a thing as a truncating indexed store?
8040 if (ST->isTruncatingStore() && ST->isUnindexed() &&
8041 Value.getValueType().isInteger()) {
8042 // See if we can simplify the input to this truncstore with knowledge that
8043 // only the low bits are being used. For example:
8044 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
8046 GetDemandedBits(Value,
8047 APInt::getLowBitsSet(
8048 Value.getValueType().getScalarType().getSizeInBits(),
8049 ST->getMemoryVT().getScalarType().getSizeInBits()));
8050 AddToWorkList(Value.getNode());
8051 if (Shorter.getNode())
8052 return DAG.getTruncStore(Chain, N->getDebugLoc(), Shorter,
8053 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8054 ST->isVolatile(), ST->isNonTemporal(),
8055 ST->getAlignment());
8057 // Otherwise, see if we can simplify the operation with
8058 // SimplifyDemandedBits, which only works if the value has a single use.
8059 if (SimplifyDemandedBits(Value,
8060 APInt::getLowBitsSet(
8061 Value.getValueType().getScalarType().getSizeInBits(),
8062 ST->getMemoryVT().getScalarType().getSizeInBits())))
8063 return SDValue(N, 0);
8066 // If this is a load followed by a store to the same location, then the store
8068 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
8069 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
8070 ST->isUnindexed() && !ST->isVolatile() &&
8071 // There can't be any side effects between the load and store, such as
8073 Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
8074 // The store is dead, remove it.
8079 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
8080 // truncating store. We can do this even if this is already a truncstore.
8081 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
8082 && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
8083 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
8084 ST->getMemoryVT())) {
8085 return DAG.getTruncStore(Chain, N->getDebugLoc(), Value.getOperand(0),
8086 Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
8087 ST->isVolatile(), ST->isNonTemporal(),
8088 ST->getAlignment());
8091 // Only perform this optimization before the types are legal, because we
8092 // don't want to perform this optimization on every DAGCombine invocation.
8093 if (!LegalTypes && MergeConsecutiveStores(ST))
8094 return SDValue(N, 0);
8096 return ReduceLoadOpStoreWidth(N);
8099 SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
8100 SDValue InVec = N->getOperand(0);
8101 SDValue InVal = N->getOperand(1);
8102 SDValue EltNo = N->getOperand(2);
8103 DebugLoc dl = N->getDebugLoc();
8105 // If the inserted element is an UNDEF, just use the input vector.
8106 if (InVal.getOpcode() == ISD::UNDEF)
8109 EVT VT = InVec.getValueType();
8111 // If we can't generate a legal BUILD_VECTOR, exit
8112 if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
8115 // Check that we know which element is being inserted
8116 if (!isa<ConstantSDNode>(EltNo))
8118 unsigned Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8120 // Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
8121 // be converted to a BUILD_VECTOR). Fill in the Ops vector with the
8123 SmallVector<SDValue, 8> Ops;
8124 if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
8125 Ops.append(InVec.getNode()->op_begin(),
8126 InVec.getNode()->op_end());
8127 } else if (InVec.getOpcode() == ISD::UNDEF) {
8128 unsigned NElts = VT.getVectorNumElements();
8129 Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
8134 // Insert the element
8135 if (Elt < Ops.size()) {
8136 // All the operands of BUILD_VECTOR must have the same type;
8137 // we enforce that here.
8138 EVT OpVT = Ops[0].getValueType();
8139 if (InVal.getValueType() != OpVT)
8140 InVal = OpVT.bitsGT(InVal.getValueType()) ?
8141 DAG.getNode(ISD::ANY_EXTEND, dl, OpVT, InVal) :
8142 DAG.getNode(ISD::TRUNCATE, dl, OpVT, InVal);
8146 // Return the new vector
8147 return DAG.getNode(ISD::BUILD_VECTOR, dl,
8148 VT, &Ops[0], Ops.size());
8151 SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
8152 // (vextract (scalar_to_vector val, 0) -> val
8153 SDValue InVec = N->getOperand(0);
8154 EVT VT = InVec.getValueType();
8155 EVT NVT = N->getValueType(0);
8157 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
8158 // Check if the result type doesn't match the inserted element type. A
8159 // SCALAR_TO_VECTOR may truncate the inserted element and the
8160 // EXTRACT_VECTOR_ELT may widen the extracted vector.
8161 SDValue InOp = InVec.getOperand(0);
8162 if (InOp.getValueType() != NVT) {
8163 assert(InOp.getValueType().isInteger() && NVT.isInteger());
8164 return DAG.getSExtOrTrunc(InOp, InVec.getDebugLoc(), NVT);
8169 SDValue EltNo = N->getOperand(1);
8170 bool ConstEltNo = isa<ConstantSDNode>(EltNo);
8172 // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
8173 // We only perform this optimization before the op legalization phase because
8174 // we may introduce new vector instructions which are not backed by TD
8175 // patterns. For example on AVX, extracting elements from a wide vector
8176 // without using extract_subvector.
8177 if (InVec.getOpcode() == ISD::VECTOR_SHUFFLE
8178 && ConstEltNo && !LegalOperations) {
8179 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8180 int NumElem = VT.getVectorNumElements();
8181 ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
8182 // Find the new index to extract from.
8183 int OrigElt = SVOp->getMaskElt(Elt);
8185 // Extracting an undef index is undef.
8187 return DAG.getUNDEF(NVT);
8189 // Select the right vector half to extract from.
8190 if (OrigElt < NumElem) {
8191 InVec = InVec->getOperand(0);
8193 InVec = InVec->getOperand(1);
8197 EVT IndexTy = N->getOperand(1).getValueType();
8198 return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, N->getDebugLoc(), NVT,
8199 InVec, DAG.getConstant(OrigElt, IndexTy));
8202 // Perform only after legalization to ensure build_vector / vector_shuffle
8203 // optimizations have already been done.
8204 if (!LegalOperations) return SDValue();
8206 // (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
8207 // (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
8208 // (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)
8211 int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
8212 bool NewLoad = false;
8213 bool BCNumEltsChanged = false;
8214 EVT ExtVT = VT.getVectorElementType();
8217 // If the result of load has to be truncated, then it's not necessarily
8219 if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
8222 if (InVec.getOpcode() == ISD::BITCAST) {
8223 // Don't duplicate a load with other uses.
8224 if (!InVec.hasOneUse())
8227 EVT BCVT = InVec.getOperand(0).getValueType();
8228 if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
8230 if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
8231 BCNumEltsChanged = true;
8232 InVec = InVec.getOperand(0);
8233 ExtVT = BCVT.getVectorElementType();
8237 LoadSDNode *LN0 = NULL;
8238 const ShuffleVectorSDNode *SVN = NULL;
8239 if (ISD::isNormalLoad(InVec.getNode())) {
8240 LN0 = cast<LoadSDNode>(InVec);
8241 } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
8242 InVec.getOperand(0).getValueType() == ExtVT &&
8243 ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
8244 // Don't duplicate a load with other uses.
8245 if (!InVec.hasOneUse())
8248 LN0 = cast<LoadSDNode>(InVec.getOperand(0));
8249 } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
8250 // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
8252 // (load $addr+1*size)
8254 // Don't duplicate a load with other uses.
8255 if (!InVec.hasOneUse())
8258 // If the bit convert changed the number of elements, it is unsafe
8259 // to examine the mask.
8260 if (BCNumEltsChanged)
8263 // Select the input vector, guarding against out of range extract vector.
8264 unsigned NumElems = VT.getVectorNumElements();
8265 int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
8266 InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);
8268 if (InVec.getOpcode() == ISD::BITCAST) {
8269 // Don't duplicate a load with other uses.
8270 if (!InVec.hasOneUse())
8273 InVec = InVec.getOperand(0);
8275 if (ISD::isNormalLoad(InVec.getNode())) {
8276 LN0 = cast<LoadSDNode>(InVec);
8277 Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
8281 // Make sure we found a non-volatile load and the extractelement is
8283 if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
8286 // If Idx was -1 above, Elt is going to be -1, so just return undef.
8288 return DAG.getUNDEF(LVT);
8290 unsigned Align = LN0->getAlignment();
8292 // Check the resultant load doesn't need a higher alignment than the
8296 ->getABITypeAlignment(LVT.getTypeForEVT(*DAG.getContext()));
8298 if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, LVT))
8304 SDValue NewPtr = LN0->getBasePtr();
8305 unsigned PtrOff = 0;
8308 PtrOff = LVT.getSizeInBits() * Elt / 8;
8309 EVT PtrType = NewPtr.getValueType();
8310 if (TLI.isBigEndian())
8311 PtrOff = VT.getSizeInBits() / 8 - PtrOff;
8312 NewPtr = DAG.getNode(ISD::ADD, N->getDebugLoc(), PtrType, NewPtr,
8313 DAG.getConstant(PtrOff, PtrType));
8316 // The replacement we need to do here is a little tricky: we need to
8317 // replace an extractelement of a load with a load.
8318 // Use ReplaceAllUsesOfValuesWith to do the replacement.
8319 // Note that this replacement assumes that the extractvalue is the only
8320 // use of the load; that's okay because we don't want to perform this
8321 // transformation in other cases anyway.
8324 if (NVT.bitsGT(LVT)) {
8325 // If the result type of vextract is wider than the load, then issue an
8326 // extending load instead.
8327 ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, LVT)
8328 ? ISD::ZEXTLOAD : ISD::EXTLOAD;
8329 Load = DAG.getExtLoad(ExtType, N->getDebugLoc(), NVT, LN0->getChain(),
8330 NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
8331 LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
8332 Chain = Load.getValue(1);
8334 Load = DAG.getLoad(LVT, N->getDebugLoc(), LN0->getChain(), NewPtr,
8335 LN0->getPointerInfo().getWithOffset(PtrOff),
8336 LN0->isVolatile(), LN0->isNonTemporal(),
8337 LN0->isInvariant(), Align);
8338 Chain = Load.getValue(1);
8339 if (NVT.bitsLT(LVT))
8340 Load = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), NVT, Load);
8342 Load = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), NVT, Load);
8344 WorkListRemover DeadNodes(*this);
8345 SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
8346 SDValue To[] = { Load, Chain };
8347 DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
8348 // Since we're explcitly calling ReplaceAllUses, add the new node to the
8349 // worklist explicitly as well.
8350 AddToWorkList(Load.getNode());
8351 AddUsersToWorkList(Load.getNode()); // Add users too
8352 // Make sure to revisit this node to clean it up; it will usually be dead.
8354 return SDValue(N, 0);
8360 // Simplify (build_vec (ext )) to (bitcast (build_vec ))
8361 SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
8362 // We perform this optimization post type-legalization because
8363 // the type-legalizer often scalarizes integer-promoted vectors.
8364 // Performing this optimization before may create bit-casts which
8365 // will be type-legalized to complex code sequences.
8366 // We perform this optimization only before the operation legalizer because we
8367 // may introduce illegal operations.
8368 if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
8371 unsigned NumInScalars = N->getNumOperands();
8372 DebugLoc dl = N->getDebugLoc();
8373 EVT VT = N->getValueType(0);
8375 // Check to see if this is a BUILD_VECTOR of a bunch of values
8376 // which come from any_extend or zero_extend nodes. If so, we can create
8377 // a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
8378 // optimizations. We do not handle sign-extend because we can't fill the sign
8380 EVT SourceType = MVT::Other;
8381 bool AllAnyExt = true;
8383 for (unsigned i = 0; i != NumInScalars; ++i) {
8384 SDValue In = N->getOperand(i);
8385 // Ignore undef inputs.
8386 if (In.getOpcode() == ISD::UNDEF) continue;
8388 bool AnyExt = In.getOpcode() == ISD::ANY_EXTEND;
8389 bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;
8391 // Abort if the element is not an extension.
8392 if (!ZeroExt && !AnyExt) {
8393 SourceType = MVT::Other;
8397 // The input is a ZeroExt or AnyExt. Check the original type.
8398 EVT InTy = In.getOperand(0).getValueType();
8400 // Check that all of the widened source types are the same.
8401 if (SourceType == MVT::Other)
8404 else if (InTy != SourceType) {
8405 // Multiple income types. Abort.
8406 SourceType = MVT::Other;
8410 // Check if all of the extends are ANY_EXTENDs.
8411 AllAnyExt &= AnyExt;
8414 // In order to have valid types, all of the inputs must be extended from the
8415 // same source type and all of the inputs must be any or zero extend.
8416 // Scalar sizes must be a power of two.
8417 EVT OutScalarTy = VT.getScalarType();
8418 bool ValidTypes = SourceType != MVT::Other &&
8419 isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
8420 isPowerOf2_32(SourceType.getSizeInBits());
8422 // Create a new simpler BUILD_VECTOR sequence which other optimizations can
8423 // turn into a single shuffle instruction.
8427 bool isLE = TLI.isLittleEndian();
8428 unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
8429 assert(ElemRatio > 1 && "Invalid element size ratio");
8430 SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
8431 DAG.getConstant(0, SourceType);
8433 unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
8434 SmallVector<SDValue, 8> Ops(NewBVElems, Filler);
8436 // Populate the new build_vector
8437 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
8438 SDValue Cast = N->getOperand(i);
8439 assert((Cast.getOpcode() == ISD::ANY_EXTEND ||
8440 Cast.getOpcode() == ISD::ZERO_EXTEND ||
8441 Cast.getOpcode() == ISD::UNDEF) && "Invalid cast opcode");
8443 if (Cast.getOpcode() == ISD::UNDEF)
8444 In = DAG.getUNDEF(SourceType);
8446 In = Cast->getOperand(0);
8447 unsigned Index = isLE ? (i * ElemRatio) :
8448 (i * ElemRatio + (ElemRatio - 1));
8450 assert(Index < Ops.size() && "Invalid index");
8454 // The type of the new BUILD_VECTOR node.
8455 EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
8456 assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&
8457 "Invalid vector size");
8458 // Check if the new vector type is legal.
8459 if (!isTypeLegal(VecVT)) return SDValue();
8461 // Make the new BUILD_VECTOR.
8462 SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, &Ops[0], Ops.size());
8464 // The new BUILD_VECTOR node has the potential to be further optimized.
8465 AddToWorkList(BV.getNode());
8466 // Bitcast to the desired type.
8467 return DAG.getNode(ISD::BITCAST, dl, VT, BV);
8470 SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
8471 unsigned NumInScalars = N->getNumOperands();
8472 DebugLoc dl = N->getDebugLoc();
8473 EVT VT = N->getValueType(0);
8475 // A vector built entirely of undefs is undef.
8476 if (ISD::allOperandsUndef(N))
8477 return DAG.getUNDEF(VT);
8479 SDValue V = reduceBuildVecExtToExtBuildVec(N);
8483 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
8484 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
8485 // at most two distinct vectors, turn this into a shuffle node.
8487 // May only combine to shuffle after legalize if shuffle is legal.
8488 if (LegalOperations &&
8489 !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
8492 SDValue VecIn1, VecIn2;
8493 for (unsigned i = 0; i != NumInScalars; ++i) {
8494 // Ignore undef inputs.
8495 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
8497 // If this input is something other than a EXTRACT_VECTOR_ELT with a
8498 // constant index, bail out.
8499 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
8500 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
8501 VecIn1 = VecIn2 = SDValue(0, 0);
8505 // We allow up to two distinct input vectors.
8506 SDValue ExtractedFromVec = N->getOperand(i).getOperand(0);
8507 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
8510 if (VecIn1.getNode() == 0) {
8511 VecIn1 = ExtractedFromVec;
8512 } else if (VecIn2.getNode() == 0) {
8513 VecIn2 = ExtractedFromVec;
8516 VecIn1 = VecIn2 = SDValue(0, 0);
8521 // If everything is good, we can make a shuffle operation.
8522 if (VecIn1.getNode()) {
8523 SmallVector<int, 8> Mask;
8524 for (unsigned i = 0; i != NumInScalars; ++i) {
8525 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
8530 // If extracting from the first vector, just use the index directly.
8531 SDValue Extract = N->getOperand(i);
8532 SDValue ExtVal = Extract.getOperand(1);
8533 if (Extract.getOperand(0) == VecIn1) {
8534 unsigned ExtIndex = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8535 if (ExtIndex > VT.getVectorNumElements())
8538 Mask.push_back(ExtIndex);
8542 // Otherwise, use InIdx + VecSize
8543 unsigned Idx = cast<ConstantSDNode>(ExtVal)->getZExtValue();
8544 Mask.push_back(Idx+NumInScalars);
8547 // We can't generate a shuffle node with mismatched input and output types.
8548 // Attempt to transform a single input vector to the correct type.
8549 if ((VT != VecIn1.getValueType())) {
8550 // We don't support shuffeling between TWO values of different types.
8551 if (VecIn2.getNode() != 0)
8554 // We only support widening of vectors which are half the size of the
8555 // output registers. For example XMM->YMM widening on X86 with AVX.
8556 if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
8559 // If the input vector type has a different base type to the output
8560 // vector type, bail out.
8561 if (VecIn1.getValueType().getVectorElementType() !=
8562 VT.getVectorElementType())
8565 // Widen the input vector by adding undef values.
8566 VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
8567 VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
8570 // If VecIn2 is unused then change it to undef.
8571 VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT);
8573 // Check that we were able to transform all incoming values to the same
8575 if (VecIn2.getValueType() != VecIn1.getValueType() ||
8576 VecIn1.getValueType() != VT)
8579 // Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
8580 if (!isTypeLegal(VT))
8583 // Return the new VECTOR_SHUFFLE node.
8587 return DAG.getVectorShuffle(VT, dl, Ops[0], Ops[1], &Mask[0]);
8593 SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
8594 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
8595 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
8596 // inputs come from at most two distinct vectors, turn this into a shuffle
8599 // If we only have one input vector, we don't need to do any concatenation.
8600 if (N->getNumOperands() == 1)
8601 return N->getOperand(0);
8603 // Check if all of the operands are undefs.
8604 if (ISD::allOperandsUndef(N))
8605 return DAG.getUNDEF(N->getValueType(0));
8610 SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
8611 EVT NVT = N->getValueType(0);
8612 SDValue V = N->getOperand(0);
8614 if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
8615 // Handle only simple case where vector being inserted and vector
8616 // being extracted are of same type, and are half size of larger vectors.
8617 EVT BigVT = V->getOperand(0).getValueType();
8618 EVT SmallVT = V->getOperand(1).getValueType();
8619 if (NVT != SmallVT || NVT.getSizeInBits()*2 != BigVT.getSizeInBits())
8622 // Only handle cases where both indexes are constants with the same type.
8623 ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
8624 ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));
8626 if (InsIdx && ExtIdx &&
8627 InsIdx->getValueType(0).getSizeInBits() <= 64 &&
8628 ExtIdx->getValueType(0).getSizeInBits() <= 64) {
8630 // (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
8632 // indices are equal => V1
8633 // otherwise => (extract_subvec V1, ExtIdx)
8634 if (InsIdx->getZExtValue() == ExtIdx->getZExtValue())
8635 return V->getOperand(1);
8636 return DAG.getNode(ISD::EXTRACT_SUBVECTOR, N->getDebugLoc(), NVT,
8637 V->getOperand(0), N->getOperand(1));
8641 if (V->getOpcode() == ISD::CONCAT_VECTORS) {
8643 // (extract_subvec (concat V1, V2, ...), i)
8646 // Only operand 0 is checked as 'concat' assumes all inputs of the same type.
8647 if (V->getOperand(0).getValueType() != NVT)
8649 unsigned Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
8650 unsigned NumElems = NVT.getVectorNumElements();
8651 assert((Idx % NumElems) == 0 &&
8652 "IDX in concat is not a multiple of the result vector length.");
8653 return V->getOperand(Idx / NumElems);
8659 SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
8660 EVT VT = N->getValueType(0);
8661 unsigned NumElts = VT.getVectorNumElements();
8663 SDValue N0 = N->getOperand(0);
8664 SDValue N1 = N->getOperand(1);
8666 assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG");
8668 // Canonicalize shuffle undef, undef -> undef
8669 if (N0.getOpcode() == ISD::UNDEF && N1.getOpcode() == ISD::UNDEF)
8670 return DAG.getUNDEF(VT);
8672 ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
8674 // Canonicalize shuffle v, v -> v, undef
8676 SmallVector<int, 8> NewMask;
8677 for (unsigned i = 0; i != NumElts; ++i) {
8678 int Idx = SVN->getMaskElt(i);
8679 if (Idx >= (int)NumElts) Idx -= NumElts;
8680 NewMask.push_back(Idx);
8682 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, DAG.getUNDEF(VT),
8686 // Canonicalize shuffle undef, v -> v, undef. Commute the shuffle mask.
8687 if (N0.getOpcode() == ISD::UNDEF) {
8688 SmallVector<int, 8> NewMask;
8689 for (unsigned i = 0; i != NumElts; ++i) {
8690 int Idx = SVN->getMaskElt(i);
8692 if (Idx < (int)NumElts)
8697 NewMask.push_back(Idx);
8699 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N1, DAG.getUNDEF(VT),
8703 // Remove references to rhs if it is undef
8704 if (N1.getOpcode() == ISD::UNDEF) {
8705 bool Changed = false;
8706 SmallVector<int, 8> NewMask;
8707 for (unsigned i = 0; i != NumElts; ++i) {
8708 int Idx = SVN->getMaskElt(i);
8709 if (Idx >= (int)NumElts) {
8713 NewMask.push_back(Idx);
8716 return DAG.getVectorShuffle(VT, N->getDebugLoc(), N0, N1, &NewMask[0]);
8719 // If it is a splat, check if the argument vector is another splat or a
8720 // build_vector with all scalar elements the same.
8721 if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
8722 SDNode *V = N0.getNode();
8724 // If this is a bit convert that changes the element type of the vector but
8725 // not the number of vector elements, look through it. Be careful not to
8726 // look though conversions that change things like v4f32 to v2f64.
8727 if (V->getOpcode() == ISD::BITCAST) {
8728 SDValue ConvInput = V->getOperand(0);
8729 if (ConvInput.getValueType().isVector() &&
8730 ConvInput.getValueType().getVectorNumElements() == NumElts)
8731 V = ConvInput.getNode();
8734 if (V->getOpcode() == ISD::BUILD_VECTOR) {
8735 assert(V->getNumOperands() == NumElts &&
8736 "BUILD_VECTOR has wrong number of operands");
8738 bool AllSame = true;
8739 for (unsigned i = 0; i != NumElts; ++i) {
8740 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
8741 Base = V->getOperand(i);
8745 // Splat of <u, u, u, u>, return <u, u, u, u>
8746 if (!Base.getNode())
8748 for (unsigned i = 0; i != NumElts; ++i) {
8749 if (V->getOperand(i) != Base) {
8754 // Splat of <x, x, x, x>, return <x, x, x, x>
8760 // If this shuffle node is simply a swizzle of another shuffle node,
8761 // and it reverses the swizzle of the previous shuffle then we can
8762 // optimize shuffle(shuffle(x, undef), undef) -> x.
8763 if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
8764 N1.getOpcode() == ISD::UNDEF) {
8766 ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);
8768 // Shuffle nodes can only reverse shuffles with a single non-undef value.
8769 if (N0.getOperand(1).getOpcode() != ISD::UNDEF)
8772 // The incoming shuffle must be of the same type as the result of the
8774 assert(OtherSV->getOperand(0).getValueType() == VT &&
8775 "Shuffle types don't match");
8777 for (unsigned i = 0; i != NumElts; ++i) {
8778 int Idx = SVN->getMaskElt(i);
8779 assert(Idx < (int)NumElts && "Index references undef operand");
8780 // Next, this index comes from the first value, which is the incoming
8781 // shuffle. Adopt the incoming index.
8783 Idx = OtherSV->getMaskElt(Idx);
8785 // The combined shuffle must map each index to itself.
8786 if (Idx >= 0 && (unsigned)Idx != i)
8790 return OtherSV->getOperand(0);
8796 SDValue DAGCombiner::visitMEMBARRIER(SDNode* N) {
8797 if (!TLI.getShouldFoldAtomicFences())
8800 SDValue atomic = N->getOperand(0);
8801 switch (atomic.getOpcode()) {
8802 case ISD::ATOMIC_CMP_SWAP:
8803 case ISD::ATOMIC_SWAP:
8804 case ISD::ATOMIC_LOAD_ADD:
8805 case ISD::ATOMIC_LOAD_SUB:
8806 case ISD::ATOMIC_LOAD_AND:
8807 case ISD::ATOMIC_LOAD_OR:
8808 case ISD::ATOMIC_LOAD_XOR:
8809 case ISD::ATOMIC_LOAD_NAND:
8810 case ISD::ATOMIC_LOAD_MIN:
8811 case ISD::ATOMIC_LOAD_MAX:
8812 case ISD::ATOMIC_LOAD_UMIN:
8813 case ISD::ATOMIC_LOAD_UMAX:
8819 SDValue fence = atomic.getOperand(0);
8820 if (fence.getOpcode() != ISD::MEMBARRIER)
8823 switch (atomic.getOpcode()) {
8824 case ISD::ATOMIC_CMP_SWAP:
8825 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8826 fence.getOperand(0),
8827 atomic.getOperand(1), atomic.getOperand(2),
8828 atomic.getOperand(3)), atomic.getResNo());
8829 case ISD::ATOMIC_SWAP:
8830 case ISD::ATOMIC_LOAD_ADD:
8831 case ISD::ATOMIC_LOAD_SUB:
8832 case ISD::ATOMIC_LOAD_AND:
8833 case ISD::ATOMIC_LOAD_OR:
8834 case ISD::ATOMIC_LOAD_XOR:
8835 case ISD::ATOMIC_LOAD_NAND:
8836 case ISD::ATOMIC_LOAD_MIN:
8837 case ISD::ATOMIC_LOAD_MAX:
8838 case ISD::ATOMIC_LOAD_UMIN:
8839 case ISD::ATOMIC_LOAD_UMAX:
8840 return SDValue(DAG.UpdateNodeOperands(atomic.getNode(),
8841 fence.getOperand(0),
8842 atomic.getOperand(1), atomic.getOperand(2)),
8849 /// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
8850 /// an AND to a vector_shuffle with the destination vector and a zero vector.
8851 /// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
8852 /// vector_shuffle V, Zero, <0, 4, 2, 4>
8853 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
8854 EVT VT = N->getValueType(0);
8855 DebugLoc dl = N->getDebugLoc();
8856 SDValue LHS = N->getOperand(0);
8857 SDValue RHS = N->getOperand(1);
8858 if (N->getOpcode() == ISD::AND) {
8859 if (RHS.getOpcode() == ISD::BITCAST)
8860 RHS = RHS.getOperand(0);
8861 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
8862 SmallVector<int, 8> Indices;
8863 unsigned NumElts = RHS.getNumOperands();
8864 for (unsigned i = 0; i != NumElts; ++i) {
8865 SDValue Elt = RHS.getOperand(i);
8866 if (!isa<ConstantSDNode>(Elt))
8869 if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
8870 Indices.push_back(i);
8871 else if (cast<ConstantSDNode>(Elt)->isNullValue())
8872 Indices.push_back(NumElts);
8877 // Let's see if the target supports this vector_shuffle.
8878 EVT RVT = RHS.getValueType();
8879 if (!TLI.isVectorClearMaskLegal(Indices, RVT))
8882 // Return the new VECTOR_SHUFFLE node.
8883 EVT EltVT = RVT.getVectorElementType();
8884 SmallVector<SDValue,8> ZeroOps(RVT.getVectorNumElements(),
8885 DAG.getConstant(0, EltVT));
8886 SDValue Zero = DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8887 RVT, &ZeroOps[0], ZeroOps.size());
8888 LHS = DAG.getNode(ISD::BITCAST, dl, RVT, LHS);
8889 SDValue Shuf = DAG.getVectorShuffle(RVT, dl, LHS, Zero, &Indices[0]);
8890 return DAG.getNode(ISD::BITCAST, dl, VT, Shuf);
8897 /// SimplifyVBinOp - Visit a binary vector operation, like ADD.
8898 SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
8899 // After legalize, the target may be depending on adds and other
8900 // binary ops to provide legal ways to construct constants or other
8901 // things. Simplifying them may result in a loss of legality.
8902 if (LegalOperations) return SDValue();
8904 assert(N->getValueType(0).isVector() &&
8905 "SimplifyVBinOp only works on vectors!");
8907 SDValue LHS = N->getOperand(0);
8908 SDValue RHS = N->getOperand(1);
8909 SDValue Shuffle = XformToShuffleWithZero(N);
8910 if (Shuffle.getNode()) return Shuffle;
8912 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
8914 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
8915 RHS.getOpcode() == ISD::BUILD_VECTOR) {
8916 SmallVector<SDValue, 8> Ops;
8917 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
8918 SDValue LHSOp = LHS.getOperand(i);
8919 SDValue RHSOp = RHS.getOperand(i);
8920 // If these two elements can't be folded, bail out.
8921 if ((LHSOp.getOpcode() != ISD::UNDEF &&
8922 LHSOp.getOpcode() != ISD::Constant &&
8923 LHSOp.getOpcode() != ISD::ConstantFP) ||
8924 (RHSOp.getOpcode() != ISD::UNDEF &&
8925 RHSOp.getOpcode() != ISD::Constant &&
8926 RHSOp.getOpcode() != ISD::ConstantFP))
8929 // Can't fold divide by zero.
8930 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
8931 N->getOpcode() == ISD::FDIV) {
8932 if ((RHSOp.getOpcode() == ISD::Constant &&
8933 cast<ConstantSDNode>(RHSOp.getNode())->isNullValue()) ||
8934 (RHSOp.getOpcode() == ISD::ConstantFP &&
8935 cast<ConstantFPSDNode>(RHSOp.getNode())->getValueAPF().isZero()))
8939 EVT VT = LHSOp.getValueType();
8940 EVT RVT = RHSOp.getValueType();
8942 // Integer BUILD_VECTOR operands may have types larger than the element
8943 // size (e.g., when the element type is not legal). Prior to type
8944 // legalization, the types may not match between the two BUILD_VECTORS.
8945 // Truncate one of the operands to make them match.
8946 if (RVT.getSizeInBits() > VT.getSizeInBits()) {
8947 RHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, RHSOp);
8949 LHSOp = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), RVT, LHSOp);
8953 SDValue FoldOp = DAG.getNode(N->getOpcode(), LHS.getDebugLoc(), VT,
8955 if (FoldOp.getOpcode() != ISD::UNDEF &&
8956 FoldOp.getOpcode() != ISD::Constant &&
8957 FoldOp.getOpcode() != ISD::ConstantFP)
8959 Ops.push_back(FoldOp);
8960 AddToWorkList(FoldOp.getNode());
8963 if (Ops.size() == LHS.getNumOperands())
8964 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
8965 LHS.getValueType(), &Ops[0], Ops.size());
8971 /// SimplifyVUnaryOp - Visit a binary vector operation, like FABS/FNEG.
8972 SDValue DAGCombiner::SimplifyVUnaryOp(SDNode *N) {
8973 // After legalize, the target may be depending on adds and other
8974 // binary ops to provide legal ways to construct constants or other
8975 // things. Simplifying them may result in a loss of legality.
8976 if (LegalOperations) return SDValue();
8978 assert(N->getValueType(0).isVector() &&
8979 "SimplifyVUnaryOp only works on vectors!");
8981 SDValue N0 = N->getOperand(0);
8983 if (N0.getOpcode() != ISD::BUILD_VECTOR)
8986 // Operand is a BUILD_VECTOR node, see if we can constant fold it.
8987 SmallVector<SDValue, 8> Ops;
8988 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
8989 SDValue Op = N0.getOperand(i);
8990 if (Op.getOpcode() != ISD::UNDEF &&
8991 Op.getOpcode() != ISD::ConstantFP)
8993 EVT EltVT = Op.getValueType();
8994 SDValue FoldOp = DAG.getNode(N->getOpcode(), N0.getDebugLoc(), EltVT, Op);
8995 if (FoldOp.getOpcode() != ISD::UNDEF &&
8996 FoldOp.getOpcode() != ISD::ConstantFP)
8998 Ops.push_back(FoldOp);
8999 AddToWorkList(FoldOp.getNode());
9002 if (Ops.size() != N0.getNumOperands())
9005 return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
9006 N0.getValueType(), &Ops[0], Ops.size());
9009 SDValue DAGCombiner::SimplifySelect(DebugLoc DL, SDValue N0,
9010 SDValue N1, SDValue N2){
9011 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
9013 SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
9014 cast<CondCodeSDNode>(N0.getOperand(2))->get());
9016 // If we got a simplified select_cc node back from SimplifySelectCC, then
9017 // break it down into a new SETCC node, and a new SELECT node, and then return
9018 // the SELECT node, since we were called with a SELECT node.
9019 if (SCC.getNode()) {
9020 // Check to see if we got a select_cc back (to turn into setcc/select).
9021 // Otherwise, just return whatever node we got back, like fabs.
9022 if (SCC.getOpcode() == ISD::SELECT_CC) {
9023 SDValue SETCC = DAG.getNode(ISD::SETCC, N0.getDebugLoc(),
9025 SCC.getOperand(0), SCC.getOperand(1),
9027 AddToWorkList(SETCC.getNode());
9028 return DAG.getNode(ISD::SELECT, SCC.getDebugLoc(), SCC.getValueType(),
9029 SCC.getOperand(2), SCC.getOperand(3), SETCC);
9037 /// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
9038 /// are the two values being selected between, see if we can simplify the
9039 /// select. Callers of this should assume that TheSelect is deleted if this
9040 /// returns true. As such, they should return the appropriate thing (e.g. the
9041 /// node) back to the top-level of the DAG combiner loop to avoid it being
9043 bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
9046 // Cannot simplify select with vector condition
9047 if (TheSelect->getOperand(0).getValueType().isVector()) return false;
9049 // If this is a select from two identical things, try to pull the operation
9050 // through the select.
9051 if (LHS.getOpcode() != RHS.getOpcode() ||
9052 !LHS.hasOneUse() || !RHS.hasOneUse())
9055 // If this is a load and the token chain is identical, replace the select
9056 // of two loads with a load through a select of the address to load from.
9057 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
9058 // constants have been dropped into the constant pool.
9059 if (LHS.getOpcode() == ISD::LOAD) {
9060 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
9061 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
9063 // Token chains must be identical.
9064 if (LHS.getOperand(0) != RHS.getOperand(0) ||
9065 // Do not let this transformation reduce the number of volatile loads.
9066 LLD->isVolatile() || RLD->isVolatile() ||
9067 // If this is an EXTLOAD, the VT's must match.
9068 LLD->getMemoryVT() != RLD->getMemoryVT() ||
9069 // If this is an EXTLOAD, the kind of extension must match.
9070 (LLD->getExtensionType() != RLD->getExtensionType() &&
9071 // The only exception is if one of the extensions is anyext.
9072 LLD->getExtensionType() != ISD::EXTLOAD &&
9073 RLD->getExtensionType() != ISD::EXTLOAD) ||
9074 // FIXME: this discards src value information. This is
9075 // over-conservative. It would be beneficial to be able to remember
9076 // both potential memory locations. Since we are discarding
9077 // src value info, don't do the transformation if the memory
9078 // locations are not in the default address space.
9079 LLD->getPointerInfo().getAddrSpace() != 0 ||
9080 RLD->getPointerInfo().getAddrSpace() != 0)
9083 // Check that the select condition doesn't reach either load. If so,
9084 // folding this will induce a cycle into the DAG. If not, this is safe to
9085 // xform, so create a select of the addresses.
9087 if (TheSelect->getOpcode() == ISD::SELECT) {
9088 SDNode *CondNode = TheSelect->getOperand(0).getNode();
9089 if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
9090 (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
9092 // The loads must not depend on one another.
9093 if (LLD->isPredecessorOf(RLD) ||
9094 RLD->isPredecessorOf(LLD))
9096 Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
9097 LLD->getBasePtr().getValueType(),
9098 TheSelect->getOperand(0), LLD->getBasePtr(),
9100 } else { // Otherwise SELECT_CC
9101 SDNode *CondLHS = TheSelect->getOperand(0).getNode();
9102 SDNode *CondRHS = TheSelect->getOperand(1).getNode();
9104 if ((LLD->hasAnyUseOfValue(1) &&
9105 (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
9106 (RLD->hasAnyUseOfValue(1) &&
9107 (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
9110 Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(),
9111 LLD->getBasePtr().getValueType(),
9112 TheSelect->getOperand(0),
9113 TheSelect->getOperand(1),
9114 LLD->getBasePtr(), RLD->getBasePtr(),
9115 TheSelect->getOperand(4));
9119 if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
9120 Load = DAG.getLoad(TheSelect->getValueType(0),
9121 TheSelect->getDebugLoc(),
9122 // FIXME: Discards pointer info.
9123 LLD->getChain(), Addr, MachinePointerInfo(),
9124 LLD->isVolatile(), LLD->isNonTemporal(),
9125 LLD->isInvariant(), LLD->getAlignment());
9127 Load = DAG.getExtLoad(LLD->getExtensionType() == ISD::EXTLOAD ?
9128 RLD->getExtensionType() : LLD->getExtensionType(),
9129 TheSelect->getDebugLoc(),
9130 TheSelect->getValueType(0),
9131 // FIXME: Discards pointer info.
9132 LLD->getChain(), Addr, MachinePointerInfo(),
9133 LLD->getMemoryVT(), LLD->isVolatile(),
9134 LLD->isNonTemporal(), LLD->getAlignment());
9137 // Users of the select now use the result of the load.
9138 CombineTo(TheSelect, Load);
9140 // Users of the old loads now use the new load's chain. We know the
9141 // old-load value is dead now.
9142 CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
9143 CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
9150 /// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
9151 /// where 'cond' is the comparison specified by CC.
9152 SDValue DAGCombiner::SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1,
9153 SDValue N2, SDValue N3,
9154 ISD::CondCode CC, bool NotExtCompare) {
9155 // (x ? y : y) -> y.
9156 if (N2 == N3) return N2;
9158 EVT VT = N2.getValueType();
9159 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
9160 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
9161 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
9163 // Determine if the condition we're dealing with is constant
9164 SDValue SCC = SimplifySetCC(TLI.getSetCCResultType(N0.getValueType()),
9165 N0, N1, CC, DL, false);
9166 if (SCC.getNode()) AddToWorkList(SCC.getNode());
9167 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode());
9169 // fold select_cc true, x, y -> x
9170 if (SCCC && !SCCC->isNullValue())
9172 // fold select_cc false, x, y -> y
9173 if (SCCC && SCCC->isNullValue())
9176 // Check to see if we can simplify the select into an fabs node
9177 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
9178 // Allow either -0.0 or 0.0
9179 if (CFP->getValueAPF().isZero()) {
9180 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
9181 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
9182 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
9183 N2 == N3.getOperand(0))
9184 return DAG.getNode(ISD::FABS, DL, VT, N0);
9186 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
9187 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
9188 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
9189 N2.getOperand(0) == N3)
9190 return DAG.getNode(ISD::FABS, DL, VT, N3);
9194 // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
9195 // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
9196 // in it. This is a win when the constant is not otherwise available because
9197 // it replaces two constant pool loads with one. We only do this if the FP
9198 // type is known to be legal, because if it isn't, then we are before legalize
9199 // types an we want the other legalization to happen first (e.g. to avoid
9200 // messing with soft float) and if the ConstantFP is not legal, because if
9201 // it is legal, we may not need to store the FP constant in a constant pool.
9202 if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
9203 if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
9204 if (TLI.isTypeLegal(N2.getValueType()) &&
9205 (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
9206 TargetLowering::Legal) &&
9207 // If both constants have multiple uses, then we won't need to do an
9208 // extra load, they are likely around in registers for other users.
9209 (TV->hasOneUse() || FV->hasOneUse())) {
9210 Constant *Elts[] = {
9211 const_cast<ConstantFP*>(FV->getConstantFPValue()),
9212 const_cast<ConstantFP*>(TV->getConstantFPValue())
9214 Type *FPTy = Elts[0]->getType();
9215 const DataLayout &TD = *TLI.getDataLayout();
9217 // Create a ConstantArray of the two constants.
9218 Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
9219 SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
9220 TD.getPrefTypeAlignment(FPTy));
9221 unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
9223 // Get the offsets to the 0 and 1 element of the array so that we can
9224 // select between them.
9225 SDValue Zero = DAG.getIntPtrConstant(0);
9226 unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
9227 SDValue One = DAG.getIntPtrConstant(EltSize);
9229 SDValue Cond = DAG.getSetCC(DL,
9230 TLI.getSetCCResultType(N0.getValueType()),
9232 AddToWorkList(Cond.getNode());
9233 SDValue CstOffset = DAG.getNode(ISD::SELECT, DL, Zero.getValueType(),
9235 AddToWorkList(CstOffset.getNode());
9236 CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
9238 AddToWorkList(CPIdx.getNode());
9239 return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
9240 MachinePointerInfo::getConstantPool(), false,
9241 false, false, Alignment);
9246 // Check to see if we can perform the "gzip trick", transforming
9247 // (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)
9248 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
9249 (N1C->isNullValue() || // (a < 0) ? b : 0
9250 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
9251 EVT XType = N0.getValueType();
9252 EVT AType = N2.getValueType();
9253 if (XType.bitsGE(AType)) {
9254 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
9255 // single-bit constant.
9256 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
9257 unsigned ShCtV = N2C->getAPIntValue().logBase2();
9258 ShCtV = XType.getSizeInBits()-ShCtV-1;
9259 SDValue ShCt = DAG.getConstant(ShCtV,
9260 getShiftAmountTy(N0.getValueType()));
9261 SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(),
9263 AddToWorkList(Shift.getNode());
9265 if (XType.bitsGT(AType)) {
9266 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9267 AddToWorkList(Shift.getNode());
9270 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9273 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(),
9275 DAG.getConstant(XType.getSizeInBits()-1,
9276 getShiftAmountTy(N0.getValueType())));
9277 AddToWorkList(Shift.getNode());
9279 if (XType.bitsGT(AType)) {
9280 Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
9281 AddToWorkList(Shift.getNode());
9284 return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
9288 // fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
9289 // where y is has a single bit set.
9290 // A plaintext description would be, we can turn the SELECT_CC into an AND
9291 // when the condition can be materialized as an all-ones register. Any
9292 // single bit-test can be materialized as an all-ones register with
9293 // shift-left and shift-right-arith.
9294 if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
9295 N0->getValueType(0) == VT &&
9296 N1C && N1C->isNullValue() &&
9297 N2C && N2C->isNullValue()) {
9298 SDValue AndLHS = N0->getOperand(0);
9299 ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
9300 if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
9301 // Shift the tested bit over the sign bit.
9302 APInt AndMask = ConstAndRHS->getAPIntValue();
9304 DAG.getConstant(AndMask.countLeadingZeros(),
9305 getShiftAmountTy(AndLHS.getValueType()));
9306 SDValue Shl = DAG.getNode(ISD::SHL, N0.getDebugLoc(), VT, AndLHS, ShlAmt);
9308 // Now arithmetic right shift it all the way over, so the result is either
9309 // all-ones, or zero.
9311 DAG.getConstant(AndMask.getBitWidth()-1,
9312 getShiftAmountTy(Shl.getValueType()));
9313 SDValue Shr = DAG.getNode(ISD::SRA, N0.getDebugLoc(), VT, Shl, ShrAmt);
9315 return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
9319 // fold select C, 16, 0 -> shl C, 4
9320 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
9321 TLI.getBooleanContents(N0.getValueType().isVector()) ==
9322 TargetLowering::ZeroOrOneBooleanContent) {
9324 // If the caller doesn't want us to simplify this into a zext of a compare,
9326 if (NotExtCompare && N2C->getAPIntValue() == 1)
9329 // Get a SetCC of the condition
9330 // FIXME: Should probably make sure that setcc is legal if we ever have a
9331 // target where it isn't.
9333 // cast from setcc result type to select result type
9335 SCC = DAG.getSetCC(DL, TLI.getSetCCResultType(N0.getValueType()),
9337 if (N2.getValueType().bitsLT(SCC.getValueType()))
9338 Temp = DAG.getZeroExtendInReg(SCC, N2.getDebugLoc(), N2.getValueType());
9340 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
9341 N2.getValueType(), SCC);
9343 SCC = DAG.getSetCC(N0.getDebugLoc(), MVT::i1, N0, N1, CC);
9344 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getDebugLoc(),
9345 N2.getValueType(), SCC);
9348 AddToWorkList(SCC.getNode());
9349 AddToWorkList(Temp.getNode());
9351 if (N2C->getAPIntValue() == 1)
9354 // shl setcc result by log2 n2c
9355 return DAG.getNode(ISD::SHL, DL, N2.getValueType(), Temp,
9356 DAG.getConstant(N2C->getAPIntValue().logBase2(),
9357 getShiftAmountTy(Temp.getValueType())));
9360 // Check to see if this is the equivalent of setcc
9361 // FIXME: Turn all of these into setcc if setcc if setcc is legal
9362 // otherwise, go ahead with the folds.
9363 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
9364 EVT XType = N0.getValueType();
9365 if (!LegalOperations ||
9366 TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(XType))) {
9367 SDValue Res = DAG.getSetCC(DL, TLI.getSetCCResultType(XType), N0, N1, CC);
9368 if (Res.getValueType() != VT)
9369 Res = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Res);
9373 // fold (seteq X, 0) -> (srl (ctlz X, log2(size(X))))
9374 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
9375 (!LegalOperations ||
9376 TLI.isOperationLegal(ISD::CTLZ, XType))) {
9377 SDValue Ctlz = DAG.getNode(ISD::CTLZ, N0.getDebugLoc(), XType, N0);
9378 return DAG.getNode(ISD::SRL, DL, XType, Ctlz,
9379 DAG.getConstant(Log2_32(XType.getSizeInBits()),
9380 getShiftAmountTy(Ctlz.getValueType())));
9382 // fold (setgt X, 0) -> (srl (and (-X, ~X), size(X)-1))
9383 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
9384 SDValue NegN0 = DAG.getNode(ISD::SUB, N0.getDebugLoc(),
9385 XType, DAG.getConstant(0, XType), N0);
9386 SDValue NotN0 = DAG.getNOT(N0.getDebugLoc(), N0, XType);
9387 return DAG.getNode(ISD::SRL, DL, XType,
9388 DAG.getNode(ISD::AND, DL, XType, NegN0, NotN0),
9389 DAG.getConstant(XType.getSizeInBits()-1,
9390 getShiftAmountTy(XType)));
9392 // fold (setgt X, -1) -> (xor (srl (X, size(X)-1), 1))
9393 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
9394 SDValue Sign = DAG.getNode(ISD::SRL, N0.getDebugLoc(), XType, N0,
9395 DAG.getConstant(XType.getSizeInBits()-1,
9396 getShiftAmountTy(N0.getValueType())));
9397 return DAG.getNode(ISD::XOR, DL, XType, Sign, DAG.getConstant(1, XType));
9401 // Check to see if this is an integer abs.
9402 // select_cc setg[te] X, 0, X, -X ->
9403 // select_cc setgt X, -1, X, -X ->
9404 // select_cc setl[te] X, 0, -X, X ->
9405 // select_cc setlt X, 1, -X, X ->
9406 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
9408 ConstantSDNode *SubC = NULL;
9409 if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
9410 (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
9411 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
9412 SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
9413 else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
9414 (N1C->isOne() && CC == ISD::SETLT)) &&
9415 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
9416 SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
9418 EVT XType = N0.getValueType();
9419 if (SubC && SubC->isNullValue() && XType.isInteger()) {
9420 SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
9422 DAG.getConstant(XType.getSizeInBits()-1,
9423 getShiftAmountTy(N0.getValueType())));
9424 SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
9426 AddToWorkList(Shift.getNode());
9427 AddToWorkList(Add.getNode());
9428 return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
9435 /// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
9436 SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
9437 SDValue N1, ISD::CondCode Cond,
9438 DebugLoc DL, bool foldBooleans) {
9439 TargetLowering::DAGCombinerInfo
9440 DagCombineInfo(DAG, !LegalTypes, !LegalOperations, false, this);
9441 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
9444 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
9445 /// return a DAG expression to select that will generate the same value by
9446 /// multiplying by a magic number. See:
9447 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
9448 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
9449 std::vector<SDNode*> Built;
9450 SDValue S = TLI.BuildSDIV(N, DAG, LegalOperations, &Built);
9452 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
9458 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
9459 /// return a DAG expression to select that will generate the same value by
9460 /// multiplying by a magic number. See:
9461 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
9462 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
9463 std::vector<SDNode*> Built;
9464 SDValue S = TLI.BuildUDIV(N, DAG, LegalOperations, &Built);
9466 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
9472 /// FindBaseOffset - Return true if base is a frame index, which is known not
9473 // to alias with anything but itself. Provides base object and offset as
9475 static bool FindBaseOffset(SDValue Ptr, SDValue &Base, int64_t &Offset,
9476 const GlobalValue *&GV, const void *&CV) {
9477 // Assume it is a primitive operation.
9478 Base = Ptr; Offset = 0; GV = 0; CV = 0;
9480 // If it's an adding a simple constant then integrate the offset.
9481 if (Base.getOpcode() == ISD::ADD) {
9482 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
9483 Base = Base.getOperand(0);
9484 Offset += C->getZExtValue();
9488 // Return the underlying GlobalValue, and update the Offset. Return false
9489 // for GlobalAddressSDNode since the same GlobalAddress may be represented
9490 // by multiple nodes with different offsets.
9491 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Base)) {
9492 GV = G->getGlobal();
9493 Offset += G->getOffset();
9497 // Return the underlying Constant value, and update the Offset. Return false
9498 // for ConstantSDNodes since the same constant pool entry may be represented
9499 // by multiple nodes with different offsets.
9500 if (ConstantPoolSDNode *C = dyn_cast<ConstantPoolSDNode>(Base)) {
9501 CV = C->isMachineConstantPoolEntry() ? (const void *)C->getMachineCPVal()
9502 : (const void *)C->getConstVal();
9503 Offset += C->getOffset();
9506 // If it's any of the following then it can't alias with anything but itself.
9507 return isa<FrameIndexSDNode>(Base);
9510 /// isAlias - Return true if there is any possibility that the two addresses
9512 bool DAGCombiner::isAlias(SDValue Ptr1, int64_t Size1,
9513 const Value *SrcValue1, int SrcValueOffset1,
9514 unsigned SrcValueAlign1,
9515 const MDNode *TBAAInfo1,
9516 SDValue Ptr2, int64_t Size2,
9517 const Value *SrcValue2, int SrcValueOffset2,
9518 unsigned SrcValueAlign2,
9519 const MDNode *TBAAInfo2) const {
9520 // If they are the same then they must be aliases.
9521 if (Ptr1 == Ptr2) return true;
9523 // Gather base node and offset information.
9524 SDValue Base1, Base2;
9525 int64_t Offset1, Offset2;
9526 const GlobalValue *GV1, *GV2;
9527 const void *CV1, *CV2;
9528 bool isFrameIndex1 = FindBaseOffset(Ptr1, Base1, Offset1, GV1, CV1);
9529 bool isFrameIndex2 = FindBaseOffset(Ptr2, Base2, Offset2, GV2, CV2);
9531 // If they have a same base address then check to see if they overlap.
9532 if (Base1 == Base2 || (GV1 && (GV1 == GV2)) || (CV1 && (CV1 == CV2)))
9533 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9535 // It is possible for different frame indices to alias each other, mostly
9536 // when tail call optimization reuses return address slots for arguments.
9537 // To catch this case, look up the actual index of frame indices to compute
9538 // the real alias relationship.
9539 if (isFrameIndex1 && isFrameIndex2) {
9540 MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
9541 Offset1 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base1)->getIndex());
9542 Offset2 += MFI->getObjectOffset(cast<FrameIndexSDNode>(Base2)->getIndex());
9543 return !((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
9546 // Otherwise, if we know what the bases are, and they aren't identical, then
9547 // we know they cannot alias.
9548 if ((isFrameIndex1 || CV1 || GV1) && (isFrameIndex2 || CV2 || GV2))
9551 // If we know required SrcValue1 and SrcValue2 have relatively large alignment
9552 // compared to the size and offset of the access, we may be able to prove they
9553 // do not alias. This check is conservative for now to catch cases created by
9554 // splitting vector types.
9555 if ((SrcValueAlign1 == SrcValueAlign2) &&
9556 (SrcValueOffset1 != SrcValueOffset2) &&
9557 (Size1 == Size2) && (SrcValueAlign1 > Size1)) {
9558 int64_t OffAlign1 = SrcValueOffset1 % SrcValueAlign1;
9559 int64_t OffAlign2 = SrcValueOffset2 % SrcValueAlign1;
9561 // There is no overlap between these relatively aligned accesses of similar
9562 // size, return no alias.
9563 if ((OffAlign1 + Size1) <= OffAlign2 || (OffAlign2 + Size2) <= OffAlign1)
9567 if (CombinerGlobalAA) {
9568 // Use alias analysis information.
9569 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
9570 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
9571 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
9572 AliasAnalysis::AliasResult AAResult =
9573 AA.alias(AliasAnalysis::Location(SrcValue1, Overlap1, TBAAInfo1),
9574 AliasAnalysis::Location(SrcValue2, Overlap2, TBAAInfo2));
9575 if (AAResult == AliasAnalysis::NoAlias)
9579 // Otherwise we have to assume they alias.
9583 /// FindAliasInfo - Extracts the relevant alias information from the memory
9584 /// node. Returns true if the operand was a load.
9585 bool DAGCombiner::FindAliasInfo(SDNode *N,
9586 SDValue &Ptr, int64_t &Size,
9587 const Value *&SrcValue,
9588 int &SrcValueOffset,
9589 unsigned &SrcValueAlign,
9590 const MDNode *&TBAAInfo) const {
9591 LSBaseSDNode *LS = cast<LSBaseSDNode>(N);
9593 Ptr = LS->getBasePtr();
9594 Size = LS->getMemoryVT().getSizeInBits() >> 3;
9595 SrcValue = LS->getSrcValue();
9596 SrcValueOffset = LS->getSrcValueOffset();
9597 SrcValueAlign = LS->getOriginalAlignment();
9598 TBAAInfo = LS->getTBAAInfo();
9599 return isa<LoadSDNode>(LS);
9602 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
9603 /// looking for aliasing nodes and adding them to the Aliases vector.
9604 void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
9605 SmallVector<SDValue, 8> &Aliases) {
9606 SmallVector<SDValue, 8> Chains; // List of chains to visit.
9607 SmallPtrSet<SDNode *, 16> Visited; // Visited node set.
9609 // Get alias information for node.
9612 const Value *SrcValue;
9614 unsigned SrcValueAlign;
9615 const MDNode *SrcTBAAInfo;
9616 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset,
9617 SrcValueAlign, SrcTBAAInfo);
9620 Chains.push_back(OriginalChain);
9623 // Look at each chain and determine if it is an alias. If so, add it to the
9624 // aliases list. If not, then continue up the chain looking for the next
9626 while (!Chains.empty()) {
9627 SDValue Chain = Chains.back();
9630 // For TokenFactor nodes, look at each operand and only continue up the
9631 // chain until we find two aliases. If we've seen two aliases, assume we'll
9632 // find more and revert to original chain since the xform is unlikely to be
9635 // FIXME: The depth check could be made to return the last non-aliasing
9636 // chain we found before we hit a tokenfactor rather than the original
9638 if (Depth > 6 || Aliases.size() == 2) {
9640 Aliases.push_back(OriginalChain);
9644 // Don't bother if we've been before.
9645 if (!Visited.insert(Chain.getNode()))
9648 switch (Chain.getOpcode()) {
9649 case ISD::EntryToken:
9650 // Entry token is ideal chain operand, but handled in FindBetterChain.
9655 // Get alias information for Chain.
9658 const Value *OpSrcValue;
9659 int OpSrcValueOffset;
9660 unsigned OpSrcValueAlign;
9661 const MDNode *OpSrcTBAAInfo;
9662 bool IsOpLoad = FindAliasInfo(Chain.getNode(), OpPtr, OpSize,
9663 OpSrcValue, OpSrcValueOffset,
9667 // If chain is alias then stop here.
9668 if (!(IsLoad && IsOpLoad) &&
9669 isAlias(Ptr, Size, SrcValue, SrcValueOffset, SrcValueAlign,
9671 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset,
9672 OpSrcValueAlign, OpSrcTBAAInfo)) {
9673 Aliases.push_back(Chain);
9675 // Look further up the chain.
9676 Chains.push_back(Chain.getOperand(0));
9682 case ISD::TokenFactor:
9683 // We have to check each of the operands of the token factor for "small"
9684 // token factors, so we queue them up. Adding the operands to the queue
9685 // (stack) in reverse order maintains the original order and increases the
9686 // likelihood that getNode will find a matching token factor (CSE.)
9687 if (Chain.getNumOperands() > 16) {
9688 Aliases.push_back(Chain);
9691 for (unsigned n = Chain.getNumOperands(); n;)
9692 Chains.push_back(Chain.getOperand(--n));
9697 // For all other instructions we will just have to take what we can get.
9698 Aliases.push_back(Chain);
9704 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
9705 /// for a better chain (aliasing node.)
9706 SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
9707 SmallVector<SDValue, 8> Aliases; // Ops for replacing token factor.
9709 // Accumulate all the aliases to this node.
9710 GatherAllAliases(N, OldChain, Aliases);
9712 // If no operands then chain to entry token.
9713 if (Aliases.size() == 0)
9714 return DAG.getEntryNode();
9716 // If a single operand then chain to it. We don't need to revisit it.
9717 if (Aliases.size() == 1)
9720 // Construct a custom tailored token factor.
9721 return DAG.getNode(ISD::TokenFactor, N->getDebugLoc(), MVT::Other,
9722 &Aliases[0], Aliases.size());
9725 // SelectionDAG::Combine - This is the entry point for the file.
9727 void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
9728 CodeGenOpt::Level OptLevel) {
9729 /// run - This is the main entry point to this class.
9731 DAGCombiner(*this, AA, OptLevel).Run(Level);