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Nate Begeman4ebd8052005-09-01 23:24:04 +00001//===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
Nate Begeman1d4d4142005-09-01 00:19:25 +00002//
3// The LLVM Compiler Infrastructure
4//
Chris Lattner4ee451d2007-12-29 20:36:04 +00005// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
Nate Begeman1d4d4142005-09-01 00:19:25 +00007//
8//===----------------------------------------------------------------------===//
9//
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.
Nate Begeman1d4d4142005-09-01 00:19:25 +000012//
13//===----------------------------------------------------------------------===//
14
15#define DEBUG_TYPE "dagcombine"
Nate Begeman1d4d4142005-09-01 00:19:25 +000016#include "llvm/CodeGen/SelectionDAG.h"
Chris Lattner00161a62008-01-25 07:20:16 +000017#include "llvm/CodeGen/MachineFunction.h"
18#include "llvm/CodeGen/MachineFrameInfo.h"
Chris Lattnerc76d4412007-05-16 06:37:59 +000019#include "llvm/Analysis/AliasAnalysis.h"
Evan Cheng59d5b682007-05-07 21:27:48 +000020#include "llvm/Target/TargetData.h"
Chris Lattner1329cb82008-01-26 19:45:50 +000021#include "llvm/Target/TargetFrameInfo.h"
Nate Begeman1d4d4142005-09-01 00:19:25 +000022#include "llvm/Target/TargetLowering.h"
Evan Cheng59d5b682007-05-07 21:27:48 +000023#include "llvm/Target/TargetMachine.h"
Chris Lattnerddae4bd2007-01-08 23:04:05 +000024#include "llvm/Target/TargetOptions.h"
Chris Lattnerc76d4412007-05-16 06:37:59 +000025#include "llvm/ADT/SmallPtrSet.h"
26#include "llvm/ADT/Statistic.h"
Chris Lattnera4f0b3a2006-08-27 12:54:02 +000027#include "llvm/Support/Compiler.h"
Jim Laskeyd1aed7a2006-09-21 16:28:59 +000028#include "llvm/Support/CommandLine.h"
Chris Lattnerc76d4412007-05-16 06:37:59 +000029#include "llvm/Support/Debug.h"
30#include "llvm/Support/MathExtras.h"
Chris Lattnera500fc62005-09-09 23:53:39 +000031#include <algorithm>
Nate Begeman1d4d4142005-09-01 00:19:25 +000032using namespace llvm;
33
Chris Lattnercd3245a2006-12-19 22:41:21 +000034STATISTIC(NodesCombined , "Number of dag nodes combined");
35STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
36STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
37
Nate Begeman1d4d4142005-09-01 00:19:25 +000038namespace {
Chris Lattner938ab022007-01-16 04:55:25 +000039#ifndef NDEBUG
40 static cl::opt<bool>
41 ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
42 cl::desc("Pop up a window to show dags before the first "
43 "dag combine pass"));
44 static cl::opt<bool>
45 ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
46 cl::desc("Pop up a window to show dags before the second "
47 "dag combine pass"));
48#else
49 static const bool ViewDAGCombine1 = false;
50 static const bool ViewDAGCombine2 = false;
51#endif
52
Jim Laskey71382342006-10-07 23:37:56 +000053 static cl::opt<bool>
54 CombinerAA("combiner-alias-analysis", cl::Hidden,
Jim Laskey26f7fa72006-10-17 19:33:52 +000055 cl::desc("Turn on alias analysis during testing"));
Jim Laskey3ad175b2006-10-12 15:22:24 +000056
Jim Laskey07a27092006-10-18 19:08:31 +000057 static cl::opt<bool>
58 CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
59 cl::desc("Include global information in alias analysis"));
60
Jim Laskeybc588b82006-10-05 15:07:25 +000061//------------------------------ DAGCombiner ---------------------------------//
62
Jim Laskey71382342006-10-07 23:37:56 +000063 class VISIBILITY_HIDDEN DAGCombiner {
Nate Begeman1d4d4142005-09-01 00:19:25 +000064 SelectionDAG &DAG;
65 TargetLowering &TLI;
Nate Begeman4ebd8052005-09-01 23:24:04 +000066 bool AfterLegalize;
Nate Begeman1d4d4142005-09-01 00:19:25 +000067
68 // Worklist of all of the nodes that need to be simplified.
69 std::vector<SDNode*> WorkList;
70
Jim Laskeyc7c3f112006-10-16 20:52:31 +000071 // AA - Used for DAG load/store alias analysis.
72 AliasAnalysis &AA;
73
Nate Begeman1d4d4142005-09-01 00:19:25 +000074 /// AddUsersToWorkList - When an instruction is simplified, add all users of
75 /// the instruction to the work lists because they might get more simplified
76 /// now.
77 ///
78 void AddUsersToWorkList(SDNode *N) {
79 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
Nate Begeman4ebd8052005-09-01 23:24:04 +000080 UI != UE; ++UI)
Jim Laskey6ff23e52006-10-04 16:53:27 +000081 AddToWorkList(*UI);
Nate Begeman1d4d4142005-09-01 00:19:25 +000082 }
83
Dan Gohman389079b2007-10-08 17:57:15 +000084 /// visit - call the node-specific routine that knows how to fold each
85 /// particular type of node.
86 SDOperand visit(SDNode *N);
87
Chris Lattner24664722006-03-01 04:53:38 +000088 public:
Jim Laskey6ff23e52006-10-04 16:53:27 +000089 /// AddToWorkList - Add to the work list making sure it's instance is at the
90 /// the back (next to be processed.)
Chris Lattner5750df92006-03-01 04:03:14 +000091 void AddToWorkList(SDNode *N) {
Jim Laskey6ff23e52006-10-04 16:53:27 +000092 removeFromWorkList(N);
Chris Lattner5750df92006-03-01 04:03:14 +000093 WorkList.push_back(N);
94 }
Jim Laskey6ff23e52006-10-04 16:53:27 +000095
Chris Lattnerf8dc0612008-02-03 06:49:24 +000096 /// removeFromWorkList - remove all instances of N from the worklist.
97 ///
98 void removeFromWorkList(SDNode *N) {
99 WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
100 WorkList.end());
Chris Lattner01a22022005-10-10 22:04:48 +0000101 }
Nate Begeman368e18d2006-02-16 21:11:51 +0000102
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000103 SDOperand CombineTo(SDNode *N, const SDOperand *To, unsigned NumTo,
104 bool AddTo = true);
105
Jim Laskey274062c2006-10-13 23:32:28 +0000106 SDOperand CombineTo(SDNode *N, SDOperand Res, bool AddTo = true) {
107 return CombineTo(N, &Res, 1, AddTo);
Chris Lattner24664722006-03-01 04:53:38 +0000108 }
109
Jim Laskey274062c2006-10-13 23:32:28 +0000110 SDOperand CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1,
111 bool AddTo = true) {
Chris Lattner3577e382006-08-11 17:56:38 +0000112 SDOperand To[] = { Res0, Res1 };
Jim Laskey274062c2006-10-13 23:32:28 +0000113 return CombineTo(N, To, 2, AddTo);
Chris Lattner24664722006-03-01 04:53:38 +0000114 }
Chris Lattner0bd48932008-01-17 07:00:52 +0000115
Chris Lattner24664722006-03-01 04:53:38 +0000116 private:
117
Chris Lattner012f2412006-02-17 21:58:01 +0000118 /// SimplifyDemandedBits - Check the specified integer node value to see if
Chris Lattnerb2742f42006-03-01 19:55:35 +0000119 /// it can be simplified or if things it uses can be simplified by bit
Chris Lattner012f2412006-02-17 21:58:01 +0000120 /// propagation. If so, return true.
Dan Gohman7b8d4a92008-02-27 00:25:32 +0000121 bool SimplifyDemandedBits(SDOperand Op) {
122 APInt Demanded = APInt::getAllOnesValue(Op.getValueSizeInBits());
123 return SimplifyDemandedBits(Op, Demanded);
124 }
125
126 bool SimplifyDemandedBits(SDOperand Op, const APInt &Demanded);
Chris Lattner87514ca2005-10-10 22:31:19 +0000127
Chris Lattner448f2192006-11-11 00:39:41 +0000128 bool CombineToPreIndexedLoadStore(SDNode *N);
129 bool CombineToPostIndexedLoadStore(SDNode *N);
130
131
Dan Gohman389079b2007-10-08 17:57:15 +0000132 /// combine - call the node-specific routine that knows how to fold each
133 /// particular type of node. If that doesn't do anything, try the
134 /// target-specific DAG combines.
135 SDOperand combine(SDNode *N);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000136
137 // Visitation implementation - Implement dag node combining for different
138 // node types. The semantics are as follows:
139 // Return Value:
Nate Begeman2300f552005-09-07 00:15:36 +0000140 // SDOperand.Val == 0 - No change was made
Chris Lattner01a22022005-10-10 22:04:48 +0000141 // SDOperand.Val == N - N was replaced, is dead, and is already handled.
Nate Begeman2300f552005-09-07 00:15:36 +0000142 // otherwise - N should be replaced by the returned Operand.
Nate Begeman1d4d4142005-09-01 00:19:25 +0000143 //
Nate Begeman83e75ec2005-09-06 04:43:02 +0000144 SDOperand visitTokenFactor(SDNode *N);
Chris Lattnerfec42eb2008-02-13 07:25:05 +0000145 SDOperand visitMERGE_VALUES(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000146 SDOperand visitADD(SDNode *N);
147 SDOperand visitSUB(SDNode *N);
Chris Lattner91153682007-03-04 20:03:15 +0000148 SDOperand visitADDC(SDNode *N);
149 SDOperand visitADDE(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000150 SDOperand visitMUL(SDNode *N);
151 SDOperand visitSDIV(SDNode *N);
152 SDOperand visitUDIV(SDNode *N);
153 SDOperand visitSREM(SDNode *N);
154 SDOperand visitUREM(SDNode *N);
155 SDOperand visitMULHU(SDNode *N);
156 SDOperand visitMULHS(SDNode *N);
Dan Gohman389079b2007-10-08 17:57:15 +0000157 SDOperand visitSMUL_LOHI(SDNode *N);
158 SDOperand visitUMUL_LOHI(SDNode *N);
159 SDOperand visitSDIVREM(SDNode *N);
160 SDOperand visitUDIVREM(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000161 SDOperand visitAND(SDNode *N);
162 SDOperand visitOR(SDNode *N);
163 SDOperand visitXOR(SDNode *N);
Dan Gohman7f321562007-06-25 16:23:39 +0000164 SDOperand SimplifyVBinOp(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000165 SDOperand visitSHL(SDNode *N);
166 SDOperand visitSRA(SDNode *N);
167 SDOperand visitSRL(SDNode *N);
168 SDOperand visitCTLZ(SDNode *N);
169 SDOperand visitCTTZ(SDNode *N);
170 SDOperand visitCTPOP(SDNode *N);
Nate Begeman452d7be2005-09-16 00:54:12 +0000171 SDOperand visitSELECT(SDNode *N);
172 SDOperand visitSELECT_CC(SDNode *N);
173 SDOperand visitSETCC(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000174 SDOperand visitSIGN_EXTEND(SDNode *N);
175 SDOperand visitZERO_EXTEND(SDNode *N);
Chris Lattner5ffc0662006-05-05 05:58:59 +0000176 SDOperand visitANY_EXTEND(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000177 SDOperand visitSIGN_EXTEND_INREG(SDNode *N);
178 SDOperand visitTRUNCATE(SDNode *N);
Chris Lattner94683772005-12-23 05:30:37 +0000179 SDOperand visitBIT_CONVERT(SDNode *N);
Chris Lattner01b3d732005-09-28 22:28:18 +0000180 SDOperand visitFADD(SDNode *N);
181 SDOperand visitFSUB(SDNode *N);
182 SDOperand visitFMUL(SDNode *N);
183 SDOperand visitFDIV(SDNode *N);
184 SDOperand visitFREM(SDNode *N);
Chris Lattner12d83032006-03-05 05:30:57 +0000185 SDOperand visitFCOPYSIGN(SDNode *N);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000186 SDOperand visitSINT_TO_FP(SDNode *N);
187 SDOperand visitUINT_TO_FP(SDNode *N);
188 SDOperand visitFP_TO_SINT(SDNode *N);
189 SDOperand visitFP_TO_UINT(SDNode *N);
190 SDOperand visitFP_ROUND(SDNode *N);
191 SDOperand visitFP_ROUND_INREG(SDNode *N);
192 SDOperand visitFP_EXTEND(SDNode *N);
193 SDOperand visitFNEG(SDNode *N);
194 SDOperand visitFABS(SDNode *N);
Nate Begeman452d7be2005-09-16 00:54:12 +0000195 SDOperand visitBRCOND(SDNode *N);
Nate Begeman44728a72005-09-19 22:34:01 +0000196 SDOperand visitBR_CC(SDNode *N);
Chris Lattner01a22022005-10-10 22:04:48 +0000197 SDOperand visitLOAD(SDNode *N);
Chris Lattner87514ca2005-10-10 22:31:19 +0000198 SDOperand visitSTORE(SDNode *N);
Chris Lattnerca242442006-03-19 01:27:56 +0000199 SDOperand visitINSERT_VECTOR_ELT(SDNode *N);
Evan Cheng513da432007-10-06 08:19:55 +0000200 SDOperand visitEXTRACT_VECTOR_ELT(SDNode *N);
Dan Gohman7f321562007-06-25 16:23:39 +0000201 SDOperand visitBUILD_VECTOR(SDNode *N);
202 SDOperand visitCONCAT_VECTORS(SDNode *N);
Chris Lattner66445d32006-03-28 22:11:53 +0000203 SDOperand visitVECTOR_SHUFFLE(SDNode *N);
Chris Lattner01a22022005-10-10 22:04:48 +0000204
Evan Cheng44f1f092006-04-20 08:56:16 +0000205 SDOperand XformToShuffleWithZero(SDNode *N);
Nate Begemancd4d58c2006-02-03 06:46:56 +0000206 SDOperand ReassociateOps(unsigned Opc, SDOperand LHS, SDOperand RHS);
207
Chris Lattnere70da202007-12-06 07:33:36 +0000208 SDOperand visitShiftByConstant(SDNode *N, unsigned Amt);
209
Chris Lattner40c62d52005-10-18 06:04:22 +0000210 bool SimplifySelectOps(SDNode *SELECT, SDOperand LHS, SDOperand RHS);
Chris Lattner35e5c142006-05-05 05:51:50 +0000211 SDOperand SimplifyBinOpWithSameOpcodeHands(SDNode *N);
Nate Begeman44728a72005-09-19 22:34:01 +0000212 SDOperand SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2);
213 SDOperand SimplifySelectCC(SDOperand N0, SDOperand N1, SDOperand N2,
Chris Lattner1eba01e2007-04-11 06:50:51 +0000214 SDOperand N3, ISD::CondCode CC,
215 bool NotExtCompare = false);
Nate Begeman452d7be2005-09-16 00:54:12 +0000216 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
Nate Begemane17daeb2005-10-05 21:43:42 +0000217 ISD::CondCode Cond, bool foldBooleans = true);
Chris Lattner5eee4272008-01-26 01:09:19 +0000218 SDOperand SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
219 unsigned HiOp);
Dan Gohman7f321562007-06-25 16:23:39 +0000220 SDOperand ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *, MVT::ValueType);
Nate Begeman69575232005-10-20 02:15:44 +0000221 SDOperand BuildSDIV(SDNode *N);
Chris Lattner516b9622006-09-14 20:50:57 +0000222 SDOperand BuildUDIV(SDNode *N);
223 SDNode *MatchRotate(SDOperand LHS, SDOperand RHS);
Evan Chengc88138f2007-03-22 01:54:19 +0000224 SDOperand ReduceLoadWidth(SDNode *N);
Jim Laskey279f0532006-09-25 16:29:54 +0000225
Dan Gohman2e68b6f2008-02-25 21:11:39 +0000226 SDOperand GetDemandedBits(SDOperand V, const APInt &Mask);
Chris Lattner2b4c2792007-10-13 06:35:54 +0000227
Jim Laskey6ff23e52006-10-04 16:53:27 +0000228 /// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
229 /// looking for aliasing nodes and adding them to the Aliases vector.
Jim Laskeybc588b82006-10-05 15:07:25 +0000230 void GatherAllAliases(SDNode *N, SDOperand OriginalChain,
Jim Laskey6ff23e52006-10-04 16:53:27 +0000231 SmallVector<SDOperand, 8> &Aliases);
232
Jim Laskey096c22e2006-10-18 12:29:57 +0000233 /// isAlias - Return true if there is any possibility that the two addresses
234 /// overlap.
235 bool isAlias(SDOperand Ptr1, int64_t Size1,
236 const Value *SrcValue1, int SrcValueOffset1,
237 SDOperand Ptr2, int64_t Size2,
Jeff Cohend41b30d2006-11-05 19:31:28 +0000238 const Value *SrcValue2, int SrcValueOffset2);
Jim Laskey096c22e2006-10-18 12:29:57 +0000239
Jim Laskey7ca56af2006-10-11 13:47:09 +0000240 /// FindAliasInfo - Extracts the relevant alias information from the memory
241 /// node. Returns true if the operand was a load.
242 bool FindAliasInfo(SDNode *N,
Jim Laskey096c22e2006-10-18 12:29:57 +0000243 SDOperand &Ptr, int64_t &Size,
244 const Value *&SrcValue, int &SrcValueOffset);
Jim Laskey7ca56af2006-10-11 13:47:09 +0000245
Jim Laskey279f0532006-09-25 16:29:54 +0000246 /// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
Jim Laskey6ff23e52006-10-04 16:53:27 +0000247 /// looking for a better chain (aliasing node.)
Jim Laskey279f0532006-09-25 16:29:54 +0000248 SDOperand FindBetterChain(SDNode *N, SDOperand Chain);
249
Nate Begeman1d4d4142005-09-01 00:19:25 +0000250public:
Jim Laskeyc7c3f112006-10-16 20:52:31 +0000251 DAGCombiner(SelectionDAG &D, AliasAnalysis &A)
252 : DAG(D),
253 TLI(D.getTargetLoweringInfo()),
254 AfterLegalize(false),
255 AA(A) {}
Nate Begeman1d4d4142005-09-01 00:19:25 +0000256
257 /// Run - runs the dag combiner on all nodes in the work list
Nate Begeman4ebd8052005-09-01 23:24:04 +0000258 void Run(bool RunningAfterLegalize);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000259 };
260}
261
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000262
263namespace {
264/// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
265/// nodes from the worklist.
266class VISIBILITY_HIDDEN WorkListRemover :
267 public SelectionDAG::DAGUpdateListener {
268 DAGCombiner &DC;
269public:
Dan Gohmanb5660dc2008-02-20 16:44:09 +0000270 explicit WorkListRemover(DAGCombiner &dc) : DC(dc) {}
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000271
272 virtual void NodeDeleted(SDNode *N) {
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000273 DC.removeFromWorkList(N);
274 }
275
276 virtual void NodeUpdated(SDNode *N) {
277 // Ignore updates.
278 }
279};
280}
281
Chris Lattner24664722006-03-01 04:53:38 +0000282//===----------------------------------------------------------------------===//
283// TargetLowering::DAGCombinerInfo implementation
284//===----------------------------------------------------------------------===//
285
286void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
287 ((DAGCombiner*)DC)->AddToWorkList(N);
288}
289
290SDOperand TargetLowering::DAGCombinerInfo::
291CombineTo(SDNode *N, const std::vector<SDOperand> &To) {
Chris Lattner3577e382006-08-11 17:56:38 +0000292 return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size());
Chris Lattner24664722006-03-01 04:53:38 +0000293}
294
295SDOperand TargetLowering::DAGCombinerInfo::
296CombineTo(SDNode *N, SDOperand Res) {
297 return ((DAGCombiner*)DC)->CombineTo(N, Res);
298}
299
300
301SDOperand TargetLowering::DAGCombinerInfo::
302CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1) {
303 return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
304}
305
306
Chris Lattner24664722006-03-01 04:53:38 +0000307//===----------------------------------------------------------------------===//
Chris Lattner29446522007-05-14 22:04:50 +0000308// Helper Functions
309//===----------------------------------------------------------------------===//
310
311/// isNegatibleForFree - Return 1 if we can compute the negated form of the
312/// specified expression for the same cost as the expression itself, or 2 if we
313/// can compute the negated form more cheaply than the expression itself.
Chris Lattner0254e702008-02-26 07:04:54 +0000314static char isNegatibleForFree(SDOperand Op, bool AfterLegalize,
315 unsigned Depth = 0) {
Dale Johannesendb44bf82007-10-16 23:38:29 +0000316 // No compile time optimizations on this type.
317 if (Op.getValueType() == MVT::ppcf128)
318 return 0;
319
Chris Lattner29446522007-05-14 22:04:50 +0000320 // fneg is removable even if it has multiple uses.
321 if (Op.getOpcode() == ISD::FNEG) return 2;
322
323 // Don't allow anything with multiple uses.
324 if (!Op.hasOneUse()) return 0;
325
Chris Lattner3adf9512007-05-25 02:19:06 +0000326 // Don't recurse exponentially.
327 if (Depth > 6) return 0;
328
Chris Lattner29446522007-05-14 22:04:50 +0000329 switch (Op.getOpcode()) {
330 default: return false;
331 case ISD::ConstantFP:
Chris Lattner0254e702008-02-26 07:04:54 +0000332 // Don't invert constant FP values after legalize. The negated constant
333 // isn't necessarily legal.
334 return AfterLegalize ? 0 : 1;
Chris Lattner29446522007-05-14 22:04:50 +0000335 case ISD::FADD:
336 // FIXME: determine better conditions for this xform.
337 if (!UnsafeFPMath) return 0;
338
339 // -(A+B) -> -A - B
Chris Lattner0254e702008-02-26 07:04:54 +0000340 if (char V = isNegatibleForFree(Op.getOperand(0), AfterLegalize, Depth+1))
Chris Lattner29446522007-05-14 22:04:50 +0000341 return V;
342 // -(A+B) -> -B - A
Chris Lattner0254e702008-02-26 07:04:54 +0000343 return isNegatibleForFree(Op.getOperand(1), AfterLegalize, Depth+1);
Chris Lattner29446522007-05-14 22:04:50 +0000344 case ISD::FSUB:
345 // We can't turn -(A-B) into B-A when we honor signed zeros.
346 if (!UnsafeFPMath) return 0;
347
348 // -(A-B) -> B-A
349 return 1;
350
351 case ISD::FMUL:
352 case ISD::FDIV:
353 if (HonorSignDependentRoundingFPMath()) return 0;
354
355 // -(X*Y) -> (-X * Y) or (X*-Y)
Chris Lattner0254e702008-02-26 07:04:54 +0000356 if (char V = isNegatibleForFree(Op.getOperand(0), AfterLegalize, Depth+1))
Chris Lattner29446522007-05-14 22:04:50 +0000357 return V;
358
Chris Lattner0254e702008-02-26 07:04:54 +0000359 return isNegatibleForFree(Op.getOperand(1), AfterLegalize, Depth+1);
Chris Lattner29446522007-05-14 22:04:50 +0000360
361 case ISD::FP_EXTEND:
362 case ISD::FP_ROUND:
363 case ISD::FSIN:
Chris Lattner0254e702008-02-26 07:04:54 +0000364 return isNegatibleForFree(Op.getOperand(0), AfterLegalize, Depth+1);
Chris Lattner29446522007-05-14 22:04:50 +0000365 }
366}
367
368/// GetNegatedExpression - If isNegatibleForFree returns true, this function
369/// returns the newly negated expression.
Chris Lattner3adf9512007-05-25 02:19:06 +0000370static SDOperand GetNegatedExpression(SDOperand Op, SelectionDAG &DAG,
Chris Lattner0254e702008-02-26 07:04:54 +0000371 bool AfterLegalize, unsigned Depth = 0) {
Chris Lattner29446522007-05-14 22:04:50 +0000372 // fneg is removable even if it has multiple uses.
373 if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
374
375 // Don't allow anything with multiple uses.
376 assert(Op.hasOneUse() && "Unknown reuse!");
377
Chris Lattner3adf9512007-05-25 02:19:06 +0000378 assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
Chris Lattner29446522007-05-14 22:04:50 +0000379 switch (Op.getOpcode()) {
380 default: assert(0 && "Unknown code");
Dale Johannesenc4dd3c32007-08-31 23:34:27 +0000381 case ISD::ConstantFP: {
382 APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
383 V.changeSign();
384 return DAG.getConstantFP(V, Op.getValueType());
385 }
Chris Lattner29446522007-05-14 22:04:50 +0000386 case ISD::FADD:
387 // FIXME: determine better conditions for this xform.
388 assert(UnsafeFPMath);
389
390 // -(A+B) -> -A - B
Chris Lattner0254e702008-02-26 07:04:54 +0000391 if (isNegatibleForFree(Op.getOperand(0), AfterLegalize, Depth+1))
Chris Lattner29446522007-05-14 22:04:50 +0000392 return DAG.getNode(ISD::FSUB, Op.getValueType(),
Chris Lattner0254e702008-02-26 07:04:54 +0000393 GetNegatedExpression(Op.getOperand(0), DAG,
394 AfterLegalize, Depth+1),
Chris Lattner29446522007-05-14 22:04:50 +0000395 Op.getOperand(1));
396 // -(A+B) -> -B - A
397 return DAG.getNode(ISD::FSUB, Op.getValueType(),
Chris Lattner0254e702008-02-26 07:04:54 +0000398 GetNegatedExpression(Op.getOperand(1), DAG,
399 AfterLegalize, Depth+1),
Chris Lattner29446522007-05-14 22:04:50 +0000400 Op.getOperand(0));
401 case ISD::FSUB:
402 // We can't turn -(A-B) into B-A when we honor signed zeros.
403 assert(UnsafeFPMath);
Dan Gohman23ff1822007-07-02 15:48:56 +0000404
405 // -(0-B) -> B
406 if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
Dale Johannesenc4dd3c32007-08-31 23:34:27 +0000407 if (N0CFP->getValueAPF().isZero())
Dan Gohman23ff1822007-07-02 15:48:56 +0000408 return Op.getOperand(1);
Chris Lattner29446522007-05-14 22:04:50 +0000409
410 // -(A-B) -> B-A
411 return DAG.getNode(ISD::FSUB, Op.getValueType(), Op.getOperand(1),
412 Op.getOperand(0));
413
414 case ISD::FMUL:
415 case ISD::FDIV:
416 assert(!HonorSignDependentRoundingFPMath());
417
418 // -(X*Y) -> -X * Y
Chris Lattneraeecb6c2008-02-26 17:09:59 +0000419 if (isNegatibleForFree(Op.getOperand(0), AfterLegalize, Depth+1))
Chris Lattner29446522007-05-14 22:04:50 +0000420 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
Chris Lattner0254e702008-02-26 07:04:54 +0000421 GetNegatedExpression(Op.getOperand(0), DAG,
422 AfterLegalize, Depth+1),
Chris Lattner29446522007-05-14 22:04:50 +0000423 Op.getOperand(1));
424
425 // -(X*Y) -> X * -Y
426 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
427 Op.getOperand(0),
Chris Lattner0254e702008-02-26 07:04:54 +0000428 GetNegatedExpression(Op.getOperand(1), DAG,
429 AfterLegalize, Depth+1));
Chris Lattner29446522007-05-14 22:04:50 +0000430
431 case ISD::FP_EXTEND:
Chris Lattner29446522007-05-14 22:04:50 +0000432 case ISD::FSIN:
433 return DAG.getNode(Op.getOpcode(), Op.getValueType(),
Chris Lattner0254e702008-02-26 07:04:54 +0000434 GetNegatedExpression(Op.getOperand(0), DAG,
435 AfterLegalize, Depth+1));
Chris Lattner0bd48932008-01-17 07:00:52 +0000436 case ISD::FP_ROUND:
437 return DAG.getNode(ISD::FP_ROUND, Op.getValueType(),
Chris Lattner0254e702008-02-26 07:04:54 +0000438 GetNegatedExpression(Op.getOperand(0), DAG,
439 AfterLegalize, Depth+1),
Chris Lattner0bd48932008-01-17 07:00:52 +0000440 Op.getOperand(1));
Chris Lattner29446522007-05-14 22:04:50 +0000441 }
442}
Chris Lattner24664722006-03-01 04:53:38 +0000443
444
Nate Begeman4ebd8052005-09-01 23:24:04 +0000445// isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
446// that selects between the values 1 and 0, making it equivalent to a setcc.
Nate Begeman646d7e22005-09-02 21:18:40 +0000447// Also, set the incoming LHS, RHS, and CC references to the appropriate
448// nodes based on the type of node we are checking. This simplifies life a
449// bit for the callers.
450static bool isSetCCEquivalent(SDOperand N, SDOperand &LHS, SDOperand &RHS,
451 SDOperand &CC) {
452 if (N.getOpcode() == ISD::SETCC) {
453 LHS = N.getOperand(0);
454 RHS = N.getOperand(1);
455 CC = N.getOperand(2);
Nate Begeman4ebd8052005-09-01 23:24:04 +0000456 return true;
Nate Begeman646d7e22005-09-02 21:18:40 +0000457 }
Nate Begeman1d4d4142005-09-01 00:19:25 +0000458 if (N.getOpcode() == ISD::SELECT_CC &&
459 N.getOperand(2).getOpcode() == ISD::Constant &&
460 N.getOperand(3).getOpcode() == ISD::Constant &&
Dan Gohman002e5d02008-03-13 22:13:53 +0000461 cast<ConstantSDNode>(N.getOperand(2))->getAPIntValue() == 1 &&
Nate Begeman646d7e22005-09-02 21:18:40 +0000462 cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
463 LHS = N.getOperand(0);
464 RHS = N.getOperand(1);
465 CC = N.getOperand(4);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000466 return true;
Nate Begeman646d7e22005-09-02 21:18:40 +0000467 }
Nate Begeman1d4d4142005-09-01 00:19:25 +0000468 return false;
469}
470
Nate Begeman99801192005-09-07 23:25:52 +0000471// isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
472// one use. If this is true, it allows the users to invert the operation for
473// free when it is profitable to do so.
474static bool isOneUseSetCC(SDOperand N) {
Nate Begeman646d7e22005-09-02 21:18:40 +0000475 SDOperand N0, N1, N2;
Nate Begeman646d7e22005-09-02 21:18:40 +0000476 if (isSetCCEquivalent(N, N0, N1, N2) && N.Val->hasOneUse())
Nate Begeman4ebd8052005-09-01 23:24:04 +0000477 return true;
478 return false;
479}
480
Nate Begemancd4d58c2006-02-03 06:46:56 +0000481SDOperand DAGCombiner::ReassociateOps(unsigned Opc, SDOperand N0, SDOperand N1){
482 MVT::ValueType VT = N0.getValueType();
483 // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
484 // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
485 if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
486 if (isa<ConstantSDNode>(N1)) {
487 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(1), N1);
Chris Lattner5750df92006-03-01 04:03:14 +0000488 AddToWorkList(OpNode.Val);
Nate Begemancd4d58c2006-02-03 06:46:56 +0000489 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(0));
490 } else if (N0.hasOneUse()) {
491 SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(0), N1);
Chris Lattner5750df92006-03-01 04:03:14 +0000492 AddToWorkList(OpNode.Val);
Nate Begemancd4d58c2006-02-03 06:46:56 +0000493 return DAG.getNode(Opc, VT, OpNode, N0.getOperand(1));
494 }
495 }
496 // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
497 // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
498 if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
499 if (isa<ConstantSDNode>(N0)) {
500 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(1), N0);
Chris Lattner5750df92006-03-01 04:03:14 +0000501 AddToWorkList(OpNode.Val);
Nate Begemancd4d58c2006-02-03 06:46:56 +0000502 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(0));
503 } else if (N1.hasOneUse()) {
504 SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(0), N0);
Chris Lattner5750df92006-03-01 04:03:14 +0000505 AddToWorkList(OpNode.Val);
Nate Begemancd4d58c2006-02-03 06:46:56 +0000506 return DAG.getNode(Opc, VT, OpNode, N1.getOperand(1));
507 }
508 }
509 return SDOperand();
510}
511
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000512SDOperand DAGCombiner::CombineTo(SDNode *N, const SDOperand *To, unsigned NumTo,
513 bool AddTo) {
514 assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
515 ++NodesCombined;
516 DOUT << "\nReplacing.1 "; DEBUG(N->dump(&DAG));
517 DOUT << "\nWith: "; DEBUG(To[0].Val->dump(&DAG));
518 DOUT << " and " << NumTo-1 << " other values\n";
519 WorkListRemover DeadNodes(*this);
520 DAG.ReplaceAllUsesWith(N, To, &DeadNodes);
521
522 if (AddTo) {
523 // Push the new nodes and any users onto the worklist
524 for (unsigned i = 0, e = NumTo; i != e; ++i) {
525 AddToWorkList(To[i].Val);
526 AddUsersToWorkList(To[i].Val);
527 }
528 }
529
530 // Nodes can be reintroduced into the worklist. Make sure we do not
531 // process a node that has been replaced.
532 removeFromWorkList(N);
533
534 // Finally, since the node is now dead, remove it from the graph.
535 DAG.DeleteNode(N);
536 return SDOperand(N, 0);
537}
538
539/// SimplifyDemandedBits - Check the specified integer node value to see if
540/// it can be simplified or if things it uses can be simplified by bit
541/// propagation. If so, return true.
Dan Gohman7b8d4a92008-02-27 00:25:32 +0000542bool DAGCombiner::SimplifyDemandedBits(SDOperand Op, const APInt &Demanded) {
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000543 TargetLowering::TargetLoweringOpt TLO(DAG, AfterLegalize);
Dan Gohman7b8d4a92008-02-27 00:25:32 +0000544 APInt KnownZero, KnownOne;
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000545 if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
546 return false;
547
548 // Revisit the node.
549 AddToWorkList(Op.Val);
550
551 // Replace the old value with the new one.
552 ++NodesCombined;
553 DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.Val->dump(&DAG));
554 DOUT << "\nWith: "; DEBUG(TLO.New.Val->dump(&DAG));
555 DOUT << '\n';
556
557 // Replace all uses. If any nodes become isomorphic to other nodes and
558 // are deleted, make sure to remove them from our worklist.
559 WorkListRemover DeadNodes(*this);
560 DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
561
562 // Push the new node and any (possibly new) users onto the worklist.
563 AddToWorkList(TLO.New.Val);
564 AddUsersToWorkList(TLO.New.Val);
565
566 // Finally, if the node is now dead, remove it from the graph. The node
567 // may not be dead if the replacement process recursively simplified to
568 // something else needing this node.
569 if (TLO.Old.Val->use_empty()) {
570 removeFromWorkList(TLO.Old.Val);
571
572 // If the operands of this node are only used by the node, they will now
573 // be dead. Make sure to visit them first to delete dead nodes early.
574 for (unsigned i = 0, e = TLO.Old.Val->getNumOperands(); i != e; ++i)
575 if (TLO.Old.Val->getOperand(i).Val->hasOneUse())
576 AddToWorkList(TLO.Old.Val->getOperand(i).Val);
577
578 DAG.DeleteNode(TLO.Old.Val);
579 }
580 return true;
581}
582
Chris Lattner29446522007-05-14 22:04:50 +0000583//===----------------------------------------------------------------------===//
584// Main DAG Combiner implementation
585//===----------------------------------------------------------------------===//
586
Nate Begeman4ebd8052005-09-01 23:24:04 +0000587void DAGCombiner::Run(bool RunningAfterLegalize) {
588 // set the instance variable, so that the various visit routines may use it.
589 AfterLegalize = RunningAfterLegalize;
590
Nate Begeman646d7e22005-09-02 21:18:40 +0000591 // Add all the dag nodes to the worklist.
Chris Lattnerde202b32005-11-09 23:47:37 +0000592 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
593 E = DAG.allnodes_end(); I != E; ++I)
594 WorkList.push_back(I);
Nate Begeman83e75ec2005-09-06 04:43:02 +0000595
Chris Lattner95038592005-10-05 06:35:28 +0000596 // Create a dummy node (which is not added to allnodes), that adds a reference
597 // to the root node, preventing it from being deleted, and tracking any
598 // changes of the root.
599 HandleSDNode Dummy(DAG.getRoot());
600
Jim Laskey26f7fa72006-10-17 19:33:52 +0000601 // The root of the dag may dangle to deleted nodes until the dag combiner is
602 // done. Set it to null to avoid confusion.
603 DAG.setRoot(SDOperand());
Chris Lattner24664722006-03-01 04:53:38 +0000604
Nate Begeman1d4d4142005-09-01 00:19:25 +0000605 // while the worklist isn't empty, inspect the node on the end of it and
606 // try and combine it.
607 while (!WorkList.empty()) {
608 SDNode *N = WorkList.back();
609 WorkList.pop_back();
610
611 // If N has no uses, it is dead. Make sure to revisit all N's operands once
Chris Lattner95038592005-10-05 06:35:28 +0000612 // N is deleted from the DAG, since they too may now be dead or may have a
613 // reduced number of uses, allowing other xforms.
614 if (N->use_empty() && N != &Dummy) {
Nate Begeman1d4d4142005-09-01 00:19:25 +0000615 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
Jim Laskey6ff23e52006-10-04 16:53:27 +0000616 AddToWorkList(N->getOperand(i).Val);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000617
Chris Lattner95038592005-10-05 06:35:28 +0000618 DAG.DeleteNode(N);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000619 continue;
620 }
621
Dan Gohman389079b2007-10-08 17:57:15 +0000622 SDOperand RV = combine(N);
Chris Lattner24664722006-03-01 04:53:38 +0000623
Chris Lattner50d8e492008-01-25 23:34:24 +0000624 if (RV.Val == 0)
625 continue;
626
627 ++NodesCombined;
Chris Lattner5eee4272008-01-26 01:09:19 +0000628
Chris Lattner50d8e492008-01-25 23:34:24 +0000629 // If we get back the same node we passed in, rather than a new node or
630 // zero, we know that the node must have defined multiple values and
631 // CombineTo was used. Since CombineTo takes care of the worklist
632 // mechanics for us, we have no work to do in this case.
633 if (RV.Val == N)
634 continue;
635
636 assert(N->getOpcode() != ISD::DELETED_NODE &&
637 RV.Val->getOpcode() != ISD::DELETED_NODE &&
638 "Node was deleted but visit returned new node!");
Chris Lattner729c6d12006-05-27 00:43:02 +0000639
Chris Lattner50d8e492008-01-25 23:34:24 +0000640 DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
641 DOUT << "\nWith: "; DEBUG(RV.Val->dump(&DAG));
642 DOUT << '\n';
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000643 WorkListRemover DeadNodes(*this);
Chris Lattner50d8e492008-01-25 23:34:24 +0000644 if (N->getNumValues() == RV.Val->getNumValues())
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000645 DAG.ReplaceAllUsesWith(N, RV.Val, &DeadNodes);
Chris Lattner50d8e492008-01-25 23:34:24 +0000646 else {
Chris Lattner5eee4272008-01-26 01:09:19 +0000647 assert(N->getValueType(0) == RV.getValueType() &&
648 N->getNumValues() == 1 && "Type mismatch");
Chris Lattner50d8e492008-01-25 23:34:24 +0000649 SDOperand OpV = RV;
Chris Lattnerf8dc0612008-02-03 06:49:24 +0000650 DAG.ReplaceAllUsesWith(N, &OpV, &DeadNodes);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000651 }
Chris Lattner50d8e492008-01-25 23:34:24 +0000652
653 // Push the new node and any users onto the worklist
654 AddToWorkList(RV.Val);
655 AddUsersToWorkList(RV.Val);
656
657 // Add any uses of the old node to the worklist in case this node is the
658 // last one that uses them. They may become dead after this node is
659 // deleted.
660 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
661 AddToWorkList(N->getOperand(i).Val);
662
663 // Nodes can be reintroduced into the worklist. Make sure we do not
664 // process a node that has been replaced.
665 removeFromWorkList(N);
Chris Lattner50d8e492008-01-25 23:34:24 +0000666
667 // Finally, since the node is now dead, remove it from the graph.
668 DAG.DeleteNode(N);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000669 }
Chris Lattner95038592005-10-05 06:35:28 +0000670
671 // If the root changed (e.g. it was a dead load, update the root).
672 DAG.setRoot(Dummy.getValue());
Nate Begeman1d4d4142005-09-01 00:19:25 +0000673}
674
Nate Begeman83e75ec2005-09-06 04:43:02 +0000675SDOperand DAGCombiner::visit(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +0000676 switch(N->getOpcode()) {
677 default: break;
Nate Begeman4942a962005-09-01 00:33:32 +0000678 case ISD::TokenFactor: return visitTokenFactor(N);
Chris Lattnerfec42eb2008-02-13 07:25:05 +0000679 case ISD::MERGE_VALUES: return visitMERGE_VALUES(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000680 case ISD::ADD: return visitADD(N);
681 case ISD::SUB: return visitSUB(N);
Chris Lattner91153682007-03-04 20:03:15 +0000682 case ISD::ADDC: return visitADDC(N);
683 case ISD::ADDE: return visitADDE(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000684 case ISD::MUL: return visitMUL(N);
685 case ISD::SDIV: return visitSDIV(N);
686 case ISD::UDIV: return visitUDIV(N);
687 case ISD::SREM: return visitSREM(N);
688 case ISD::UREM: return visitUREM(N);
689 case ISD::MULHU: return visitMULHU(N);
690 case ISD::MULHS: return visitMULHS(N);
Dan Gohman389079b2007-10-08 17:57:15 +0000691 case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
692 case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
693 case ISD::SDIVREM: return visitSDIVREM(N);
694 case ISD::UDIVREM: return visitUDIVREM(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000695 case ISD::AND: return visitAND(N);
696 case ISD::OR: return visitOR(N);
697 case ISD::XOR: return visitXOR(N);
698 case ISD::SHL: return visitSHL(N);
699 case ISD::SRA: return visitSRA(N);
700 case ISD::SRL: return visitSRL(N);
701 case ISD::CTLZ: return visitCTLZ(N);
702 case ISD::CTTZ: return visitCTTZ(N);
703 case ISD::CTPOP: return visitCTPOP(N);
Nate Begeman452d7be2005-09-16 00:54:12 +0000704 case ISD::SELECT: return visitSELECT(N);
705 case ISD::SELECT_CC: return visitSELECT_CC(N);
706 case ISD::SETCC: return visitSETCC(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000707 case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
708 case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
Chris Lattner5ffc0662006-05-05 05:58:59 +0000709 case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000710 case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
711 case ISD::TRUNCATE: return visitTRUNCATE(N);
Chris Lattner94683772005-12-23 05:30:37 +0000712 case ISD::BIT_CONVERT: return visitBIT_CONVERT(N);
Chris Lattner01b3d732005-09-28 22:28:18 +0000713 case ISD::FADD: return visitFADD(N);
714 case ISD::FSUB: return visitFSUB(N);
715 case ISD::FMUL: return visitFMUL(N);
716 case ISD::FDIV: return visitFDIV(N);
717 case ISD::FREM: return visitFREM(N);
Chris Lattner12d83032006-03-05 05:30:57 +0000718 case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
Nate Begeman646d7e22005-09-02 21:18:40 +0000719 case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
720 case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
721 case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
722 case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
723 case ISD::FP_ROUND: return visitFP_ROUND(N);
724 case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
725 case ISD::FP_EXTEND: return visitFP_EXTEND(N);
726 case ISD::FNEG: return visitFNEG(N);
727 case ISD::FABS: return visitFABS(N);
Nate Begeman44728a72005-09-19 22:34:01 +0000728 case ISD::BRCOND: return visitBRCOND(N);
Nate Begeman44728a72005-09-19 22:34:01 +0000729 case ISD::BR_CC: return visitBR_CC(N);
Chris Lattner01a22022005-10-10 22:04:48 +0000730 case ISD::LOAD: return visitLOAD(N);
Chris Lattner87514ca2005-10-10 22:31:19 +0000731 case ISD::STORE: return visitSTORE(N);
Chris Lattnerca242442006-03-19 01:27:56 +0000732 case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
Evan Cheng513da432007-10-06 08:19:55 +0000733 case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
Dan Gohman7f321562007-06-25 16:23:39 +0000734 case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
735 case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
Chris Lattner66445d32006-03-28 22:11:53 +0000736 case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000737 }
Nate Begeman83e75ec2005-09-06 04:43:02 +0000738 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +0000739}
740
Dan Gohman389079b2007-10-08 17:57:15 +0000741SDOperand DAGCombiner::combine(SDNode *N) {
742
743 SDOperand RV = visit(N);
744
745 // If nothing happened, try a target-specific DAG combine.
746 if (RV.Val == 0) {
747 assert(N->getOpcode() != ISD::DELETED_NODE &&
748 "Node was deleted but visit returned NULL!");
749
750 if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
751 TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
752
753 // Expose the DAG combiner to the target combiner impls.
754 TargetLowering::DAGCombinerInfo
755 DagCombineInfo(DAG, !AfterLegalize, false, this);
756
757 RV = TLI.PerformDAGCombine(N, DagCombineInfo);
758 }
759 }
760
761 return RV;
762}
763
Chris Lattner6270f682006-10-08 22:57:01 +0000764/// getInputChainForNode - Given a node, return its input chain if it has one,
765/// otherwise return a null sd operand.
766static SDOperand getInputChainForNode(SDNode *N) {
767 if (unsigned NumOps = N->getNumOperands()) {
768 if (N->getOperand(0).getValueType() == MVT::Other)
769 return N->getOperand(0);
770 else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
771 return N->getOperand(NumOps-1);
772 for (unsigned i = 1; i < NumOps-1; ++i)
773 if (N->getOperand(i).getValueType() == MVT::Other)
774 return N->getOperand(i);
775 }
776 return SDOperand(0, 0);
777}
778
Nate Begeman83e75ec2005-09-06 04:43:02 +0000779SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
Chris Lattner6270f682006-10-08 22:57:01 +0000780 // If N has two operands, where one has an input chain equal to the other,
781 // the 'other' chain is redundant.
782 if (N->getNumOperands() == 2) {
783 if (getInputChainForNode(N->getOperand(0).Val) == N->getOperand(1))
784 return N->getOperand(0);
785 if (getInputChainForNode(N->getOperand(1).Val) == N->getOperand(0))
786 return N->getOperand(1);
787 }
788
Chris Lattnerc76d4412007-05-16 06:37:59 +0000789 SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
790 SmallVector<SDOperand, 8> Ops; // Ops for replacing token factor.
791 SmallPtrSet<SDNode*, 16> SeenOps;
792 bool Changed = false; // If we should replace this token factor.
Jim Laskey6ff23e52006-10-04 16:53:27 +0000793
794 // Start out with this token factor.
Jim Laskey279f0532006-09-25 16:29:54 +0000795 TFs.push_back(N);
Jim Laskey279f0532006-09-25 16:29:54 +0000796
Jim Laskey71382342006-10-07 23:37:56 +0000797 // Iterate through token factors. The TFs grows when new token factors are
Jim Laskeybc588b82006-10-05 15:07:25 +0000798 // encountered.
799 for (unsigned i = 0; i < TFs.size(); ++i) {
800 SDNode *TF = TFs[i];
801
Jim Laskey6ff23e52006-10-04 16:53:27 +0000802 // Check each of the operands.
803 for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
804 SDOperand Op = TF->getOperand(i);
Jim Laskey279f0532006-09-25 16:29:54 +0000805
Jim Laskey6ff23e52006-10-04 16:53:27 +0000806 switch (Op.getOpcode()) {
807 case ISD::EntryToken:
Jim Laskeybc588b82006-10-05 15:07:25 +0000808 // Entry tokens don't need to be added to the list. They are
809 // rededundant.
810 Changed = true;
Jim Laskey6ff23e52006-10-04 16:53:27 +0000811 break;
Jim Laskey279f0532006-09-25 16:29:54 +0000812
Jim Laskey6ff23e52006-10-04 16:53:27 +0000813 case ISD::TokenFactor:
Jim Laskeybc588b82006-10-05 15:07:25 +0000814 if ((CombinerAA || Op.hasOneUse()) &&
815 std::find(TFs.begin(), TFs.end(), Op.Val) == TFs.end()) {
Jim Laskey6ff23e52006-10-04 16:53:27 +0000816 // Queue up for processing.
817 TFs.push_back(Op.Val);
818 // Clean up in case the token factor is removed.
819 AddToWorkList(Op.Val);
820 Changed = true;
821 break;
Jim Laskey279f0532006-09-25 16:29:54 +0000822 }
Jim Laskey6ff23e52006-10-04 16:53:27 +0000823 // Fall thru
824
825 default:
Chris Lattnerc76d4412007-05-16 06:37:59 +0000826 // Only add if it isn't already in the list.
827 if (SeenOps.insert(Op.Val))
Jim Laskeybc588b82006-10-05 15:07:25 +0000828 Ops.push_back(Op);
Chris Lattnerc76d4412007-05-16 06:37:59 +0000829 else
830 Changed = true;
Jim Laskey6ff23e52006-10-04 16:53:27 +0000831 break;
Jim Laskey279f0532006-09-25 16:29:54 +0000832 }
833 }
Jim Laskey6ff23e52006-10-04 16:53:27 +0000834 }
835
836 SDOperand Result;
837
838 // If we've change things around then replace token factor.
839 if (Changed) {
Dan Gohman30359592008-01-29 13:02:09 +0000840 if (Ops.empty()) {
Jim Laskey6ff23e52006-10-04 16:53:27 +0000841 // The entry token is the only possible outcome.
842 Result = DAG.getEntryNode();
843 } else {
844 // New and improved token factor.
845 Result = DAG.getNode(ISD::TokenFactor, MVT::Other, &Ops[0], Ops.size());
Nate Begemanded49632005-10-13 03:11:28 +0000846 }
Jim Laskey274062c2006-10-13 23:32:28 +0000847
848 // Don't add users to work list.
849 return CombineTo(N, Result, false);
Nate Begemanded49632005-10-13 03:11:28 +0000850 }
Jim Laskey279f0532006-09-25 16:29:54 +0000851
Jim Laskey6ff23e52006-10-04 16:53:27 +0000852 return Result;
Nate Begeman1d4d4142005-09-01 00:19:25 +0000853}
854
Chris Lattnerfec42eb2008-02-13 07:25:05 +0000855/// MERGE_VALUES can always be eliminated.
856SDOperand DAGCombiner::visitMERGE_VALUES(SDNode *N) {
857 WorkListRemover DeadNodes(*this);
858 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
859 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, i), N->getOperand(i),
860 &DeadNodes);
861 removeFromWorkList(N);
862 DAG.DeleteNode(N);
863 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
864}
865
866
Evan Cheng42d7ccf2007-01-19 17:51:44 +0000867static
868SDOperand combineShlAddConstant(SDOperand N0, SDOperand N1, SelectionDAG &DAG) {
869 MVT::ValueType VT = N0.getValueType();
870 SDOperand N00 = N0.getOperand(0);
871 SDOperand N01 = N0.getOperand(1);
872 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
873 if (N01C && N00.getOpcode() == ISD::ADD && N00.Val->hasOneUse() &&
874 isa<ConstantSDNode>(N00.getOperand(1))) {
875 N0 = DAG.getNode(ISD::ADD, VT,
876 DAG.getNode(ISD::SHL, VT, N00.getOperand(0), N01),
877 DAG.getNode(ISD::SHL, VT, N00.getOperand(1), N01));
878 return DAG.getNode(ISD::ADD, VT, N0, N1);
879 }
880 return SDOperand();
881}
882
Evan Chengb13cdbd2007-06-21 07:39:16 +0000883static
884SDOperand combineSelectAndUse(SDNode *N, SDOperand Slct, SDOperand OtherOp,
885 SelectionDAG &DAG) {
886 MVT::ValueType VT = N->getValueType(0);
887 unsigned Opc = N->getOpcode();
888 bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
889 SDOperand LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
890 SDOperand RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
891 ISD::CondCode CC = ISD::SETCC_INVALID;
892 if (isSlctCC)
893 CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
894 else {
895 SDOperand CCOp = Slct.getOperand(0);
896 if (CCOp.getOpcode() == ISD::SETCC)
897 CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
898 }
899
900 bool DoXform = false;
901 bool InvCC = false;
902 assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
903 "Bad input!");
904 if (LHS.getOpcode() == ISD::Constant &&
905 cast<ConstantSDNode>(LHS)->isNullValue())
906 DoXform = true;
907 else if (CC != ISD::SETCC_INVALID &&
908 RHS.getOpcode() == ISD::Constant &&
909 cast<ConstantSDNode>(RHS)->isNullValue()) {
910 std::swap(LHS, RHS);
Chris Lattner4626b252008-01-17 07:20:38 +0000911 SDOperand Op0 = Slct.getOperand(0);
912 bool isInt = MVT::isInteger(isSlctCC ? Op0.getValueType()
913 : Op0.getOperand(0).getValueType());
Evan Chengb13cdbd2007-06-21 07:39:16 +0000914 CC = ISD::getSetCCInverse(CC, isInt);
915 DoXform = true;
916 InvCC = true;
917 }
918
919 if (DoXform) {
920 SDOperand Result = DAG.getNode(Opc, VT, OtherOp, RHS);
921 if (isSlctCC)
922 return DAG.getSelectCC(OtherOp, Result,
923 Slct.getOperand(0), Slct.getOperand(1), CC);
924 SDOperand CCOp = Slct.getOperand(0);
925 if (InvCC)
926 CCOp = DAG.getSetCC(CCOp.getValueType(), CCOp.getOperand(0),
927 CCOp.getOperand(1), CC);
928 return DAG.getNode(ISD::SELECT, VT, CCOp, OtherOp, Result);
929 }
930 return SDOperand();
931}
932
Nate Begeman83e75ec2005-09-06 04:43:02 +0000933SDOperand DAGCombiner::visitADD(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +0000934 SDOperand N0 = N->getOperand(0);
935 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +0000936 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
937 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begemanf89d78d2005-09-07 16:09:19 +0000938 MVT::ValueType VT = N0.getValueType();
Dan Gohman7f321562007-06-25 16:23:39 +0000939
940 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +0000941 if (MVT::isVector(VT)) {
942 SDOperand FoldedVOp = SimplifyVBinOp(N);
943 if (FoldedVOp.Val) return FoldedVOp;
944 }
Nate Begeman1d4d4142005-09-01 00:19:25 +0000945
Dan Gohman613e0d82007-07-03 14:03:57 +0000946 // fold (add x, undef) -> undef
Dan Gohman70fb1ae2007-07-10 15:19:29 +0000947 if (N0.getOpcode() == ISD::UNDEF)
948 return N0;
949 if (N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +0000950 return N1;
Nate Begeman1d4d4142005-09-01 00:19:25 +0000951 // fold (add c1, c2) -> c1+c2
Nate Begeman646d7e22005-09-02 21:18:40 +0000952 if (N0C && N1C)
Dan Gohman002e5d02008-03-13 22:13:53 +0000953 return DAG.getConstant(N0C->getAPIntValue() + N1C->getAPIntValue(), VT);
Nate Begeman99801192005-09-07 23:25:52 +0000954 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +0000955 if (N0C && !N1C)
956 return DAG.getNode(ISD::ADD, VT, N1, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +0000957 // fold (add x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +0000958 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +0000959 return N0;
Chris Lattner4aafb4f2006-01-12 20:22:43 +0000960 // fold ((c1-A)+c2) -> (c1+c2)-A
961 if (N1C && N0.getOpcode() == ISD::SUB)
962 if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
963 return DAG.getNode(ISD::SUB, VT,
Dan Gohman002e5d02008-03-13 22:13:53 +0000964 DAG.getConstant(N1C->getAPIntValue()+
965 N0C->getAPIntValue(), VT),
Chris Lattner4aafb4f2006-01-12 20:22:43 +0000966 N0.getOperand(1));
Nate Begemancd4d58c2006-02-03 06:46:56 +0000967 // reassociate add
968 SDOperand RADD = ReassociateOps(ISD::ADD, N0, N1);
969 if (RADD.Val != 0)
970 return RADD;
Nate Begeman1d4d4142005-09-01 00:19:25 +0000971 // fold ((0-A) + B) -> B-A
972 if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
973 cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
Nate Begemanf89d78d2005-09-07 16:09:19 +0000974 return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(1));
Nate Begeman1d4d4142005-09-01 00:19:25 +0000975 // fold (A + (0-B)) -> A-B
976 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
977 cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
Nate Begemanf89d78d2005-09-07 16:09:19 +0000978 return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(1));
Chris Lattner01b3d732005-09-28 22:28:18 +0000979 // fold (A+(B-A)) -> B
980 if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
Nate Begeman83e75ec2005-09-06 04:43:02 +0000981 return N1.getOperand(0);
Chris Lattner947c2892006-03-13 06:51:27 +0000982
Evan Cheng860771d2006-03-01 01:09:54 +0000983 if (!MVT::isVector(VT) && SimplifyDemandedBits(SDOperand(N, 0)))
Chris Lattneref027f92006-04-21 15:32:26 +0000984 return SDOperand(N, 0);
Chris Lattner947c2892006-03-13 06:51:27 +0000985
986 // fold (a+b) -> (a|b) iff a and b share no bits.
987 if (MVT::isInteger(VT) && !MVT::isVector(VT)) {
Dan Gohman948d8ea2008-02-20 16:33:30 +0000988 APInt LHSZero, LHSOne;
989 APInt RHSZero, RHSOne;
990 APInt Mask = APInt::getAllOnesValue(MVT::getSizeInBits(VT));
Dan Gohmanea859be2007-06-22 14:59:07 +0000991 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
Dan Gohman948d8ea2008-02-20 16:33:30 +0000992 if (LHSZero.getBoolValue()) {
Dan Gohmanea859be2007-06-22 14:59:07 +0000993 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
Chris Lattner947c2892006-03-13 06:51:27 +0000994
995 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
996 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
997 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
998 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
999 return DAG.getNode(ISD::OR, VT, N0, N1);
1000 }
1001 }
Evan Cheng3ef554d2006-11-06 08:14:30 +00001002
Evan Cheng42d7ccf2007-01-19 17:51:44 +00001003 // fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
1004 if (N0.getOpcode() == ISD::SHL && N0.Val->hasOneUse()) {
1005 SDOperand Result = combineShlAddConstant(N0, N1, DAG);
1006 if (Result.Val) return Result;
1007 }
1008 if (N1.getOpcode() == ISD::SHL && N1.Val->hasOneUse()) {
1009 SDOperand Result = combineShlAddConstant(N1, N0, DAG);
1010 if (Result.Val) return Result;
1011 }
1012
Evan Chengb13cdbd2007-06-21 07:39:16 +00001013 // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
1014 if (N0.getOpcode() == ISD::SELECT && N0.Val->hasOneUse()) {
1015 SDOperand Result = combineSelectAndUse(N, N0, N1, DAG);
1016 if (Result.Val) return Result;
1017 }
1018 if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
1019 SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
1020 if (Result.Val) return Result;
1021 }
1022
Nate Begeman83e75ec2005-09-06 04:43:02 +00001023 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001024}
1025
Chris Lattner91153682007-03-04 20:03:15 +00001026SDOperand DAGCombiner::visitADDC(SDNode *N) {
1027 SDOperand N0 = N->getOperand(0);
1028 SDOperand N1 = N->getOperand(1);
1029 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1030 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
1031 MVT::ValueType VT = N0.getValueType();
1032
1033 // If the flag result is dead, turn this into an ADD.
1034 if (N->hasNUsesOfValue(0, 1))
1035 return CombineTo(N, DAG.getNode(ISD::ADD, VT, N1, N0),
Chris Lattnerb6541762007-03-04 20:40:38 +00001036 DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
Chris Lattner91153682007-03-04 20:03:15 +00001037
1038 // canonicalize constant to RHS.
Chris Lattnerbcf24842007-03-04 20:08:45 +00001039 if (N0C && !N1C) {
1040 SDOperand Ops[] = { N1, N0 };
1041 return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
1042 }
Chris Lattner91153682007-03-04 20:03:15 +00001043
Chris Lattnerb6541762007-03-04 20:40:38 +00001044 // fold (addc x, 0) -> x + no carry out
1045 if (N1C && N1C->isNullValue())
1046 return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
1047
1048 // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
Dan Gohman948d8ea2008-02-20 16:33:30 +00001049 APInt LHSZero, LHSOne;
1050 APInt RHSZero, RHSOne;
1051 APInt Mask = APInt::getAllOnesValue(MVT::getSizeInBits(VT));
Dan Gohmanea859be2007-06-22 14:59:07 +00001052 DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
Dan Gohman948d8ea2008-02-20 16:33:30 +00001053 if (LHSZero.getBoolValue()) {
Dan Gohmanea859be2007-06-22 14:59:07 +00001054 DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
Chris Lattnerb6541762007-03-04 20:40:38 +00001055
1056 // If all possibly-set bits on the LHS are clear on the RHS, return an OR.
1057 // If all possibly-set bits on the RHS are clear on the LHS, return an OR.
1058 if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
1059 (LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
1060 return CombineTo(N, DAG.getNode(ISD::OR, VT, N0, N1),
1061 DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
1062 }
Chris Lattner91153682007-03-04 20:03:15 +00001063
1064 return SDOperand();
1065}
1066
1067SDOperand DAGCombiner::visitADDE(SDNode *N) {
1068 SDOperand N0 = N->getOperand(0);
1069 SDOperand N1 = N->getOperand(1);
Chris Lattnerb6541762007-03-04 20:40:38 +00001070 SDOperand CarryIn = N->getOperand(2);
Chris Lattner91153682007-03-04 20:03:15 +00001071 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1072 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Chris Lattnerbcf24842007-03-04 20:08:45 +00001073 //MVT::ValueType VT = N0.getValueType();
Chris Lattner91153682007-03-04 20:03:15 +00001074
1075 // canonicalize constant to RHS
Chris Lattnerbcf24842007-03-04 20:08:45 +00001076 if (N0C && !N1C) {
Chris Lattnerb6541762007-03-04 20:40:38 +00001077 SDOperand Ops[] = { N1, N0, CarryIn };
Chris Lattnerbcf24842007-03-04 20:08:45 +00001078 return DAG.getNode(ISD::ADDE, N->getVTList(), Ops, 3);
1079 }
Chris Lattner91153682007-03-04 20:03:15 +00001080
Chris Lattnerb6541762007-03-04 20:40:38 +00001081 // fold (adde x, y, false) -> (addc x, y)
1082 if (CarryIn.getOpcode() == ISD::CARRY_FALSE) {
1083 SDOperand Ops[] = { N1, N0 };
1084 return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
1085 }
Chris Lattner91153682007-03-04 20:03:15 +00001086
1087 return SDOperand();
1088}
1089
1090
1091
Nate Begeman83e75ec2005-09-06 04:43:02 +00001092SDOperand DAGCombiner::visitSUB(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001093 SDOperand N0 = N->getOperand(0);
1094 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001095 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1096 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
Nate Begemana148d982006-01-18 22:35:16 +00001097 MVT::ValueType VT = N0.getValueType();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001098
Dan Gohman7f321562007-06-25 16:23:39 +00001099 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001100 if (MVT::isVector(VT)) {
1101 SDOperand FoldedVOp = SimplifyVBinOp(N);
1102 if (FoldedVOp.Val) return FoldedVOp;
1103 }
Dan Gohman7f321562007-06-25 16:23:39 +00001104
Chris Lattner854077d2005-10-17 01:07:11 +00001105 // fold (sub x, x) -> 0
Evan Chengc8e3b142008-03-12 07:02:50 +00001106 if (N0 == N1)
Chris Lattner854077d2005-10-17 01:07:11 +00001107 return DAG.getConstant(0, N->getValueType(0));
Nate Begeman1d4d4142005-09-01 00:19:25 +00001108 // fold (sub c1, c2) -> c1-c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001109 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00001110 return DAG.getNode(ISD::SUB, VT, N0, N1);
Chris Lattner05b57432005-10-11 06:07:15 +00001111 // fold (sub x, c) -> (add x, -c)
1112 if (N1C)
Dan Gohman002e5d02008-03-13 22:13:53 +00001113 return DAG.getNode(ISD::ADD, VT, N0,
1114 DAG.getConstant(-N1C->getAPIntValue(), VT));
Nate Begeman1d4d4142005-09-01 00:19:25 +00001115 // fold (A+B)-A -> B
Chris Lattner01b3d732005-09-28 22:28:18 +00001116 if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
Nate Begeman83e75ec2005-09-06 04:43:02 +00001117 return N0.getOperand(1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001118 // fold (A+B)-B -> A
Chris Lattner01b3d732005-09-28 22:28:18 +00001119 if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
Nate Begeman83e75ec2005-09-06 04:43:02 +00001120 return N0.getOperand(0);
Evan Chengb13cdbd2007-06-21 07:39:16 +00001121 // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
1122 if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
1123 SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
1124 if (Result.Val) return Result;
1125 }
Dan Gohman613e0d82007-07-03 14:03:57 +00001126 // If either operand of a sub is undef, the result is undef
Dan Gohman70fb1ae2007-07-10 15:19:29 +00001127 if (N0.getOpcode() == ISD::UNDEF)
1128 return N0;
1129 if (N1.getOpcode() == ISD::UNDEF)
1130 return N1;
Dan Gohman7f321562007-06-25 16:23:39 +00001131
Nate Begeman83e75ec2005-09-06 04:43:02 +00001132 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001133}
1134
Nate Begeman83e75ec2005-09-06 04:43:02 +00001135SDOperand DAGCombiner::visitMUL(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001136 SDOperand N0 = N->getOperand(0);
1137 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001138 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1139 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman223df222005-09-08 20:18:10 +00001140 MVT::ValueType VT = N0.getValueType();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001141
Dan Gohman7f321562007-06-25 16:23:39 +00001142 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001143 if (MVT::isVector(VT)) {
1144 SDOperand FoldedVOp = SimplifyVBinOp(N);
1145 if (FoldedVOp.Val) return FoldedVOp;
1146 }
Dan Gohman7f321562007-06-25 16:23:39 +00001147
Dan Gohman613e0d82007-07-03 14:03:57 +00001148 // fold (mul x, undef) -> 0
Dan Gohmand595b5f2007-07-10 14:20:37 +00001149 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +00001150 return DAG.getConstant(0, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001151 // fold (mul c1, c2) -> c1*c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001152 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00001153 return DAG.getNode(ISD::MUL, VT, N0, N1);
Nate Begeman99801192005-09-07 23:25:52 +00001154 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +00001155 if (N0C && !N1C)
1156 return DAG.getNode(ISD::MUL, VT, N1, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001157 // fold (mul x, 0) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00001158 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001159 return N1;
Nate Begeman1d4d4142005-09-01 00:19:25 +00001160 // fold (mul x, -1) -> 0-x
Nate Begeman646d7e22005-09-02 21:18:40 +00001161 if (N1C && N1C->isAllOnesValue())
Nate Begeman405e3ec2005-10-21 00:02:42 +00001162 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001163 // fold (mul x, (1 << c)) -> x << c
Dan Gohman002e5d02008-03-13 22:13:53 +00001164 if (N1C && N1C->getAPIntValue().isPowerOf2())
Chris Lattner3e6099b2005-10-30 06:41:49 +00001165 return DAG.getNode(ISD::SHL, VT, N0,
Dan Gohman002e5d02008-03-13 22:13:53 +00001166 DAG.getConstant(N1C->getAPIntValue().logBase2(),
Nate Begeman83e75ec2005-09-06 04:43:02 +00001167 TLI.getShiftAmountTy()));
Chris Lattner3e6099b2005-10-30 06:41:49 +00001168 // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
1169 if (N1C && isPowerOf2_64(-N1C->getSignExtended())) {
1170 // FIXME: If the input is something that is easily negated (e.g. a
1171 // single-use add), we should put the negate there.
1172 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT),
1173 DAG.getNode(ISD::SHL, VT, N0,
1174 DAG.getConstant(Log2_64(-N1C->getSignExtended()),
1175 TLI.getShiftAmountTy())));
1176 }
Andrew Lenharth50a0d422006-04-02 21:42:45 +00001177
Chris Lattner0b1a85f2006-03-01 03:44:24 +00001178 // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
1179 if (N1C && N0.getOpcode() == ISD::SHL &&
1180 isa<ConstantSDNode>(N0.getOperand(1))) {
1181 SDOperand C3 = DAG.getNode(ISD::SHL, VT, N1, N0.getOperand(1));
Chris Lattner5750df92006-03-01 04:03:14 +00001182 AddToWorkList(C3.Val);
Chris Lattner0b1a85f2006-03-01 03:44:24 +00001183 return DAG.getNode(ISD::MUL, VT, N0.getOperand(0), C3);
1184 }
1185
1186 // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
1187 // use.
1188 {
1189 SDOperand Sh(0,0), Y(0,0);
1190 // Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
1191 if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
1192 N0.Val->hasOneUse()) {
1193 Sh = N0; Y = N1;
1194 } else if (N1.getOpcode() == ISD::SHL &&
1195 isa<ConstantSDNode>(N1.getOperand(1)) && N1.Val->hasOneUse()) {
1196 Sh = N1; Y = N0;
1197 }
1198 if (Sh.Val) {
1199 SDOperand Mul = DAG.getNode(ISD::MUL, VT, Sh.getOperand(0), Y);
1200 return DAG.getNode(ISD::SHL, VT, Mul, Sh.getOperand(1));
1201 }
1202 }
Chris Lattnera1deca32006-03-04 23:33:26 +00001203 // fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
1204 if (N1C && N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse() &&
1205 isa<ConstantSDNode>(N0.getOperand(1))) {
1206 return DAG.getNode(ISD::ADD, VT,
1207 DAG.getNode(ISD::MUL, VT, N0.getOperand(0), N1),
1208 DAG.getNode(ISD::MUL, VT, N0.getOperand(1), N1));
1209 }
Chris Lattner0b1a85f2006-03-01 03:44:24 +00001210
Nate Begemancd4d58c2006-02-03 06:46:56 +00001211 // reassociate mul
1212 SDOperand RMUL = ReassociateOps(ISD::MUL, N0, N1);
1213 if (RMUL.Val != 0)
1214 return RMUL;
Dan Gohman7f321562007-06-25 16:23:39 +00001215
Nate Begeman83e75ec2005-09-06 04:43:02 +00001216 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001217}
1218
Nate Begeman83e75ec2005-09-06 04:43:02 +00001219SDOperand DAGCombiner::visitSDIV(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001220 SDOperand N0 = N->getOperand(0);
1221 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001222 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1223 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
Nate Begemana148d982006-01-18 22:35:16 +00001224 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001225
Dan Gohman7f321562007-06-25 16:23:39 +00001226 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001227 if (MVT::isVector(VT)) {
1228 SDOperand FoldedVOp = SimplifyVBinOp(N);
1229 if (FoldedVOp.Val) return FoldedVOp;
1230 }
Dan Gohman7f321562007-06-25 16:23:39 +00001231
Nate Begeman1d4d4142005-09-01 00:19:25 +00001232 // fold (sdiv c1, c2) -> c1/c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001233 if (N0C && N1C && !N1C->isNullValue())
Nate Begemana148d982006-01-18 22:35:16 +00001234 return DAG.getNode(ISD::SDIV, VT, N0, N1);
Nate Begeman405e3ec2005-10-21 00:02:42 +00001235 // fold (sdiv X, 1) -> X
1236 if (N1C && N1C->getSignExtended() == 1LL)
1237 return N0;
1238 // fold (sdiv X, -1) -> 0-X
1239 if (N1C && N1C->isAllOnesValue())
1240 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
Chris Lattner094c8fc2005-10-07 06:10:46 +00001241 // If we know the sign bits of both operands are zero, strength reduce to a
1242 // udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
Chris Lattnerf32aac32008-01-27 23:32:17 +00001243 if (!MVT::isVector(VT)) {
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001244 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
Chris Lattnerf32aac32008-01-27 23:32:17 +00001245 return DAG.getNode(ISD::UDIV, N1.getValueType(), N0, N1);
1246 }
Nate Begemancd6a6ed2006-02-17 07:26:20 +00001247 // fold (sdiv X, pow2) -> simple ops after legalize
Dan Gohman002e5d02008-03-13 22:13:53 +00001248 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap() &&
Nate Begeman405e3ec2005-10-21 00:02:42 +00001249 (isPowerOf2_64(N1C->getSignExtended()) ||
1250 isPowerOf2_64(-N1C->getSignExtended()))) {
1251 // If dividing by powers of two is cheap, then don't perform the following
1252 // fold.
1253 if (TLI.isPow2DivCheap())
1254 return SDOperand();
1255 int64_t pow2 = N1C->getSignExtended();
1256 int64_t abs2 = pow2 > 0 ? pow2 : -pow2;
Chris Lattner8f4880b2006-02-16 08:02:36 +00001257 unsigned lg2 = Log2_64(abs2);
1258 // Splat the sign bit into the register
1259 SDOperand SGN = DAG.getNode(ISD::SRA, VT, N0,
Nate Begeman405e3ec2005-10-21 00:02:42 +00001260 DAG.getConstant(MVT::getSizeInBits(VT)-1,
1261 TLI.getShiftAmountTy()));
Chris Lattner5750df92006-03-01 04:03:14 +00001262 AddToWorkList(SGN.Val);
Chris Lattner8f4880b2006-02-16 08:02:36 +00001263 // Add (N0 < 0) ? abs2 - 1 : 0;
1264 SDOperand SRL = DAG.getNode(ISD::SRL, VT, SGN,
1265 DAG.getConstant(MVT::getSizeInBits(VT)-lg2,
Nate Begeman405e3ec2005-10-21 00:02:42 +00001266 TLI.getShiftAmountTy()));
Chris Lattner8f4880b2006-02-16 08:02:36 +00001267 SDOperand ADD = DAG.getNode(ISD::ADD, VT, N0, SRL);
Chris Lattner5750df92006-03-01 04:03:14 +00001268 AddToWorkList(SRL.Val);
1269 AddToWorkList(ADD.Val); // Divide by pow2
Chris Lattner8f4880b2006-02-16 08:02:36 +00001270 SDOperand SRA = DAG.getNode(ISD::SRA, VT, ADD,
1271 DAG.getConstant(lg2, TLI.getShiftAmountTy()));
Nate Begeman405e3ec2005-10-21 00:02:42 +00001272 // If we're dividing by a positive value, we're done. Otherwise, we must
1273 // negate the result.
1274 if (pow2 > 0)
1275 return SRA;
Chris Lattner5750df92006-03-01 04:03:14 +00001276 AddToWorkList(SRA.Val);
Nate Begeman405e3ec2005-10-21 00:02:42 +00001277 return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), SRA);
1278 }
Nate Begeman69575232005-10-20 02:15:44 +00001279 // if integer divide is expensive and we satisfy the requirements, emit an
1280 // alternate sequence.
Nate Begeman405e3ec2005-10-21 00:02:42 +00001281 if (N1C && (N1C->getSignExtended() < -1 || N1C->getSignExtended() > 1) &&
Chris Lattnere9936d12005-10-22 18:50:15 +00001282 !TLI.isIntDivCheap()) {
1283 SDOperand Op = BuildSDIV(N);
1284 if (Op.Val) return Op;
Nate Begeman69575232005-10-20 02:15:44 +00001285 }
Dan Gohman7f321562007-06-25 16:23:39 +00001286
Dan Gohman613e0d82007-07-03 14:03:57 +00001287 // undef / X -> 0
1288 if (N0.getOpcode() == ISD::UNDEF)
1289 return DAG.getConstant(0, VT);
1290 // X / undef -> undef
1291 if (N1.getOpcode() == ISD::UNDEF)
1292 return N1;
Dan Gohman7f321562007-06-25 16:23:39 +00001293
Nate Begeman83e75ec2005-09-06 04:43:02 +00001294 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001295}
1296
Nate Begeman83e75ec2005-09-06 04:43:02 +00001297SDOperand DAGCombiner::visitUDIV(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001298 SDOperand N0 = N->getOperand(0);
1299 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001300 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
1301 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
Nate Begemana148d982006-01-18 22:35:16 +00001302 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001303
Dan Gohman7f321562007-06-25 16:23:39 +00001304 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001305 if (MVT::isVector(VT)) {
1306 SDOperand FoldedVOp = SimplifyVBinOp(N);
1307 if (FoldedVOp.Val) return FoldedVOp;
1308 }
Dan Gohman7f321562007-06-25 16:23:39 +00001309
Nate Begeman1d4d4142005-09-01 00:19:25 +00001310 // fold (udiv c1, c2) -> c1/c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001311 if (N0C && N1C && !N1C->isNullValue())
Nate Begemana148d982006-01-18 22:35:16 +00001312 return DAG.getNode(ISD::UDIV, VT, N0, N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001313 // fold (udiv x, (1 << c)) -> x >>u c
Dan Gohman002e5d02008-03-13 22:13:53 +00001314 if (N1C && N1C->getAPIntValue().isPowerOf2())
Nate Begemanfb5e4bd2006-02-05 07:20:23 +00001315 return DAG.getNode(ISD::SRL, VT, N0,
Dan Gohman002e5d02008-03-13 22:13:53 +00001316 DAG.getConstant(N1C->getAPIntValue().logBase2(),
Nate Begeman83e75ec2005-09-06 04:43:02 +00001317 TLI.getShiftAmountTy()));
Nate Begemanfb5e4bd2006-02-05 07:20:23 +00001318 // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
1319 if (N1.getOpcode() == ISD::SHL) {
1320 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00001321 if (SHC->getAPIntValue().isPowerOf2()) {
Nate Begemanfb5e4bd2006-02-05 07:20:23 +00001322 MVT::ValueType ADDVT = N1.getOperand(1).getValueType();
Nate Begemanc031e332006-02-05 07:36:48 +00001323 SDOperand Add = DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1),
Dan Gohman002e5d02008-03-13 22:13:53 +00001324 DAG.getConstant(SHC->getAPIntValue()
1325 .logBase2(),
Nate Begemanc031e332006-02-05 07:36:48 +00001326 ADDVT));
Chris Lattner5750df92006-03-01 04:03:14 +00001327 AddToWorkList(Add.Val);
Nate Begemanc031e332006-02-05 07:36:48 +00001328 return DAG.getNode(ISD::SRL, VT, N0, Add);
Nate Begemanfb5e4bd2006-02-05 07:20:23 +00001329 }
1330 }
1331 }
Nate Begeman69575232005-10-20 02:15:44 +00001332 // fold (udiv x, c) -> alternate
Dan Gohman002e5d02008-03-13 22:13:53 +00001333 if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap()) {
Chris Lattnere9936d12005-10-22 18:50:15 +00001334 SDOperand Op = BuildUDIV(N);
1335 if (Op.Val) return Op;
1336 }
Dan Gohman7f321562007-06-25 16:23:39 +00001337
Dan Gohman613e0d82007-07-03 14:03:57 +00001338 // undef / X -> 0
1339 if (N0.getOpcode() == ISD::UNDEF)
1340 return DAG.getConstant(0, VT);
1341 // X / undef -> undef
1342 if (N1.getOpcode() == ISD::UNDEF)
1343 return N1;
Dan Gohman7f321562007-06-25 16:23:39 +00001344
Nate Begeman83e75ec2005-09-06 04:43:02 +00001345 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001346}
1347
Nate Begeman83e75ec2005-09-06 04:43:02 +00001348SDOperand DAGCombiner::visitSREM(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001349 SDOperand N0 = N->getOperand(0);
1350 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001351 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1352 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begemana148d982006-01-18 22:35:16 +00001353 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001354
1355 // fold (srem c1, c2) -> c1%c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001356 if (N0C && N1C && !N1C->isNullValue())
Nate Begemana148d982006-01-18 22:35:16 +00001357 return DAG.getNode(ISD::SREM, VT, N0, N1);
Nate Begeman07ed4172005-10-10 21:26:48 +00001358 // If we know the sign bits of both operands are zero, strength reduce to a
1359 // urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
Chris Lattneree339f42008-01-27 23:21:58 +00001360 if (!MVT::isVector(VT)) {
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001361 if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
Chris Lattneree339f42008-01-27 23:21:58 +00001362 return DAG.getNode(ISD::UREM, VT, N0, N1);
1363 }
Chris Lattner26d29902006-10-12 20:58:32 +00001364
Dan Gohman77003042007-11-26 23:46:11 +00001365 // If X/C can be simplified by the division-by-constant logic, lower
1366 // X%C to the equivalent of X-X/C*C.
Chris Lattner26d29902006-10-12 20:58:32 +00001367 if (N1C && !N1C->isNullValue()) {
1368 SDOperand Div = DAG.getNode(ISD::SDIV, VT, N0, N1);
Chris Lattner5eee4272008-01-26 01:09:19 +00001369 AddToWorkList(Div.Val);
Dan Gohman77003042007-11-26 23:46:11 +00001370 SDOperand OptimizedDiv = combine(Div.Val);
1371 if (OptimizedDiv.Val && OptimizedDiv.Val != Div.Val) {
1372 SDOperand Mul = DAG.getNode(ISD::MUL, VT, OptimizedDiv, N1);
1373 SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
1374 AddToWorkList(Mul.Val);
1375 return Sub;
1376 }
Chris Lattner26d29902006-10-12 20:58:32 +00001377 }
1378
Dan Gohman613e0d82007-07-03 14:03:57 +00001379 // undef % X -> 0
1380 if (N0.getOpcode() == ISD::UNDEF)
1381 return DAG.getConstant(0, VT);
1382 // X % undef -> undef
1383 if (N1.getOpcode() == ISD::UNDEF)
1384 return N1;
Dan Gohman7f321562007-06-25 16:23:39 +00001385
Nate Begeman83e75ec2005-09-06 04:43:02 +00001386 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001387}
1388
Nate Begeman83e75ec2005-09-06 04:43:02 +00001389SDOperand DAGCombiner::visitUREM(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001390 SDOperand N0 = N->getOperand(0);
1391 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001392 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1393 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begemana148d982006-01-18 22:35:16 +00001394 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001395
1396 // fold (urem c1, c2) -> c1%c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001397 if (N0C && N1C && !N1C->isNullValue())
Nate Begemana148d982006-01-18 22:35:16 +00001398 return DAG.getNode(ISD::UREM, VT, N0, N1);
Nate Begeman07ed4172005-10-10 21:26:48 +00001399 // fold (urem x, pow2) -> (and x, pow2-1)
Dan Gohman002e5d02008-03-13 22:13:53 +00001400 if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
1401 return DAG.getNode(ISD::AND, VT, N0,
1402 DAG.getConstant(N1C->getAPIntValue()-1,VT));
Nate Begemanc031e332006-02-05 07:36:48 +00001403 // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
1404 if (N1.getOpcode() == ISD::SHL) {
1405 if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00001406 if (SHC->getAPIntValue().isPowerOf2()) {
1407 SDOperand Add =
1408 DAG.getNode(ISD::ADD, VT, N1,
1409 DAG.getConstant(APInt::getAllOnesValue(MVT::getSizeInBits(VT)),
1410 VT));
Chris Lattner5750df92006-03-01 04:03:14 +00001411 AddToWorkList(Add.Val);
Nate Begemanc031e332006-02-05 07:36:48 +00001412 return DAG.getNode(ISD::AND, VT, N0, Add);
1413 }
1414 }
1415 }
Chris Lattner26d29902006-10-12 20:58:32 +00001416
Dan Gohman77003042007-11-26 23:46:11 +00001417 // If X/C can be simplified by the division-by-constant logic, lower
1418 // X%C to the equivalent of X-X/C*C.
Chris Lattner26d29902006-10-12 20:58:32 +00001419 if (N1C && !N1C->isNullValue()) {
1420 SDOperand Div = DAG.getNode(ISD::UDIV, VT, N0, N1);
Dan Gohman77003042007-11-26 23:46:11 +00001421 SDOperand OptimizedDiv = combine(Div.Val);
1422 if (OptimizedDiv.Val && OptimizedDiv.Val != Div.Val) {
1423 SDOperand Mul = DAG.getNode(ISD::MUL, VT, OptimizedDiv, N1);
1424 SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
1425 AddToWorkList(Mul.Val);
1426 return Sub;
1427 }
Chris Lattner26d29902006-10-12 20:58:32 +00001428 }
1429
Dan Gohman613e0d82007-07-03 14:03:57 +00001430 // undef % X -> 0
1431 if (N0.getOpcode() == ISD::UNDEF)
1432 return DAG.getConstant(0, VT);
1433 // X % undef -> undef
1434 if (N1.getOpcode() == ISD::UNDEF)
1435 return N1;
Dan Gohman7f321562007-06-25 16:23:39 +00001436
Nate Begeman83e75ec2005-09-06 04:43:02 +00001437 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001438}
1439
Nate Begeman83e75ec2005-09-06 04:43:02 +00001440SDOperand DAGCombiner::visitMULHS(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001441 SDOperand N0 = N->getOperand(0);
1442 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001443 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Dan Gohman7f321562007-06-25 16:23:39 +00001444 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001445
1446 // fold (mulhs x, 0) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00001447 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001448 return N1;
Nate Begeman1d4d4142005-09-01 00:19:25 +00001449 // fold (mulhs x, 1) -> (sra x, size(x)-1)
Dan Gohman002e5d02008-03-13 22:13:53 +00001450 if (N1C && N1C->getAPIntValue() == 1)
Nate Begeman1d4d4142005-09-01 00:19:25 +00001451 return DAG.getNode(ISD::SRA, N0.getValueType(), N0,
1452 DAG.getConstant(MVT::getSizeInBits(N0.getValueType())-1,
Nate Begeman83e75ec2005-09-06 04:43:02 +00001453 TLI.getShiftAmountTy()));
Dan Gohman613e0d82007-07-03 14:03:57 +00001454 // fold (mulhs x, undef) -> 0
Dan Gohmand595b5f2007-07-10 14:20:37 +00001455 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +00001456 return DAG.getConstant(0, VT);
Dan Gohman7f321562007-06-25 16:23:39 +00001457
Nate Begeman83e75ec2005-09-06 04:43:02 +00001458 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001459}
1460
Nate Begeman83e75ec2005-09-06 04:43:02 +00001461SDOperand DAGCombiner::visitMULHU(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001462 SDOperand N0 = N->getOperand(0);
1463 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00001464 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Dan Gohman7f321562007-06-25 16:23:39 +00001465 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001466
1467 // fold (mulhu x, 0) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00001468 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001469 return N1;
Nate Begeman1d4d4142005-09-01 00:19:25 +00001470 // fold (mulhu x, 1) -> 0
Dan Gohman002e5d02008-03-13 22:13:53 +00001471 if (N1C && N1C->getAPIntValue() == 1)
Nate Begeman83e75ec2005-09-06 04:43:02 +00001472 return DAG.getConstant(0, N0.getValueType());
Dan Gohman613e0d82007-07-03 14:03:57 +00001473 // fold (mulhu x, undef) -> 0
Dan Gohmand595b5f2007-07-10 14:20:37 +00001474 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +00001475 return DAG.getConstant(0, VT);
Dan Gohman7f321562007-06-25 16:23:39 +00001476
Nate Begeman83e75ec2005-09-06 04:43:02 +00001477 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001478}
1479
Dan Gohman389079b2007-10-08 17:57:15 +00001480/// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
1481/// compute two values. LoOp and HiOp give the opcodes for the two computations
1482/// that are being performed. Return true if a simplification was made.
1483///
Chris Lattner5eee4272008-01-26 01:09:19 +00001484SDOperand DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
1485 unsigned HiOp) {
Dan Gohman389079b2007-10-08 17:57:15 +00001486 // If the high half is not needed, just compute the low half.
Evan Cheng44711942007-11-08 09:25:29 +00001487 bool HiExists = N->hasAnyUseOfValue(1);
1488 if (!HiExists &&
Dan Gohman389079b2007-10-08 17:57:15 +00001489 (!AfterLegalize ||
1490 TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001491 SDOperand Res = DAG.getNode(LoOp, N->getValueType(0), N->op_begin(),
1492 N->getNumOperands());
1493 return CombineTo(N, Res, Res);
Dan Gohman389079b2007-10-08 17:57:15 +00001494 }
1495
1496 // If the low half is not needed, just compute the high half.
Evan Cheng44711942007-11-08 09:25:29 +00001497 bool LoExists = N->hasAnyUseOfValue(0);
1498 if (!LoExists &&
Dan Gohman389079b2007-10-08 17:57:15 +00001499 (!AfterLegalize ||
1500 TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001501 SDOperand Res = DAG.getNode(HiOp, N->getValueType(1), N->op_begin(),
1502 N->getNumOperands());
1503 return CombineTo(N, Res, Res);
Dan Gohman389079b2007-10-08 17:57:15 +00001504 }
1505
Evan Cheng44711942007-11-08 09:25:29 +00001506 // If both halves are used, return as it is.
1507 if (LoExists && HiExists)
Chris Lattner5eee4272008-01-26 01:09:19 +00001508 return SDOperand();
Evan Cheng44711942007-11-08 09:25:29 +00001509
1510 // If the two computed results can be simplified separately, separate them.
Evan Cheng44711942007-11-08 09:25:29 +00001511 if (LoExists) {
1512 SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
1513 N->op_begin(), N->getNumOperands());
Chris Lattner5eee4272008-01-26 01:09:19 +00001514 AddToWorkList(Lo.Val);
Evan Cheng44711942007-11-08 09:25:29 +00001515 SDOperand LoOpt = combine(Lo.Val);
Chris Lattner5eee4272008-01-26 01:09:19 +00001516 if (LoOpt.Val && LoOpt.Val != Lo.Val &&
1517 TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType()))
1518 return CombineTo(N, LoOpt, LoOpt);
Dan Gohman389079b2007-10-08 17:57:15 +00001519 }
1520
Evan Cheng44711942007-11-08 09:25:29 +00001521 if (HiExists) {
1522 SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
1523 N->op_begin(), N->getNumOperands());
Chris Lattner5eee4272008-01-26 01:09:19 +00001524 AddToWorkList(Hi.Val);
Evan Cheng44711942007-11-08 09:25:29 +00001525 SDOperand HiOpt = combine(Hi.Val);
1526 if (HiOpt.Val && HiOpt != Hi &&
Chris Lattner5eee4272008-01-26 01:09:19 +00001527 TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType()))
1528 return CombineTo(N, HiOpt, HiOpt);
Evan Cheng44711942007-11-08 09:25:29 +00001529 }
Chris Lattner5eee4272008-01-26 01:09:19 +00001530 return SDOperand();
Dan Gohman389079b2007-10-08 17:57:15 +00001531}
1532
1533SDOperand DAGCombiner::visitSMUL_LOHI(SDNode *N) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001534 SDOperand Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS);
1535 if (Res.Val) return Res;
Dan Gohman389079b2007-10-08 17:57:15 +00001536
1537 return SDOperand();
1538}
1539
1540SDOperand DAGCombiner::visitUMUL_LOHI(SDNode *N) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001541 SDOperand Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU);
1542 if (Res.Val) return Res;
Dan Gohman389079b2007-10-08 17:57:15 +00001543
1544 return SDOperand();
1545}
1546
1547SDOperand DAGCombiner::visitSDIVREM(SDNode *N) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001548 SDOperand Res = SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM);
1549 if (Res.Val) return Res;
Dan Gohman389079b2007-10-08 17:57:15 +00001550
1551 return SDOperand();
1552}
1553
1554SDOperand DAGCombiner::visitUDIVREM(SDNode *N) {
Chris Lattner5eee4272008-01-26 01:09:19 +00001555 SDOperand Res = SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM);
1556 if (Res.Val) return Res;
Dan Gohman389079b2007-10-08 17:57:15 +00001557
1558 return SDOperand();
1559}
1560
Chris Lattner35e5c142006-05-05 05:51:50 +00001561/// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
1562/// two operands of the same opcode, try to simplify it.
1563SDOperand DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
1564 SDOperand N0 = N->getOperand(0), N1 = N->getOperand(1);
1565 MVT::ValueType VT = N0.getValueType();
1566 assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
1567
Chris Lattner540121f2006-05-05 06:31:05 +00001568 // For each of OP in AND/OR/XOR:
1569 // fold (OP (zext x), (zext y)) -> (zext (OP x, y))
1570 // fold (OP (sext x), (sext y)) -> (sext (OP x, y))
1571 // fold (OP (aext x), (aext y)) -> (aext (OP x, y))
Chris Lattner0d8dae72006-05-05 06:32:04 +00001572 // fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y))
Chris Lattner540121f2006-05-05 06:31:05 +00001573 if ((N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND||
Chris Lattner0d8dae72006-05-05 06:32:04 +00001574 N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::TRUNCATE) &&
Chris Lattner35e5c142006-05-05 05:51:50 +00001575 N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()) {
1576 SDOperand ORNode = DAG.getNode(N->getOpcode(),
1577 N0.getOperand(0).getValueType(),
1578 N0.getOperand(0), N1.getOperand(0));
1579 AddToWorkList(ORNode.Val);
Chris Lattner540121f2006-05-05 06:31:05 +00001580 return DAG.getNode(N0.getOpcode(), VT, ORNode);
Chris Lattner35e5c142006-05-05 05:51:50 +00001581 }
1582
Chris Lattnera3dc3f62006-05-05 06:10:43 +00001583 // For each of OP in SHL/SRL/SRA/AND...
1584 // fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
1585 // fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
1586 // fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
Chris Lattner35e5c142006-05-05 05:51:50 +00001587 if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
Chris Lattnera3dc3f62006-05-05 06:10:43 +00001588 N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
Chris Lattner35e5c142006-05-05 05:51:50 +00001589 N0.getOperand(1) == N1.getOperand(1)) {
1590 SDOperand ORNode = DAG.getNode(N->getOpcode(),
1591 N0.getOperand(0).getValueType(),
1592 N0.getOperand(0), N1.getOperand(0));
1593 AddToWorkList(ORNode.Val);
1594 return DAG.getNode(N0.getOpcode(), VT, ORNode, N0.getOperand(1));
1595 }
1596
1597 return SDOperand();
1598}
1599
Nate Begeman83e75ec2005-09-06 04:43:02 +00001600SDOperand DAGCombiner::visitAND(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001601 SDOperand N0 = N->getOperand(0);
1602 SDOperand N1 = N->getOperand(1);
Nate Begemanfb7217b2006-02-17 19:54:08 +00001603 SDOperand LL, LR, RL, RR, CC0, CC1;
Nate Begeman646d7e22005-09-02 21:18:40 +00001604 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1605 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001606 MVT::ValueType VT = N1.getValueType();
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001607 unsigned BitWidth = MVT::getSizeInBits(VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001608
Dan Gohman7f321562007-06-25 16:23:39 +00001609 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001610 if (MVT::isVector(VT)) {
1611 SDOperand FoldedVOp = SimplifyVBinOp(N);
1612 if (FoldedVOp.Val) return FoldedVOp;
1613 }
Dan Gohman7f321562007-06-25 16:23:39 +00001614
Dan Gohman613e0d82007-07-03 14:03:57 +00001615 // fold (and x, undef) -> 0
Dan Gohmand595b5f2007-07-10 14:20:37 +00001616 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +00001617 return DAG.getConstant(0, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001618 // fold (and c1, c2) -> c1&c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001619 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00001620 return DAG.getNode(ISD::AND, VT, N0, N1);
Nate Begeman99801192005-09-07 23:25:52 +00001621 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +00001622 if (N0C && !N1C)
1623 return DAG.getNode(ISD::AND, VT, N1, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001624 // fold (and x, -1) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00001625 if (N1C && N1C->isAllOnesValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001626 return N0;
1627 // if (and x, c) is known to be zero, return 0
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001628 if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0),
1629 APInt::getAllOnesValue(BitWidth)))
Nate Begeman83e75ec2005-09-06 04:43:02 +00001630 return DAG.getConstant(0, VT);
Nate Begemancd4d58c2006-02-03 06:46:56 +00001631 // reassociate and
1632 SDOperand RAND = ReassociateOps(ISD::AND, N0, N1);
1633 if (RAND.Val != 0)
1634 return RAND;
Nate Begeman1d4d4142005-09-01 00:19:25 +00001635 // fold (and (or x, 0xFFFF), 0xFF) -> 0xFF
Nate Begeman5dc7e862005-11-02 18:42:59 +00001636 if (N1C && N0.getOpcode() == ISD::OR)
Nate Begeman1d4d4142005-09-01 00:19:25 +00001637 if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
Dan Gohman002e5d02008-03-13 22:13:53 +00001638 if ((ORI->getAPIntValue() & N1C->getAPIntValue()) == N1C->getAPIntValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001639 return N1;
Chris Lattner3603cd62006-02-02 07:17:31 +00001640 // fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
1641 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001642 SDOperand N0Op0 = N0.getOperand(0);
1643 APInt Mask = ~N1C->getAPIntValue();
1644 Mask.trunc(N0Op0.getValueSizeInBits());
1645 if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
Chris Lattner1ec05d12006-03-01 21:47:21 +00001646 SDOperand Zext = DAG.getNode(ISD::ZERO_EXTEND, N0.getValueType(),
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001647 N0Op0);
Chris Lattner1ec05d12006-03-01 21:47:21 +00001648
1649 // Replace uses of the AND with uses of the Zero extend node.
1650 CombineTo(N, Zext);
1651
Chris Lattner3603cd62006-02-02 07:17:31 +00001652 // We actually want to replace all uses of the any_extend with the
1653 // zero_extend, to avoid duplicating things. This will later cause this
1654 // AND to be folded.
Chris Lattner1ec05d12006-03-01 21:47:21 +00001655 CombineTo(N0.Val, Zext);
Chris Lattnerfedced72006-04-20 23:55:59 +00001656 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Chris Lattner3603cd62006-02-02 07:17:31 +00001657 }
1658 }
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001659 // fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
1660 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1661 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1662 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1663
1664 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1665 MVT::isInteger(LL.getValueType())) {
1666 // fold (X == 0) & (Y == 0) -> (X|Y == 0)
Dan Gohman002e5d02008-03-13 22:13:53 +00001667 if (cast<ConstantSDNode>(LR)->isNullValue() && Op1 == ISD::SETEQ) {
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001668 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
Chris Lattner5750df92006-03-01 04:03:14 +00001669 AddToWorkList(ORNode.Val);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001670 return DAG.getSetCC(VT, ORNode, LR, Op1);
1671 }
1672 // fold (X == -1) & (Y == -1) -> (X&Y == -1)
1673 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
1674 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
Chris Lattner5750df92006-03-01 04:03:14 +00001675 AddToWorkList(ANDNode.Val);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001676 return DAG.getSetCC(VT, ANDNode, LR, Op1);
1677 }
1678 // fold (X > -1) & (Y > -1) -> (X|Y > -1)
1679 if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
1680 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
Chris Lattner5750df92006-03-01 04:03:14 +00001681 AddToWorkList(ORNode.Val);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001682 return DAG.getSetCC(VT, ORNode, LR, Op1);
1683 }
1684 }
1685 // canonicalize equivalent to ll == rl
1686 if (LL == RR && LR == RL) {
1687 Op1 = ISD::getSetCCSwappedOperands(Op1);
1688 std::swap(RL, RR);
1689 }
1690 if (LL == RL && LR == RR) {
1691 bool isInteger = MVT::isInteger(LL.getValueType());
1692 ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
1693 if (Result != ISD::SETCC_INVALID)
1694 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1695 }
1696 }
Chris Lattner35e5c142006-05-05 05:51:50 +00001697
1698 // Simplify: and (op x...), (op y...) -> (op (and x, y))
1699 if (N0.getOpcode() == N1.getOpcode()) {
1700 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1701 if (Tmp.Val) return Tmp;
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001702 }
Chris Lattner35e5c142006-05-05 05:51:50 +00001703
Nate Begemande996292006-02-03 22:24:05 +00001704 // fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
1705 // fold (and (sra)) -> (and (srl)) when possible.
Chris Lattner6ea2dee2006-03-25 22:19:00 +00001706 if (!MVT::isVector(VT) &&
1707 SimplifyDemandedBits(SDOperand(N, 0)))
Chris Lattneref027f92006-04-21 15:32:26 +00001708 return SDOperand(N, 0);
Nate Begemanded49632005-10-13 03:11:28 +00001709 // fold (zext_inreg (extload x)) -> (zextload x)
Evan Cheng83060c52007-03-07 08:07:03 +00001710 if (ISD::isEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val)) {
Evan Cheng466685d2006-10-09 20:57:25 +00001711 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Dan Gohmanb625f2f2008-01-30 00:15:11 +00001712 MVT::ValueType EVT = LN0->getMemoryVT();
Nate Begemanbfd65a02005-10-13 18:34:58 +00001713 // If we zero all the possible extended bits, then we can turn this into
1714 // a zextload if we are running before legalize or the operation is legal.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001715 unsigned BitWidth = N1.getValueSizeInBits();
1716 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
1717 BitWidth - MVT::getSizeInBits(EVT))) &&
Evan Chengc5484282006-10-04 00:56:09 +00001718 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
Evan Cheng466685d2006-10-09 20:57:25 +00001719 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
1720 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00001721 LN0->getSrcValueOffset(), EVT,
1722 LN0->isVolatile(),
1723 LN0->getAlignment());
Chris Lattner5750df92006-03-01 04:03:14 +00001724 AddToWorkList(N);
Chris Lattner67a44cd2005-10-13 18:16:34 +00001725 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
Chris Lattnerfedced72006-04-20 23:55:59 +00001726 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Nate Begemanded49632005-10-13 03:11:28 +00001727 }
1728 }
1729 // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
Evan Cheng83060c52007-03-07 08:07:03 +00001730 if (ISD::isSEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
1731 N0.hasOneUse()) {
Evan Cheng466685d2006-10-09 20:57:25 +00001732 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Dan Gohmanb625f2f2008-01-30 00:15:11 +00001733 MVT::ValueType EVT = LN0->getMemoryVT();
Nate Begemanbfd65a02005-10-13 18:34:58 +00001734 // If we zero all the possible extended bits, then we can turn this into
1735 // a zextload if we are running before legalize or the operation is legal.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001736 unsigned BitWidth = N1.getValueSizeInBits();
1737 if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
1738 BitWidth - MVT::getSizeInBits(EVT))) &&
Evan Chengc5484282006-10-04 00:56:09 +00001739 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
Evan Cheng466685d2006-10-09 20:57:25 +00001740 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
1741 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00001742 LN0->getSrcValueOffset(), EVT,
1743 LN0->isVolatile(),
1744 LN0->getAlignment());
Chris Lattner5750df92006-03-01 04:03:14 +00001745 AddToWorkList(N);
Chris Lattner67a44cd2005-10-13 18:16:34 +00001746 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
Chris Lattnerfedced72006-04-20 23:55:59 +00001747 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Nate Begemanded49632005-10-13 03:11:28 +00001748 }
1749 }
Chris Lattner15045b62006-02-28 06:35:35 +00001750
Chris Lattner35a9f5a2006-02-28 06:49:37 +00001751 // fold (and (load x), 255) -> (zextload x, i8)
1752 // fold (and (extload x, i16), 255) -> (zextload x, i8)
Evan Cheng466685d2006-10-09 20:57:25 +00001753 if (N1C && N0.getOpcode() == ISD::LOAD) {
1754 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
1755 if (LN0->getExtensionType() != ISD::SEXTLOAD &&
Chris Lattnerddf89562008-01-17 19:59:44 +00001756 LN0->isUnindexed() && N0.hasOneUse()) {
Evan Cheng466685d2006-10-09 20:57:25 +00001757 MVT::ValueType EVT, LoadedVT;
Dan Gohman002e5d02008-03-13 22:13:53 +00001758 if (N1C->getAPIntValue() == 255)
Evan Cheng466685d2006-10-09 20:57:25 +00001759 EVT = MVT::i8;
Dan Gohman002e5d02008-03-13 22:13:53 +00001760 else if (N1C->getAPIntValue() == 65535)
Evan Cheng466685d2006-10-09 20:57:25 +00001761 EVT = MVT::i16;
Dan Gohman002e5d02008-03-13 22:13:53 +00001762 else if (N1C->getAPIntValue() == ~0U)
Evan Cheng466685d2006-10-09 20:57:25 +00001763 EVT = MVT::i32;
1764 else
1765 EVT = MVT::Other;
Chris Lattner35a9f5a2006-02-28 06:49:37 +00001766
Dan Gohmanb625f2f2008-01-30 00:15:11 +00001767 LoadedVT = LN0->getMemoryVT();
Evan Cheng466685d2006-10-09 20:57:25 +00001768 if (EVT != MVT::Other && LoadedVT > EVT &&
1769 (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
1770 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
1771 // For big endian targets, we need to add an offset to the pointer to
1772 // load the correct bytes. For little endian systems, we merely need to
1773 // read fewer bytes from the same pointer.
Duncan Sandsc6fa1702007-11-09 08:57:19 +00001774 unsigned LVTStoreBytes = MVT::getStoreSizeInBits(LoadedVT)/8;
1775 unsigned EVTStoreBytes = MVT::getStoreSizeInBits(EVT)/8;
1776 unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
Duncan Sandsdc846502007-10-28 12:59:45 +00001777 unsigned Alignment = LN0->getAlignment();
Evan Cheng466685d2006-10-09 20:57:25 +00001778 SDOperand NewPtr = LN0->getBasePtr();
Duncan Sands0753fc12008-02-11 10:37:04 +00001779 if (TLI.isBigEndian()) {
Evan Cheng466685d2006-10-09 20:57:25 +00001780 NewPtr = DAG.getNode(ISD::ADD, PtrType, NewPtr,
1781 DAG.getConstant(PtrOff, PtrType));
Duncan Sandsdc846502007-10-28 12:59:45 +00001782 Alignment = MinAlign(Alignment, PtrOff);
1783 }
Evan Cheng466685d2006-10-09 20:57:25 +00001784 AddToWorkList(NewPtr.Val);
1785 SDOperand Load =
1786 DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(), NewPtr,
Christopher Lamb95c218a2007-04-22 23:15:30 +00001787 LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
Duncan Sandsdc846502007-10-28 12:59:45 +00001788 LN0->isVolatile(), Alignment);
Evan Cheng466685d2006-10-09 20:57:25 +00001789 AddToWorkList(N);
1790 CombineTo(N0.Val, Load, Load.getValue(1));
1791 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
1792 }
Chris Lattner15045b62006-02-28 06:35:35 +00001793 }
1794 }
1795
Nate Begeman83e75ec2005-09-06 04:43:02 +00001796 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001797}
1798
Nate Begeman83e75ec2005-09-06 04:43:02 +00001799SDOperand DAGCombiner::visitOR(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00001800 SDOperand N0 = N->getOperand(0);
1801 SDOperand N1 = N->getOperand(1);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001802 SDOperand LL, LR, RL, RR, CC0, CC1;
Nate Begeman646d7e22005-09-02 21:18:40 +00001803 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
1804 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman83e75ec2005-09-06 04:43:02 +00001805 MVT::ValueType VT = N1.getValueType();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001806
Dan Gohman7f321562007-06-25 16:23:39 +00001807 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00001808 if (MVT::isVector(VT)) {
1809 SDOperand FoldedVOp = SimplifyVBinOp(N);
1810 if (FoldedVOp.Val) return FoldedVOp;
1811 }
Dan Gohman7f321562007-06-25 16:23:39 +00001812
Dan Gohman613e0d82007-07-03 14:03:57 +00001813 // fold (or x, undef) -> -1
Dan Gohmand595b5f2007-07-10 14:20:37 +00001814 if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
Chris Lattnere094f542007-07-09 16:16:34 +00001815 return DAG.getConstant(~0ULL, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001816 // fold (or c1, c2) -> c1|c2
Nate Begeman646d7e22005-09-02 21:18:40 +00001817 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00001818 return DAG.getNode(ISD::OR, VT, N0, N1);
Nate Begeman99801192005-09-07 23:25:52 +00001819 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +00001820 if (N0C && !N1C)
1821 return DAG.getNode(ISD::OR, VT, N1, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00001822 // fold (or x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00001823 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001824 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00001825 // fold (or x, -1) -> -1
Nate Begeman646d7e22005-09-02 21:18:40 +00001826 if (N1C && N1C->isAllOnesValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00001827 return N1;
1828 // fold (or x, c) -> c iff (x & ~c) == 0
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001829 if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
Nate Begeman83e75ec2005-09-06 04:43:02 +00001830 return N1;
Nate Begemancd4d58c2006-02-03 06:46:56 +00001831 // reassociate or
1832 SDOperand ROR = ReassociateOps(ISD::OR, N0, N1);
1833 if (ROR.Val != 0)
1834 return ROR;
1835 // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
1836 if (N1C && N0.getOpcode() == ISD::AND && N0.Val->hasOneUse() &&
Chris Lattner731d3482005-10-27 05:06:38 +00001837 isa<ConstantSDNode>(N0.getOperand(1))) {
Chris Lattner731d3482005-10-27 05:06:38 +00001838 ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
1839 return DAG.getNode(ISD::AND, VT, DAG.getNode(ISD::OR, VT, N0.getOperand(0),
1840 N1),
Dan Gohman002e5d02008-03-13 22:13:53 +00001841 DAG.getConstant(N1C->getAPIntValue() |
1842 C1->getAPIntValue(), VT));
Nate Begeman223df222005-09-08 20:18:10 +00001843 }
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001844 // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
1845 if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
1846 ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
1847 ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
1848
1849 if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
1850 MVT::isInteger(LL.getValueType())) {
1851 // fold (X != 0) | (Y != 0) -> (X|Y != 0)
1852 // fold (X < 0) | (Y < 0) -> (X|Y < 0)
Dan Gohman002e5d02008-03-13 22:13:53 +00001853 if (cast<ConstantSDNode>(LR)->isNullValue() &&
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001854 (Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
1855 SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
Chris Lattner5750df92006-03-01 04:03:14 +00001856 AddToWorkList(ORNode.Val);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001857 return DAG.getSetCC(VT, ORNode, LR, Op1);
1858 }
1859 // fold (X != -1) | (Y != -1) -> (X&Y != -1)
1860 // fold (X > -1) | (Y > -1) -> (X&Y > -1)
1861 if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
1862 (Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
1863 SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
Chris Lattner5750df92006-03-01 04:03:14 +00001864 AddToWorkList(ANDNode.Val);
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001865 return DAG.getSetCC(VT, ANDNode, LR, Op1);
1866 }
1867 }
1868 // canonicalize equivalent to ll == rl
1869 if (LL == RR && LR == RL) {
1870 Op1 = ISD::getSetCCSwappedOperands(Op1);
1871 std::swap(RL, RR);
1872 }
1873 if (LL == RL && LR == RR) {
1874 bool isInteger = MVT::isInteger(LL.getValueType());
1875 ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
1876 if (Result != ISD::SETCC_INVALID)
1877 return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
1878 }
1879 }
Chris Lattner35e5c142006-05-05 05:51:50 +00001880
1881 // Simplify: or (op x...), (op y...) -> (op (or x, y))
1882 if (N0.getOpcode() == N1.getOpcode()) {
1883 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
1884 if (Tmp.Val) return Tmp;
Nate Begeman39ee1ac2005-09-09 19:49:52 +00001885 }
Chris Lattner516b9622006-09-14 20:50:57 +00001886
Chris Lattner1ec72732006-09-14 21:11:37 +00001887 // (X & C1) | (Y & C2) -> (X|Y) & C3 if possible.
1888 if (N0.getOpcode() == ISD::AND &&
1889 N1.getOpcode() == ISD::AND &&
1890 N0.getOperand(1).getOpcode() == ISD::Constant &&
1891 N1.getOperand(1).getOpcode() == ISD::Constant &&
1892 // Don't increase # computations.
1893 (N0.Val->hasOneUse() || N1.Val->hasOneUse())) {
1894 // We can only do this xform if we know that bits from X that are set in C2
1895 // but not in C1 are already zero. Likewise for Y.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00001896 const APInt &LHSMask =
1897 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
1898 const APInt &RHSMask =
1899 cast<ConstantSDNode>(N1.getOperand(1))->getAPIntValue();
Chris Lattner1ec72732006-09-14 21:11:37 +00001900
Dan Gohmanea859be2007-06-22 14:59:07 +00001901 if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
1902 DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
Chris Lattner1ec72732006-09-14 21:11:37 +00001903 SDOperand X =DAG.getNode(ISD::OR, VT, N0.getOperand(0), N1.getOperand(0));
1904 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(LHSMask|RHSMask, VT));
1905 }
1906 }
1907
1908
Chris Lattner516b9622006-09-14 20:50:57 +00001909 // See if this is some rotate idiom.
1910 if (SDNode *Rot = MatchRotate(N0, N1))
1911 return SDOperand(Rot, 0);
Chris Lattner35e5c142006-05-05 05:51:50 +00001912
Nate Begeman83e75ec2005-09-06 04:43:02 +00001913 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00001914}
1915
Chris Lattner516b9622006-09-14 20:50:57 +00001916
1917/// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
1918static bool MatchRotateHalf(SDOperand Op, SDOperand &Shift, SDOperand &Mask) {
1919 if (Op.getOpcode() == ISD::AND) {
Reid Spencer3ed469c2006-11-02 20:25:50 +00001920 if (isa<ConstantSDNode>(Op.getOperand(1))) {
Chris Lattner516b9622006-09-14 20:50:57 +00001921 Mask = Op.getOperand(1);
1922 Op = Op.getOperand(0);
1923 } else {
1924 return false;
1925 }
1926 }
1927
1928 if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
1929 Shift = Op;
1930 return true;
1931 }
1932 return false;
1933}
1934
1935
1936// MatchRotate - Handle an 'or' of two operands. If this is one of the many
1937// idioms for rotate, and if the target supports rotation instructions, generate
1938// a rot[lr].
1939SDNode *DAGCombiner::MatchRotate(SDOperand LHS, SDOperand RHS) {
1940 // Must be a legal type. Expanded an promoted things won't work with rotates.
1941 MVT::ValueType VT = LHS.getValueType();
1942 if (!TLI.isTypeLegal(VT)) return 0;
1943
1944 // The target must have at least one rotate flavor.
1945 bool HasROTL = TLI.isOperationLegal(ISD::ROTL, VT);
1946 bool HasROTR = TLI.isOperationLegal(ISD::ROTR, VT);
1947 if (!HasROTL && !HasROTR) return 0;
1948
1949 // Match "(X shl/srl V1) & V2" where V2 may not be present.
1950 SDOperand LHSShift; // The shift.
1951 SDOperand LHSMask; // AND value if any.
1952 if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
1953 return 0; // Not part of a rotate.
1954
1955 SDOperand RHSShift; // The shift.
1956 SDOperand RHSMask; // AND value if any.
1957 if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
1958 return 0; // Not part of a rotate.
1959
1960 if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
1961 return 0; // Not shifting the same value.
1962
1963 if (LHSShift.getOpcode() == RHSShift.getOpcode())
1964 return 0; // Shifts must disagree.
1965
1966 // Canonicalize shl to left side in a shl/srl pair.
1967 if (RHSShift.getOpcode() == ISD::SHL) {
1968 std::swap(LHS, RHS);
1969 std::swap(LHSShift, RHSShift);
1970 std::swap(LHSMask , RHSMask );
1971 }
1972
1973 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
Scott Michelc9dc1142007-04-02 21:36:32 +00001974 SDOperand LHSShiftArg = LHSShift.getOperand(0);
1975 SDOperand LHSShiftAmt = LHSShift.getOperand(1);
1976 SDOperand RHSShiftAmt = RHSShift.getOperand(1);
Chris Lattner516b9622006-09-14 20:50:57 +00001977
1978 // fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
1979 // fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
Scott Michelc9dc1142007-04-02 21:36:32 +00001980 if (LHSShiftAmt.getOpcode() == ISD::Constant &&
1981 RHSShiftAmt.getOpcode() == ISD::Constant) {
1982 uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getValue();
1983 uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getValue();
Chris Lattner516b9622006-09-14 20:50:57 +00001984 if ((LShVal + RShVal) != OpSizeInBits)
1985 return 0;
1986
1987 SDOperand Rot;
1988 if (HasROTL)
Scott Michelc9dc1142007-04-02 21:36:32 +00001989 Rot = DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt);
Chris Lattner516b9622006-09-14 20:50:57 +00001990 else
Scott Michelc9dc1142007-04-02 21:36:32 +00001991 Rot = DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt);
Chris Lattner516b9622006-09-14 20:50:57 +00001992
1993 // If there is an AND of either shifted operand, apply it to the result.
1994 if (LHSMask.Val || RHSMask.Val) {
Dan Gohman220a8232008-03-03 23:51:38 +00001995 APInt Mask = APInt::getAllOnesValue(OpSizeInBits);
Chris Lattner516b9622006-09-14 20:50:57 +00001996
1997 if (LHSMask.Val) {
Dan Gohman220a8232008-03-03 23:51:38 +00001998 APInt RHSBits = APInt::getLowBitsSet(OpSizeInBits, LShVal);
1999 Mask &= cast<ConstantSDNode>(LHSMask)->getAPIntValue() | RHSBits;
Chris Lattner516b9622006-09-14 20:50:57 +00002000 }
2001 if (RHSMask.Val) {
Dan Gohman220a8232008-03-03 23:51:38 +00002002 APInt LHSBits = APInt::getHighBitsSet(OpSizeInBits, RShVal);
2003 Mask &= cast<ConstantSDNode>(RHSMask)->getAPIntValue() | LHSBits;
Chris Lattner516b9622006-09-14 20:50:57 +00002004 }
2005
2006 Rot = DAG.getNode(ISD::AND, VT, Rot, DAG.getConstant(Mask, VT));
2007 }
2008
2009 return Rot.Val;
2010 }
2011
2012 // If there is a mask here, and we have a variable shift, we can't be sure
2013 // that we're masking out the right stuff.
2014 if (LHSMask.Val || RHSMask.Val)
2015 return 0;
2016
2017 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
2018 // fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
Scott Michelc9dc1142007-04-02 21:36:32 +00002019 if (RHSShiftAmt.getOpcode() == ISD::SUB &&
2020 LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
Chris Lattner516b9622006-09-14 20:50:57 +00002021 if (ConstantSDNode *SUBC =
Scott Michelc9dc1142007-04-02 21:36:32 +00002022 dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00002023 if (SUBC->getAPIntValue() == OpSizeInBits) {
Chris Lattner516b9622006-09-14 20:50:57 +00002024 if (HasROTL)
Scott Michelc9dc1142007-04-02 21:36:32 +00002025 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
Chris Lattner516b9622006-09-14 20:50:57 +00002026 else
Scott Michelc9dc1142007-04-02 21:36:32 +00002027 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00002028 }
Chris Lattner516b9622006-09-14 20:50:57 +00002029 }
2030 }
2031
2032 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
2033 // fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
Scott Michelc9dc1142007-04-02 21:36:32 +00002034 if (LHSShiftAmt.getOpcode() == ISD::SUB &&
2035 RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
Chris Lattner516b9622006-09-14 20:50:57 +00002036 if (ConstantSDNode *SUBC =
Scott Michelc9dc1142007-04-02 21:36:32 +00002037 dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00002038 if (SUBC->getAPIntValue() == OpSizeInBits) {
Chris Lattner516b9622006-09-14 20:50:57 +00002039 if (HasROTL)
Scott Michelc9dc1142007-04-02 21:36:32 +00002040 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
Chris Lattner516b9622006-09-14 20:50:57 +00002041 else
Scott Michelc9dc1142007-04-02 21:36:32 +00002042 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00002043 }
Scott Michelc9dc1142007-04-02 21:36:32 +00002044 }
2045 }
2046
2047 // Look for sign/zext/any-extended cases:
2048 if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
2049 || LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
2050 || LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND) &&
2051 (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
2052 || RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
2053 || RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND)) {
2054 SDOperand LExtOp0 = LHSShiftAmt.getOperand(0);
2055 SDOperand RExtOp0 = RHSShiftAmt.getOperand(0);
2056 if (RExtOp0.getOpcode() == ISD::SUB &&
2057 RExtOp0.getOperand(1) == LExtOp0) {
2058 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
2059 // (rotr x, y)
2060 // fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
2061 // (rotl x, (sub 32, y))
2062 if (ConstantSDNode *SUBC = cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00002063 if (SUBC->getAPIntValue() == OpSizeInBits) {
Scott Michelc9dc1142007-04-02 21:36:32 +00002064 if (HasROTL)
2065 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
2066 else
2067 return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
2068 }
2069 }
2070 } else if (LExtOp0.getOpcode() == ISD::SUB &&
2071 RExtOp0 == LExtOp0.getOperand(1)) {
2072 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
2073 // (rotl x, y)
2074 // fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
2075 // (rotr x, (sub 32, y))
2076 if (ConstantSDNode *SUBC = cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
Dan Gohman002e5d02008-03-13 22:13:53 +00002077 if (SUBC->getAPIntValue() == OpSizeInBits) {
Scott Michelc9dc1142007-04-02 21:36:32 +00002078 if (HasROTL)
2079 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, RHSShiftAmt).Val;
2080 else
2081 return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
2082 }
2083 }
Chris Lattner516b9622006-09-14 20:50:57 +00002084 }
2085 }
2086
2087 return 0;
2088}
2089
2090
Nate Begeman83e75ec2005-09-06 04:43:02 +00002091SDOperand DAGCombiner::visitXOR(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002092 SDOperand N0 = N->getOperand(0);
2093 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00002094 SDOperand LHS, RHS, CC;
2095 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2096 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002097 MVT::ValueType VT = N0.getValueType();
2098
Dan Gohman7f321562007-06-25 16:23:39 +00002099 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00002100 if (MVT::isVector(VT)) {
2101 SDOperand FoldedVOp = SimplifyVBinOp(N);
2102 if (FoldedVOp.Val) return FoldedVOp;
2103 }
Dan Gohman7f321562007-06-25 16:23:39 +00002104
Dan Gohman613e0d82007-07-03 14:03:57 +00002105 // fold (xor x, undef) -> undef
Dan Gohman70fb1ae2007-07-10 15:19:29 +00002106 if (N0.getOpcode() == ISD::UNDEF)
2107 return N0;
2108 if (N1.getOpcode() == ISD::UNDEF)
Dan Gohman613e0d82007-07-03 14:03:57 +00002109 return N1;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002110 // fold (xor c1, c2) -> c1^c2
Nate Begeman646d7e22005-09-02 21:18:40 +00002111 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00002112 return DAG.getNode(ISD::XOR, VT, N0, N1);
Nate Begeman99801192005-09-07 23:25:52 +00002113 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +00002114 if (N0C && !N1C)
2115 return DAG.getNode(ISD::XOR, VT, N1, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002116 // fold (xor x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00002117 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002118 return N0;
Nate Begemancd4d58c2006-02-03 06:46:56 +00002119 // reassociate xor
2120 SDOperand RXOR = ReassociateOps(ISD::XOR, N0, N1);
2121 if (RXOR.Val != 0)
2122 return RXOR;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002123 // fold !(x cc y) -> (x !cc y)
Dan Gohman002e5d02008-03-13 22:13:53 +00002124 if (N1C && N1C->getAPIntValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
Nate Begeman646d7e22005-09-02 21:18:40 +00002125 bool isInt = MVT::isInteger(LHS.getValueType());
2126 ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
2127 isInt);
2128 if (N0.getOpcode() == ISD::SETCC)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002129 return DAG.getSetCC(VT, LHS, RHS, NotCC);
Nate Begeman646d7e22005-09-02 21:18:40 +00002130 if (N0.getOpcode() == ISD::SELECT_CC)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002131 return DAG.getSelectCC(LHS, RHS, N0.getOperand(2),N0.getOperand(3),NotCC);
Nate Begeman646d7e22005-09-02 21:18:40 +00002132 assert(0 && "Unhandled SetCC Equivalent!");
2133 abort();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002134 }
Chris Lattner61c5ff42007-09-10 21:39:07 +00002135 // fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
Dan Gohman002e5d02008-03-13 22:13:53 +00002136 if (N1C && N1C->getAPIntValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
Chris Lattner61c5ff42007-09-10 21:39:07 +00002137 N0.Val->hasOneUse() && isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
2138 SDOperand V = N0.getOperand(0);
2139 V = DAG.getNode(ISD::XOR, V.getValueType(), V,
Duncan Sands272dce02007-10-10 09:54:50 +00002140 DAG.getConstant(1, V.getValueType()));
Chris Lattner61c5ff42007-09-10 21:39:07 +00002141 AddToWorkList(V.Val);
2142 return DAG.getNode(ISD::ZERO_EXTEND, VT, V);
2143 }
2144
Nate Begeman99801192005-09-07 23:25:52 +00002145 // fold !(x or y) -> (!x and !y) iff x or y are setcc
Dan Gohman002e5d02008-03-13 22:13:53 +00002146 if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
Nate Begeman99801192005-09-07 23:25:52 +00002147 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002148 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
Nate Begeman99801192005-09-07 23:25:52 +00002149 if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
2150 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002151 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
2152 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
Chris Lattner5750df92006-03-01 04:03:14 +00002153 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
Nate Begeman99801192005-09-07 23:25:52 +00002154 return DAG.getNode(NewOpcode, VT, LHS, RHS);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002155 }
2156 }
Nate Begeman99801192005-09-07 23:25:52 +00002157 // fold !(x or y) -> (!x and !y) iff x or y are constants
2158 if (N1C && N1C->isAllOnesValue() &&
2159 (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002160 SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
Nate Begeman99801192005-09-07 23:25:52 +00002161 if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
2162 unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002163 LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
2164 RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
Chris Lattner5750df92006-03-01 04:03:14 +00002165 AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
Nate Begeman99801192005-09-07 23:25:52 +00002166 return DAG.getNode(NewOpcode, VT, LHS, RHS);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002167 }
2168 }
Nate Begeman223df222005-09-08 20:18:10 +00002169 // fold (xor (xor x, c1), c2) -> (xor x, c1^c2)
2170 if (N1C && N0.getOpcode() == ISD::XOR) {
2171 ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
2172 ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
2173 if (N00C)
2174 return DAG.getNode(ISD::XOR, VT, N0.getOperand(1),
Dan Gohman002e5d02008-03-13 22:13:53 +00002175 DAG.getConstant(N1C->getAPIntValue()^
2176 N00C->getAPIntValue(), VT));
Nate Begeman223df222005-09-08 20:18:10 +00002177 if (N01C)
2178 return DAG.getNode(ISD::XOR, VT, N0.getOperand(0),
Dan Gohman002e5d02008-03-13 22:13:53 +00002179 DAG.getConstant(N1C->getAPIntValue()^
2180 N01C->getAPIntValue(), VT));
Nate Begeman223df222005-09-08 20:18:10 +00002181 }
2182 // fold (xor x, x) -> 0
Chris Lattner4fbdd592006-03-28 19:11:05 +00002183 if (N0 == N1) {
2184 if (!MVT::isVector(VT)) {
2185 return DAG.getConstant(0, VT);
2186 } else if (!AfterLegalize || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
2187 // Produce a vector of zeros.
Dan Gohman51eaa862007-06-14 22:58:02 +00002188 SDOperand El = DAG.getConstant(0, MVT::getVectorElementType(VT));
Chris Lattner4fbdd592006-03-28 19:11:05 +00002189 std::vector<SDOperand> Ops(MVT::getVectorNumElements(VT), El);
Chris Lattnerbd564bf2006-08-08 02:23:42 +00002190 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
Chris Lattner4fbdd592006-03-28 19:11:05 +00002191 }
2192 }
Chris Lattner35e5c142006-05-05 05:51:50 +00002193
2194 // Simplify: xor (op x...), (op y...) -> (op (xor x, y))
2195 if (N0.getOpcode() == N1.getOpcode()) {
2196 SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
2197 if (Tmp.Val) return Tmp;
Nate Begeman39ee1ac2005-09-09 19:49:52 +00002198 }
Chris Lattner35e5c142006-05-05 05:51:50 +00002199
Chris Lattner3e104b12006-04-08 04:15:24 +00002200 // Simplify the expression using non-local knowledge.
2201 if (!MVT::isVector(VT) &&
2202 SimplifyDemandedBits(SDOperand(N, 0)))
Chris Lattneref027f92006-04-21 15:32:26 +00002203 return SDOperand(N, 0);
Chris Lattner3e104b12006-04-08 04:15:24 +00002204
Nate Begeman83e75ec2005-09-06 04:43:02 +00002205 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002206}
2207
Chris Lattnere70da202007-12-06 07:33:36 +00002208/// visitShiftByConstant - Handle transforms common to the three shifts, when
2209/// the shift amount is a constant.
2210SDOperand DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
2211 SDNode *LHS = N->getOperand(0).Val;
2212 if (!LHS->hasOneUse()) return SDOperand();
2213
2214 // We want to pull some binops through shifts, so that we have (and (shift))
2215 // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
2216 // thing happens with address calculations, so it's important to canonicalize
2217 // it.
2218 bool HighBitSet = false; // Can we transform this if the high bit is set?
2219
2220 switch (LHS->getOpcode()) {
2221 default: return SDOperand();
2222 case ISD::OR:
2223 case ISD::XOR:
2224 HighBitSet = false; // We can only transform sra if the high bit is clear.
2225 break;
2226 case ISD::AND:
2227 HighBitSet = true; // We can only transform sra if the high bit is set.
2228 break;
2229 case ISD::ADD:
2230 if (N->getOpcode() != ISD::SHL)
2231 return SDOperand(); // only shl(add) not sr[al](add).
2232 HighBitSet = false; // We can only transform sra if the high bit is clear.
2233 break;
2234 }
2235
2236 // We require the RHS of the binop to be a constant as well.
2237 ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
2238 if (!BinOpCst) return SDOperand();
2239
Chris Lattnerd3fd6d22007-12-06 07:47:55 +00002240
2241 // FIXME: disable this for unless the input to the binop is a shift by a
2242 // constant. If it is not a shift, it pessimizes some common cases like:
2243 //
2244 //void foo(int *X, int i) { X[i & 1235] = 1; }
2245 //int bar(int *X, int i) { return X[i & 255]; }
2246 SDNode *BinOpLHSVal = LHS->getOperand(0).Val;
2247 if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
2248 BinOpLHSVal->getOpcode() != ISD::SRA &&
2249 BinOpLHSVal->getOpcode() != ISD::SRL) ||
2250 !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
2251 return SDOperand();
2252
Chris Lattnere70da202007-12-06 07:33:36 +00002253 MVT::ValueType VT = N->getValueType(0);
2254
2255 // If this is a signed shift right, and the high bit is modified
2256 // by the logical operation, do not perform the transformation.
2257 // The highBitSet boolean indicates the value of the high bit of
2258 // the constant which would cause it to be modified for this
2259 // operation.
2260 if (N->getOpcode() == ISD::SRA) {
Dan Gohman220a8232008-03-03 23:51:38 +00002261 bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
2262 if (BinOpRHSSignSet != HighBitSet)
Chris Lattnere70da202007-12-06 07:33:36 +00002263 return SDOperand();
2264 }
2265
2266 // Fold the constants, shifting the binop RHS by the shift amount.
2267 SDOperand NewRHS = DAG.getNode(N->getOpcode(), N->getValueType(0),
2268 LHS->getOperand(1), N->getOperand(1));
2269
2270 // Create the new shift.
2271 SDOperand NewShift = DAG.getNode(N->getOpcode(), VT, LHS->getOperand(0),
2272 N->getOperand(1));
2273
2274 // Create the new binop.
2275 return DAG.getNode(LHS->getOpcode(), VT, NewShift, NewRHS);
2276}
2277
2278
Nate Begeman83e75ec2005-09-06 04:43:02 +00002279SDOperand DAGCombiner::visitSHL(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002280 SDOperand N0 = N->getOperand(0);
2281 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00002282 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2283 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002284 MVT::ValueType VT = N0.getValueType();
2285 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
2286
2287 // fold (shl c1, c2) -> c1<<c2
Nate Begeman646d7e22005-09-02 21:18:40 +00002288 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00002289 return DAG.getNode(ISD::SHL, VT, N0, N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002290 // fold (shl 0, x) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00002291 if (N0C && N0C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002292 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002293 // fold (shl x, c >= size(x)) -> undef
Nate Begeman646d7e22005-09-02 21:18:40 +00002294 if (N1C && N1C->getValue() >= OpSizeInBits)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002295 return DAG.getNode(ISD::UNDEF, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002296 // fold (shl x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00002297 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002298 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002299 // if (shl x, c) is known to be zero, return 0
Dan Gohman2e68b6f2008-02-25 21:11:39 +00002300 if (DAG.MaskedValueIsZero(SDOperand(N, 0),
2301 APInt::getAllOnesValue(MVT::getSizeInBits(VT))))
Nate Begeman83e75ec2005-09-06 04:43:02 +00002302 return DAG.getConstant(0, VT);
Chris Lattner61a4c072007-04-18 03:06:49 +00002303 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
Chris Lattneref027f92006-04-21 15:32:26 +00002304 return SDOperand(N, 0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002305 // fold (shl (shl x, c1), c2) -> 0 or (shl x, c1+c2)
Nate Begeman646d7e22005-09-02 21:18:40 +00002306 if (N1C && N0.getOpcode() == ISD::SHL &&
Nate Begeman1d4d4142005-09-01 00:19:25 +00002307 N0.getOperand(1).getOpcode() == ISD::Constant) {
2308 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
Nate Begeman646d7e22005-09-02 21:18:40 +00002309 uint64_t c2 = N1C->getValue();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002310 if (c1 + c2 > OpSizeInBits)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002311 return DAG.getConstant(0, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002312 return DAG.getNode(ISD::SHL, VT, N0.getOperand(0),
Nate Begeman83e75ec2005-09-06 04:43:02 +00002313 DAG.getConstant(c1 + c2, N1.getValueType()));
Nate Begeman1d4d4142005-09-01 00:19:25 +00002314 }
2315 // fold (shl (srl x, c1), c2) -> (shl (and x, -1 << c1), c2-c1) or
2316 // (srl (and x, -1 << c1), c1-c2)
Nate Begeman646d7e22005-09-02 21:18:40 +00002317 if (N1C && N0.getOpcode() == ISD::SRL &&
Nate Begeman1d4d4142005-09-01 00:19:25 +00002318 N0.getOperand(1).getOpcode() == ISD::Constant) {
2319 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
Nate Begeman646d7e22005-09-02 21:18:40 +00002320 uint64_t c2 = N1C->getValue();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002321 SDOperand Mask = DAG.getNode(ISD::AND, VT, N0.getOperand(0),
2322 DAG.getConstant(~0ULL << c1, VT));
2323 if (c2 > c1)
2324 return DAG.getNode(ISD::SHL, VT, Mask,
Nate Begeman83e75ec2005-09-06 04:43:02 +00002325 DAG.getConstant(c2-c1, N1.getValueType()));
Nate Begeman1d4d4142005-09-01 00:19:25 +00002326 else
Nate Begeman83e75ec2005-09-06 04:43:02 +00002327 return DAG.getNode(ISD::SRL, VT, Mask,
2328 DAG.getConstant(c1-c2, N1.getValueType()));
Nate Begeman1d4d4142005-09-01 00:19:25 +00002329 }
2330 // fold (shl (sra x, c1), c1) -> (and x, -1 << c1)
Nate Begeman646d7e22005-09-02 21:18:40 +00002331 if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
Nate Begeman4ebd8052005-09-01 23:24:04 +00002332 return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
Nate Begeman83e75ec2005-09-06 04:43:02 +00002333 DAG.getConstant(~0ULL << N1C->getValue(), VT));
Chris Lattnere70da202007-12-06 07:33:36 +00002334
2335 return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002336}
2337
Nate Begeman83e75ec2005-09-06 04:43:02 +00002338SDOperand DAGCombiner::visitSRA(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002339 SDOperand N0 = N->getOperand(0);
2340 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00002341 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2342 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002343 MVT::ValueType VT = N0.getValueType();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002344
2345 // fold (sra c1, c2) -> c1>>c2
Nate Begeman646d7e22005-09-02 21:18:40 +00002346 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00002347 return DAG.getNode(ISD::SRA, VT, N0, N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002348 // fold (sra 0, x) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00002349 if (N0C && N0C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002350 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002351 // fold (sra -1, x) -> -1
Nate Begeman646d7e22005-09-02 21:18:40 +00002352 if (N0C && N0C->isAllOnesValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002353 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002354 // fold (sra x, c >= size(x)) -> undef
Nate Begemanfb7217b2006-02-17 19:54:08 +00002355 if (N1C && N1C->getValue() >= MVT::getSizeInBits(VT))
Nate Begeman83e75ec2005-09-06 04:43:02 +00002356 return DAG.getNode(ISD::UNDEF, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002357 // fold (sra x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00002358 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002359 return N0;
Nate Begemanfb7217b2006-02-17 19:54:08 +00002360 // fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
2361 // sext_inreg.
2362 if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
2363 unsigned LowBits = MVT::getSizeInBits(VT) - (unsigned)N1C->getValue();
2364 MVT::ValueType EVT;
2365 switch (LowBits) {
2366 default: EVT = MVT::Other; break;
2367 case 1: EVT = MVT::i1; break;
2368 case 8: EVT = MVT::i8; break;
2369 case 16: EVT = MVT::i16; break;
2370 case 32: EVT = MVT::i32; break;
2371 }
2372 if (EVT > MVT::Other && TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT))
2373 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
2374 DAG.getValueType(EVT));
2375 }
Chris Lattner71d9ebc2006-02-28 06:23:04 +00002376
2377 // fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
2378 if (N1C && N0.getOpcode() == ISD::SRA) {
2379 if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
2380 unsigned Sum = N1C->getValue() + C1->getValue();
2381 if (Sum >= MVT::getSizeInBits(VT)) Sum = MVT::getSizeInBits(VT)-1;
2382 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0),
2383 DAG.getConstant(Sum, N1C->getValueType(0)));
2384 }
2385 }
2386
Chris Lattnera8504462006-05-08 20:51:54 +00002387 // Simplify, based on bits shifted out of the LHS.
2388 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
2389 return SDOperand(N, 0);
2390
2391
Nate Begeman1d4d4142005-09-01 00:19:25 +00002392 // If the sign bit is known to be zero, switch this to a SRL.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00002393 if (DAG.SignBitIsZero(N0))
Nate Begeman83e75ec2005-09-06 04:43:02 +00002394 return DAG.getNode(ISD::SRL, VT, N0, N1);
Chris Lattnere70da202007-12-06 07:33:36 +00002395
2396 return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002397}
2398
Nate Begeman83e75ec2005-09-06 04:43:02 +00002399SDOperand DAGCombiner::visitSRL(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002400 SDOperand N0 = N->getOperand(0);
2401 SDOperand N1 = N->getOperand(1);
Nate Begeman646d7e22005-09-02 21:18:40 +00002402 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2403 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002404 MVT::ValueType VT = N0.getValueType();
2405 unsigned OpSizeInBits = MVT::getSizeInBits(VT);
2406
2407 // fold (srl c1, c2) -> c1 >>u c2
Nate Begeman646d7e22005-09-02 21:18:40 +00002408 if (N0C && N1C)
Nate Begemana148d982006-01-18 22:35:16 +00002409 return DAG.getNode(ISD::SRL, VT, N0, N1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002410 // fold (srl 0, x) -> 0
Nate Begeman646d7e22005-09-02 21:18:40 +00002411 if (N0C && N0C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002412 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002413 // fold (srl x, c >= size(x)) -> undef
Nate Begeman646d7e22005-09-02 21:18:40 +00002414 if (N1C && N1C->getValue() >= OpSizeInBits)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002415 return DAG.getNode(ISD::UNDEF, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002416 // fold (srl x, 0) -> x
Nate Begeman646d7e22005-09-02 21:18:40 +00002417 if (N1C && N1C->isNullValue())
Nate Begeman83e75ec2005-09-06 04:43:02 +00002418 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00002419 // if (srl x, c) is known to be zero, return 0
Dan Gohman2e68b6f2008-02-25 21:11:39 +00002420 if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0),
2421 APInt::getAllOnesValue(OpSizeInBits)))
Nate Begeman83e75ec2005-09-06 04:43:02 +00002422 return DAG.getConstant(0, VT);
Chris Lattnerec06e9a2007-04-18 03:05:22 +00002423
Nate Begeman1d4d4142005-09-01 00:19:25 +00002424 // fold (srl (srl x, c1), c2) -> 0 or (srl x, c1+c2)
Nate Begeman646d7e22005-09-02 21:18:40 +00002425 if (N1C && N0.getOpcode() == ISD::SRL &&
Nate Begeman1d4d4142005-09-01 00:19:25 +00002426 N0.getOperand(1).getOpcode() == ISD::Constant) {
2427 uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
Nate Begeman646d7e22005-09-02 21:18:40 +00002428 uint64_t c2 = N1C->getValue();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002429 if (c1 + c2 > OpSizeInBits)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002430 return DAG.getConstant(0, VT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002431 return DAG.getNode(ISD::SRL, VT, N0.getOperand(0),
Nate Begeman83e75ec2005-09-06 04:43:02 +00002432 DAG.getConstant(c1 + c2, N1.getValueType()));
Nate Begeman1d4d4142005-09-01 00:19:25 +00002433 }
Chris Lattner350bec02006-04-02 06:11:11 +00002434
Chris Lattner06afe072006-05-05 22:53:17 +00002435 // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
2436 if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
2437 // Shifting in all undef bits?
2438 MVT::ValueType SmallVT = N0.getOperand(0).getValueType();
2439 if (N1C->getValue() >= MVT::getSizeInBits(SmallVT))
2440 return DAG.getNode(ISD::UNDEF, VT);
2441
2442 SDOperand SmallShift = DAG.getNode(ISD::SRL, SmallVT, N0.getOperand(0), N1);
2443 AddToWorkList(SmallShift.Val);
2444 return DAG.getNode(ISD::ANY_EXTEND, VT, SmallShift);
2445 }
2446
Chris Lattner3657ffe2006-10-12 20:23:19 +00002447 // fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
2448 // bit, which is unmodified by sra.
2449 if (N1C && N1C->getValue()+1 == MVT::getSizeInBits(VT)) {
2450 if (N0.getOpcode() == ISD::SRA)
2451 return DAG.getNode(ISD::SRL, VT, N0.getOperand(0), N1);
2452 }
2453
Chris Lattner350bec02006-04-02 06:11:11 +00002454 // fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
2455 if (N1C && N0.getOpcode() == ISD::CTLZ &&
Dan Gohman002e5d02008-03-13 22:13:53 +00002456 N1C->getAPIntValue() == Log2_32(MVT::getSizeInBits(VT))) {
Dan Gohman948d8ea2008-02-20 16:33:30 +00002457 APInt KnownZero, KnownOne;
2458 APInt Mask = APInt::getAllOnesValue(MVT::getSizeInBits(VT));
Dan Gohmanea859be2007-06-22 14:59:07 +00002459 DAG.ComputeMaskedBits(N0.getOperand(0), Mask, KnownZero, KnownOne);
Chris Lattner350bec02006-04-02 06:11:11 +00002460
2461 // If any of the input bits are KnownOne, then the input couldn't be all
2462 // zeros, thus the result of the srl will always be zero.
Dan Gohman948d8ea2008-02-20 16:33:30 +00002463 if (KnownOne.getBoolValue()) return DAG.getConstant(0, VT);
Chris Lattner350bec02006-04-02 06:11:11 +00002464
2465 // If all of the bits input the to ctlz node are known to be zero, then
2466 // the result of the ctlz is "32" and the result of the shift is one.
Dan Gohman948d8ea2008-02-20 16:33:30 +00002467 APInt UnknownBits = ~KnownZero & Mask;
Chris Lattner350bec02006-04-02 06:11:11 +00002468 if (UnknownBits == 0) return DAG.getConstant(1, VT);
2469
2470 // Otherwise, check to see if there is exactly one bit input to the ctlz.
2471 if ((UnknownBits & (UnknownBits-1)) == 0) {
2472 // Okay, we know that only that the single bit specified by UnknownBits
2473 // could be set on input to the CTLZ node. If this bit is set, the SRL
2474 // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
2475 // to an SRL,XOR pair, which is likely to simplify more.
Dan Gohman948d8ea2008-02-20 16:33:30 +00002476 unsigned ShAmt = UnknownBits.countTrailingZeros();
Chris Lattner350bec02006-04-02 06:11:11 +00002477 SDOperand Op = N0.getOperand(0);
2478 if (ShAmt) {
2479 Op = DAG.getNode(ISD::SRL, VT, Op,
2480 DAG.getConstant(ShAmt, TLI.getShiftAmountTy()));
2481 AddToWorkList(Op.Val);
2482 }
2483 return DAG.getNode(ISD::XOR, VT, Op, DAG.getConstant(1, VT));
2484 }
2485 }
Chris Lattner61a4c072007-04-18 03:06:49 +00002486
2487 // fold operands of srl based on knowledge that the low bits are not
2488 // demanded.
2489 if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
2490 return SDOperand(N, 0);
2491
Chris Lattnere70da202007-12-06 07:33:36 +00002492 return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002493}
2494
Nate Begeman83e75ec2005-09-06 04:43:02 +00002495SDOperand DAGCombiner::visitCTLZ(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002496 SDOperand N0 = N->getOperand(0);
Nate Begemana148d982006-01-18 22:35:16 +00002497 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002498
2499 // fold (ctlz c1) -> c2
Chris Lattner310b5782006-05-06 23:06:26 +00002500 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00002501 return DAG.getNode(ISD::CTLZ, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00002502 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002503}
2504
Nate Begeman83e75ec2005-09-06 04:43:02 +00002505SDOperand DAGCombiner::visitCTTZ(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002506 SDOperand N0 = N->getOperand(0);
Nate Begemana148d982006-01-18 22:35:16 +00002507 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002508
2509 // fold (cttz c1) -> c2
Chris Lattner310b5782006-05-06 23:06:26 +00002510 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00002511 return DAG.getNode(ISD::CTTZ, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00002512 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002513}
2514
Nate Begeman83e75ec2005-09-06 04:43:02 +00002515SDOperand DAGCombiner::visitCTPOP(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002516 SDOperand N0 = N->getOperand(0);
Nate Begemana148d982006-01-18 22:35:16 +00002517 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002518
2519 // fold (ctpop c1) -> c2
Chris Lattner310b5782006-05-06 23:06:26 +00002520 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00002521 return DAG.getNode(ISD::CTPOP, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00002522 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002523}
2524
Nate Begeman452d7be2005-09-16 00:54:12 +00002525SDOperand DAGCombiner::visitSELECT(SDNode *N) {
2526 SDOperand N0 = N->getOperand(0);
2527 SDOperand N1 = N->getOperand(1);
2528 SDOperand N2 = N->getOperand(2);
2529 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
2530 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
2531 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
2532 MVT::ValueType VT = N->getValueType(0);
Evan Cheng571c4782007-08-18 05:57:05 +00002533 MVT::ValueType VT0 = N0.getValueType();
Nate Begeman44728a72005-09-19 22:34:01 +00002534
Nate Begeman452d7be2005-09-16 00:54:12 +00002535 // fold select C, X, X -> X
2536 if (N1 == N2)
2537 return N1;
2538 // fold select true, X, Y -> X
2539 if (N0C && !N0C->isNullValue())
2540 return N1;
2541 // fold select false, X, Y -> Y
2542 if (N0C && N0C->isNullValue())
2543 return N2;
2544 // fold select C, 1, X -> C | X
Dan Gohman002e5d02008-03-13 22:13:53 +00002545 if (MVT::i1 == VT && N1C && N1C->getAPIntValue() == 1)
Nate Begeman452d7be2005-09-16 00:54:12 +00002546 return DAG.getNode(ISD::OR, VT, N0, N2);
Evan Cheng571c4782007-08-18 05:57:05 +00002547 // fold select C, 0, 1 -> ~C
2548 if (MVT::isInteger(VT) && MVT::isInteger(VT0) &&
Dan Gohman002e5d02008-03-13 22:13:53 +00002549 N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
Evan Cheng571c4782007-08-18 05:57:05 +00002550 SDOperand XORNode = DAG.getNode(ISD::XOR, VT0, N0, DAG.getConstant(1, VT0));
2551 if (VT == VT0)
2552 return XORNode;
2553 AddToWorkList(XORNode.Val);
2554 if (MVT::getSizeInBits(VT) > MVT::getSizeInBits(VT0))
2555 return DAG.getNode(ISD::ZERO_EXTEND, VT, XORNode);
2556 return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
2557 }
Nate Begeman452d7be2005-09-16 00:54:12 +00002558 // fold select C, 0, X -> ~C & X
Dale Johannesene0e6fac2007-12-06 17:53:31 +00002559 if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
2560 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
Chris Lattner5750df92006-03-01 04:03:14 +00002561 AddToWorkList(XORNode.Val);
Nate Begeman452d7be2005-09-16 00:54:12 +00002562 return DAG.getNode(ISD::AND, VT, XORNode, N2);
2563 }
2564 // fold select C, X, 1 -> ~C | X
Dan Gohman002e5d02008-03-13 22:13:53 +00002565 if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getAPIntValue() == 1) {
Dale Johannesene0e6fac2007-12-06 17:53:31 +00002566 SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
Chris Lattner5750df92006-03-01 04:03:14 +00002567 AddToWorkList(XORNode.Val);
Nate Begeman452d7be2005-09-16 00:54:12 +00002568 return DAG.getNode(ISD::OR, VT, XORNode, N1);
2569 }
2570 // fold select C, X, 0 -> C & X
2571 // FIXME: this should check for C type == X type, not i1?
2572 if (MVT::i1 == VT && N2C && N2C->isNullValue())
2573 return DAG.getNode(ISD::AND, VT, N0, N1);
2574 // fold X ? X : Y --> X ? 1 : Y --> X | Y
2575 if (MVT::i1 == VT && N0 == N1)
2576 return DAG.getNode(ISD::OR, VT, N0, N2);
2577 // fold X ? Y : X --> X ? Y : 0 --> X & Y
2578 if (MVT::i1 == VT && N0 == N2)
2579 return DAG.getNode(ISD::AND, VT, N0, N1);
Chris Lattner729c6d12006-05-27 00:43:02 +00002580
Chris Lattner40c62d52005-10-18 06:04:22 +00002581 // If we can fold this based on the true/false value, do so.
2582 if (SimplifySelectOps(N, N1, N2))
Chris Lattner729c6d12006-05-27 00:43:02 +00002583 return SDOperand(N, 0); // Don't revisit N.
2584
Nate Begeman44728a72005-09-19 22:34:01 +00002585 // fold selects based on a setcc into other things, such as min/max/abs
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00002586 if (N0.getOpcode() == ISD::SETCC) {
Nate Begeman750ac1b2006-02-01 07:19:44 +00002587 // FIXME:
2588 // Check against MVT::Other for SELECT_CC, which is a workaround for targets
2589 // having to say they don't support SELECT_CC on every type the DAG knows
2590 // about, since there is no way to mark an opcode illegal at all value types
2591 if (TLI.isOperationLegal(ISD::SELECT_CC, MVT::Other))
2592 return DAG.getNode(ISD::SELECT_CC, VT, N0.getOperand(0), N0.getOperand(1),
2593 N1, N2, N0.getOperand(2));
2594 else
2595 return SimplifySelect(N0, N1, N2);
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00002596 }
Nate Begeman452d7be2005-09-16 00:54:12 +00002597 return SDOperand();
2598}
2599
2600SDOperand DAGCombiner::visitSELECT_CC(SDNode *N) {
Nate Begeman44728a72005-09-19 22:34:01 +00002601 SDOperand N0 = N->getOperand(0);
2602 SDOperand N1 = N->getOperand(1);
2603 SDOperand N2 = N->getOperand(2);
2604 SDOperand N3 = N->getOperand(3);
2605 SDOperand N4 = N->getOperand(4);
Nate Begeman44728a72005-09-19 22:34:01 +00002606 ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
2607
Nate Begeman44728a72005-09-19 22:34:01 +00002608 // fold select_cc lhs, rhs, x, x, cc -> x
2609 if (N2 == N3)
2610 return N2;
Chris Lattner40c62d52005-10-18 06:04:22 +00002611
Chris Lattner5f42a242006-09-20 06:19:26 +00002612 // Determine if the condition we're dealing with is constant
Scott Michel5b8f82e2008-03-10 15:42:14 +00002613 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultType(N0), N0, N1, CC, false);
Chris Lattner30f73e72006-10-14 03:52:46 +00002614 if (SCC.Val) AddToWorkList(SCC.Val);
Chris Lattner5f42a242006-09-20 06:19:26 +00002615
2616 if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val)) {
Dan Gohman002e5d02008-03-13 22:13:53 +00002617 if (!SCCC->isNullValue())
Chris Lattner5f42a242006-09-20 06:19:26 +00002618 return N2; // cond always true -> true val
2619 else
2620 return N3; // cond always false -> false val
2621 }
2622
2623 // Fold to a simpler select_cc
2624 if (SCC.Val && SCC.getOpcode() == ISD::SETCC)
2625 return DAG.getNode(ISD::SELECT_CC, N2.getValueType(),
2626 SCC.getOperand(0), SCC.getOperand(1), N2, N3,
2627 SCC.getOperand(2));
2628
Chris Lattner40c62d52005-10-18 06:04:22 +00002629 // If we can fold this based on the true/false value, do so.
2630 if (SimplifySelectOps(N, N2, N3))
Chris Lattner729c6d12006-05-27 00:43:02 +00002631 return SDOperand(N, 0); // Don't revisit N.
Chris Lattner40c62d52005-10-18 06:04:22 +00002632
Nate Begeman44728a72005-09-19 22:34:01 +00002633 // fold select_cc into other things, such as min/max/abs
2634 return SimplifySelectCC(N0, N1, N2, N3, CC);
Nate Begeman452d7be2005-09-16 00:54:12 +00002635}
2636
2637SDOperand DAGCombiner::visitSETCC(SDNode *N) {
2638 return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
2639 cast<CondCodeSDNode>(N->getOperand(2))->get());
2640}
2641
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002642// ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
2643// "fold ({s|z}ext (load x)) -> ({s|z}ext (truncate ({s|z}extload x)))"
2644// transformation. Returns true if extension are possible and the above
2645// mentioned transformation is profitable.
2646static bool ExtendUsesToFormExtLoad(SDNode *N, SDOperand N0,
2647 unsigned ExtOpc,
2648 SmallVector<SDNode*, 4> &ExtendNodes,
2649 TargetLowering &TLI) {
2650 bool HasCopyToRegUses = false;
2651 bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
2652 for (SDNode::use_iterator UI = N0.Val->use_begin(), UE = N0.Val->use_end();
2653 UI != UE; ++UI) {
2654 SDNode *User = *UI;
2655 if (User == N)
2656 continue;
2657 // FIXME: Only extend SETCC N, N and SETCC N, c for now.
2658 if (User->getOpcode() == ISD::SETCC) {
2659 ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
2660 if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
2661 // Sign bits will be lost after a zext.
2662 return false;
2663 bool Add = false;
2664 for (unsigned i = 0; i != 2; ++i) {
2665 SDOperand UseOp = User->getOperand(i);
2666 if (UseOp == N0)
2667 continue;
2668 if (!isa<ConstantSDNode>(UseOp))
2669 return false;
2670 Add = true;
2671 }
2672 if (Add)
2673 ExtendNodes.push_back(User);
2674 } else {
2675 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2676 SDOperand UseOp = User->getOperand(i);
2677 if (UseOp == N0) {
2678 // If truncate from extended type to original load type is free
2679 // on this target, then it's ok to extend a CopyToReg.
2680 if (isTruncFree && User->getOpcode() == ISD::CopyToReg)
2681 HasCopyToRegUses = true;
2682 else
2683 return false;
2684 }
2685 }
2686 }
2687 }
2688
2689 if (HasCopyToRegUses) {
2690 bool BothLiveOut = false;
2691 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
2692 UI != UE; ++UI) {
2693 SDNode *User = *UI;
2694 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
2695 SDOperand UseOp = User->getOperand(i);
2696 if (UseOp.Val == N && UseOp.ResNo == 0) {
2697 BothLiveOut = true;
2698 break;
2699 }
2700 }
2701 }
2702 if (BothLiveOut)
2703 // Both unextended and extended values are live out. There had better be
2704 // good a reason for the transformation.
2705 return ExtendNodes.size();
2706 }
2707 return true;
2708}
2709
Nate Begeman83e75ec2005-09-06 04:43:02 +00002710SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002711 SDOperand N0 = N->getOperand(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002712 MVT::ValueType VT = N->getValueType(0);
2713
Nate Begeman1d4d4142005-09-01 00:19:25 +00002714 // fold (sext c1) -> c1
Reid Spencer3ed469c2006-11-02 20:25:50 +00002715 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00002716 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0);
Chris Lattner310b5782006-05-06 23:06:26 +00002717
Nate Begeman1d4d4142005-09-01 00:19:25 +00002718 // fold (sext (sext x)) -> (sext x)
Chris Lattner310b5782006-05-06 23:06:26 +00002719 // fold (sext (aext x)) -> (sext x)
2720 if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002721 return DAG.getNode(ISD::SIGN_EXTEND, VT, N0.getOperand(0));
Chris Lattner310b5782006-05-06 23:06:26 +00002722
Evan Chengc88138f2007-03-22 01:54:19 +00002723 // fold (sext (truncate (load x))) -> (sext (smaller load x))
2724 // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
Chris Lattner22558872007-02-26 03:13:59 +00002725 if (N0.getOpcode() == ISD::TRUNCATE) {
Evan Chengc88138f2007-03-22 01:54:19 +00002726 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
Evan Cheng0b063de2007-03-23 02:16:52 +00002727 if (NarrowLoad.Val) {
2728 if (NarrowLoad.Val != N0.Val)
2729 CombineTo(N0.Val, NarrowLoad);
2730 return DAG.getNode(ISD::SIGN_EXTEND, VT, NarrowLoad);
2731 }
Evan Chengc88138f2007-03-22 01:54:19 +00002732 }
2733
2734 // See if the value being truncated is already sign extended. If so, just
2735 // eliminate the trunc/sext pair.
2736 if (N0.getOpcode() == ISD::TRUNCATE) {
Chris Lattner6007b842006-09-21 06:00:20 +00002737 SDOperand Op = N0.getOperand(0);
Chris Lattner22558872007-02-26 03:13:59 +00002738 unsigned OpBits = MVT::getSizeInBits(Op.getValueType());
2739 unsigned MidBits = MVT::getSizeInBits(N0.getValueType());
2740 unsigned DestBits = MVT::getSizeInBits(VT);
Dan Gohmanea859be2007-06-22 14:59:07 +00002741 unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
Chris Lattner22558872007-02-26 03:13:59 +00002742
2743 if (OpBits == DestBits) {
2744 // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
2745 // bits, it is already ready.
2746 if (NumSignBits > DestBits-MidBits)
2747 return Op;
2748 } else if (OpBits < DestBits) {
2749 // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
2750 // bits, just sext from i32.
2751 if (NumSignBits > OpBits-MidBits)
2752 return DAG.getNode(ISD::SIGN_EXTEND, VT, Op);
2753 } else {
2754 // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
2755 // bits, just truncate to i32.
2756 if (NumSignBits > OpBits-MidBits)
2757 return DAG.getNode(ISD::TRUNCATE, VT, Op);
Chris Lattner6007b842006-09-21 06:00:20 +00002758 }
Chris Lattner22558872007-02-26 03:13:59 +00002759
2760 // fold (sext (truncate x)) -> (sextinreg x).
2761 if (!AfterLegalize || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
2762 N0.getValueType())) {
2763 if (Op.getValueType() < VT)
2764 Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
2765 else if (Op.getValueType() > VT)
2766 Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
2767 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, Op,
2768 DAG.getValueType(N0.getValueType()));
2769 }
Chris Lattner6007b842006-09-21 06:00:20 +00002770 }
Chris Lattner310b5782006-05-06 23:06:26 +00002771
Evan Cheng110dec22005-12-14 02:19:23 +00002772 // fold (sext (load x)) -> (sext (truncate (sextload x)))
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002773 if (ISD::isNON_EXTLoad(N0.Val) &&
Evan Chengc5484282006-10-04 00:56:09 +00002774 (!AfterLegalize||TLI.isLoadXLegal(ISD::SEXTLOAD, N0.getValueType()))){
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002775 bool DoXform = true;
2776 SmallVector<SDNode*, 4> SetCCs;
2777 if (!N0.hasOneUse())
2778 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
2779 if (DoXform) {
2780 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2781 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
2782 LN0->getBasePtr(), LN0->getSrcValue(),
2783 LN0->getSrcValueOffset(),
2784 N0.getValueType(),
2785 LN0->isVolatile(),
2786 LN0->getAlignment());
2787 CombineTo(N, ExtLoad);
2788 SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
2789 CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
2790 // Extend SetCC uses if necessary.
2791 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
2792 SDNode *SetCC = SetCCs[i];
2793 SmallVector<SDOperand, 4> Ops;
2794 for (unsigned j = 0; j != 2; ++j) {
2795 SDOperand SOp = SetCC->getOperand(j);
2796 if (SOp == Trunc)
2797 Ops.push_back(ExtLoad);
2798 else
2799 Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND, VT, SOp));
2800 }
2801 Ops.push_back(SetCC->getOperand(2));
2802 CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
2803 &Ops[0], Ops.size()));
2804 }
2805 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2806 }
Nate Begeman3df4d522005-10-12 20:40:40 +00002807 }
Chris Lattnerad25d4e2005-12-14 19:05:06 +00002808
2809 // fold (sext (sextload x)) -> (sext (truncate (sextload x)))
2810 // fold (sext ( extload x)) -> (sext (truncate (sextload x)))
Evan Cheng83060c52007-03-07 08:07:03 +00002811 if ((ISD::isSEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
2812 ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
Evan Cheng466685d2006-10-09 20:57:25 +00002813 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Dan Gohmanb625f2f2008-01-30 00:15:11 +00002814 MVT::ValueType EVT = LN0->getMemoryVT();
Jim Laskeyf6c4ccf2006-12-15 21:38:30 +00002815 if (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT)) {
2816 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
2817 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00002818 LN0->getSrcValueOffset(), EVT,
2819 LN0->isVolatile(),
2820 LN0->getAlignment());
Jim Laskeyf6c4ccf2006-12-15 21:38:30 +00002821 CombineTo(N, ExtLoad);
2822 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2823 ExtLoad.getValue(1));
2824 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2825 }
Chris Lattnerad25d4e2005-12-14 19:05:06 +00002826 }
2827
Chris Lattner20a35c32007-04-11 05:32:27 +00002828 // sext(setcc x,y,cc) -> select_cc x, y, -1, 0, cc
2829 if (N0.getOpcode() == ISD::SETCC) {
2830 SDOperand SCC =
Chris Lattner1eba01e2007-04-11 06:50:51 +00002831 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
2832 DAG.getConstant(~0ULL, VT), DAG.getConstant(0, VT),
2833 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
2834 if (SCC.Val) return SCC;
Chris Lattner20a35c32007-04-11 05:32:27 +00002835 }
2836
Nate Begeman83e75ec2005-09-06 04:43:02 +00002837 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002838}
2839
Nate Begeman83e75ec2005-09-06 04:43:02 +00002840SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00002841 SDOperand N0 = N->getOperand(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002842 MVT::ValueType VT = N->getValueType(0);
2843
Nate Begeman1d4d4142005-09-01 00:19:25 +00002844 // fold (zext c1) -> c1
Reid Spencer3ed469c2006-11-02 20:25:50 +00002845 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00002846 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00002847 // fold (zext (zext x)) -> (zext x)
Chris Lattner310b5782006-05-06 23:06:26 +00002848 // fold (zext (aext x)) -> (zext x)
2849 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
Nate Begeman83e75ec2005-09-06 04:43:02 +00002850 return DAG.getNode(ISD::ZERO_EXTEND, VT, N0.getOperand(0));
Chris Lattner6007b842006-09-21 06:00:20 +00002851
Evan Chengc88138f2007-03-22 01:54:19 +00002852 // fold (zext (truncate (load x))) -> (zext (smaller load x))
2853 // fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
Dale Johannesen2041a0e2007-03-30 21:38:07 +00002854 if (N0.getOpcode() == ISD::TRUNCATE) {
Evan Chengc88138f2007-03-22 01:54:19 +00002855 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
Evan Cheng0b063de2007-03-23 02:16:52 +00002856 if (NarrowLoad.Val) {
2857 if (NarrowLoad.Val != N0.Val)
2858 CombineTo(N0.Val, NarrowLoad);
2859 return DAG.getNode(ISD::ZERO_EXTEND, VT, NarrowLoad);
2860 }
Evan Chengc88138f2007-03-22 01:54:19 +00002861 }
2862
Chris Lattner6007b842006-09-21 06:00:20 +00002863 // fold (zext (truncate x)) -> (and x, mask)
2864 if (N0.getOpcode() == ISD::TRUNCATE &&
2865 (!AfterLegalize || TLI.isOperationLegal(ISD::AND, VT))) {
2866 SDOperand Op = N0.getOperand(0);
2867 if (Op.getValueType() < VT) {
2868 Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
2869 } else if (Op.getValueType() > VT) {
2870 Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
2871 }
2872 return DAG.getZeroExtendInReg(Op, N0.getValueType());
2873 }
2874
Chris Lattner111c2282006-09-21 06:14:31 +00002875 // fold (zext (and (trunc x), cst)) -> (and x, cst).
2876 if (N0.getOpcode() == ISD::AND &&
2877 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
2878 N0.getOperand(1).getOpcode() == ISD::Constant) {
2879 SDOperand X = N0.getOperand(0).getOperand(0);
2880 if (X.getValueType() < VT) {
2881 X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
2882 } else if (X.getValueType() > VT) {
2883 X = DAG.getNode(ISD::TRUNCATE, VT, X);
2884 }
Dan Gohman220a8232008-03-03 23:51:38 +00002885 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
2886 Mask.zext(MVT::getSizeInBits(VT));
Chris Lattner111c2282006-09-21 06:14:31 +00002887 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
2888 }
2889
Evan Cheng110dec22005-12-14 02:19:23 +00002890 // fold (zext (load x)) -> (zext (truncate (zextload x)))
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002891 if (ISD::isNON_EXTLoad(N0.Val) &&
Evan Chengc5484282006-10-04 00:56:09 +00002892 (!AfterLegalize||TLI.isLoadXLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002893 bool DoXform = true;
2894 SmallVector<SDNode*, 4> SetCCs;
2895 if (!N0.hasOneUse())
2896 DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
2897 if (DoXform) {
2898 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
2899 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
2900 LN0->getBasePtr(), LN0->getSrcValue(),
2901 LN0->getSrcValueOffset(),
2902 N0.getValueType(),
2903 LN0->isVolatile(),
2904 LN0->getAlignment());
2905 CombineTo(N, ExtLoad);
2906 SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
2907 CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
2908 // Extend SetCC uses if necessary.
2909 for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
2910 SDNode *SetCC = SetCCs[i];
2911 SmallVector<SDOperand, 4> Ops;
2912 for (unsigned j = 0; j != 2; ++j) {
2913 SDOperand SOp = SetCC->getOperand(j);
2914 if (SOp == Trunc)
2915 Ops.push_back(ExtLoad);
2916 else
Evan Chengde1631b2007-10-30 20:11:21 +00002917 Ops.push_back(DAG.getNode(ISD::ZERO_EXTEND, VT, SOp));
Evan Cheng3c3ddb32007-10-29 19:58:20 +00002918 }
2919 Ops.push_back(SetCC->getOperand(2));
2920 CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
2921 &Ops[0], Ops.size()));
2922 }
2923 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
2924 }
Evan Cheng110dec22005-12-14 02:19:23 +00002925 }
Chris Lattnerad25d4e2005-12-14 19:05:06 +00002926
2927 // fold (zext (zextload x)) -> (zext (truncate (zextload x)))
2928 // fold (zext ( extload x)) -> (zext (truncate (zextload x)))
Evan Cheng83060c52007-03-07 08:07:03 +00002929 if ((ISD::isZEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
2930 ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
Evan Cheng466685d2006-10-09 20:57:25 +00002931 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Dan Gohmanb625f2f2008-01-30 00:15:11 +00002932 MVT::ValueType EVT = LN0->getMemoryVT();
Evan Cheng466685d2006-10-09 20:57:25 +00002933 SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
2934 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00002935 LN0->getSrcValueOffset(), EVT,
2936 LN0->isVolatile(),
2937 LN0->getAlignment());
Chris Lattnerd4771842005-12-14 19:25:30 +00002938 CombineTo(N, ExtLoad);
Chris Lattnerad25d4e2005-12-14 19:05:06 +00002939 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
2940 ExtLoad.getValue(1));
Chris Lattnerfedced72006-04-20 23:55:59 +00002941 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Chris Lattnerad25d4e2005-12-14 19:05:06 +00002942 }
Chris Lattner20a35c32007-04-11 05:32:27 +00002943
2944 // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
2945 if (N0.getOpcode() == ISD::SETCC) {
2946 SDOperand SCC =
2947 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
2948 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
Chris Lattner1eba01e2007-04-11 06:50:51 +00002949 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
2950 if (SCC.Val) return SCC;
Chris Lattner20a35c32007-04-11 05:32:27 +00002951 }
2952
Nate Begeman83e75ec2005-09-06 04:43:02 +00002953 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00002954}
2955
Chris Lattner5ffc0662006-05-05 05:58:59 +00002956SDOperand DAGCombiner::visitANY_EXTEND(SDNode *N) {
2957 SDOperand N0 = N->getOperand(0);
Chris Lattner5ffc0662006-05-05 05:58:59 +00002958 MVT::ValueType VT = N->getValueType(0);
2959
2960 // fold (aext c1) -> c1
Chris Lattner310b5782006-05-06 23:06:26 +00002961 if (isa<ConstantSDNode>(N0))
Chris Lattner5ffc0662006-05-05 05:58:59 +00002962 return DAG.getNode(ISD::ANY_EXTEND, VT, N0);
2963 // fold (aext (aext x)) -> (aext x)
2964 // fold (aext (zext x)) -> (zext x)
2965 // fold (aext (sext x)) -> (sext x)
2966 if (N0.getOpcode() == ISD::ANY_EXTEND ||
2967 N0.getOpcode() == ISD::ZERO_EXTEND ||
2968 N0.getOpcode() == ISD::SIGN_EXTEND)
2969 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
2970
Evan Chengc88138f2007-03-22 01:54:19 +00002971 // fold (aext (truncate (load x))) -> (aext (smaller load x))
2972 // fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
2973 if (N0.getOpcode() == ISD::TRUNCATE) {
2974 SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
Evan Cheng0b063de2007-03-23 02:16:52 +00002975 if (NarrowLoad.Val) {
2976 if (NarrowLoad.Val != N0.Val)
2977 CombineTo(N0.Val, NarrowLoad);
2978 return DAG.getNode(ISD::ANY_EXTEND, VT, NarrowLoad);
2979 }
Evan Chengc88138f2007-03-22 01:54:19 +00002980 }
2981
Chris Lattner84750582006-09-20 06:29:17 +00002982 // fold (aext (truncate x))
2983 if (N0.getOpcode() == ISD::TRUNCATE) {
2984 SDOperand TruncOp = N0.getOperand(0);
2985 if (TruncOp.getValueType() == VT)
2986 return TruncOp; // x iff x size == zext size.
2987 if (TruncOp.getValueType() > VT)
2988 return DAG.getNode(ISD::TRUNCATE, VT, TruncOp);
2989 return DAG.getNode(ISD::ANY_EXTEND, VT, TruncOp);
2990 }
Chris Lattner0e4b9222006-09-21 06:40:43 +00002991
2992 // fold (aext (and (trunc x), cst)) -> (and x, cst).
2993 if (N0.getOpcode() == ISD::AND &&
2994 N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
2995 N0.getOperand(1).getOpcode() == ISD::Constant) {
2996 SDOperand X = N0.getOperand(0).getOperand(0);
2997 if (X.getValueType() < VT) {
2998 X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
2999 } else if (X.getValueType() > VT) {
3000 X = DAG.getNode(ISD::TRUNCATE, VT, X);
3001 }
Dan Gohman220a8232008-03-03 23:51:38 +00003002 APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
3003 Mask.zext(MVT::getSizeInBits(VT));
Chris Lattner0e4b9222006-09-21 06:40:43 +00003004 return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
3005 }
3006
Chris Lattner5ffc0662006-05-05 05:58:59 +00003007 // fold (aext (load x)) -> (aext (truncate (extload x)))
Evan Cheng466685d2006-10-09 20:57:25 +00003008 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
Evan Chengc5484282006-10-04 00:56:09 +00003009 (!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
Evan Cheng466685d2006-10-09 20:57:25 +00003010 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3011 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
3012 LN0->getBasePtr(), LN0->getSrcValue(),
3013 LN0->getSrcValueOffset(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00003014 N0.getValueType(),
3015 LN0->isVolatile(),
3016 LN0->getAlignment());
Chris Lattner5ffc0662006-05-05 05:58:59 +00003017 CombineTo(N, ExtLoad);
3018 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
3019 ExtLoad.getValue(1));
3020 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3021 }
3022
3023 // fold (aext (zextload x)) -> (aext (truncate (zextload x)))
3024 // fold (aext (sextload x)) -> (aext (truncate (sextload x)))
3025 // fold (aext ( extload x)) -> (aext (truncate (extload x)))
Evan Cheng83060c52007-03-07 08:07:03 +00003026 if (N0.getOpcode() == ISD::LOAD &&
3027 !ISD::isNON_EXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
Evan Cheng466685d2006-10-09 20:57:25 +00003028 N0.hasOneUse()) {
3029 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Dan Gohmanb625f2f2008-01-30 00:15:11 +00003030 MVT::ValueType EVT = LN0->getMemoryVT();
Evan Cheng466685d2006-10-09 20:57:25 +00003031 SDOperand ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), VT,
3032 LN0->getChain(), LN0->getBasePtr(),
3033 LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00003034 LN0->getSrcValueOffset(), EVT,
3035 LN0->isVolatile(),
3036 LN0->getAlignment());
Chris Lattner5ffc0662006-05-05 05:58:59 +00003037 CombineTo(N, ExtLoad);
3038 CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
3039 ExtLoad.getValue(1));
3040 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3041 }
Chris Lattner20a35c32007-04-11 05:32:27 +00003042
3043 // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
3044 if (N0.getOpcode() == ISD::SETCC) {
3045 SDOperand SCC =
Chris Lattner1eba01e2007-04-11 06:50:51 +00003046 SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
3047 DAG.getConstant(1, VT), DAG.getConstant(0, VT),
Chris Lattnerc24bbad2007-04-11 16:51:53 +00003048 cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
Chris Lattner1eba01e2007-04-11 06:50:51 +00003049 if (SCC.Val)
Chris Lattnerc56a81d2007-04-11 06:43:25 +00003050 return SCC;
Chris Lattner20a35c32007-04-11 05:32:27 +00003051 }
3052
Chris Lattner5ffc0662006-05-05 05:58:59 +00003053 return SDOperand();
3054}
3055
Chris Lattner2b4c2792007-10-13 06:35:54 +00003056/// GetDemandedBits - See if the specified operand can be simplified with the
3057/// knowledge that only the bits specified by Mask are used. If so, return the
3058/// simpler operand, otherwise return a null SDOperand.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00003059SDOperand DAGCombiner::GetDemandedBits(SDOperand V, const APInt &Mask) {
Chris Lattner2b4c2792007-10-13 06:35:54 +00003060 switch (V.getOpcode()) {
3061 default: break;
3062 case ISD::OR:
3063 case ISD::XOR:
3064 // If the LHS or RHS don't contribute bits to the or, drop them.
3065 if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
3066 return V.getOperand(1);
3067 if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
3068 return V.getOperand(0);
3069 break;
Chris Lattnere33544c2007-10-13 06:58:48 +00003070 case ISD::SRL:
3071 // Only look at single-use SRLs.
3072 if (!V.Val->hasOneUse())
3073 break;
3074 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
3075 // See if we can recursively simplify the LHS.
3076 unsigned Amt = RHSC->getValue();
Dan Gohman2e68b6f2008-02-25 21:11:39 +00003077 APInt NewMask = Mask << Amt;
3078 SDOperand SimplifyLHS = GetDemandedBits(V.getOperand(0), NewMask);
Chris Lattnere33544c2007-10-13 06:58:48 +00003079 if (SimplifyLHS.Val) {
3080 return DAG.getNode(ISD::SRL, V.getValueType(),
3081 SimplifyLHS, V.getOperand(1));
3082 }
3083 }
Chris Lattner2b4c2792007-10-13 06:35:54 +00003084 }
3085 return SDOperand();
3086}
3087
Evan Chengc88138f2007-03-22 01:54:19 +00003088/// ReduceLoadWidth - If the result of a wider load is shifted to right of N
3089/// bits and then truncated to a narrower type and where N is a multiple
3090/// of number of bits of the narrower type, transform it to a narrower load
3091/// from address + N / num of bits of new type. If the result is to be
3092/// extended, also fold the extension to form a extending load.
3093SDOperand DAGCombiner::ReduceLoadWidth(SDNode *N) {
3094 unsigned Opc = N->getOpcode();
3095 ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
3096 SDOperand N0 = N->getOperand(0);
3097 MVT::ValueType VT = N->getValueType(0);
3098 MVT::ValueType EVT = N->getValueType(0);
3099
Evan Chenge177e302007-03-23 22:13:36 +00003100 // Special case: SIGN_EXTEND_INREG is basically truncating to EVT then
3101 // extended to VT.
Evan Chengc88138f2007-03-22 01:54:19 +00003102 if (Opc == ISD::SIGN_EXTEND_INREG) {
3103 ExtType = ISD::SEXTLOAD;
3104 EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
Evan Chenge177e302007-03-23 22:13:36 +00003105 if (AfterLegalize && !TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))
3106 return SDOperand();
Evan Chengc88138f2007-03-22 01:54:19 +00003107 }
3108
3109 unsigned EVTBits = MVT::getSizeInBits(EVT);
3110 unsigned ShAmt = 0;
Evan Chengb37b80c2007-03-23 20:55:21 +00003111 bool CombineSRL = false;
Evan Chengc88138f2007-03-22 01:54:19 +00003112 if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
3113 if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
3114 ShAmt = N01->getValue();
3115 // Is the shift amount a multiple of size of VT?
3116 if ((ShAmt & (EVTBits-1)) == 0) {
3117 N0 = N0.getOperand(0);
3118 if (MVT::getSizeInBits(N0.getValueType()) <= EVTBits)
3119 return SDOperand();
Evan Chengb37b80c2007-03-23 20:55:21 +00003120 CombineSRL = true;
Evan Chengc88138f2007-03-22 01:54:19 +00003121 }
3122 }
3123 }
3124
3125 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
3126 // Do not allow folding to i1 here. i1 is implicitly stored in memory in
3127 // zero extended form: by shrinking the load, we lose track of the fact
3128 // that it is already zero extended.
3129 // FIXME: This should be reevaluated.
3130 VT != MVT::i1) {
3131 assert(MVT::getSizeInBits(N0.getValueType()) > EVTBits &&
3132 "Cannot truncate to larger type!");
3133 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3134 MVT::ValueType PtrType = N0.getOperand(1).getValueType();
Evan Chengdae54ce2007-03-24 00:02:43 +00003135 // For big endian targets, we need to adjust the offset to the pointer to
3136 // load the correct bytes.
Duncan Sands0753fc12008-02-11 10:37:04 +00003137 if (TLI.isBigEndian()) {
Duncan Sandsc6fa1702007-11-09 08:57:19 +00003138 unsigned LVTStoreBits = MVT::getStoreSizeInBits(N0.getValueType());
3139 unsigned EVTStoreBits = MVT::getStoreSizeInBits(EVT);
3140 ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
3141 }
Evan Chengdae54ce2007-03-24 00:02:43 +00003142 uint64_t PtrOff = ShAmt / 8;
Duncan Sandsdc846502007-10-28 12:59:45 +00003143 unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
Evan Chengc88138f2007-03-22 01:54:19 +00003144 SDOperand NewPtr = DAG.getNode(ISD::ADD, PtrType, LN0->getBasePtr(),
3145 DAG.getConstant(PtrOff, PtrType));
3146 AddToWorkList(NewPtr.Val);
3147 SDOperand Load = (ExtType == ISD::NON_EXTLOAD)
3148 ? DAG.getLoad(VT, LN0->getChain(), NewPtr,
Christopher Lamb95c218a2007-04-22 23:15:30 +00003149 LN0->getSrcValue(), LN0->getSrcValueOffset(),
Duncan Sandsdc846502007-10-28 12:59:45 +00003150 LN0->isVolatile(), NewAlign)
Evan Chengc88138f2007-03-22 01:54:19 +00003151 : DAG.getExtLoad(ExtType, VT, LN0->getChain(), NewPtr,
Christopher Lamb95c218a2007-04-22 23:15:30 +00003152 LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
Duncan Sandsdc846502007-10-28 12:59:45 +00003153 LN0->isVolatile(), NewAlign);
Evan Chengc88138f2007-03-22 01:54:19 +00003154 AddToWorkList(N);
Evan Chengb37b80c2007-03-23 20:55:21 +00003155 if (CombineSRL) {
Chris Lattnerf8dc0612008-02-03 06:49:24 +00003156 WorkListRemover DeadNodes(*this);
3157 DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1),
3158 &DeadNodes);
Evan Chengb37b80c2007-03-23 20:55:21 +00003159 CombineTo(N->getOperand(0).Val, Load);
3160 } else
3161 CombineTo(N0.Val, Load, Load.getValue(1));
Evan Cheng15213b72007-03-26 07:12:51 +00003162 if (ShAmt) {
3163 if (Opc == ISD::SIGN_EXTEND_INREG)
3164 return DAG.getNode(Opc, VT, Load, N->getOperand(1));
3165 else
3166 return DAG.getNode(Opc, VT, Load);
3167 }
Evan Chengc88138f2007-03-22 01:54:19 +00003168 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3169 }
3170
3171 return SDOperand();
3172}
3173
Chris Lattner5ffc0662006-05-05 05:58:59 +00003174
Nate Begeman83e75ec2005-09-06 04:43:02 +00003175SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00003176 SDOperand N0 = N->getOperand(0);
Nate Begeman646d7e22005-09-02 21:18:40 +00003177 SDOperand N1 = N->getOperand(1);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003178 MVT::ValueType VT = N->getValueType(0);
Nate Begeman646d7e22005-09-02 21:18:40 +00003179 MVT::ValueType EVT = cast<VTSDNode>(N1)->getVT();
Dan Gohman2e68b6f2008-02-25 21:11:39 +00003180 unsigned VTBits = MVT::getSizeInBits(VT);
Nate Begeman07ed4172005-10-10 21:26:48 +00003181 unsigned EVTBits = MVT::getSizeInBits(EVT);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003182
Nate Begeman1d4d4142005-09-01 00:19:25 +00003183 // fold (sext_in_reg c1) -> c1
Chris Lattnereaeda562006-05-08 20:59:41 +00003184 if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
Chris Lattner310b5782006-05-06 23:06:26 +00003185 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0, N1);
Chris Lattneree4ea922006-05-06 09:30:03 +00003186
Chris Lattner541a24f2006-05-06 22:43:44 +00003187 // If the input is already sign extended, just drop the extension.
Dan Gohmanea859be2007-06-22 14:59:07 +00003188 if (DAG.ComputeNumSignBits(N0) >= MVT::getSizeInBits(VT)-EVTBits+1)
Chris Lattneree4ea922006-05-06 09:30:03 +00003189 return N0;
3190
Nate Begeman646d7e22005-09-02 21:18:40 +00003191 // fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
3192 if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
3193 EVT < cast<VTSDNode>(N0.getOperand(1))->getVT()) {
Nate Begeman83e75ec2005-09-06 04:43:02 +00003194 return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0), N1);
Nate Begeman646d7e22005-09-02 21:18:40 +00003195 }
Chris Lattner4b37e872006-05-08 21:18:59 +00003196
Chris Lattner95a5e052007-04-17 19:03:21 +00003197 // fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
Dan Gohman2e68b6f2008-02-25 21:11:39 +00003198 if (DAG.MaskedValueIsZero(N0, APInt::getBitsSet(VTBits, EVTBits-1, EVTBits)))
Nate Begemande996292006-02-03 22:24:05 +00003199 return DAG.getZeroExtendInReg(N0, EVT);
Chris Lattner4b37e872006-05-08 21:18:59 +00003200
Chris Lattner95a5e052007-04-17 19:03:21 +00003201 // fold operands of sext_in_reg based on knowledge that the top bits are not
3202 // demanded.
3203 if (SimplifyDemandedBits(SDOperand(N, 0)))
3204 return SDOperand(N, 0);
3205
Evan Chengc88138f2007-03-22 01:54:19 +00003206 // fold (sext_in_reg (load x)) -> (smaller sextload x)
3207 // fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
3208 SDOperand NarrowLoad = ReduceLoadWidth(N);
3209 if (NarrowLoad.Val)
3210 return NarrowLoad;
3211
Chris Lattner4b37e872006-05-08 21:18:59 +00003212 // fold (sext_in_reg (srl X, 24), i8) -> sra X, 24
3213 // fold (sext_in_reg (srl X, 23), i8) -> sra X, 23 iff possible.
3214 // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
3215 if (N0.getOpcode() == ISD::SRL) {
3216 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
3217 if (ShAmt->getValue()+EVTBits <= MVT::getSizeInBits(VT)) {
3218 // We can turn this into an SRA iff the input to the SRL is already sign
3219 // extended enough.
Dan Gohmanea859be2007-06-22 14:59:07 +00003220 unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
Chris Lattner4b37e872006-05-08 21:18:59 +00003221 if (MVT::getSizeInBits(VT)-(ShAmt->getValue()+EVTBits) < InSignBits)
3222 return DAG.getNode(ISD::SRA, VT, N0.getOperand(0), N0.getOperand(1));
3223 }
3224 }
Evan Chengc88138f2007-03-22 01:54:19 +00003225
Nate Begemanded49632005-10-13 03:11:28 +00003226 // fold (sext_inreg (extload x)) -> (sextload x)
Evan Chengc5484282006-10-04 00:56:09 +00003227 if (ISD::isEXTLoad(N0.Val) &&
Evan Cheng83060c52007-03-07 08:07:03 +00003228 ISD::isUNINDEXEDLoad(N0.Val) &&
Dan Gohmanb625f2f2008-01-30 00:15:11 +00003229 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
Evan Chengc5484282006-10-04 00:56:09 +00003230 (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
Evan Cheng466685d2006-10-09 20:57:25 +00003231 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3232 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
3233 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00003234 LN0->getSrcValueOffset(), EVT,
3235 LN0->isVolatile(),
3236 LN0->getAlignment());
Chris Lattnerd4771842005-12-14 19:25:30 +00003237 CombineTo(N, ExtLoad);
Nate Begemanbfd65a02005-10-13 18:34:58 +00003238 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
Chris Lattnerfedced72006-04-20 23:55:59 +00003239 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Nate Begemanded49632005-10-13 03:11:28 +00003240 }
3241 // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
Evan Cheng83060c52007-03-07 08:07:03 +00003242 if (ISD::isZEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
3243 N0.hasOneUse() &&
Dan Gohmanb625f2f2008-01-30 00:15:11 +00003244 EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
Evan Chengc5484282006-10-04 00:56:09 +00003245 (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
Evan Cheng466685d2006-10-09 20:57:25 +00003246 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3247 SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
3248 LN0->getBasePtr(), LN0->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00003249 LN0->getSrcValueOffset(), EVT,
3250 LN0->isVolatile(),
3251 LN0->getAlignment());
Chris Lattnerd4771842005-12-14 19:25:30 +00003252 CombineTo(N, ExtLoad);
Nate Begemanbfd65a02005-10-13 18:34:58 +00003253 CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
Chris Lattnerfedced72006-04-20 23:55:59 +00003254 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Nate Begemanded49632005-10-13 03:11:28 +00003255 }
Nate Begeman83e75ec2005-09-06 04:43:02 +00003256 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003257}
3258
Nate Begeman83e75ec2005-09-06 04:43:02 +00003259SDOperand DAGCombiner::visitTRUNCATE(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00003260 SDOperand N0 = N->getOperand(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003261 MVT::ValueType VT = N->getValueType(0);
3262
3263 // noop truncate
3264 if (N0.getValueType() == N->getValueType(0))
Nate Begeman83e75ec2005-09-06 04:43:02 +00003265 return N0;
Nate Begeman1d4d4142005-09-01 00:19:25 +00003266 // fold (truncate c1) -> c1
Chris Lattner310b5782006-05-06 23:06:26 +00003267 if (isa<ConstantSDNode>(N0))
Nate Begemana148d982006-01-18 22:35:16 +00003268 return DAG.getNode(ISD::TRUNCATE, VT, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003269 // fold (truncate (truncate x)) -> (truncate x)
3270 if (N0.getOpcode() == ISD::TRUNCATE)
Nate Begeman83e75ec2005-09-06 04:43:02 +00003271 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
Nate Begeman1d4d4142005-09-01 00:19:25 +00003272 // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
Chris Lattnerb72773b2006-05-05 22:56:26 +00003273 if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
3274 N0.getOpcode() == ISD::ANY_EXTEND) {
Chris Lattner32ba1aa2006-11-20 18:05:46 +00003275 if (N0.getOperand(0).getValueType() < VT)
Nate Begeman1d4d4142005-09-01 00:19:25 +00003276 // if the source is smaller than the dest, we still need an extend
Nate Begeman83e75ec2005-09-06 04:43:02 +00003277 return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
Chris Lattner32ba1aa2006-11-20 18:05:46 +00003278 else if (N0.getOperand(0).getValueType() > VT)
Nate Begeman1d4d4142005-09-01 00:19:25 +00003279 // if the source is larger than the dest, than we just need the truncate
Nate Begeman83e75ec2005-09-06 04:43:02 +00003280 return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
Nate Begeman1d4d4142005-09-01 00:19:25 +00003281 else
3282 // if the source and dest are the same type, we can drop both the extend
3283 // and the truncate
Nate Begeman83e75ec2005-09-06 04:43:02 +00003284 return N0.getOperand(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003285 }
Evan Cheng007b69e2007-03-21 20:14:05 +00003286
Chris Lattner2b4c2792007-10-13 06:35:54 +00003287 // See if we can simplify the input to this truncate through knowledge that
3288 // only the low bits are being used. For example "trunc (or (shl x, 8), y)"
3289 // -> trunc y
Dan Gohman2e68b6f2008-02-25 21:11:39 +00003290 SDOperand Shorter =
3291 GetDemandedBits(N0, APInt::getLowBitsSet(N0.getValueSizeInBits(),
3292 MVT::getSizeInBits(VT)));
Chris Lattner2b4c2792007-10-13 06:35:54 +00003293 if (Shorter.Val)
3294 return DAG.getNode(ISD::TRUNCATE, VT, Shorter);
3295
Nate Begeman3df4d522005-10-12 20:40:40 +00003296 // fold (truncate (load x)) -> (smaller load x)
Evan Cheng007b69e2007-03-21 20:14:05 +00003297 // fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
Evan Chengc88138f2007-03-22 01:54:19 +00003298 return ReduceLoadWidth(N);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003299}
3300
Chris Lattner94683772005-12-23 05:30:37 +00003301SDOperand DAGCombiner::visitBIT_CONVERT(SDNode *N) {
3302 SDOperand N0 = N->getOperand(0);
3303 MVT::ValueType VT = N->getValueType(0);
3304
Dan Gohman7f321562007-06-25 16:23:39 +00003305 // If the input is a BUILD_VECTOR with all constant elements, fold this now.
3306 // Only do this before legalize, since afterward the target may be depending
3307 // on the bitconvert.
3308 // First check to see if this is all constant.
3309 if (!AfterLegalize &&
3310 N0.getOpcode() == ISD::BUILD_VECTOR && N0.Val->hasOneUse() &&
3311 MVT::isVector(VT)) {
3312 bool isSimple = true;
3313 for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
3314 if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
3315 N0.getOperand(i).getOpcode() != ISD::Constant &&
3316 N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
3317 isSimple = false;
3318 break;
3319 }
3320
3321 MVT::ValueType DestEltVT = MVT::getVectorElementType(N->getValueType(0));
3322 assert(!MVT::isVector(DestEltVT) &&
3323 "Element type of vector ValueType must not be vector!");
3324 if (isSimple) {
3325 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(N0.Val, DestEltVT);
3326 }
3327 }
3328
Chris Lattner94683772005-12-23 05:30:37 +00003329 // If the input is a constant, let getNode() fold it.
3330 if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
3331 SDOperand Res = DAG.getNode(ISD::BIT_CONVERT, VT, N0);
3332 if (Res.Val != N) return Res;
3333 }
3334
Chris Lattnerc8547d82005-12-23 05:37:50 +00003335 if (N0.getOpcode() == ISD::BIT_CONVERT) // conv(conv(x,t1),t2) -> conv(x,t2)
3336 return DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
Chris Lattner6258fb22006-04-02 02:53:43 +00003337
Chris Lattner57104102005-12-23 05:44:41 +00003338 // fold (conv (load x)) -> (load (conv*)x)
Evan Cheng513da432007-10-06 08:19:55 +00003339 // If the resultant load doesn't need a higher alignment than the original!
3340 if (ISD::isNormalLoad(N0.Val) && N0.hasOneUse() &&
Evan Cheng59d5b682007-05-07 21:27:48 +00003341 TLI.isOperationLegal(ISD::LOAD, VT)) {
Evan Cheng466685d2006-10-09 20:57:25 +00003342 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
Evan Cheng59d5b682007-05-07 21:27:48 +00003343 unsigned Align = TLI.getTargetMachine().getTargetData()->
Dan Gohmanfcc4dd92007-05-18 18:41:29 +00003344 getABITypeAlignment(MVT::getTypeForValueType(VT));
Evan Cheng59d5b682007-05-07 21:27:48 +00003345 unsigned OrigAlign = LN0->getAlignment();
3346 if (Align <= OrigAlign) {
3347 SDOperand Load = DAG.getLoad(VT, LN0->getChain(), LN0->getBasePtr(),
3348 LN0->getSrcValue(), LN0->getSrcValueOffset(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00003349 LN0->isVolatile(), Align);
Evan Cheng59d5b682007-05-07 21:27:48 +00003350 AddToWorkList(N);
3351 CombineTo(N0.Val, DAG.getNode(ISD::BIT_CONVERT, N0.getValueType(), Load),
3352 Load.getValue(1));
3353 return Load;
3354 }
Chris Lattner57104102005-12-23 05:44:41 +00003355 }
3356
Chris Lattner3bd39d42008-01-27 17:42:27 +00003357 // Fold bitconvert(fneg(x)) -> xor(bitconvert(x), signbit)
3358 // Fold bitconvert(fabs(x)) -> and(bitconvert(x), ~signbit)
3359 // This often reduces constant pool loads.
3360 if ((N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FABS) &&
3361 N0.Val->hasOneUse() && MVT::isInteger(VT) && !MVT::isVector(VT)) {
3362 SDOperand NewConv = DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
3363 AddToWorkList(NewConv.Val);
3364
Dan Gohman220a8232008-03-03 23:51:38 +00003365 APInt SignBit = APInt::getSignBit(MVT::getSizeInBits(VT));
Chris Lattner3bd39d42008-01-27 17:42:27 +00003366 if (N0.getOpcode() == ISD::FNEG)
3367 return DAG.getNode(ISD::XOR, VT, NewConv, DAG.getConstant(SignBit, VT));
3368 assert(N0.getOpcode() == ISD::FABS);
3369 return DAG.getNode(ISD::AND, VT, NewConv, DAG.getConstant(~SignBit, VT));
3370 }
3371
3372 // Fold bitconvert(fcopysign(cst, x)) -> bitconvert(x)&sign | cst&~sign'
3373 // Note that we don't handle copysign(x,cst) because this can always be folded
3374 // to an fneg or fabs.
3375 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse() &&
Chris Lattnerf32aac32008-01-27 23:32:17 +00003376 isa<ConstantFPSDNode>(N0.getOperand(0)) &&
3377 MVT::isInteger(VT) && !MVT::isVector(VT)) {
Chris Lattner3bd39d42008-01-27 17:42:27 +00003378 unsigned OrigXWidth = MVT::getSizeInBits(N0.getOperand(1).getValueType());
3379 SDOperand X = DAG.getNode(ISD::BIT_CONVERT, MVT::getIntegerType(OrigXWidth),
3380 N0.getOperand(1));
3381 AddToWorkList(X.Val);
3382
3383 // If X has a different width than the result/lhs, sext it or truncate it.
3384 unsigned VTWidth = MVT::getSizeInBits(VT);
3385 if (OrigXWidth < VTWidth) {
3386 X = DAG.getNode(ISD::SIGN_EXTEND, VT, X);
3387 AddToWorkList(X.Val);
3388 } else if (OrigXWidth > VTWidth) {
3389 // To get the sign bit in the right place, we have to shift it right
3390 // before truncating.
3391 X = DAG.getNode(ISD::SRL, X.getValueType(), X,
3392 DAG.getConstant(OrigXWidth-VTWidth, X.getValueType()));
3393 AddToWorkList(X.Val);
3394 X = DAG.getNode(ISD::TRUNCATE, VT, X);
3395 AddToWorkList(X.Val);
3396 }
3397
Dan Gohman220a8232008-03-03 23:51:38 +00003398 APInt SignBit = APInt::getSignBit(MVT::getSizeInBits(VT));
Chris Lattner3bd39d42008-01-27 17:42:27 +00003399 X = DAG.getNode(ISD::AND, VT, X, DAG.getConstant(SignBit, VT));
3400 AddToWorkList(X.Val);
3401
3402 SDOperand Cst = DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
3403 Cst = DAG.getNode(ISD::AND, VT, Cst, DAG.getConstant(~SignBit, VT));
3404 AddToWorkList(Cst.Val);
3405
3406 return DAG.getNode(ISD::OR, VT, X, Cst);
3407 }
3408
Chris Lattner94683772005-12-23 05:30:37 +00003409 return SDOperand();
3410}
3411
Dan Gohman7f321562007-06-25 16:23:39 +00003412/// ConstantFoldBIT_CONVERTofBUILD_VECTOR - We know that BV is a build_vector
Chris Lattner6258fb22006-04-02 02:53:43 +00003413/// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
3414/// destination element value type.
3415SDOperand DAGCombiner::
Dan Gohman7f321562007-06-25 16:23:39 +00003416ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *BV, MVT::ValueType DstEltVT) {
Chris Lattner6258fb22006-04-02 02:53:43 +00003417 MVT::ValueType SrcEltVT = BV->getOperand(0).getValueType();
3418
3419 // If this is already the right type, we're done.
3420 if (SrcEltVT == DstEltVT) return SDOperand(BV, 0);
3421
3422 unsigned SrcBitSize = MVT::getSizeInBits(SrcEltVT);
3423 unsigned DstBitSize = MVT::getSizeInBits(DstEltVT);
3424
3425 // If this is a conversion of N elements of one type to N elements of another
3426 // type, convert each element. This handles FP<->INT cases.
3427 if (SrcBitSize == DstBitSize) {
Chris Lattnerbd564bf2006-08-08 02:23:42 +00003428 SmallVector<SDOperand, 8> Ops;
Dan Gohman7f321562007-06-25 16:23:39 +00003429 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
Chris Lattner6258fb22006-04-02 02:53:43 +00003430 Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, DstEltVT, BV->getOperand(i)));
Chris Lattner3e104b12006-04-08 04:15:24 +00003431 AddToWorkList(Ops.back().Val);
3432 }
Dan Gohman7f321562007-06-25 16:23:39 +00003433 MVT::ValueType VT =
3434 MVT::getVectorType(DstEltVT,
3435 MVT::getVectorNumElements(BV->getValueType(0)));
3436 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
Chris Lattner6258fb22006-04-02 02:53:43 +00003437 }
3438
3439 // Otherwise, we're growing or shrinking the elements. To avoid having to
3440 // handle annoying details of growing/shrinking FP values, we convert them to
3441 // int first.
3442 if (MVT::isFloatingPoint(SrcEltVT)) {
3443 // Convert the input float vector to a int vector where the elements are the
3444 // same sizes.
3445 assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
3446 MVT::ValueType IntVT = SrcEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
Dan Gohman7f321562007-06-25 16:23:39 +00003447 BV = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, IntVT).Val;
Chris Lattner6258fb22006-04-02 02:53:43 +00003448 SrcEltVT = IntVT;
3449 }
3450
3451 // Now we know the input is an integer vector. If the output is a FP type,
3452 // convert to integer first, then to FP of the right size.
3453 if (MVT::isFloatingPoint(DstEltVT)) {
3454 assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
3455 MVT::ValueType TmpVT = DstEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
Dan Gohman7f321562007-06-25 16:23:39 +00003456 SDNode *Tmp = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, TmpVT).Val;
Chris Lattner6258fb22006-04-02 02:53:43 +00003457
3458 // Next, convert to FP elements of the same size.
Dan Gohman7f321562007-06-25 16:23:39 +00003459 return ConstantFoldBIT_CONVERTofBUILD_VECTOR(Tmp, DstEltVT);
Chris Lattner6258fb22006-04-02 02:53:43 +00003460 }
3461
3462 // Okay, we know the src/dst types are both integers of differing types.
3463 // Handling growing first.
3464 assert(MVT::isInteger(SrcEltVT) && MVT::isInteger(DstEltVT));
3465 if (SrcBitSize < DstBitSize) {
3466 unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
3467
Chris Lattnerbd564bf2006-08-08 02:23:42 +00003468 SmallVector<SDOperand, 8> Ops;
Dan Gohman7f321562007-06-25 16:23:39 +00003469 for (unsigned i = 0, e = BV->getNumOperands(); i != e;
Chris Lattner6258fb22006-04-02 02:53:43 +00003470 i += NumInputsPerOutput) {
3471 bool isLE = TLI.isLittleEndian();
Dan Gohman220a8232008-03-03 23:51:38 +00003472 APInt NewBits = APInt(DstBitSize, 0);
Chris Lattner6258fb22006-04-02 02:53:43 +00003473 bool EltIsUndef = true;
3474 for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
3475 // Shift the previously computed bits over.
3476 NewBits <<= SrcBitSize;
3477 SDOperand Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
3478 if (Op.getOpcode() == ISD::UNDEF) continue;
3479 EltIsUndef = false;
3480
Dan Gohman220a8232008-03-03 23:51:38 +00003481 NewBits |=
3482 APInt(cast<ConstantSDNode>(Op)->getAPIntValue()).zext(DstBitSize);
Chris Lattner6258fb22006-04-02 02:53:43 +00003483 }
3484
3485 if (EltIsUndef)
3486 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
3487 else
3488 Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
3489 }
3490
Evan Chengefec7512008-02-18 23:04:32 +00003491 MVT::ValueType VT = MVT::getVectorType(DstEltVT, Ops.size());
Dan Gohman7f321562007-06-25 16:23:39 +00003492 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
Chris Lattner6258fb22006-04-02 02:53:43 +00003493 }
3494
3495 // Finally, this must be the case where we are shrinking elements: each input
3496 // turns into multiple outputs.
Evan Chengefec7512008-02-18 23:04:32 +00003497 bool isS2V = ISD::isScalarToVector(BV);
Chris Lattner6258fb22006-04-02 02:53:43 +00003498 unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
Evan Chengefec7512008-02-18 23:04:32 +00003499 MVT::ValueType VT = MVT::getVectorType(DstEltVT,
3500 NumOutputsPerInput * BV->getNumOperands());
Chris Lattnerbd564bf2006-08-08 02:23:42 +00003501 SmallVector<SDOperand, 8> Ops;
Dan Gohman7f321562007-06-25 16:23:39 +00003502 for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
Chris Lattner6258fb22006-04-02 02:53:43 +00003503 if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
3504 for (unsigned j = 0; j != NumOutputsPerInput; ++j)
3505 Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
3506 continue;
3507 }
Dan Gohman220a8232008-03-03 23:51:38 +00003508 APInt OpVal = cast<ConstantSDNode>(BV->getOperand(i))->getAPIntValue();
Chris Lattner6258fb22006-04-02 02:53:43 +00003509 for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
Dan Gohman220a8232008-03-03 23:51:38 +00003510 APInt ThisVal = APInt(OpVal).trunc(DstBitSize);
Chris Lattner6258fb22006-04-02 02:53:43 +00003511 Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
Dan Gohman220a8232008-03-03 23:51:38 +00003512 if (isS2V && i == 0 && j == 0 && APInt(ThisVal).zext(SrcBitSize) == OpVal)
Evan Chengefec7512008-02-18 23:04:32 +00003513 // Simply turn this into a SCALAR_TO_VECTOR of the new type.
3514 return DAG.getNode(ISD::SCALAR_TO_VECTOR, VT, Ops[0]);
Dan Gohman220a8232008-03-03 23:51:38 +00003515 OpVal = OpVal.lshr(DstBitSize);
Chris Lattner6258fb22006-04-02 02:53:43 +00003516 }
3517
3518 // For big endian targets, swap the order of the pieces of each element.
Duncan Sands0753fc12008-02-11 10:37:04 +00003519 if (TLI.isBigEndian())
Chris Lattner6258fb22006-04-02 02:53:43 +00003520 std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
3521 }
Dan Gohman7f321562007-06-25 16:23:39 +00003522 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
Chris Lattner6258fb22006-04-02 02:53:43 +00003523}
3524
3525
3526
Chris Lattner01b3d732005-09-28 22:28:18 +00003527SDOperand DAGCombiner::visitFADD(SDNode *N) {
3528 SDOperand N0 = N->getOperand(0);
3529 SDOperand N1 = N->getOperand(1);
Nate Begemana0e221d2005-10-18 00:28:13 +00003530 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3531 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
Chris Lattner01b3d732005-09-28 22:28:18 +00003532 MVT::ValueType VT = N->getValueType(0);
Nate Begemana0e221d2005-10-18 00:28:13 +00003533
Dan Gohman7f321562007-06-25 16:23:39 +00003534 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00003535 if (MVT::isVector(VT)) {
3536 SDOperand FoldedVOp = SimplifyVBinOp(N);
3537 if (FoldedVOp.Val) return FoldedVOp;
3538 }
Dan Gohman7f321562007-06-25 16:23:39 +00003539
Nate Begemana0e221d2005-10-18 00:28:13 +00003540 // fold (fadd c1, c2) -> c1+c2
Dale Johannesendb44bf82007-10-16 23:38:29 +00003541 if (N0CFP && N1CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003542 return DAG.getNode(ISD::FADD, VT, N0, N1);
Nate Begemana0e221d2005-10-18 00:28:13 +00003543 // canonicalize constant to RHS
3544 if (N0CFP && !N1CFP)
3545 return DAG.getNode(ISD::FADD, VT, N1, N0);
Chris Lattner01b3d732005-09-28 22:28:18 +00003546 // fold (A + (-B)) -> A-B
Chris Lattner0254e702008-02-26 07:04:54 +00003547 if (isNegatibleForFree(N1, AfterLegalize) == 2)
3548 return DAG.getNode(ISD::FSUB, VT, N0,
3549 GetNegatedExpression(N1, DAG, AfterLegalize));
Chris Lattner01b3d732005-09-28 22:28:18 +00003550 // fold ((-A) + B) -> B-A
Chris Lattner0254e702008-02-26 07:04:54 +00003551 if (isNegatibleForFree(N0, AfterLegalize) == 2)
3552 return DAG.getNode(ISD::FSUB, VT, N1,
3553 GetNegatedExpression(N0, DAG, AfterLegalize));
Chris Lattnerddae4bd2007-01-08 23:04:05 +00003554
3555 // If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
3556 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FADD &&
3557 N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
3558 return DAG.getNode(ISD::FADD, VT, N0.getOperand(0),
3559 DAG.getNode(ISD::FADD, VT, N0.getOperand(1), N1));
3560
Chris Lattner01b3d732005-09-28 22:28:18 +00003561 return SDOperand();
3562}
3563
3564SDOperand DAGCombiner::visitFSUB(SDNode *N) {
3565 SDOperand N0 = N->getOperand(0);
3566 SDOperand N1 = N->getOperand(1);
Nate Begemana0e221d2005-10-18 00:28:13 +00003567 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3568 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
Chris Lattner01b3d732005-09-28 22:28:18 +00003569 MVT::ValueType VT = N->getValueType(0);
Nate Begemana0e221d2005-10-18 00:28:13 +00003570
Dan Gohman7f321562007-06-25 16:23:39 +00003571 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00003572 if (MVT::isVector(VT)) {
3573 SDOperand FoldedVOp = SimplifyVBinOp(N);
3574 if (FoldedVOp.Val) return FoldedVOp;
3575 }
Dan Gohman7f321562007-06-25 16:23:39 +00003576
Nate Begemana0e221d2005-10-18 00:28:13 +00003577 // fold (fsub c1, c2) -> c1-c2
Dale Johannesendb44bf82007-10-16 23:38:29 +00003578 if (N0CFP && N1CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003579 return DAG.getNode(ISD::FSUB, VT, N0, N1);
Dan Gohman23ff1822007-07-02 15:48:56 +00003580 // fold (0-B) -> -B
Dale Johannesenc4dd3c32007-08-31 23:34:27 +00003581 if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) {
Chris Lattner0254e702008-02-26 07:04:54 +00003582 if (isNegatibleForFree(N1, AfterLegalize))
3583 return GetNegatedExpression(N1, DAG, AfterLegalize);
Dan Gohman23ff1822007-07-02 15:48:56 +00003584 return DAG.getNode(ISD::FNEG, VT, N1);
3585 }
Chris Lattner01b3d732005-09-28 22:28:18 +00003586 // fold (A-(-B)) -> A+B
Chris Lattner0254e702008-02-26 07:04:54 +00003587 if (isNegatibleForFree(N1, AfterLegalize))
3588 return DAG.getNode(ISD::FADD, VT, N0,
3589 GetNegatedExpression(N1, DAG, AfterLegalize));
Chris Lattner29446522007-05-14 22:04:50 +00003590
Chris Lattner01b3d732005-09-28 22:28:18 +00003591 return SDOperand();
3592}
3593
3594SDOperand DAGCombiner::visitFMUL(SDNode *N) {
3595 SDOperand N0 = N->getOperand(0);
3596 SDOperand N1 = N->getOperand(1);
Nate Begeman11af4ea2005-10-17 20:40:11 +00003597 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3598 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
Chris Lattner01b3d732005-09-28 22:28:18 +00003599 MVT::ValueType VT = N->getValueType(0);
3600
Dan Gohman7f321562007-06-25 16:23:39 +00003601 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00003602 if (MVT::isVector(VT)) {
3603 SDOperand FoldedVOp = SimplifyVBinOp(N);
3604 if (FoldedVOp.Val) return FoldedVOp;
3605 }
Dan Gohman7f321562007-06-25 16:23:39 +00003606
Nate Begeman11af4ea2005-10-17 20:40:11 +00003607 // fold (fmul c1, c2) -> c1*c2
Dale Johannesendb44bf82007-10-16 23:38:29 +00003608 if (N0CFP && N1CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003609 return DAG.getNode(ISD::FMUL, VT, N0, N1);
Nate Begeman11af4ea2005-10-17 20:40:11 +00003610 // canonicalize constant to RHS
Nate Begemana0e221d2005-10-18 00:28:13 +00003611 if (N0CFP && !N1CFP)
3612 return DAG.getNode(ISD::FMUL, VT, N1, N0);
Nate Begeman11af4ea2005-10-17 20:40:11 +00003613 // fold (fmul X, 2.0) -> (fadd X, X)
3614 if (N1CFP && N1CFP->isExactlyValue(+2.0))
3615 return DAG.getNode(ISD::FADD, VT, N0, N0);
Chris Lattner29446522007-05-14 22:04:50 +00003616 // fold (fmul X, -1.0) -> (fneg X)
3617 if (N1CFP && N1CFP->isExactlyValue(-1.0))
3618 return DAG.getNode(ISD::FNEG, VT, N0);
3619
3620 // -X * -Y -> X*Y
Chris Lattner0254e702008-02-26 07:04:54 +00003621 if (char LHSNeg = isNegatibleForFree(N0, AfterLegalize)) {
3622 if (char RHSNeg = isNegatibleForFree(N1, AfterLegalize)) {
Chris Lattner29446522007-05-14 22:04:50 +00003623 // Both can be negated for free, check to see if at least one is cheaper
3624 // negated.
3625 if (LHSNeg == 2 || RHSNeg == 2)
Chris Lattner0254e702008-02-26 07:04:54 +00003626 return DAG.getNode(ISD::FMUL, VT,
3627 GetNegatedExpression(N0, DAG, AfterLegalize),
3628 GetNegatedExpression(N1, DAG, AfterLegalize));
Chris Lattner29446522007-05-14 22:04:50 +00003629 }
3630 }
Chris Lattnerddae4bd2007-01-08 23:04:05 +00003631
3632 // If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
3633 if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FMUL &&
3634 N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
3635 return DAG.getNode(ISD::FMUL, VT, N0.getOperand(0),
3636 DAG.getNode(ISD::FMUL, VT, N0.getOperand(1), N1));
3637
Chris Lattner01b3d732005-09-28 22:28:18 +00003638 return SDOperand();
3639}
3640
3641SDOperand DAGCombiner::visitFDIV(SDNode *N) {
3642 SDOperand N0 = N->getOperand(0);
3643 SDOperand N1 = N->getOperand(1);
Nate Begemana148d982006-01-18 22:35:16 +00003644 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3645 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
Chris Lattner01b3d732005-09-28 22:28:18 +00003646 MVT::ValueType VT = N->getValueType(0);
3647
Dan Gohman7f321562007-06-25 16:23:39 +00003648 // fold vector ops
Dan Gohman05d92fe2007-07-13 20:03:40 +00003649 if (MVT::isVector(VT)) {
3650 SDOperand FoldedVOp = SimplifyVBinOp(N);
3651 if (FoldedVOp.Val) return FoldedVOp;
3652 }
Dan Gohman7f321562007-06-25 16:23:39 +00003653
Nate Begemana148d982006-01-18 22:35:16 +00003654 // fold (fdiv c1, c2) -> c1/c2
Dale Johannesendb44bf82007-10-16 23:38:29 +00003655 if (N0CFP && N1CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003656 return DAG.getNode(ISD::FDIV, VT, N0, N1);
Chris Lattner29446522007-05-14 22:04:50 +00003657
3658
3659 // -X / -Y -> X*Y
Chris Lattner0254e702008-02-26 07:04:54 +00003660 if (char LHSNeg = isNegatibleForFree(N0, AfterLegalize)) {
3661 if (char RHSNeg = isNegatibleForFree(N1, AfterLegalize)) {
Chris Lattner29446522007-05-14 22:04:50 +00003662 // Both can be negated for free, check to see if at least one is cheaper
3663 // negated.
3664 if (LHSNeg == 2 || RHSNeg == 2)
Chris Lattner0254e702008-02-26 07:04:54 +00003665 return DAG.getNode(ISD::FDIV, VT,
3666 GetNegatedExpression(N0, DAG, AfterLegalize),
3667 GetNegatedExpression(N1, DAG, AfterLegalize));
Chris Lattner29446522007-05-14 22:04:50 +00003668 }
3669 }
3670
Chris Lattner01b3d732005-09-28 22:28:18 +00003671 return SDOperand();
3672}
3673
3674SDOperand DAGCombiner::visitFREM(SDNode *N) {
3675 SDOperand N0 = N->getOperand(0);
3676 SDOperand N1 = N->getOperand(1);
Nate Begemana148d982006-01-18 22:35:16 +00003677 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3678 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
Chris Lattner01b3d732005-09-28 22:28:18 +00003679 MVT::ValueType VT = N->getValueType(0);
3680
Nate Begemana148d982006-01-18 22:35:16 +00003681 // fold (frem c1, c2) -> fmod(c1,c2)
Dale Johannesendb44bf82007-10-16 23:38:29 +00003682 if (N0CFP && N1CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003683 return DAG.getNode(ISD::FREM, VT, N0, N1);
Dan Gohman7f321562007-06-25 16:23:39 +00003684
Chris Lattner01b3d732005-09-28 22:28:18 +00003685 return SDOperand();
3686}
3687
Chris Lattner12d83032006-03-05 05:30:57 +00003688SDOperand DAGCombiner::visitFCOPYSIGN(SDNode *N) {
3689 SDOperand N0 = N->getOperand(0);
3690 SDOperand N1 = N->getOperand(1);
3691 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3692 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
3693 MVT::ValueType VT = N->getValueType(0);
3694
Dale Johannesendb44bf82007-10-16 23:38:29 +00003695 if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
Chris Lattner12d83032006-03-05 05:30:57 +00003696 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1);
3697
3698 if (N1CFP) {
Dale Johannesene6c17422007-08-26 01:18:27 +00003699 const APFloat& V = N1CFP->getValueAPF();
Chris Lattner12d83032006-03-05 05:30:57 +00003700 // copysign(x, c1) -> fabs(x) iff ispos(c1)
3701 // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
Dale Johannesen87503a62007-08-25 22:10:57 +00003702 if (!V.isNegative())
Chris Lattner12d83032006-03-05 05:30:57 +00003703 return DAG.getNode(ISD::FABS, VT, N0);
3704 else
3705 return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0));
3706 }
3707
3708 // copysign(fabs(x), y) -> copysign(x, y)
3709 // copysign(fneg(x), y) -> copysign(x, y)
3710 // copysign(copysign(x,z), y) -> copysign(x, y)
3711 if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
3712 N0.getOpcode() == ISD::FCOPYSIGN)
3713 return DAG.getNode(ISD::FCOPYSIGN, VT, N0.getOperand(0), N1);
3714
3715 // copysign(x, abs(y)) -> abs(x)
3716 if (N1.getOpcode() == ISD::FABS)
3717 return DAG.getNode(ISD::FABS, VT, N0);
3718
3719 // copysign(x, copysign(y,z)) -> copysign(x, z)
3720 if (N1.getOpcode() == ISD::FCOPYSIGN)
3721 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(1));
3722
3723 // copysign(x, fp_extend(y)) -> copysign(x, y)
3724 // copysign(x, fp_round(y)) -> copysign(x, y)
3725 if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
3726 return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(0));
3727
3728 return SDOperand();
3729}
3730
3731
Chris Lattner01b3d732005-09-28 22:28:18 +00003732
Nate Begeman83e75ec2005-09-06 04:43:02 +00003733SDOperand DAGCombiner::visitSINT_TO_FP(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00003734 SDOperand N0 = N->getOperand(0);
Nate Begeman646d7e22005-09-02 21:18:40 +00003735 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
Nate Begemana148d982006-01-18 22:35:16 +00003736 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003737
3738 // fold (sint_to_fp c1) -> c1fp
Dale Johannesendb44bf82007-10-16 23:38:29 +00003739 if (N0C && N0.getValueType() != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003740 return DAG.getNode(ISD::SINT_TO_FP, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00003741 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003742}
3743
Nate Begeman83e75ec2005-09-06 04:43:02 +00003744SDOperand DAGCombiner::visitUINT_TO_FP(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00003745 SDOperand N0 = N->getOperand(0);
Nate Begeman646d7e22005-09-02 21:18:40 +00003746 ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
Nate Begemana148d982006-01-18 22:35:16 +00003747 MVT::ValueType VT = N->getValueType(0);
3748
Nate Begeman1d4d4142005-09-01 00:19:25 +00003749 // fold (uint_to_fp c1) -> c1fp
Dale Johannesendb44bf82007-10-16 23:38:29 +00003750 if (N0C && N0.getValueType() != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003751 return DAG.getNode(ISD::UINT_TO_FP, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00003752 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003753}
3754
Nate Begeman83e75ec2005-09-06 04:43:02 +00003755SDOperand DAGCombiner::visitFP_TO_SINT(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003756 SDOperand N0 = N->getOperand(0);
3757 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3758 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003759
3760 // fold (fp_to_sint c1fp) -> c1
Nate Begeman646d7e22005-09-02 21:18:40 +00003761 if (N0CFP)
Nate Begemana148d982006-01-18 22:35:16 +00003762 return DAG.getNode(ISD::FP_TO_SINT, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00003763 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003764}
3765
Nate Begeman83e75ec2005-09-06 04:43:02 +00003766SDOperand DAGCombiner::visitFP_TO_UINT(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003767 SDOperand N0 = N->getOperand(0);
3768 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3769 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003770
3771 // fold (fp_to_uint c1fp) -> c1
Dale Johannesendb44bf82007-10-16 23:38:29 +00003772 if (N0CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003773 return DAG.getNode(ISD::FP_TO_UINT, VT, N0);
Nate Begeman83e75ec2005-09-06 04:43:02 +00003774 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003775}
3776
Nate Begeman83e75ec2005-09-06 04:43:02 +00003777SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003778 SDOperand N0 = N->getOperand(0);
Chris Lattner0bd48932008-01-17 07:00:52 +00003779 SDOperand N1 = N->getOperand(1);
Nate Begemana148d982006-01-18 22:35:16 +00003780 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3781 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003782
3783 // fold (fp_round c1fp) -> c1fp
Dale Johannesendb44bf82007-10-16 23:38:29 +00003784 if (N0CFP && N0.getValueType() != MVT::ppcf128)
Chris Lattner0bd48932008-01-17 07:00:52 +00003785 return DAG.getNode(ISD::FP_ROUND, VT, N0, N1);
Chris Lattner79dbea52006-03-13 06:26:26 +00003786
3787 // fold (fp_round (fp_extend x)) -> x
3788 if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
3789 return N0.getOperand(0);
3790
Chris Lattner0aa5e6f2008-01-24 06:45:35 +00003791 // fold (fp_round (fp_round x)) -> (fp_round x)
3792 if (N0.getOpcode() == ISD::FP_ROUND) {
3793 // This is a value preserving truncation if both round's are.
3794 bool IsTrunc = N->getConstantOperandVal(1) == 1 &&
3795 N0.Val->getConstantOperandVal(1) == 1;
3796 return DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0),
3797 DAG.getIntPtrConstant(IsTrunc));
3798 }
3799
Chris Lattner79dbea52006-03-13 06:26:26 +00003800 // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
3801 if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) {
Chris Lattner0bd48932008-01-17 07:00:52 +00003802 SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0), N1);
Chris Lattner79dbea52006-03-13 06:26:26 +00003803 AddToWorkList(Tmp.Val);
3804 return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1));
3805 }
3806
Nate Begeman83e75ec2005-09-06 04:43:02 +00003807 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003808}
3809
Nate Begeman83e75ec2005-09-06 04:43:02 +00003810SDOperand DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
Nate Begeman1d4d4142005-09-01 00:19:25 +00003811 SDOperand N0 = N->getOperand(0);
3812 MVT::ValueType VT = N->getValueType(0);
3813 MVT::ValueType EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
Nate Begeman646d7e22005-09-02 21:18:40 +00003814 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003815
Nate Begeman1d4d4142005-09-01 00:19:25 +00003816 // fold (fp_round_inreg c1fp) -> c1fp
Nate Begeman646d7e22005-09-02 21:18:40 +00003817 if (N0CFP) {
Dale Johannesenc4dd3c32007-08-31 23:34:27 +00003818 SDOperand Round = DAG.getConstantFP(N0CFP->getValueAPF(), EVT);
Nate Begeman83e75ec2005-09-06 04:43:02 +00003819 return DAG.getNode(ISD::FP_EXTEND, VT, Round);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003820 }
Nate Begeman83e75ec2005-09-06 04:43:02 +00003821 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003822}
3823
Nate Begeman83e75ec2005-09-06 04:43:02 +00003824SDOperand DAGCombiner::visitFP_EXTEND(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003825 SDOperand N0 = N->getOperand(0);
3826 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3827 MVT::ValueType VT = N->getValueType(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003828
Chris Lattner5938bef2007-12-29 06:55:23 +00003829 // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
3830 if (N->hasOneUse() && (*N->use_begin())->getOpcode() == ISD::FP_ROUND)
3831 return SDOperand();
Chris Lattner0bd48932008-01-17 07:00:52 +00003832
Nate Begeman1d4d4142005-09-01 00:19:25 +00003833 // fold (fp_extend c1fp) -> c1fp
Dale Johannesendb44bf82007-10-16 23:38:29 +00003834 if (N0CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003835 return DAG.getNode(ISD::FP_EXTEND, VT, N0);
Chris Lattner0bd48932008-01-17 07:00:52 +00003836
3837 // Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
3838 // value of X.
3839 if (N0.getOpcode() == ISD::FP_ROUND && N0.Val->getConstantOperandVal(1) == 1){
3840 SDOperand In = N0.getOperand(0);
3841 if (In.getValueType() == VT) return In;
3842 if (VT < In.getValueType())
3843 return DAG.getNode(ISD::FP_ROUND, VT, In, N0.getOperand(1));
3844 return DAG.getNode(ISD::FP_EXTEND, VT, In);
3845 }
3846
3847 // fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
Dale Johannesenb6210fc2007-10-19 20:29:00 +00003848 if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
Evan Chengc5484282006-10-04 00:56:09 +00003849 (!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
Evan Cheng466685d2006-10-09 20:57:25 +00003850 LoadSDNode *LN0 = cast<LoadSDNode>(N0);
3851 SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
3852 LN0->getBasePtr(), LN0->getSrcValue(),
3853 LN0->getSrcValueOffset(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00003854 N0.getValueType(),
3855 LN0->isVolatile(),
3856 LN0->getAlignment());
Chris Lattnere564dbb2006-05-05 21:34:35 +00003857 CombineTo(N, ExtLoad);
Chris Lattner0bd48932008-01-17 07:00:52 +00003858 CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad,
3859 DAG.getIntPtrConstant(1)),
Chris Lattnere564dbb2006-05-05 21:34:35 +00003860 ExtLoad.getValue(1));
3861 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
3862 }
3863
3864
Nate Begeman83e75ec2005-09-06 04:43:02 +00003865 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003866}
3867
Nate Begeman83e75ec2005-09-06 04:43:02 +00003868SDOperand DAGCombiner::visitFNEG(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003869 SDOperand N0 = N->getOperand(0);
Nate Begemana148d982006-01-18 22:35:16 +00003870
Chris Lattner0254e702008-02-26 07:04:54 +00003871 if (isNegatibleForFree(N0, AfterLegalize))
3872 return GetNegatedExpression(N0, DAG, AfterLegalize);
Dan Gohman23ff1822007-07-02 15:48:56 +00003873
Chris Lattner3bd39d42008-01-27 17:42:27 +00003874 // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading
3875 // constant pool values.
Chris Lattnerf32aac32008-01-27 23:32:17 +00003876 if (N0.getOpcode() == ISD::BIT_CONVERT && N0.Val->hasOneUse() &&
3877 MVT::isInteger(N0.getOperand(0).getValueType()) &&
3878 !MVT::isVector(N0.getOperand(0).getValueType())) {
Chris Lattner3bd39d42008-01-27 17:42:27 +00003879 SDOperand Int = N0.getOperand(0);
3880 MVT::ValueType IntVT = Int.getValueType();
3881 if (MVT::isInteger(IntVT) && !MVT::isVector(IntVT)) {
3882 Int = DAG.getNode(ISD::XOR, IntVT, Int,
3883 DAG.getConstant(MVT::getIntVTSignBit(IntVT), IntVT));
3884 AddToWorkList(Int.Val);
3885 return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), Int);
3886 }
3887 }
3888
Nate Begeman83e75ec2005-09-06 04:43:02 +00003889 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003890}
3891
Nate Begeman83e75ec2005-09-06 04:43:02 +00003892SDOperand DAGCombiner::visitFABS(SDNode *N) {
Nate Begemana148d982006-01-18 22:35:16 +00003893 SDOperand N0 = N->getOperand(0);
3894 ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
3895 MVT::ValueType VT = N->getValueType(0);
3896
Nate Begeman1d4d4142005-09-01 00:19:25 +00003897 // fold (fabs c1) -> fabs(c1)
Dale Johannesendb44bf82007-10-16 23:38:29 +00003898 if (N0CFP && VT != MVT::ppcf128)
Nate Begemana148d982006-01-18 22:35:16 +00003899 return DAG.getNode(ISD::FABS, VT, N0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003900 // fold (fabs (fabs x)) -> (fabs x)
Chris Lattner12d83032006-03-05 05:30:57 +00003901 if (N0.getOpcode() == ISD::FABS)
Nate Begeman83e75ec2005-09-06 04:43:02 +00003902 return N->getOperand(0);
Nate Begeman1d4d4142005-09-01 00:19:25 +00003903 // fold (fabs (fneg x)) -> (fabs x)
Chris Lattner12d83032006-03-05 05:30:57 +00003904 // fold (fabs (fcopysign x, y)) -> (fabs x)
3905 if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
3906 return DAG.getNode(ISD::FABS, VT, N0.getOperand(0));
3907
Chris Lattner3bd39d42008-01-27 17:42:27 +00003908 // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading
3909 // constant pool values.
Chris Lattnerf32aac32008-01-27 23:32:17 +00003910 if (N0.getOpcode() == ISD::BIT_CONVERT && N0.Val->hasOneUse() &&
3911 MVT::isInteger(N0.getOperand(0).getValueType()) &&
3912 !MVT::isVector(N0.getOperand(0).getValueType())) {
Chris Lattner3bd39d42008-01-27 17:42:27 +00003913 SDOperand Int = N0.getOperand(0);
3914 MVT::ValueType IntVT = Int.getValueType();
3915 if (MVT::isInteger(IntVT) && !MVT::isVector(IntVT)) {
3916 Int = DAG.getNode(ISD::AND, IntVT, Int,
3917 DAG.getConstant(~MVT::getIntVTSignBit(IntVT), IntVT));
3918 AddToWorkList(Int.Val);
3919 return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), Int);
3920 }
3921 }
3922
Nate Begeman83e75ec2005-09-06 04:43:02 +00003923 return SDOperand();
Nate Begeman1d4d4142005-09-01 00:19:25 +00003924}
3925
Nate Begeman44728a72005-09-19 22:34:01 +00003926SDOperand DAGCombiner::visitBRCOND(SDNode *N) {
3927 SDOperand Chain = N->getOperand(0);
3928 SDOperand N1 = N->getOperand(1);
3929 SDOperand N2 = N->getOperand(2);
3930 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
3931
3932 // never taken branch, fold to chain
3933 if (N1C && N1C->isNullValue())
3934 return Chain;
3935 // unconditional branch
Dan Gohman002e5d02008-03-13 22:13:53 +00003936 if (N1C && N1C->getAPIntValue() == 1)
Nate Begeman44728a72005-09-19 22:34:01 +00003937 return DAG.getNode(ISD::BR, MVT::Other, Chain, N2);
Nate Begeman750ac1b2006-02-01 07:19:44 +00003938 // fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
3939 // on the target.
3940 if (N1.getOpcode() == ISD::SETCC &&
3941 TLI.isOperationLegal(ISD::BR_CC, MVT::Other)) {
3942 return DAG.getNode(ISD::BR_CC, MVT::Other, Chain, N1.getOperand(2),
3943 N1.getOperand(0), N1.getOperand(1), N2);
3944 }
Nate Begeman44728a72005-09-19 22:34:01 +00003945 return SDOperand();
3946}
3947
Chris Lattner3ea0b472005-10-05 06:47:48 +00003948// Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
3949//
Nate Begeman44728a72005-09-19 22:34:01 +00003950SDOperand DAGCombiner::visitBR_CC(SDNode *N) {
Chris Lattner3ea0b472005-10-05 06:47:48 +00003951 CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
3952 SDOperand CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
3953
3954 // Use SimplifySetCC to simplify SETCC's.
Nate Begemane17daeb2005-10-05 21:43:42 +00003955 SDOperand Simp = SimplifySetCC(MVT::i1, CondLHS, CondRHS, CC->get(), false);
Chris Lattner30f73e72006-10-14 03:52:46 +00003956 if (Simp.Val) AddToWorkList(Simp.Val);
3957
Nate Begemane17daeb2005-10-05 21:43:42 +00003958 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(Simp.Val);
3959
3960 // fold br_cc true, dest -> br dest (unconditional branch)
Dan Gohman002e5d02008-03-13 22:13:53 +00003961 if (SCCC && !SCCC->isNullValue())
Nate Begemane17daeb2005-10-05 21:43:42 +00003962 return DAG.getNode(ISD::BR, MVT::Other, N->getOperand(0),
3963 N->getOperand(4));
3964 // fold br_cc false, dest -> unconditional fall through
3965 if (SCCC && SCCC->isNullValue())
3966 return N->getOperand(0);
Chris Lattner30f73e72006-10-14 03:52:46 +00003967
Nate Begemane17daeb2005-10-05 21:43:42 +00003968 // fold to a simpler setcc
3969 if (Simp.Val && Simp.getOpcode() == ISD::SETCC)
3970 return DAG.getNode(ISD::BR_CC, MVT::Other, N->getOperand(0),
3971 Simp.getOperand(2), Simp.getOperand(0),
3972 Simp.getOperand(1), N->getOperand(4));
Nate Begeman44728a72005-09-19 22:34:01 +00003973 return SDOperand();
3974}
3975
Chris Lattner448f2192006-11-11 00:39:41 +00003976
3977/// CombineToPreIndexedLoadStore - Try turning a load / store and a
3978/// pre-indexed load / store when the base pointer is a add or subtract
3979/// and it has other uses besides the load / store. After the
3980/// transformation, the new indexed load / store has effectively folded
3981/// the add / subtract in and all of its other uses are redirected to the
3982/// new load / store.
3983bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
3984 if (!AfterLegalize)
3985 return false;
3986
3987 bool isLoad = true;
3988 SDOperand Ptr;
3989 MVT::ValueType VT;
3990 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
Chris Lattnerddf89562008-01-17 19:59:44 +00003991 if (LD->isIndexed())
Evan Chenge90460e2006-12-16 06:25:23 +00003992 return false;
Dan Gohmanb625f2f2008-01-30 00:15:11 +00003993 VT = LD->getMemoryVT();
Evan Cheng83060c52007-03-07 08:07:03 +00003994 if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
Chris Lattner448f2192006-11-11 00:39:41 +00003995 !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
3996 return false;
3997 Ptr = LD->getBasePtr();
3998 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
Chris Lattnerddf89562008-01-17 19:59:44 +00003999 if (ST->isIndexed())
Evan Chenge90460e2006-12-16 06:25:23 +00004000 return false;
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004001 VT = ST->getMemoryVT();
Chris Lattner448f2192006-11-11 00:39:41 +00004002 if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
4003 !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
4004 return false;
4005 Ptr = ST->getBasePtr();
4006 isLoad = false;
4007 } else
4008 return false;
4009
Chris Lattner9f1794e2006-11-11 00:56:29 +00004010 // If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
4011 // out. There is no reason to make this a preinc/predec.
4012 if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
4013 Ptr.Val->hasOneUse())
4014 return false;
Chris Lattner448f2192006-11-11 00:39:41 +00004015
Chris Lattner9f1794e2006-11-11 00:56:29 +00004016 // Ask the target to do addressing mode selection.
4017 SDOperand BasePtr;
4018 SDOperand Offset;
4019 ISD::MemIndexedMode AM = ISD::UNINDEXED;
4020 if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
4021 return false;
Evan Chenga7d4a042007-05-03 23:52:19 +00004022 // Don't create a indexed load / store with zero offset.
4023 if (isa<ConstantSDNode>(Offset) &&
Dan Gohman002e5d02008-03-13 22:13:53 +00004024 cast<ConstantSDNode>(Offset)->isNullValue())
Evan Chenga7d4a042007-05-03 23:52:19 +00004025 return false;
Chris Lattner9f1794e2006-11-11 00:56:29 +00004026
Chris Lattner41e53fd2006-11-11 01:00:15 +00004027 // Try turning it into a pre-indexed load / store except when:
Evan Chengc843abe2007-05-24 02:35:39 +00004028 // 1) The new base ptr is a frame index.
4029 // 2) If N is a store and the new base ptr is either the same as or is a
Chris Lattner9f1794e2006-11-11 00:56:29 +00004030 // predecessor of the value being stored.
Evan Chengc843abe2007-05-24 02:35:39 +00004031 // 3) Another use of old base ptr is a predecessor of N. If ptr is folded
Chris Lattner9f1794e2006-11-11 00:56:29 +00004032 // that would create a cycle.
Evan Chengc843abe2007-05-24 02:35:39 +00004033 // 4) All uses are load / store ops that use it as old base ptr.
Chris Lattner448f2192006-11-11 00:39:41 +00004034
Chris Lattner41e53fd2006-11-11 01:00:15 +00004035 // Check #1. Preinc'ing a frame index would require copying the stack pointer
4036 // (plus the implicit offset) to a register to preinc anyway.
4037 if (isa<FrameIndexSDNode>(BasePtr))
4038 return false;
4039
4040 // Check #2.
Chris Lattner9f1794e2006-11-11 00:56:29 +00004041 if (!isLoad) {
4042 SDOperand Val = cast<StoreSDNode>(N)->getValue();
Evan Cheng917be682008-03-04 00:41:45 +00004043 if (Val == BasePtr || BasePtr.Val->isPredecessorOf(Val.Val))
Chris Lattner9f1794e2006-11-11 00:56:29 +00004044 return false;
Chris Lattner448f2192006-11-11 00:39:41 +00004045 }
Chris Lattner9f1794e2006-11-11 00:56:29 +00004046
Evan Chengc843abe2007-05-24 02:35:39 +00004047 // Now check for #3 and #4.
Chris Lattner9f1794e2006-11-11 00:56:29 +00004048 bool RealUse = false;
4049 for (SDNode::use_iterator I = Ptr.Val->use_begin(),
4050 E = Ptr.Val->use_end(); I != E; ++I) {
4051 SDNode *Use = *I;
4052 if (Use == N)
4053 continue;
Evan Cheng917be682008-03-04 00:41:45 +00004054 if (Use->isPredecessorOf(N))
Chris Lattner9f1794e2006-11-11 00:56:29 +00004055 return false;
4056
4057 if (!((Use->getOpcode() == ISD::LOAD &&
4058 cast<LoadSDNode>(Use)->getBasePtr() == Ptr) ||
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00004059 (Use->getOpcode() == ISD::STORE &&
4060 cast<StoreSDNode>(Use)->getBasePtr() == Ptr)))
Chris Lattner9f1794e2006-11-11 00:56:29 +00004061 RealUse = true;
4062 }
4063 if (!RealUse)
4064 return false;
4065
4066 SDOperand Result;
4067 if (isLoad)
4068 Result = DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM);
4069 else
4070 Result = DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
4071 ++PreIndexedNodes;
4072 ++NodesCombined;
Dan Gohmanb5bec2b2007-06-19 14:13:56 +00004073 DOUT << "\nReplacing.4 "; DEBUG(N->dump(&DAG));
Bill Wendling832171c2006-12-07 20:04:42 +00004074 DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
4075 DOUT << '\n';
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004076 WorkListRemover DeadNodes(*this);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004077 if (isLoad) {
4078 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004079 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004080 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004081 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004082 } else {
4083 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004084 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004085 }
4086
Chris Lattner9f1794e2006-11-11 00:56:29 +00004087 // Finally, since the node is now dead, remove it from the graph.
4088 DAG.DeleteNode(N);
4089
4090 // Replace the uses of Ptr with uses of the updated base value.
4091 DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004092 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004093 removeFromWorkList(Ptr.Val);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004094 DAG.DeleteNode(Ptr.Val);
4095
4096 return true;
Chris Lattner448f2192006-11-11 00:39:41 +00004097}
4098
4099/// CombineToPostIndexedLoadStore - Try combine a load / store with a
4100/// add / sub of the base pointer node into a post-indexed load / store.
4101/// The transformation folded the add / subtract into the new indexed
4102/// load / store effectively and all of its uses are redirected to the
4103/// new load / store.
4104bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
4105 if (!AfterLegalize)
4106 return false;
4107
4108 bool isLoad = true;
4109 SDOperand Ptr;
4110 MVT::ValueType VT;
4111 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
Chris Lattnerddf89562008-01-17 19:59:44 +00004112 if (LD->isIndexed())
Evan Chenge90460e2006-12-16 06:25:23 +00004113 return false;
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004114 VT = LD->getMemoryVT();
Chris Lattner448f2192006-11-11 00:39:41 +00004115 if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
4116 !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
4117 return false;
4118 Ptr = LD->getBasePtr();
4119 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
Chris Lattnerddf89562008-01-17 19:59:44 +00004120 if (ST->isIndexed())
Evan Chenge90460e2006-12-16 06:25:23 +00004121 return false;
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004122 VT = ST->getMemoryVT();
Chris Lattner448f2192006-11-11 00:39:41 +00004123 if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
4124 !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
4125 return false;
4126 Ptr = ST->getBasePtr();
4127 isLoad = false;
4128 } else
4129 return false;
4130
Evan Chengcc470212006-11-16 00:08:20 +00004131 if (Ptr.Val->hasOneUse())
Chris Lattner9f1794e2006-11-11 00:56:29 +00004132 return false;
4133
4134 for (SDNode::use_iterator I = Ptr.Val->use_begin(),
4135 E = Ptr.Val->use_end(); I != E; ++I) {
4136 SDNode *Op = *I;
4137 if (Op == N ||
4138 (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
4139 continue;
4140
4141 SDOperand BasePtr;
4142 SDOperand Offset;
4143 ISD::MemIndexedMode AM = ISD::UNINDEXED;
4144 if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
4145 if (Ptr == Offset)
4146 std::swap(BasePtr, Offset);
4147 if (Ptr != BasePtr)
Chris Lattner448f2192006-11-11 00:39:41 +00004148 continue;
Evan Chenga7d4a042007-05-03 23:52:19 +00004149 // Don't create a indexed load / store with zero offset.
4150 if (isa<ConstantSDNode>(Offset) &&
Dan Gohman002e5d02008-03-13 22:13:53 +00004151 cast<ConstantSDNode>(Offset)->isNullValue())
Evan Chenga7d4a042007-05-03 23:52:19 +00004152 continue;
Chris Lattner448f2192006-11-11 00:39:41 +00004153
Chris Lattner9f1794e2006-11-11 00:56:29 +00004154 // Try turning it into a post-indexed load / store except when
4155 // 1) All uses are load / store ops that use it as base ptr.
4156 // 2) Op must be independent of N, i.e. Op is neither a predecessor
4157 // nor a successor of N. Otherwise, if Op is folded that would
4158 // create a cycle.
4159
4160 // Check for #1.
4161 bool TryNext = false;
4162 for (SDNode::use_iterator II = BasePtr.Val->use_begin(),
4163 EE = BasePtr.Val->use_end(); II != EE; ++II) {
4164 SDNode *Use = *II;
4165 if (Use == Ptr.Val)
Chris Lattner448f2192006-11-11 00:39:41 +00004166 continue;
4167
Chris Lattner9f1794e2006-11-11 00:56:29 +00004168 // If all the uses are load / store addresses, then don't do the
4169 // transformation.
4170 if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
4171 bool RealUse = false;
4172 for (SDNode::use_iterator III = Use->use_begin(),
4173 EEE = Use->use_end(); III != EEE; ++III) {
4174 SDNode *UseUse = *III;
4175 if (!((UseUse->getOpcode() == ISD::LOAD &&
4176 cast<LoadSDNode>(UseUse)->getBasePtr().Val == Use) ||
Anton Korobeynikov4c71dfe2008-02-20 11:10:28 +00004177 (UseUse->getOpcode() == ISD::STORE &&
4178 cast<StoreSDNode>(UseUse)->getBasePtr().Val == Use)))
Chris Lattner9f1794e2006-11-11 00:56:29 +00004179 RealUse = true;
4180 }
Chris Lattner448f2192006-11-11 00:39:41 +00004181
Chris Lattner9f1794e2006-11-11 00:56:29 +00004182 if (!RealUse) {
4183 TryNext = true;
4184 break;
Chris Lattner448f2192006-11-11 00:39:41 +00004185 }
4186 }
Chris Lattner9f1794e2006-11-11 00:56:29 +00004187 }
4188 if (TryNext)
4189 continue;
Chris Lattner448f2192006-11-11 00:39:41 +00004190
Chris Lattner9f1794e2006-11-11 00:56:29 +00004191 // Check for #2
Evan Cheng917be682008-03-04 00:41:45 +00004192 if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
Chris Lattner9f1794e2006-11-11 00:56:29 +00004193 SDOperand Result = isLoad
4194 ? DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM)
4195 : DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
4196 ++PostIndexedNodes;
4197 ++NodesCombined;
Dan Gohmanb5bec2b2007-06-19 14:13:56 +00004198 DOUT << "\nReplacing.5 "; DEBUG(N->dump(&DAG));
Bill Wendling832171c2006-12-07 20:04:42 +00004199 DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
4200 DOUT << '\n';
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004201 WorkListRemover DeadNodes(*this);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004202 if (isLoad) {
4203 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004204 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004205 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004206 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004207 } else {
4208 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004209 &DeadNodes);
Chris Lattner448f2192006-11-11 00:39:41 +00004210 }
Chris Lattner9f1794e2006-11-11 00:56:29 +00004211
Chris Lattner9f1794e2006-11-11 00:56:29 +00004212 // Finally, since the node is now dead, remove it from the graph.
4213 DAG.DeleteNode(N);
4214
4215 // Replace the uses of Use with uses of the updated base value.
4216 DAG.ReplaceAllUsesOfValueWith(SDOperand(Op, 0),
4217 Result.getValue(isLoad ? 1 : 0),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004218 &DeadNodes);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004219 removeFromWorkList(Op);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004220 DAG.DeleteNode(Op);
Chris Lattner9f1794e2006-11-11 00:56:29 +00004221 return true;
Chris Lattner448f2192006-11-11 00:39:41 +00004222 }
4223 }
4224 }
4225 return false;
4226}
4227
Chris Lattner00161a62008-01-25 07:20:16 +00004228/// InferAlignment - If we can infer some alignment information from this
4229/// pointer, return it.
4230static unsigned InferAlignment(SDOperand Ptr, SelectionDAG &DAG) {
4231 // If this is a direct reference to a stack slot, use information about the
4232 // stack slot's alignment.
Chris Lattner1329cb82008-01-26 19:45:50 +00004233 int FrameIdx = 1 << 31;
4234 int64_t FrameOffset = 0;
Chris Lattner00161a62008-01-25 07:20:16 +00004235 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Ptr)) {
Chris Lattner1329cb82008-01-26 19:45:50 +00004236 FrameIdx = FI->getIndex();
4237 } else if (Ptr.getOpcode() == ISD::ADD &&
4238 isa<ConstantSDNode>(Ptr.getOperand(1)) &&
4239 isa<FrameIndexSDNode>(Ptr.getOperand(0))) {
4240 FrameIdx = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex();
4241 FrameOffset = Ptr.getConstantOperandVal(1);
Chris Lattner00161a62008-01-25 07:20:16 +00004242 }
Chris Lattner1329cb82008-01-26 19:45:50 +00004243
4244 if (FrameIdx != (1 << 31)) {
4245 // FIXME: Handle FI+CST.
4246 const MachineFrameInfo &MFI = *DAG.getMachineFunction().getFrameInfo();
4247 if (MFI.isFixedObjectIndex(FrameIdx)) {
4248 int64_t ObjectOffset = MFI.getObjectOffset(FrameIdx);
4249
4250 // The alignment of the frame index can be determined from its offset from
4251 // the incoming frame position. If the frame object is at offset 32 and
4252 // the stack is guaranteed to be 16-byte aligned, then we know that the
4253 // object is 16-byte aligned.
4254 unsigned StackAlign = DAG.getTarget().getFrameInfo()->getStackAlignment();
4255 unsigned Align = MinAlign(ObjectOffset, StackAlign);
4256
4257 // Finally, the frame object itself may have a known alignment. Factor
4258 // the alignment + offset into a new alignment. For example, if we know
4259 // the FI is 8 byte aligned, but the pointer is 4 off, we really have a
4260 // 4-byte alignment of the resultant pointer. Likewise align 4 + 4-byte
4261 // offset = 4-byte alignment, align 4 + 1-byte offset = align 1, etc.
4262 unsigned FIInfoAlign = MinAlign(MFI.getObjectAlignment(FrameIdx),
4263 FrameOffset);
4264 return std::max(Align, FIInfoAlign);
4265 }
4266 }
Chris Lattner00161a62008-01-25 07:20:16 +00004267
4268 return 0;
4269}
Chris Lattner448f2192006-11-11 00:39:41 +00004270
Chris Lattner01a22022005-10-10 22:04:48 +00004271SDOperand DAGCombiner::visitLOAD(SDNode *N) {
Evan Cheng466685d2006-10-09 20:57:25 +00004272 LoadSDNode *LD = cast<LoadSDNode>(N);
4273 SDOperand Chain = LD->getChain();
4274 SDOperand Ptr = LD->getBasePtr();
Chris Lattner00161a62008-01-25 07:20:16 +00004275
4276 // Try to infer better alignment information than the load already has.
4277 if (LD->isUnindexed()) {
4278 if (unsigned Align = InferAlignment(Ptr, DAG)) {
4279 if (Align > LD->getAlignment())
4280 return DAG.getExtLoad(LD->getExtensionType(), LD->getValueType(0),
4281 Chain, Ptr, LD->getSrcValue(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004282 LD->getSrcValueOffset(), LD->getMemoryVT(),
Chris Lattner00161a62008-01-25 07:20:16 +00004283 LD->isVolatile(), Align);
4284 }
4285 }
4286
Evan Cheng45a7ca92007-05-01 00:38:21 +00004287
4288 // If load is not volatile and there are no uses of the loaded value (and
4289 // the updated indexed value in case of indexed loads), change uses of the
4290 // chain value into uses of the chain input (i.e. delete the dead load).
4291 if (!LD->isVolatile()) {
Evan Cheng498f5592007-05-01 08:53:39 +00004292 if (N->getValueType(1) == MVT::Other) {
4293 // Unindexed loads.
Evan Cheng02c42852008-01-16 23:11:54 +00004294 if (N->hasNUsesOfValue(0, 0)) {
4295 // It's not safe to use the two value CombineTo variant here. e.g.
4296 // v1, chain2 = load chain1, loc
4297 // v2, chain3 = load chain2, loc
4298 // v3 = add v2, c
Chris Lattner125991a2008-01-24 07:57:06 +00004299 // Now we replace use of chain2 with chain1. This makes the second load
4300 // isomorphic to the one we are deleting, and thus makes this load live.
Evan Cheng02c42852008-01-16 23:11:54 +00004301 DOUT << "\nReplacing.6 "; DEBUG(N->dump(&DAG));
Chris Lattner125991a2008-01-24 07:57:06 +00004302 DOUT << "\nWith chain: "; DEBUG(Chain.Val->dump(&DAG));
4303 DOUT << "\n";
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004304 WorkListRemover DeadNodes(*this);
4305 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Chain, &DeadNodes);
Chris Lattner125991a2008-01-24 07:57:06 +00004306 if (N->use_empty()) {
4307 removeFromWorkList(N);
4308 DAG.DeleteNode(N);
4309 }
Evan Cheng02c42852008-01-16 23:11:54 +00004310 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
4311 }
Evan Cheng498f5592007-05-01 08:53:39 +00004312 } else {
4313 // Indexed loads.
4314 assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
4315 if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
Evan Cheng02c42852008-01-16 23:11:54 +00004316 SDOperand Undef = DAG.getNode(ISD::UNDEF, N->getValueType(0));
4317 DOUT << "\nReplacing.6 "; DEBUG(N->dump(&DAG));
4318 DOUT << "\nWith: "; DEBUG(Undef.Val->dump(&DAG));
4319 DOUT << " and 2 other values\n";
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004320 WorkListRemover DeadNodes(*this);
4321 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Undef, &DeadNodes);
Evan Cheng02c42852008-01-16 23:11:54 +00004322 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1),
Chris Lattner4626b252008-01-17 07:20:38 +00004323 DAG.getNode(ISD::UNDEF, N->getValueType(1)),
Chris Lattnerf8dc0612008-02-03 06:49:24 +00004324 &DeadNodes);
4325 DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 2), Chain, &DeadNodes);
Evan Cheng02c42852008-01-16 23:11:54 +00004326 removeFromWorkList(N);
Evan Cheng02c42852008-01-16 23:11:54 +00004327 DAG.DeleteNode(N);
4328 return SDOperand(N, 0); // Return N so it doesn't get rechecked!
Evan Cheng45a7ca92007-05-01 00:38:21 +00004329 }
Evan Cheng45a7ca92007-05-01 00:38:21 +00004330 }
4331 }
Chris Lattner01a22022005-10-10 22:04:48 +00004332
4333 // If this load is directly stored, replace the load value with the stored
4334 // value.
4335 // TODO: Handle store large -> read small portion.
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004336 // TODO: Handle TRUNCSTORE/LOADEXT
4337 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
Evan Cheng8b2794a2006-10-13 21:14:26 +00004338 if (ISD::isNON_TRUNCStore(Chain.Val)) {
4339 StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
4340 if (PrevST->getBasePtr() == Ptr &&
4341 PrevST->getValue().getValueType() == N->getValueType(0))
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004342 return CombineTo(N, Chain.getOperand(1), Chain);
Evan Cheng8b2794a2006-10-13 21:14:26 +00004343 }
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004344 }
Jim Laskey6ff23e52006-10-04 16:53:27 +00004345
Jim Laskey7ca56af2006-10-11 13:47:09 +00004346 if (CombinerAA) {
Jim Laskey279f0532006-09-25 16:29:54 +00004347 // Walk up chain skipping non-aliasing memory nodes.
4348 SDOperand BetterChain = FindBetterChain(N, Chain);
4349
Jim Laskey6ff23e52006-10-04 16:53:27 +00004350 // If there is a better chain.
Jim Laskey279f0532006-09-25 16:29:54 +00004351 if (Chain != BetterChain) {
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004352 SDOperand ReplLoad;
4353
Jim Laskey279f0532006-09-25 16:29:54 +00004354 // Replace the chain to void dependency.
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004355 if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
4356 ReplLoad = DAG.getLoad(N->getValueType(0), BetterChain, Ptr,
Duncan Sandsdc846502007-10-28 12:59:45 +00004357 LD->getSrcValue(), LD->getSrcValueOffset(),
4358 LD->isVolatile(), LD->getAlignment());
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004359 } else {
4360 ReplLoad = DAG.getExtLoad(LD->getExtensionType(),
4361 LD->getValueType(0),
4362 BetterChain, Ptr, LD->getSrcValue(),
4363 LD->getSrcValueOffset(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004364 LD->getMemoryVT(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00004365 LD->isVolatile(),
4366 LD->getAlignment());
Jim Laskeyc2b19f32006-10-11 17:47:52 +00004367 }
Jim Laskey279f0532006-09-25 16:29:54 +00004368
Jim Laskey6ff23e52006-10-04 16:53:27 +00004369 // Create token factor to keep old chain connected.
Jim Laskey288af5e2006-09-25 19:32:58 +00004370 SDOperand Token = DAG.getNode(ISD::TokenFactor, MVT::Other,
4371 Chain, ReplLoad.getValue(1));
Jim Laskey6ff23e52006-10-04 16:53:27 +00004372
Jim Laskey274062c2006-10-13 23:32:28 +00004373 // Replace uses with load result and token factor. Don't add users
4374 // to work list.
4375 return CombineTo(N, ReplLoad.getValue(0), Token, false);
Jim Laskey279f0532006-09-25 16:29:54 +00004376 }
4377 }
4378
Evan Cheng7fc033a2006-11-03 03:06:21 +00004379 // Try transforming N to an indexed load.
Evan Chengbbd6f6e2006-11-07 09:03:05 +00004380 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
Evan Cheng7fc033a2006-11-03 03:06:21 +00004381 return SDOperand(N, 0);
4382
Chris Lattner01a22022005-10-10 22:04:48 +00004383 return SDOperand();
4384}
4385
Chris Lattner07649d92008-01-08 23:08:06 +00004386
Chris Lattner87514ca2005-10-10 22:31:19 +00004387SDOperand DAGCombiner::visitSTORE(SDNode *N) {
Evan Cheng8b2794a2006-10-13 21:14:26 +00004388 StoreSDNode *ST = cast<StoreSDNode>(N);
4389 SDOperand Chain = ST->getChain();
4390 SDOperand Value = ST->getValue();
4391 SDOperand Ptr = ST->getBasePtr();
Jim Laskey7aed46c2006-10-11 18:55:16 +00004392
Chris Lattner00161a62008-01-25 07:20:16 +00004393 // Try to infer better alignment information than the store already has.
4394 if (ST->isUnindexed()) {
4395 if (unsigned Align = InferAlignment(Ptr, DAG)) {
4396 if (Align > ST->getAlignment())
4397 return DAG.getTruncStore(Chain, Value, Ptr, ST->getSrcValue(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004398 ST->getSrcValueOffset(), ST->getMemoryVT(),
Chris Lattner00161a62008-01-25 07:20:16 +00004399 ST->isVolatile(), Align);
4400 }
4401 }
4402
Evan Cheng59d5b682007-05-07 21:27:48 +00004403 // If this is a store of a bit convert, store the input value if the
Evan Cheng2c4f9432007-05-09 21:49:47 +00004404 // resultant store does not need a higher alignment than the original.
Dale Johannesen98a6c622007-05-16 22:45:30 +00004405 if (Value.getOpcode() == ISD::BIT_CONVERT && !ST->isTruncatingStore() &&
Chris Lattnerddf89562008-01-17 19:59:44 +00004406 ST->isUnindexed()) {
Evan Cheng59d5b682007-05-07 21:27:48 +00004407 unsigned Align = ST->getAlignment();
4408 MVT::ValueType SVT = Value.getOperand(0).getValueType();
4409 unsigned OrigAlign = TLI.getTargetMachine().getTargetData()->
Dan Gohmanfcc4dd92007-05-18 18:41:29 +00004410 getABITypeAlignment(MVT::getTypeForValueType(SVT));
Evan Chengc2cd2b22007-05-07 21:36:06 +00004411 if (Align <= OrigAlign && TLI.isOperationLegal(ISD::STORE, SVT))
Evan Cheng59d5b682007-05-07 21:27:48 +00004412 return DAG.getStore(Chain, Value.getOperand(0), Ptr, ST->getSrcValue(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004413 ST->getSrcValueOffset(), ST->isVolatile(), Align);
Jim Laskey279f0532006-09-25 16:29:54 +00004414 }
4415
Nate Begeman2cbba892006-12-11 02:23:46 +00004416 // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
Nate Begeman2cbba892006-12-11 02:23:46 +00004417 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
Evan Cheng25ece662006-12-11 17:25:19 +00004418 if (Value.getOpcode() != ISD::TargetConstantFP) {
4419 SDOperand Tmp;
Chris Lattner62be1a72006-12-12 04:16:14 +00004420 switch (CFP->getValueType(0)) {
4421 default: assert(0 && "Unknown FP type");
Dale Johannesenc7b21d52007-09-18 18:36:59 +00004422 case MVT::f80: // We don't do this for these yet.
4423 case MVT::f128:
4424 case MVT::ppcf128:
4425 break;
Chris Lattner62be1a72006-12-12 04:16:14 +00004426 case MVT::f32:
4427 if (!AfterLegalize || TLI.isTypeLegal(MVT::i32)) {
Dale Johannesen9d5f4562007-09-12 03:30:33 +00004428 Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
4429 convertToAPInt().getZExtValue(), MVT::i32);
Chris Lattner62be1a72006-12-12 04:16:14 +00004430 return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004431 ST->getSrcValueOffset(), ST->isVolatile(),
4432 ST->getAlignment());
Chris Lattner62be1a72006-12-12 04:16:14 +00004433 }
4434 break;
4435 case MVT::f64:
4436 if (!AfterLegalize || TLI.isTypeLegal(MVT::i64)) {
Dale Johannesen9d5f4562007-09-12 03:30:33 +00004437 Tmp = DAG.getConstant(CFP->getValueAPF().convertToAPInt().
4438 getZExtValue(), MVT::i64);
Chris Lattner62be1a72006-12-12 04:16:14 +00004439 return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004440 ST->getSrcValueOffset(), ST->isVolatile(),
4441 ST->getAlignment());
Chris Lattner62be1a72006-12-12 04:16:14 +00004442 } else if (TLI.isTypeLegal(MVT::i32)) {
Duncan Sandsdc846502007-10-28 12:59:45 +00004443 // Many FP stores are not made apparent until after legalize, e.g. for
Chris Lattner62be1a72006-12-12 04:16:14 +00004444 // argument passing. Since this is so common, custom legalize the
4445 // 64-bit integer store into two 32-bit stores.
Dale Johannesen9d5f4562007-09-12 03:30:33 +00004446 uint64_t Val = CFP->getValueAPF().convertToAPInt().getZExtValue();
Chris Lattner62be1a72006-12-12 04:16:14 +00004447 SDOperand Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
4448 SDOperand Hi = DAG.getConstant(Val >> 32, MVT::i32);
Duncan Sands0753fc12008-02-11 10:37:04 +00004449 if (TLI.isBigEndian()) std::swap(Lo, Hi);
Chris Lattner62be1a72006-12-12 04:16:14 +00004450
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004451 int SVOffset = ST->getSrcValueOffset();
4452 unsigned Alignment = ST->getAlignment();
4453 bool isVolatile = ST->isVolatile();
4454
Chris Lattner62be1a72006-12-12 04:16:14 +00004455 SDOperand St0 = DAG.getStore(Chain, Lo, Ptr, ST->getSrcValue(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004456 ST->getSrcValueOffset(),
4457 isVolatile, ST->getAlignment());
Chris Lattner62be1a72006-12-12 04:16:14 +00004458 Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
4459 DAG.getConstant(4, Ptr.getValueType()));
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004460 SVOffset += 4;
Duncan Sandsdc846502007-10-28 12:59:45 +00004461 Alignment = MinAlign(Alignment, 4U);
Chris Lattner62be1a72006-12-12 04:16:14 +00004462 SDOperand St1 = DAG.getStore(Chain, Hi, Ptr, ST->getSrcValue(),
Dan Gohmand6fd1bc2007-07-09 22:18:38 +00004463 SVOffset, isVolatile, Alignment);
Chris Lattner62be1a72006-12-12 04:16:14 +00004464 return DAG.getNode(ISD::TokenFactor, MVT::Other, St0, St1);
4465 }
4466 break;
Evan Cheng25ece662006-12-11 17:25:19 +00004467 }
Nate Begeman2cbba892006-12-11 02:23:46 +00004468 }
Nate Begeman2cbba892006-12-11 02:23:46 +00004469 }
4470
Jim Laskey279f0532006-09-25 16:29:54 +00004471 if (CombinerAA) {
4472 // Walk up chain skipping non-aliasing memory nodes.
4473 SDOperand BetterChain = FindBetterChain(N, Chain);
4474
Jim Laskey6ff23e52006-10-04 16:53:27 +00004475 // If there is a better chain.
Jim Laskey279f0532006-09-25 16:29:54 +00004476 if (Chain != BetterChain) {
Jim Laskey6ff23e52006-10-04 16:53:27 +00004477 // Replace the chain to avoid dependency.
Jim Laskeyd4edf2c2006-10-14 12:14:27 +00004478 SDOperand ReplStore;
4479 if (ST->isTruncatingStore()) {
4480 ReplStore = DAG.getTruncStore(BetterChain, Value, Ptr,
Chris Lattner4626b252008-01-17 07:20:38 +00004481 ST->getSrcValue(),ST->getSrcValueOffset(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004482 ST->getMemoryVT(),
Chris Lattner4626b252008-01-17 07:20:38 +00004483 ST->isVolatile(), ST->getAlignment());
Jim Laskeyd4edf2c2006-10-14 12:14:27 +00004484 } else {
4485 ReplStore = DAG.getStore(BetterChain, Value, Ptr,
Chris Lattner4626b252008-01-17 07:20:38 +00004486 ST->getSrcValue(), ST->getSrcValueOffset(),
4487 ST->isVolatile(), ST->getAlignment());
Jim Laskeyd4edf2c2006-10-14 12:14:27 +00004488 }
4489
Jim Laskey279f0532006-09-25 16:29:54 +00004490 // Create token to keep both nodes around.
Jim Laskey274062c2006-10-13 23:32:28 +00004491 SDOperand Token =
4492 DAG.getNode(ISD::TokenFactor, MVT::Other, Chain, ReplStore);
4493
4494 // Don't add users to work list.
4495 return CombineTo(N, Token, false);
Jim Laskey279f0532006-09-25 16:29:54 +00004496 }
Jim Laskeyd1aed7a2006-09-21 16:28:59 +00004497 }
Chris Lattnerc33baaa2005-12-23 05:48:07 +00004498
Evan Cheng33dbedc2006-11-05 09:31:14 +00004499 // Try transforming N to an indexed store.
Evan Chengbbd6f6e2006-11-07 09:03:05 +00004500 if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
Evan Cheng33dbedc2006-11-05 09:31:14 +00004501 return SDOperand(N, 0);
4502
Chris Lattner3c872852007-12-29 06:26:16 +00004503 // FIXME: is there such a thing as a truncating indexed store?
Chris Lattnerddf89562008-01-17 19:59:44 +00004504 if (ST->isTruncatingStore() && ST->isUnindexed() &&
Chris Lattner2b4c2792007-10-13 06:35:54 +00004505 MVT::isInteger(Value.getValueType())) {
4506 // See if we can simplify the input to this truncstore with knowledge that
4507 // only the low bits are being used. For example:
4508 // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
4509 SDOperand Shorter =
Dan Gohman2e68b6f2008-02-25 21:11:39 +00004510 GetDemandedBits(Value,
4511 APInt::getLowBitsSet(Value.getValueSizeInBits(),
4512 MVT::getSizeInBits(ST->getMemoryVT())));
Chris Lattner2b4c2792007-10-13 06:35:54 +00004513 AddToWorkList(Value.Val);
4514 if (Shorter.Val)
4515 return DAG.getTruncStore(Chain, Shorter, Ptr, ST->getSrcValue(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004516 ST->getSrcValueOffset(), ST->getMemoryVT(),
Chris Lattner2b4c2792007-10-13 06:35:54 +00004517 ST->isVolatile(), ST->getAlignment());
Chris Lattnere33544c2007-10-13 06:58:48 +00004518
4519 // Otherwise, see if we can simplify the operation with
4520 // SimplifyDemandedBits, which only works if the value has a single use.
Dan Gohman7b8d4a92008-02-27 00:25:32 +00004521 if (SimplifyDemandedBits(Value,
4522 APInt::getLowBitsSet(
4523 Value.getValueSizeInBits(),
4524 MVT::getSizeInBits(ST->getMemoryVT()))))
Chris Lattnere33544c2007-10-13 06:58:48 +00004525 return SDOperand(N, 0);
Chris Lattner2b4c2792007-10-13 06:35:54 +00004526 }
4527
Chris Lattner3c872852007-12-29 06:26:16 +00004528 // If this is a load followed by a store to the same location, then the store
4529 // is dead/noop.
4530 if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004531 if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
Chris Lattnerddf89562008-01-17 19:59:44 +00004532 ST->isUnindexed() && !ST->isVolatile() &&
Chris Lattner07649d92008-01-08 23:08:06 +00004533 // There can't be any side effects between the load and store, such as
4534 // a call or store.
Chris Lattner572dee72008-01-16 05:49:24 +00004535 Chain.reachesChainWithoutSideEffects(SDOperand(Ld, 1))) {
Chris Lattner3c872852007-12-29 06:26:16 +00004536 // The store is dead, remove it.
4537 return Chain;
4538 }
4539 }
4540
Chris Lattnerddf89562008-01-17 19:59:44 +00004541 // If this is an FP_ROUND or TRUNC followed by a store, fold this into a
4542 // truncating store. We can do this even if this is already a truncstore.
4543 if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
4544 && TLI.isTypeLegal(Value.getOperand(0).getValueType()) &&
4545 Value.Val->hasOneUse() && ST->isUnindexed() &&
4546 TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004547 ST->getMemoryVT())) {
Chris Lattnerddf89562008-01-17 19:59:44 +00004548 return DAG.getTruncStore(Chain, Value.getOperand(0), Ptr, ST->getSrcValue(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00004549 ST->getSrcValueOffset(), ST->getMemoryVT(),
Chris Lattnerddf89562008-01-17 19:59:44 +00004550 ST->isVolatile(), ST->getAlignment());
4551 }
4552
Chris Lattner87514ca2005-10-10 22:31:19 +00004553 return SDOperand();
4554}
4555
Chris Lattnerca242442006-03-19 01:27:56 +00004556SDOperand DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
4557 SDOperand InVec = N->getOperand(0);
4558 SDOperand InVal = N->getOperand(1);
4559 SDOperand EltNo = N->getOperand(2);
4560
4561 // If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new
4562 // vector with the inserted element.
4563 if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
4564 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004565 SmallVector<SDOperand, 8> Ops(InVec.Val->op_begin(), InVec.Val->op_end());
Chris Lattnerca242442006-03-19 01:27:56 +00004566 if (Elt < Ops.size())
4567 Ops[Elt] = InVal;
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004568 return DAG.getNode(ISD::BUILD_VECTOR, InVec.getValueType(),
4569 &Ops[0], Ops.size());
Chris Lattnerca242442006-03-19 01:27:56 +00004570 }
4571
4572 return SDOperand();
4573}
4574
Evan Cheng513da432007-10-06 08:19:55 +00004575SDOperand DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
4576 SDOperand InVec = N->getOperand(0);
4577 SDOperand EltNo = N->getOperand(1);
4578
4579 // (vextract (v4f32 s2v (f32 load $addr)), 0) -> (f32 load $addr)
4580 // (vextract (v4i32 bc (v4f32 s2v (f32 load $addr))), 0) -> (i32 load $addr)
4581 if (isa<ConstantSDNode>(EltNo)) {
4582 unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
4583 bool NewLoad = false;
4584 if (Elt == 0) {
4585 MVT::ValueType VT = InVec.getValueType();
4586 MVT::ValueType EVT = MVT::getVectorElementType(VT);
4587 MVT::ValueType LVT = EVT;
4588 unsigned NumElts = MVT::getVectorNumElements(VT);
4589 if (InVec.getOpcode() == ISD::BIT_CONVERT) {
4590 MVT::ValueType BCVT = InVec.getOperand(0).getValueType();
Dan Gohman090b38a2007-10-29 20:44:42 +00004591 if (!MVT::isVector(BCVT) ||
4592 NumElts != MVT::getVectorNumElements(BCVT))
Evan Cheng513da432007-10-06 08:19:55 +00004593 return SDOperand();
4594 InVec = InVec.getOperand(0);
4595 EVT = MVT::getVectorElementType(BCVT);
4596 NewLoad = true;
4597 }
4598 if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
4599 InVec.getOperand(0).getValueType() == EVT &&
4600 ISD::isNormalLoad(InVec.getOperand(0).Val) &&
4601 InVec.getOperand(0).hasOneUse()) {
4602 LoadSDNode *LN0 = cast<LoadSDNode>(InVec.getOperand(0));
4603 unsigned Align = LN0->getAlignment();
4604 if (NewLoad) {
4605 // Check the resultant load doesn't need a higher alignment than the
4606 // original load.
4607 unsigned NewAlign = TLI.getTargetMachine().getTargetData()->
4608 getABITypeAlignment(MVT::getTypeForValueType(LVT));
4609 if (!TLI.isOperationLegal(ISD::LOAD, LVT) || NewAlign > Align)
4610 return SDOperand();
4611 Align = NewAlign;
4612 }
4613
4614 return DAG.getLoad(LVT, LN0->getChain(), LN0->getBasePtr(),
4615 LN0->getSrcValue(), LN0->getSrcValueOffset(),
4616 LN0->isVolatile(), Align);
4617 }
4618 }
4619 }
4620 return SDOperand();
4621}
4622
4623
Dan Gohman7f321562007-06-25 16:23:39 +00004624SDOperand DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
4625 unsigned NumInScalars = N->getNumOperands();
4626 MVT::ValueType VT = N->getValueType(0);
4627 unsigned NumElts = MVT::getVectorNumElements(VT);
4628 MVT::ValueType EltType = MVT::getVectorElementType(VT);
Chris Lattnerca242442006-03-19 01:27:56 +00004629
Dan Gohman7f321562007-06-25 16:23:39 +00004630 // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
4631 // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
4632 // at most two distinct vectors, turn this into a shuffle node.
Chris Lattnerd7648c82006-03-28 20:28:38 +00004633 SDOperand VecIn1, VecIn2;
4634 for (unsigned i = 0; i != NumInScalars; ++i) {
4635 // Ignore undef inputs.
4636 if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
4637
Dan Gohman7f321562007-06-25 16:23:39 +00004638 // If this input is something other than a EXTRACT_VECTOR_ELT with a
Chris Lattnerd7648c82006-03-28 20:28:38 +00004639 // constant index, bail out.
Dan Gohman7f321562007-06-25 16:23:39 +00004640 if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
Chris Lattnerd7648c82006-03-28 20:28:38 +00004641 !isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
4642 VecIn1 = VecIn2 = SDOperand(0, 0);
4643 break;
4644 }
4645
Dan Gohman7f321562007-06-25 16:23:39 +00004646 // If the input vector type disagrees with the result of the build_vector,
Chris Lattnerd7648c82006-03-28 20:28:38 +00004647 // we can't make a shuffle.
4648 SDOperand ExtractedFromVec = N->getOperand(i).getOperand(0);
Dan Gohman7f321562007-06-25 16:23:39 +00004649 if (ExtractedFromVec.getValueType() != VT) {
Chris Lattnerd7648c82006-03-28 20:28:38 +00004650 VecIn1 = VecIn2 = SDOperand(0, 0);
4651 break;
4652 }
4653
4654 // Otherwise, remember this. We allow up to two distinct input vectors.
4655 if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
4656 continue;
4657
4658 if (VecIn1.Val == 0) {
4659 VecIn1 = ExtractedFromVec;
4660 } else if (VecIn2.Val == 0) {
4661 VecIn2 = ExtractedFromVec;
4662 } else {
4663 // Too many inputs.
4664 VecIn1 = VecIn2 = SDOperand(0, 0);
4665 break;
4666 }
4667 }
4668
4669 // If everything is good, we can make a shuffle operation.
4670 if (VecIn1.Val) {
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004671 SmallVector<SDOperand, 8> BuildVecIndices;
Chris Lattnerd7648c82006-03-28 20:28:38 +00004672 for (unsigned i = 0; i != NumInScalars; ++i) {
4673 if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
Evan Cheng597a3bd2007-01-20 10:10:26 +00004674 BuildVecIndices.push_back(DAG.getNode(ISD::UNDEF, TLI.getPointerTy()));
Chris Lattnerd7648c82006-03-28 20:28:38 +00004675 continue;
4676 }
4677
4678 SDOperand Extract = N->getOperand(i);
4679
4680 // If extracting from the first vector, just use the index directly.
4681 if (Extract.getOperand(0) == VecIn1) {
4682 BuildVecIndices.push_back(Extract.getOperand(1));
4683 continue;
4684 }
4685
4686 // Otherwise, use InIdx + VecSize
4687 unsigned Idx = cast<ConstantSDNode>(Extract.getOperand(1))->getValue();
Chris Lattner0bd48932008-01-17 07:00:52 +00004688 BuildVecIndices.push_back(DAG.getIntPtrConstant(Idx+NumInScalars));
Chris Lattnerd7648c82006-03-28 20:28:38 +00004689 }
4690
4691 // Add count and size info.
Chris Lattner0bd48932008-01-17 07:00:52 +00004692 MVT::ValueType BuildVecVT = MVT::getVectorType(TLI.getPointerTy(), NumElts);
Chris Lattnerd7648c82006-03-28 20:28:38 +00004693
Dan Gohman7f321562007-06-25 16:23:39 +00004694 // Return the new VECTOR_SHUFFLE node.
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004695 SDOperand Ops[5];
4696 Ops[0] = VecIn1;
Chris Lattnercef896e2006-03-28 22:19:47 +00004697 if (VecIn2.Val) {
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004698 Ops[1] = VecIn2;
Chris Lattnercef896e2006-03-28 22:19:47 +00004699 } else {
Dan Gohman7f321562007-06-25 16:23:39 +00004700 // Use an undef build_vector as input for the second operand.
Chris Lattnercef896e2006-03-28 22:19:47 +00004701 std::vector<SDOperand> UnOps(NumInScalars,
4702 DAG.getNode(ISD::UNDEF,
Dan Gohman7f321562007-06-25 16:23:39 +00004703 EltType));
4704 Ops[1] = DAG.getNode(ISD::BUILD_VECTOR, VT,
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004705 &UnOps[0], UnOps.size());
4706 AddToWorkList(Ops[1].Val);
Chris Lattnercef896e2006-03-28 22:19:47 +00004707 }
Dan Gohman7f321562007-06-25 16:23:39 +00004708 Ops[2] = DAG.getNode(ISD::BUILD_VECTOR, BuildVecVT,
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004709 &BuildVecIndices[0], BuildVecIndices.size());
Dan Gohman7f321562007-06-25 16:23:39 +00004710 return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, Ops, 3);
Chris Lattnerd7648c82006-03-28 20:28:38 +00004711 }
4712
4713 return SDOperand();
4714}
4715
Dan Gohman7f321562007-06-25 16:23:39 +00004716SDOperand DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
4717 // TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
4718 // EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
4719 // inputs come from at most two distinct vectors, turn this into a shuffle
4720 // node.
4721
4722 // If we only have one input vector, we don't need to do any concatenation.
4723 if (N->getNumOperands() == 1) {
4724 return N->getOperand(0);
4725 }
4726
4727 return SDOperand();
4728}
4729
Chris Lattner66445d32006-03-28 22:11:53 +00004730SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
Chris Lattnerf1d0c622006-03-31 22:16:43 +00004731 SDOperand ShufMask = N->getOperand(2);
4732 unsigned NumElts = ShufMask.getNumOperands();
4733
4734 // If the shuffle mask is an identity operation on the LHS, return the LHS.
4735 bool isIdentity = true;
4736 for (unsigned i = 0; i != NumElts; ++i) {
4737 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
4738 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i) {
4739 isIdentity = false;
4740 break;
4741 }
4742 }
4743 if (isIdentity) return N->getOperand(0);
4744
4745 // If the shuffle mask is an identity operation on the RHS, return the RHS.
4746 isIdentity = true;
4747 for (unsigned i = 0; i != NumElts; ++i) {
4748 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
4749 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i+NumElts) {
4750 isIdentity = false;
4751 break;
4752 }
4753 }
4754 if (isIdentity) return N->getOperand(1);
Evan Chenge7bec0d2006-07-20 22:44:41 +00004755
4756 // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
4757 // needed at all.
4758 bool isUnary = true;
Evan Cheng917ec982006-07-21 08:25:53 +00004759 bool isSplat = true;
Evan Chenge7bec0d2006-07-20 22:44:41 +00004760 int VecNum = -1;
Reid Spencer9160a6a2006-07-25 20:44:41 +00004761 unsigned BaseIdx = 0;
Evan Chenge7bec0d2006-07-20 22:44:41 +00004762 for (unsigned i = 0; i != NumElts; ++i)
4763 if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
4764 unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
4765 int V = (Idx < NumElts) ? 0 : 1;
Evan Cheng917ec982006-07-21 08:25:53 +00004766 if (VecNum == -1) {
Evan Chenge7bec0d2006-07-20 22:44:41 +00004767 VecNum = V;
Evan Cheng917ec982006-07-21 08:25:53 +00004768 BaseIdx = Idx;
4769 } else {
4770 if (BaseIdx != Idx)
4771 isSplat = false;
4772 if (VecNum != V) {
4773 isUnary = false;
4774 break;
4775 }
Evan Chenge7bec0d2006-07-20 22:44:41 +00004776 }
4777 }
4778
4779 SDOperand N0 = N->getOperand(0);
4780 SDOperand N1 = N->getOperand(1);
4781 // Normalize unary shuffle so the RHS is undef.
4782 if (isUnary && VecNum == 1)
4783 std::swap(N0, N1);
4784
Evan Cheng917ec982006-07-21 08:25:53 +00004785 // If it is a splat, check if the argument vector is a build_vector with
4786 // all scalar elements the same.
4787 if (isSplat) {
4788 SDNode *V = N0.Val;
Evan Cheng917ec982006-07-21 08:25:53 +00004789
Dan Gohman7f321562007-06-25 16:23:39 +00004790 // If this is a bit convert that changes the element type of the vector but
Evan Cheng59569222006-10-16 22:49:37 +00004791 // not the number of vector elements, look through it. Be careful not to
4792 // look though conversions that change things like v4f32 to v2f64.
Dan Gohman7f321562007-06-25 16:23:39 +00004793 if (V->getOpcode() == ISD::BIT_CONVERT) {
Evan Cheng59569222006-10-16 22:49:37 +00004794 SDOperand ConvInput = V->getOperand(0);
Dan Gohman7f321562007-06-25 16:23:39 +00004795 if (MVT::getVectorNumElements(ConvInput.getValueType()) == NumElts)
Evan Cheng59569222006-10-16 22:49:37 +00004796 V = ConvInput.Val;
4797 }
4798
Dan Gohman7f321562007-06-25 16:23:39 +00004799 if (V->getOpcode() == ISD::BUILD_VECTOR) {
4800 unsigned NumElems = V->getNumOperands();
Evan Cheng917ec982006-07-21 08:25:53 +00004801 if (NumElems > BaseIdx) {
4802 SDOperand Base;
4803 bool AllSame = true;
4804 for (unsigned i = 0; i != NumElems; ++i) {
4805 if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
4806 Base = V->getOperand(i);
4807 break;
4808 }
4809 }
4810 // Splat of <u, u, u, u>, return <u, u, u, u>
4811 if (!Base.Val)
4812 return N0;
4813 for (unsigned i = 0; i != NumElems; ++i) {
Evan Chenge0480d22007-09-18 21:54:37 +00004814 if (V->getOperand(i) != Base) {
Evan Cheng917ec982006-07-21 08:25:53 +00004815 AllSame = false;
4816 break;
4817 }
4818 }
4819 // Splat of <x, x, x, x>, return <x, x, x, x>
4820 if (AllSame)
4821 return N0;
4822 }
4823 }
4824 }
4825
Evan Chenge7bec0d2006-07-20 22:44:41 +00004826 // If it is a unary or the LHS and the RHS are the same node, turn the RHS
4827 // into an undef.
4828 if (isUnary || N0 == N1) {
Chris Lattner17614ea2006-04-08 05:34:25 +00004829 // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
4830 // first operand.
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004831 SmallVector<SDOperand, 8> MappedOps;
Chris Lattner17614ea2006-04-08 05:34:25 +00004832 for (unsigned i = 0; i != NumElts; ++i) {
4833 if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
4834 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
4835 MappedOps.push_back(ShufMask.getOperand(i));
4836 } else {
4837 unsigned NewIdx =
4838 cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
4839 MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
4840 }
4841 }
Dan Gohman7f321562007-06-25 16:23:39 +00004842 ShufMask = DAG.getNode(ISD::BUILD_VECTOR, ShufMask.getValueType(),
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004843 &MappedOps[0], MappedOps.size());
Chris Lattner17614ea2006-04-08 05:34:25 +00004844 AddToWorkList(ShufMask.Val);
Dan Gohman7f321562007-06-25 16:23:39 +00004845 return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0),
4846 N0,
4847 DAG.getNode(ISD::UNDEF, N->getValueType(0)),
4848 ShufMask);
Chris Lattner17614ea2006-04-08 05:34:25 +00004849 }
Dan Gohman7f321562007-06-25 16:23:39 +00004850
Chris Lattnerf1d0c622006-03-31 22:16:43 +00004851 return SDOperand();
4852}
4853
Evan Cheng44f1f092006-04-20 08:56:16 +00004854/// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
Dan Gohman7f321562007-06-25 16:23:39 +00004855/// an AND to a vector_shuffle with the destination vector and a zero vector.
4856/// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
Evan Cheng44f1f092006-04-20 08:56:16 +00004857/// vector_shuffle V, Zero, <0, 4, 2, 4>
4858SDOperand DAGCombiner::XformToShuffleWithZero(SDNode *N) {
4859 SDOperand LHS = N->getOperand(0);
4860 SDOperand RHS = N->getOperand(1);
Dan Gohman7f321562007-06-25 16:23:39 +00004861 if (N->getOpcode() == ISD::AND) {
4862 if (RHS.getOpcode() == ISD::BIT_CONVERT)
Evan Cheng44f1f092006-04-20 08:56:16 +00004863 RHS = RHS.getOperand(0);
Dan Gohman7f321562007-06-25 16:23:39 +00004864 if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
Evan Cheng44f1f092006-04-20 08:56:16 +00004865 std::vector<SDOperand> IdxOps;
4866 unsigned NumOps = RHS.getNumOperands();
Dan Gohman7f321562007-06-25 16:23:39 +00004867 unsigned NumElts = NumOps;
4868 MVT::ValueType EVT = MVT::getVectorElementType(RHS.getValueType());
Evan Cheng44f1f092006-04-20 08:56:16 +00004869 for (unsigned i = 0; i != NumElts; ++i) {
4870 SDOperand Elt = RHS.getOperand(i);
4871 if (!isa<ConstantSDNode>(Elt))
4872 return SDOperand();
4873 else if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
4874 IdxOps.push_back(DAG.getConstant(i, EVT));
4875 else if (cast<ConstantSDNode>(Elt)->isNullValue())
4876 IdxOps.push_back(DAG.getConstant(NumElts, EVT));
4877 else
4878 return SDOperand();
4879 }
4880
4881 // Let's see if the target supports this vector_shuffle.
4882 if (!TLI.isVectorClearMaskLegal(IdxOps, EVT, DAG))
4883 return SDOperand();
4884
Dan Gohman7f321562007-06-25 16:23:39 +00004885 // Return the new VECTOR_SHUFFLE node.
4886 MVT::ValueType VT = MVT::getVectorType(EVT, NumElts);
Evan Cheng44f1f092006-04-20 08:56:16 +00004887 std::vector<SDOperand> Ops;
Dan Gohman7f321562007-06-25 16:23:39 +00004888 LHS = DAG.getNode(ISD::BIT_CONVERT, VT, LHS);
Evan Cheng44f1f092006-04-20 08:56:16 +00004889 Ops.push_back(LHS);
4890 AddToWorkList(LHS.Val);
4891 std::vector<SDOperand> ZeroOps(NumElts, DAG.getConstant(0, EVT));
Dan Gohman7f321562007-06-25 16:23:39 +00004892 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004893 &ZeroOps[0], ZeroOps.size()));
Dan Gohman7f321562007-06-25 16:23:39 +00004894 Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004895 &IdxOps[0], IdxOps.size()));
Dan Gohman7f321562007-06-25 16:23:39 +00004896 SDOperand Result = DAG.getNode(ISD::VECTOR_SHUFFLE, VT,
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004897 &Ops[0], Ops.size());
Dan Gohman7f321562007-06-25 16:23:39 +00004898 if (VT != LHS.getValueType()) {
4899 Result = DAG.getNode(ISD::BIT_CONVERT, LHS.getValueType(), Result);
Evan Cheng44f1f092006-04-20 08:56:16 +00004900 }
4901 return Result;
4902 }
4903 }
4904 return SDOperand();
4905}
4906
Dan Gohman7f321562007-06-25 16:23:39 +00004907/// SimplifyVBinOp - Visit a binary vector operation, like ADD.
4908SDOperand DAGCombiner::SimplifyVBinOp(SDNode *N) {
4909 // After legalize, the target may be depending on adds and other
4910 // binary ops to provide legal ways to construct constants or other
4911 // things. Simplifying them may result in a loss of legality.
4912 if (AfterLegalize) return SDOperand();
4913
4914 MVT::ValueType VT = N->getValueType(0);
Dan Gohman05d92fe2007-07-13 20:03:40 +00004915 assert(MVT::isVector(VT) && "SimplifyVBinOp only works on vectors!");
Dan Gohman7f321562007-06-25 16:23:39 +00004916
4917 MVT::ValueType EltType = MVT::getVectorElementType(VT);
Chris Lattneredab1b92006-04-02 03:25:57 +00004918 SDOperand LHS = N->getOperand(0);
4919 SDOperand RHS = N->getOperand(1);
Evan Cheng44f1f092006-04-20 08:56:16 +00004920 SDOperand Shuffle = XformToShuffleWithZero(N);
4921 if (Shuffle.Val) return Shuffle;
4922
Dan Gohman7f321562007-06-25 16:23:39 +00004923 // If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
Chris Lattneredab1b92006-04-02 03:25:57 +00004924 // this operation.
Dan Gohman7f321562007-06-25 16:23:39 +00004925 if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
4926 RHS.getOpcode() == ISD::BUILD_VECTOR) {
Chris Lattnerbd564bf2006-08-08 02:23:42 +00004927 SmallVector<SDOperand, 8> Ops;
Dan Gohman7f321562007-06-25 16:23:39 +00004928 for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
Chris Lattneredab1b92006-04-02 03:25:57 +00004929 SDOperand LHSOp = LHS.getOperand(i);
4930 SDOperand RHSOp = RHS.getOperand(i);
4931 // If these two elements can't be folded, bail out.
4932 if ((LHSOp.getOpcode() != ISD::UNDEF &&
4933 LHSOp.getOpcode() != ISD::Constant &&
4934 LHSOp.getOpcode() != ISD::ConstantFP) ||
4935 (RHSOp.getOpcode() != ISD::UNDEF &&
4936 RHSOp.getOpcode() != ISD::Constant &&
4937 RHSOp.getOpcode() != ISD::ConstantFP))
4938 break;
Evan Cheng7b336a82006-05-31 06:08:35 +00004939 // Can't fold divide by zero.
Dan Gohman7f321562007-06-25 16:23:39 +00004940 if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
4941 N->getOpcode() == ISD::FDIV) {
Evan Cheng7b336a82006-05-31 06:08:35 +00004942 if ((RHSOp.getOpcode() == ISD::Constant &&
4943 cast<ConstantSDNode>(RHSOp.Val)->isNullValue()) ||
4944 (RHSOp.getOpcode() == ISD::ConstantFP &&
Dale Johannesenc4dd3c32007-08-31 23:34:27 +00004945 cast<ConstantFPSDNode>(RHSOp.Val)->getValueAPF().isZero()))
Evan Cheng7b336a82006-05-31 06:08:35 +00004946 break;
4947 }
Dan Gohman7f321562007-06-25 16:23:39 +00004948 Ops.push_back(DAG.getNode(N->getOpcode(), EltType, LHSOp, RHSOp));
Chris Lattner3e104b12006-04-08 04:15:24 +00004949 AddToWorkList(Ops.back().Val);
Chris Lattneredab1b92006-04-02 03:25:57 +00004950 assert((Ops.back().getOpcode() == ISD::UNDEF ||
4951 Ops.back().getOpcode() == ISD::Constant ||
4952 Ops.back().getOpcode() == ISD::ConstantFP) &&
4953 "Scalar binop didn't fold!");
4954 }
Chris Lattnera4c5d8c2006-04-03 17:21:50 +00004955
Dan Gohman7f321562007-06-25 16:23:39 +00004956 if (Ops.size() == LHS.getNumOperands()) {
4957 MVT::ValueType VT = LHS.getValueType();
4958 return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
Chris Lattnera4c5d8c2006-04-03 17:21:50 +00004959 }
Chris Lattneredab1b92006-04-02 03:25:57 +00004960 }
4961
4962 return SDOperand();
4963}
4964
Nate Begeman44728a72005-09-19 22:34:01 +00004965SDOperand DAGCombiner::SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2){
Nate Begemanf845b452005-10-08 00:29:44 +00004966 assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
4967
4968 SDOperand SCC = SimplifySelectCC(N0.getOperand(0), N0.getOperand(1), N1, N2,
4969 cast<CondCodeSDNode>(N0.getOperand(2))->get());
4970 // If we got a simplified select_cc node back from SimplifySelectCC, then
4971 // break it down into a new SETCC node, and a new SELECT node, and then return
4972 // the SELECT node, since we were called with a SELECT node.
4973 if (SCC.Val) {
4974 // Check to see if we got a select_cc back (to turn into setcc/select).
4975 // Otherwise, just return whatever node we got back, like fabs.
4976 if (SCC.getOpcode() == ISD::SELECT_CC) {
4977 SDOperand SETCC = DAG.getNode(ISD::SETCC, N0.getValueType(),
4978 SCC.getOperand(0), SCC.getOperand(1),
4979 SCC.getOperand(4));
Chris Lattner5750df92006-03-01 04:03:14 +00004980 AddToWorkList(SETCC.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00004981 return DAG.getNode(ISD::SELECT, SCC.getValueType(), SCC.getOperand(2),
4982 SCC.getOperand(3), SETCC);
4983 }
4984 return SCC;
4985 }
Nate Begeman44728a72005-09-19 22:34:01 +00004986 return SDOperand();
4987}
4988
Chris Lattner40c62d52005-10-18 06:04:22 +00004989/// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
4990/// are the two values being selected between, see if we can simplify the
Chris Lattner729c6d12006-05-27 00:43:02 +00004991/// select. Callers of this should assume that TheSelect is deleted if this
4992/// returns true. As such, they should return the appropriate thing (e.g. the
4993/// node) back to the top-level of the DAG combiner loop to avoid it being
4994/// looked at.
Chris Lattner40c62d52005-10-18 06:04:22 +00004995///
4996bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDOperand LHS,
4997 SDOperand RHS) {
4998
4999 // If this is a select from two identical things, try to pull the operation
5000 // through the select.
5001 if (LHS.getOpcode() == RHS.getOpcode() && LHS.hasOneUse() && RHS.hasOneUse()){
Chris Lattner40c62d52005-10-18 06:04:22 +00005002 // If this is a load and the token chain is identical, replace the select
5003 // of two loads with a load through a select of the address to load from.
5004 // This triggers in things like "select bool X, 10.0, 123.0" after the FP
5005 // constants have been dropped into the constant pool.
Evan Cheng466685d2006-10-09 20:57:25 +00005006 if (LHS.getOpcode() == ISD::LOAD &&
Chris Lattner40c62d52005-10-18 06:04:22 +00005007 // Token chains must be identical.
Evan Cheng466685d2006-10-09 20:57:25 +00005008 LHS.getOperand(0) == RHS.getOperand(0)) {
5009 LoadSDNode *LLD = cast<LoadSDNode>(LHS);
5010 LoadSDNode *RLD = cast<LoadSDNode>(RHS);
5011
5012 // If this is an EXTLOAD, the VT's must match.
Dan Gohmanb625f2f2008-01-30 00:15:11 +00005013 if (LLD->getMemoryVT() == RLD->getMemoryVT()) {
Evan Cheng466685d2006-10-09 20:57:25 +00005014 // FIXME: this conflates two src values, discarding one. This is not
5015 // the right thing to do, but nothing uses srcvalues now. When they do,
5016 // turn SrcValue into a list of locations.
5017 SDOperand Addr;
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005018 if (TheSelect->getOpcode() == ISD::SELECT) {
5019 // Check that the condition doesn't reach either load. If so, folding
5020 // this will induce a cycle into the DAG.
Evan Cheng917be682008-03-04 00:41:45 +00005021 if (!LLD->isPredecessorOf(TheSelect->getOperand(0).Val) &&
5022 !RLD->isPredecessorOf(TheSelect->getOperand(0).Val)) {
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005023 Addr = DAG.getNode(ISD::SELECT, LLD->getBasePtr().getValueType(),
5024 TheSelect->getOperand(0), LLD->getBasePtr(),
5025 RLD->getBasePtr());
5026 }
5027 } else {
5028 // Check that the condition doesn't reach either load. If so, folding
5029 // this will induce a cycle into the DAG.
Evan Cheng917be682008-03-04 00:41:45 +00005030 if (!LLD->isPredecessorOf(TheSelect->getOperand(0).Val) &&
5031 !RLD->isPredecessorOf(TheSelect->getOperand(0).Val) &&
5032 !LLD->isPredecessorOf(TheSelect->getOperand(1).Val) &&
5033 !RLD->isPredecessorOf(TheSelect->getOperand(1).Val)) {
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005034 Addr = DAG.getNode(ISD::SELECT_CC, LLD->getBasePtr().getValueType(),
Evan Cheng466685d2006-10-09 20:57:25 +00005035 TheSelect->getOperand(0),
5036 TheSelect->getOperand(1),
5037 LLD->getBasePtr(), RLD->getBasePtr(),
5038 TheSelect->getOperand(4));
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005039 }
Evan Cheng466685d2006-10-09 20:57:25 +00005040 }
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005041
5042 if (Addr.Val) {
5043 SDOperand Load;
5044 if (LLD->getExtensionType() == ISD::NON_EXTLOAD)
5045 Load = DAG.getLoad(TheSelect->getValueType(0), LLD->getChain(),
5046 Addr,LLD->getSrcValue(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00005047 LLD->getSrcValueOffset(),
5048 LLD->isVolatile(),
5049 LLD->getAlignment());
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005050 else {
5051 Load = DAG.getExtLoad(LLD->getExtensionType(),
5052 TheSelect->getValueType(0),
5053 LLD->getChain(), Addr, LLD->getSrcValue(),
5054 LLD->getSrcValueOffset(),
Dan Gohmanb625f2f2008-01-30 00:15:11 +00005055 LLD->getMemoryVT(),
Christopher Lamb95c218a2007-04-22 23:15:30 +00005056 LLD->isVolatile(),
5057 LLD->getAlignment());
Chris Lattnerc4e664b2007-01-16 05:59:59 +00005058 }
5059 // Users of the select now use the result of the load.
5060 CombineTo(TheSelect, Load);
5061
5062 // Users of the old loads now use the new load's chain. We know the
5063 // old-load value is dead now.
5064 CombineTo(LHS.Val, Load.getValue(0), Load.getValue(1));
5065 CombineTo(RHS.Val, Load.getValue(0), Load.getValue(1));
5066 return true;
5067 }
Evan Chengc5484282006-10-04 00:56:09 +00005068 }
Chris Lattner40c62d52005-10-18 06:04:22 +00005069 }
5070 }
5071
5072 return false;
5073}
5074
Nate Begeman44728a72005-09-19 22:34:01 +00005075SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1,
5076 SDOperand N2, SDOperand N3,
Chris Lattner1eba01e2007-04-11 06:50:51 +00005077 ISD::CondCode CC, bool NotExtCompare) {
Nate Begemanf845b452005-10-08 00:29:44 +00005078
5079 MVT::ValueType VT = N2.getValueType();
Nate Begemanf845b452005-10-08 00:29:44 +00005080 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
5081 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
5082 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
5083
5084 // Determine if the condition we're dealing with is constant
Scott Michel5b8f82e2008-03-10 15:42:14 +00005085 SDOperand SCC = SimplifySetCC(TLI.getSetCCResultType(N0), N0, N1, CC, false);
Chris Lattner30f73e72006-10-14 03:52:46 +00005086 if (SCC.Val) AddToWorkList(SCC.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005087 ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val);
5088
5089 // fold select_cc true, x, y -> x
Dan Gohman002e5d02008-03-13 22:13:53 +00005090 if (SCCC && !SCCC->isNullValue())
Nate Begemanf845b452005-10-08 00:29:44 +00005091 return N2;
5092 // fold select_cc false, x, y -> y
Dan Gohman002e5d02008-03-13 22:13:53 +00005093 if (SCCC && SCCC->isNullValue())
Nate Begemanf845b452005-10-08 00:29:44 +00005094 return N3;
5095
5096 // Check to see if we can simplify the select into an fabs node
5097 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
5098 // Allow either -0.0 or 0.0
Dale Johannesen87503a62007-08-25 22:10:57 +00005099 if (CFP->getValueAPF().isZero()) {
Nate Begemanf845b452005-10-08 00:29:44 +00005100 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
5101 if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
5102 N0 == N2 && N3.getOpcode() == ISD::FNEG &&
5103 N2 == N3.getOperand(0))
5104 return DAG.getNode(ISD::FABS, VT, N0);
5105
5106 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
5107 if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
5108 N0 == N3 && N2.getOpcode() == ISD::FNEG &&
5109 N2.getOperand(0) == N3)
5110 return DAG.getNode(ISD::FABS, VT, N3);
5111 }
5112 }
5113
5114 // Check to see if we can perform the "gzip trick", transforming
5115 // select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
Chris Lattnere3152e52006-09-20 06:41:35 +00005116 if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
Nate Begemanf845b452005-10-08 00:29:44 +00005117 MVT::isInteger(N0.getValueType()) &&
Chris Lattnere3152e52006-09-20 06:41:35 +00005118 MVT::isInteger(N2.getValueType()) &&
Dan Gohman002e5d02008-03-13 22:13:53 +00005119 (N1C->isNullValue() || // (a < 0) ? b : 0
5120 (N1C->getAPIntValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
Nate Begemanf845b452005-10-08 00:29:44 +00005121 MVT::ValueType XType = N0.getValueType();
5122 MVT::ValueType AType = N2.getValueType();
5123 if (XType >= AType) {
5124 // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
Nate Begeman07ed4172005-10-10 21:26:48 +00005125 // single-bit constant.
Dan Gohman002e5d02008-03-13 22:13:53 +00005126 if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
5127 unsigned ShCtV = N2C->getAPIntValue().logBase2();
Nate Begemanf845b452005-10-08 00:29:44 +00005128 ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
5129 SDOperand ShCt = DAG.getConstant(ShCtV, TLI.getShiftAmountTy());
5130 SDOperand Shift = DAG.getNode(ISD::SRL, XType, N0, ShCt);
Chris Lattner5750df92006-03-01 04:03:14 +00005131 AddToWorkList(Shift.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005132 if (XType > AType) {
5133 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
Chris Lattner5750df92006-03-01 04:03:14 +00005134 AddToWorkList(Shift.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005135 }
5136 return DAG.getNode(ISD::AND, AType, Shift, N2);
5137 }
5138 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
5139 DAG.getConstant(MVT::getSizeInBits(XType)-1,
5140 TLI.getShiftAmountTy()));
Chris Lattner5750df92006-03-01 04:03:14 +00005141 AddToWorkList(Shift.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005142 if (XType > AType) {
5143 Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
Chris Lattner5750df92006-03-01 04:03:14 +00005144 AddToWorkList(Shift.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005145 }
5146 return DAG.getNode(ISD::AND, AType, Shift, N2);
5147 }
5148 }
Nate Begeman07ed4172005-10-10 21:26:48 +00005149
5150 // fold select C, 16, 0 -> shl C, 4
Dan Gohman002e5d02008-03-13 22:13:53 +00005151 if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
Nate Begeman07ed4172005-10-10 21:26:48 +00005152 TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult) {
Chris Lattner1eba01e2007-04-11 06:50:51 +00005153
5154 // If the caller doesn't want us to simplify this into a zext of a compare,
5155 // don't do it.
Dan Gohman002e5d02008-03-13 22:13:53 +00005156 if (NotExtCompare && N2C->getAPIntValue() == 1)
Chris Lattner1eba01e2007-04-11 06:50:51 +00005157 return SDOperand();
5158
Nate Begeman07ed4172005-10-10 21:26:48 +00005159 // Get a SetCC of the condition
5160 // FIXME: Should probably make sure that setcc is legal if we ever have a
5161 // target where it isn't.
Nate Begemanb0d04a72006-02-18 02:40:58 +00005162 SDOperand Temp, SCC;
Nate Begeman07ed4172005-10-10 21:26:48 +00005163 // cast from setcc result type to select result type
Nate Begemanb0d04a72006-02-18 02:40:58 +00005164 if (AfterLegalize) {
Scott Michel5b8f82e2008-03-10 15:42:14 +00005165 SCC = DAG.getSetCC(TLI.getSetCCResultType(N0), N0, N1, CC);
Chris Lattner555d8d62006-12-07 22:36:47 +00005166 if (N2.getValueType() < SCC.getValueType())
5167 Temp = DAG.getZeroExtendInReg(SCC, N2.getValueType());
5168 else
5169 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
Nate Begemanb0d04a72006-02-18 02:40:58 +00005170 } else {
5171 SCC = DAG.getSetCC(MVT::i1, N0, N1, CC);
Nate Begeman07ed4172005-10-10 21:26:48 +00005172 Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
Nate Begemanb0d04a72006-02-18 02:40:58 +00005173 }
Chris Lattner5750df92006-03-01 04:03:14 +00005174 AddToWorkList(SCC.Val);
5175 AddToWorkList(Temp.Val);
Chris Lattnerc56a81d2007-04-11 06:43:25 +00005176
Dan Gohman002e5d02008-03-13 22:13:53 +00005177 if (N2C->getAPIntValue() == 1)
Chris Lattnerc56a81d2007-04-11 06:43:25 +00005178 return Temp;
Nate Begeman07ed4172005-10-10 21:26:48 +00005179 // shl setcc result by log2 n2c
5180 return DAG.getNode(ISD::SHL, N2.getValueType(), Temp,
Dan Gohman002e5d02008-03-13 22:13:53 +00005181 DAG.getConstant(N2C->getAPIntValue().logBase2(),
Nate Begeman07ed4172005-10-10 21:26:48 +00005182 TLI.getShiftAmountTy()));
5183 }
5184
Nate Begemanf845b452005-10-08 00:29:44 +00005185 // Check to see if this is the equivalent of setcc
5186 // FIXME: Turn all of these into setcc if setcc if setcc is legal
5187 // otherwise, go ahead with the folds.
Dan Gohman002e5d02008-03-13 22:13:53 +00005188 if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getAPIntValue() == 1ULL)) {
Nate Begemanf845b452005-10-08 00:29:44 +00005189 MVT::ValueType XType = N0.getValueType();
Scott Michel5b8f82e2008-03-10 15:42:14 +00005190 if (TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(N0))) {
5191 SDOperand Res = DAG.getSetCC(TLI.getSetCCResultType(N0), N0, N1, CC);
Nate Begemanf845b452005-10-08 00:29:44 +00005192 if (Res.getValueType() != VT)
5193 Res = DAG.getNode(ISD::ZERO_EXTEND, VT, Res);
5194 return Res;
5195 }
5196
5197 // seteq X, 0 -> srl (ctlz X, log2(size(X)))
5198 if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
5199 TLI.isOperationLegal(ISD::CTLZ, XType)) {
5200 SDOperand Ctlz = DAG.getNode(ISD::CTLZ, XType, N0);
5201 return DAG.getNode(ISD::SRL, XType, Ctlz,
5202 DAG.getConstant(Log2_32(MVT::getSizeInBits(XType)),
5203 TLI.getShiftAmountTy()));
5204 }
5205 // setgt X, 0 -> srl (and (-X, ~X), size(X)-1)
5206 if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
5207 SDOperand NegN0 = DAG.getNode(ISD::SUB, XType, DAG.getConstant(0, XType),
5208 N0);
5209 SDOperand NotN0 = DAG.getNode(ISD::XOR, XType, N0,
5210 DAG.getConstant(~0ULL, XType));
5211 return DAG.getNode(ISD::SRL, XType,
5212 DAG.getNode(ISD::AND, XType, NegN0, NotN0),
5213 DAG.getConstant(MVT::getSizeInBits(XType)-1,
5214 TLI.getShiftAmountTy()));
5215 }
5216 // setgt X, -1 -> xor (srl (X, size(X)-1), 1)
5217 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
5218 SDOperand Sign = DAG.getNode(ISD::SRL, XType, N0,
5219 DAG.getConstant(MVT::getSizeInBits(XType)-1,
5220 TLI.getShiftAmountTy()));
5221 return DAG.getNode(ISD::XOR, XType, Sign, DAG.getConstant(1, XType));
5222 }
5223 }
5224
5225 // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
5226 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5227 if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
Chris Lattner1982ef22007-04-11 05:11:38 +00005228 N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1) &&
5229 N2.getOperand(0) == N1 && MVT::isInteger(N0.getValueType())) {
5230 MVT::ValueType XType = N0.getValueType();
5231 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
5232 DAG.getConstant(MVT::getSizeInBits(XType)-1,
5233 TLI.getShiftAmountTy()));
5234 SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
5235 AddToWorkList(Shift.Val);
5236 AddToWorkList(Add.Val);
5237 return DAG.getNode(ISD::XOR, XType, Add, Shift);
5238 }
5239 // Check to see if this is an integer abs. select_cc setgt X, -1, X, -X ->
5240 // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
5241 if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT &&
5242 N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1)) {
5243 if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
Nate Begemanf845b452005-10-08 00:29:44 +00005244 MVT::ValueType XType = N0.getValueType();
5245 if (SubC->isNullValue() && MVT::isInteger(XType)) {
5246 SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
5247 DAG.getConstant(MVT::getSizeInBits(XType)-1,
Chris Lattner1982ef22007-04-11 05:11:38 +00005248 TLI.getShiftAmountTy()));
Nate Begemanf845b452005-10-08 00:29:44 +00005249 SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
Chris Lattner5750df92006-03-01 04:03:14 +00005250 AddToWorkList(Shift.Val);
5251 AddToWorkList(Add.Val);
Nate Begemanf845b452005-10-08 00:29:44 +00005252 return DAG.getNode(ISD::XOR, XType, Add, Shift);
5253 }
5254 }
5255 }
Chris Lattner1982ef22007-04-11 05:11:38 +00005256
Nate Begeman44728a72005-09-19 22:34:01 +00005257 return SDOperand();
5258}
5259
Evan Chengfa1eb272007-02-08 22:13:59 +00005260/// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
Nate Begeman452d7be2005-09-16 00:54:12 +00005261SDOperand DAGCombiner::SimplifySetCC(MVT::ValueType VT, SDOperand N0,
Nate Begemane17daeb2005-10-05 21:43:42 +00005262 SDOperand N1, ISD::CondCode Cond,
5263 bool foldBooleans) {
Evan Chengfa1eb272007-02-08 22:13:59 +00005264 TargetLowering::DAGCombinerInfo
5265 DagCombineInfo(DAG, !AfterLegalize, false, this);
5266 return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo);
Nate Begeman452d7be2005-09-16 00:54:12 +00005267}
5268
Nate Begeman69575232005-10-20 02:15:44 +00005269/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
5270/// return a DAG expression to select that will generate the same value by
5271/// multiplying by a magic number. See:
5272/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
5273SDOperand DAGCombiner::BuildSDIV(SDNode *N) {
Andrew Lenharth232c9102006-06-12 16:07:18 +00005274 std::vector<SDNode*> Built;
Andrew Lenharthdae9cbe2006-05-16 17:42:15 +00005275 SDOperand S = TLI.BuildSDIV(N, DAG, &Built);
5276
Andrew Lenharth232c9102006-06-12 16:07:18 +00005277 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
Andrew Lenharthdae9cbe2006-05-16 17:42:15 +00005278 ii != ee; ++ii)
5279 AddToWorkList(*ii);
5280 return S;
Nate Begeman69575232005-10-20 02:15:44 +00005281}
5282
5283/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
5284/// return a DAG expression to select that will generate the same value by
5285/// multiplying by a magic number. See:
5286/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
5287SDOperand DAGCombiner::BuildUDIV(SDNode *N) {
Andrew Lenharth232c9102006-06-12 16:07:18 +00005288 std::vector<SDNode*> Built;
Andrew Lenharthdae9cbe2006-05-16 17:42:15 +00005289 SDOperand S = TLI.BuildUDIV(N, DAG, &Built);
Nate Begeman69575232005-10-20 02:15:44 +00005290
Andrew Lenharth232c9102006-06-12 16:07:18 +00005291 for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
Andrew Lenharthdae9cbe2006-05-16 17:42:15 +00005292 ii != ee; ++ii)
5293 AddToWorkList(*ii);
5294 return S;
Nate Begeman69575232005-10-20 02:15:44 +00005295}
5296
Jim Laskey71382342006-10-07 23:37:56 +00005297/// FindBaseOffset - Return true if base is known not to alias with anything
5298/// but itself. Provides base object and offset as results.
5299static bool FindBaseOffset(SDOperand Ptr, SDOperand &Base, int64_t &Offset) {
5300 // Assume it is a primitive operation.
5301 Base = Ptr; Offset = 0;
5302
5303 // If it's an adding a simple constant then integrate the offset.
5304 if (Base.getOpcode() == ISD::ADD) {
5305 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
5306 Base = Base.getOperand(0);
5307 Offset += C->getValue();
5308 }
5309 }
5310
5311 // If it's any of the following then it can't alias with anything but itself.
5312 return isa<FrameIndexSDNode>(Base) ||
5313 isa<ConstantPoolSDNode>(Base) ||
5314 isa<GlobalAddressSDNode>(Base);
5315}
5316
5317/// isAlias - Return true if there is any possibility that the two addresses
5318/// overlap.
Jim Laskey096c22e2006-10-18 12:29:57 +00005319bool DAGCombiner::isAlias(SDOperand Ptr1, int64_t Size1,
5320 const Value *SrcValue1, int SrcValueOffset1,
5321 SDOperand Ptr2, int64_t Size2,
5322 const Value *SrcValue2, int SrcValueOffset2)
5323{
Jim Laskey71382342006-10-07 23:37:56 +00005324 // If they are the same then they must be aliases.
5325 if (Ptr1 == Ptr2) return true;
5326
5327 // Gather base node and offset information.
5328 SDOperand Base1, Base2;
5329 int64_t Offset1, Offset2;
5330 bool KnownBase1 = FindBaseOffset(Ptr1, Base1, Offset1);
5331 bool KnownBase2 = FindBaseOffset(Ptr2, Base2, Offset2);
5332
5333 // If they have a same base address then...
5334 if (Base1 == Base2) {
5335 // Check to see if the addresses overlap.
5336 return!((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
5337 }
5338
Jim Laskey096c22e2006-10-18 12:29:57 +00005339 // If we know both bases then they can't alias.
5340 if (KnownBase1 && KnownBase2) return false;
5341
Jim Laskey07a27092006-10-18 19:08:31 +00005342 if (CombinerGlobalAA) {
5343 // Use alias analysis information.
Dan Gohmane9c8fa02007-08-27 16:32:11 +00005344 int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
5345 int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
5346 int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
Jim Laskey07a27092006-10-18 19:08:31 +00005347 AliasAnalysis::AliasResult AAResult =
Jim Laskey096c22e2006-10-18 12:29:57 +00005348 AA.alias(SrcValue1, Overlap1, SrcValue2, Overlap2);
Jim Laskey07a27092006-10-18 19:08:31 +00005349 if (AAResult == AliasAnalysis::NoAlias)
5350 return false;
5351 }
Jim Laskey096c22e2006-10-18 12:29:57 +00005352
5353 // Otherwise we have to assume they alias.
5354 return true;
Jim Laskey71382342006-10-07 23:37:56 +00005355}
5356
5357/// FindAliasInfo - Extracts the relevant alias information from the memory
5358/// node. Returns true if the operand was a load.
Jim Laskey7ca56af2006-10-11 13:47:09 +00005359bool DAGCombiner::FindAliasInfo(SDNode *N,
Jim Laskey096c22e2006-10-18 12:29:57 +00005360 SDOperand &Ptr, int64_t &Size,
5361 const Value *&SrcValue, int &SrcValueOffset) {
Jim Laskey7ca56af2006-10-11 13:47:09 +00005362 if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
5363 Ptr = LD->getBasePtr();
Dan Gohmanb625f2f2008-01-30 00:15:11 +00005364 Size = MVT::getSizeInBits(LD->getMemoryVT()) >> 3;
Jim Laskey7ca56af2006-10-11 13:47:09 +00005365 SrcValue = LD->getSrcValue();
Jim Laskey096c22e2006-10-18 12:29:57 +00005366 SrcValueOffset = LD->getSrcValueOffset();
Jim Laskey71382342006-10-07 23:37:56 +00005367 return true;
Jim Laskey7ca56af2006-10-11 13:47:09 +00005368 } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
Jim Laskey7ca56af2006-10-11 13:47:09 +00005369 Ptr = ST->getBasePtr();
Dan Gohmanb625f2f2008-01-30 00:15:11 +00005370 Size = MVT::getSizeInBits(ST->getMemoryVT()) >> 3;
Jim Laskey7ca56af2006-10-11 13:47:09 +00005371 SrcValue = ST->getSrcValue();
Jim Laskey096c22e2006-10-18 12:29:57 +00005372 SrcValueOffset = ST->getSrcValueOffset();
Jim Laskey7ca56af2006-10-11 13:47:09 +00005373 } else {
Jim Laskey71382342006-10-07 23:37:56 +00005374 assert(0 && "FindAliasInfo expected a memory operand");
Jim Laskey71382342006-10-07 23:37:56 +00005375 }
5376
5377 return false;
5378}
5379
Jim Laskey6ff23e52006-10-04 16:53:27 +00005380/// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
5381/// looking for aliasing nodes and adding them to the Aliases vector.
Jim Laskeybc588b82006-10-05 15:07:25 +00005382void DAGCombiner::GatherAllAliases(SDNode *N, SDOperand OriginalChain,
Jim Laskey6ff23e52006-10-04 16:53:27 +00005383 SmallVector<SDOperand, 8> &Aliases) {
Jim Laskeybc588b82006-10-05 15:07:25 +00005384 SmallVector<SDOperand, 8> Chains; // List of chains to visit.
Jim Laskey6ff23e52006-10-04 16:53:27 +00005385 std::set<SDNode *> Visited; // Visited node set.
5386
Jim Laskey279f0532006-09-25 16:29:54 +00005387 // Get alias information for node.
5388 SDOperand Ptr;
5389 int64_t Size;
Jim Laskey7ca56af2006-10-11 13:47:09 +00005390 const Value *SrcValue;
Jim Laskey096c22e2006-10-18 12:29:57 +00005391 int SrcValueOffset;
5392 bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset);
Jim Laskey279f0532006-09-25 16:29:54 +00005393
Jim Laskey6ff23e52006-10-04 16:53:27 +00005394 // Starting off.
Jim Laskeybc588b82006-10-05 15:07:25 +00005395 Chains.push_back(OriginalChain);
Jim Laskey6ff23e52006-10-04 16:53:27 +00005396
Jim Laskeybc588b82006-10-05 15:07:25 +00005397 // Look at each chain and determine if it is an alias. If so, add it to the
5398 // aliases list. If not, then continue up the chain looking for the next
5399 // candidate.
5400 while (!Chains.empty()) {
5401 SDOperand Chain = Chains.back();
5402 Chains.pop_back();
Jim Laskey6ff23e52006-10-04 16:53:27 +00005403
Jim Laskeybc588b82006-10-05 15:07:25 +00005404 // Don't bother if we've been before.
5405 if (Visited.find(Chain.Val) != Visited.end()) continue;
5406 Visited.insert(Chain.Val);
5407
5408 switch (Chain.getOpcode()) {
5409 case ISD::EntryToken:
5410 // Entry token is ideal chain operand, but handled in FindBetterChain.
5411 break;
Jim Laskey6ff23e52006-10-04 16:53:27 +00005412
Jim Laskeybc588b82006-10-05 15:07:25 +00005413 case ISD::LOAD:
5414 case ISD::STORE: {
5415 // Get alias information for Chain.
5416 SDOperand OpPtr;
5417 int64_t OpSize;
Jim Laskey7ca56af2006-10-11 13:47:09 +00005418 const Value *OpSrcValue;
Jim Laskey096c22e2006-10-18 12:29:57 +00005419 int OpSrcValueOffset;
5420 bool IsOpLoad = FindAliasInfo(Chain.Val, OpPtr, OpSize,
5421 OpSrcValue, OpSrcValueOffset);
Jim Laskeybc588b82006-10-05 15:07:25 +00005422
5423 // If chain is alias then stop here.
5424 if (!(IsLoad && IsOpLoad) &&
Jim Laskey096c22e2006-10-18 12:29:57 +00005425 isAlias(Ptr, Size, SrcValue, SrcValueOffset,
5426 OpPtr, OpSize, OpSrcValue, OpSrcValueOffset)) {
Jim Laskeybc588b82006-10-05 15:07:25 +00005427 Aliases.push_back(Chain);
5428 } else {
5429 // Look further up the chain.
5430 Chains.push_back(Chain.getOperand(0));
5431 // Clean up old chain.
5432 AddToWorkList(Chain.Val);
Jim Laskey279f0532006-09-25 16:29:54 +00005433 }
Jim Laskeybc588b82006-10-05 15:07:25 +00005434 break;
5435 }
5436
5437 case ISD::TokenFactor:
5438 // We have to check each of the operands of the token factor, so we queue
5439 // then up. Adding the operands to the queue (stack) in reverse order
5440 // maintains the original order and increases the likelihood that getNode
5441 // will find a matching token factor (CSE.)
5442 for (unsigned n = Chain.getNumOperands(); n;)
5443 Chains.push_back(Chain.getOperand(--n));
5444 // Eliminate the token factor if we can.
5445 AddToWorkList(Chain.Val);
5446 break;
5447
5448 default:
5449 // For all other instructions we will just have to take what we can get.
5450 Aliases.push_back(Chain);
5451 break;
Jim Laskey279f0532006-09-25 16:29:54 +00005452 }
5453 }
Jim Laskey6ff23e52006-10-04 16:53:27 +00005454}
5455
5456/// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
5457/// for a better chain (aliasing node.)
5458SDOperand DAGCombiner::FindBetterChain(SDNode *N, SDOperand OldChain) {
5459 SmallVector<SDOperand, 8> Aliases; // Ops for replacing token factor.
Jim Laskey279f0532006-09-25 16:29:54 +00005460
Jim Laskey6ff23e52006-10-04 16:53:27 +00005461 // Accumulate all the aliases to this node.
5462 GatherAllAliases(N, OldChain, Aliases);
5463
5464 if (Aliases.size() == 0) {
5465 // If no operands then chain to entry token.
5466 return DAG.getEntryNode();
5467 } else if (Aliases.size() == 1) {
5468 // If a single operand then chain to it. We don't need to revisit it.
5469 return Aliases[0];
5470 }
5471
5472 // Construct a custom tailored token factor.
5473 SDOperand NewChain = DAG.getNode(ISD::TokenFactor, MVT::Other,
5474 &Aliases[0], Aliases.size());
5475
5476 // Make sure the old chain gets cleaned up.
5477 if (NewChain != OldChain) AddToWorkList(OldChain.Val);
5478
5479 return NewChain;
Jim Laskey279f0532006-09-25 16:29:54 +00005480}
5481
Nate Begeman1d4d4142005-09-01 00:19:25 +00005482// SelectionDAG::Combine - This is the entry point for the file.
5483//
Jim Laskeyc7c3f112006-10-16 20:52:31 +00005484void SelectionDAG::Combine(bool RunningAfterLegalize, AliasAnalysis &AA) {
Chris Lattner938ab022007-01-16 04:55:25 +00005485 if (!RunningAfterLegalize && ViewDAGCombine1)
5486 viewGraph();
5487 if (RunningAfterLegalize && ViewDAGCombine2)
5488 viewGraph();
Nate Begeman1d4d4142005-09-01 00:19:25 +00005489 /// run - This is the main entry point to this class.
5490 ///
Jim Laskeyc7c3f112006-10-16 20:52:31 +00005491 DAGCombiner(*this, AA).Run(RunningAfterLegalize);
Nate Begeman1d4d4142005-09-01 00:19:25 +00005492}