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-rw-r--r--lib/Analysis/ScalarEvolution.cpp64
1 files changed, 40 insertions, 24 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 622b214..daf7742 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -74,6 +74,7 @@
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/Debug.h"
@@ -108,6 +109,7 @@ INITIALIZE_PASS_BEGIN(ScalarEvolution, "scalar-evolution",
"Scalar Evolution Analysis", false, true)
INITIALIZE_PASS_DEPENDENCY(LoopInfo)
INITIALIZE_PASS_DEPENDENCY(DominatorTree)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
INITIALIZE_PASS_END(ScalarEvolution, "scalar-evolution",
"Scalar Evolution Analysis", false, true)
char ScalarEvolution::ID = 0;
@@ -188,6 +190,14 @@ void SCEV::print(raw_ostream &OS) const {
OS << OpStr;
}
OS << ")";
+ switch (NAry->getSCEVType()) {
+ case scAddExpr:
+ case scMulExpr:
+ if (NAry->getNoWrapFlags(FlagNUW))
+ OS << "<nuw>";
+ if (NAry->getNoWrapFlags(FlagNSW))
+ OS << "<nsw>";
+ }
return;
}
case scUDivExpr: {
@@ -2581,7 +2591,7 @@ const SCEV *ScalarEvolution::getSizeOfExpr(Type *AllocTy) {
Constant *C = ConstantExpr::getSizeOf(AllocTy);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI))
C = Folded;
Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
return getTruncateOrZeroExtend(getSCEV(C), Ty);
@@ -2590,7 +2600,7 @@ const SCEV *ScalarEvolution::getSizeOfExpr(Type *AllocTy) {
const SCEV *ScalarEvolution::getAlignOfExpr(Type *AllocTy) {
Constant *C = ConstantExpr::getAlignOf(AllocTy);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI))
C = Folded;
Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
return getTruncateOrZeroExtend(getSCEV(C), Ty);
@@ -2607,7 +2617,7 @@ const SCEV *ScalarEvolution::getOffsetOfExpr(StructType *STy,
Constant *C = ConstantExpr::getOffsetOf(STy, FieldNo);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI))
C = Folded;
Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
return getTruncateOrZeroExtend(getSCEV(C), Ty);
@@ -2617,7 +2627,7 @@ const SCEV *ScalarEvolution::getOffsetOfExpr(Type *CTy,
Constant *FieldNo) {
Constant *C = ConstantExpr::getOffsetOf(CTy, FieldNo);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI))
C = Folded;
Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(CTy));
return getTruncateOrZeroExtend(getSCEV(C), Ty);
@@ -3108,7 +3118,7 @@ const SCEV *ScalarEvolution::createNodeForPHI(PHINode *PN) {
// PHI's incoming blocks are in a different loop, in which case doing so
// risks breaking LCSSA form. Instcombine would normally zap these, but
// it doesn't have DominatorTree information, so it may miss cases.
- if (Value *V = SimplifyInstruction(PN, TD, DT))
+ if (Value *V = SimplifyInstruction(PN, TD, TLI, DT))
if (LI->replacementPreservesLCSSAForm(PN, V))
return getSCEV(V);
@@ -3584,6 +3594,12 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) {
// because it leads to N-1 getAddExpr calls for N ultimate operands.
// Instead, gather up all the operands and make a single getAddExpr call.
// LLVM IR canonical form means we need only traverse the left operands.
+ //
+ // Don't apply this instruction's NSW or NUW flags to the new
+ // expression. The instruction may be guarded by control flow that the
+ // no-wrap behavior depends on. Non-control-equivalent instructions can be
+ // mapped to the same SCEV expression, and it would be incorrect to transfer
+ // NSW/NUW semantics to those operations.
SmallVector<const SCEV *, 4> AddOps;
AddOps.push_back(getSCEV(U->getOperand(1)));
for (Value *Op = U->getOperand(0); ; Op = U->getOperand(0)) {
@@ -3598,16 +3614,10 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) {
AddOps.push_back(Op1);
}
AddOps.push_back(getSCEV(U->getOperand(0)));
- SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
- OverflowingBinaryOperator *OBO = cast<OverflowingBinaryOperator>(V);
- if (OBO->hasNoSignedWrap())
- Flags = setFlags(Flags, SCEV::FlagNSW);
- if (OBO->hasNoUnsignedWrap())
- Flags = setFlags(Flags, SCEV::FlagNUW);
- return getAddExpr(AddOps, Flags);
+ return getAddExpr(AddOps);
}
case Instruction::Mul: {
- // See the Add code above.
+ // Don't transfer NSW/NUW for the same reason as AddExpr.
SmallVector<const SCEV *, 4> MulOps;
MulOps.push_back(getSCEV(U->getOperand(1)));
for (Value *Op = U->getOperand(0);
@@ -4762,7 +4772,8 @@ static PHINode *getConstantEvolvingPHI(Value *V, const Loop *L) {
/// reason, return null.
static Constant *EvaluateExpression(Value *V, const Loop *L,
DenseMap<Instruction *, Constant *> &Vals,
- const TargetData *TD) {
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI) {
// Convenient constant check, but redundant for recursive calls.
if (Constant *C = dyn_cast<Constant>(V)) return C;
Instruction *I = dyn_cast<Instruction>(V);
@@ -4788,7 +4799,7 @@ static Constant *EvaluateExpression(Value *V, const Loop *L,
if (!Operands[i]) return 0;
continue;
}
- Constant *C = EvaluateExpression(Operand, L, Vals, TD);
+ Constant *C = EvaluateExpression(Operand, L, Vals, TD, TLI);
Vals[Operand] = C;
if (!C) return 0;
Operands[i] = C;
@@ -4796,12 +4807,13 @@ static Constant *EvaluateExpression(Value *V, const Loop *L,
if (CmpInst *CI = dyn_cast<CmpInst>(I))
return ConstantFoldCompareInstOperands(CI->getPredicate(), Operands[0],
- Operands[1], TD);
+ Operands[1], TD, TLI);
if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
if (!LI->isVolatile())
return ConstantFoldLoadFromConstPtr(Operands[0], TD);
}
- return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Operands, TD);
+ return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Operands, TD,
+ TLI);
}
/// getConstantEvolutionLoopExitValue - If we know that the specified Phi is
@@ -4856,7 +4868,8 @@ ScalarEvolution::getConstantEvolutionLoopExitValue(PHINode *PN,
// Compute the value of the PHIs for the next iteration.
// EvaluateExpression adds non-phi values to the CurrentIterVals map.
DenseMap<Instruction *, Constant *> NextIterVals;
- Constant *NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD);
+ Constant *NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD,
+ TLI);
if (NextPHI == 0)
return 0; // Couldn't evaluate!
NextIterVals[PN] = NextPHI;
@@ -4881,7 +4894,7 @@ ScalarEvolution::getConstantEvolutionLoopExitValue(PHINode *PN,
Constant *&NextPHI = NextIterVals[PHI];
if (!NextPHI) { // Not already computed.
Value *BEValue = PHI->getIncomingValue(SecondIsBackedge);
- NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD);
+ NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD, TLI);
}
if (NextPHI != I->second)
StoppedEvolving = false;
@@ -4936,8 +4949,8 @@ const SCEV *ScalarEvolution::ComputeExitCountExhaustively(const Loop *L,
unsigned MaxIterations = MaxBruteForceIterations; // Limit analysis.
for (unsigned IterationNum = 0; IterationNum != MaxIterations;++IterationNum){
ConstantInt *CondVal =
- dyn_cast_or_null<ConstantInt>(EvaluateExpression(Cond, L,
- CurrentIterVals, TD));
+ dyn_cast_or_null<ConstantInt>(EvaluateExpression(Cond, L, CurrentIterVals,
+ TD, TLI));
// Couldn't symbolically evaluate.
if (!CondVal) return getCouldNotCompute();
@@ -4967,7 +4980,7 @@ const SCEV *ScalarEvolution::ComputeExitCountExhaustively(const Loop *L,
if (NextPHI) continue; // Already computed!
Value *BEValue = PHI->getIncomingValue(SecondIsBackedge);
- NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD);
+ NextPHI = EvaluateExpression(BEValue, L, CurrentIterVals, TD, TLI);
}
CurrentIterVals.swap(NextIterVals);
}
@@ -5159,13 +5172,14 @@ const SCEV *ScalarEvolution::computeSCEVAtScope(const SCEV *V, const Loop *L) {
Constant *C = 0;
if (const CmpInst *CI = dyn_cast<CmpInst>(I))
C = ConstantFoldCompareInstOperands(CI->getPredicate(),
- Operands[0], Operands[1], TD);
+ Operands[0], Operands[1], TD,
+ TLI);
else if (const LoadInst *LI = dyn_cast<LoadInst>(I)) {
if (!LI->isVolatile())
C = ConstantFoldLoadFromConstPtr(Operands[0], TD);
} else
C = ConstantFoldInstOperands(I->getOpcode(), I->getType(),
- Operands, TD);
+ Operands, TD, TLI);
if (!C) return V;
return getSCEV(C);
}
@@ -6552,6 +6566,7 @@ bool ScalarEvolution::runOnFunction(Function &F) {
this->F = &F;
LI = &getAnalysis<LoopInfo>();
TD = getAnalysisIfAvailable<TargetData>();
+ TLI = &getAnalysis<TargetLibraryInfo>();
DT = &getAnalysis<DominatorTree>();
return false;
}
@@ -6588,6 +6603,7 @@ void ScalarEvolution::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequiredTransitive<LoopInfo>();
AU.addRequiredTransitive<DominatorTree>();
+ AU.addRequired<TargetLibraryInfo>();
}
bool ScalarEvolution::hasLoopInvariantBackedgeTakenCount(const Loop *L) {
generated by cgit v1.1 at 2025-06-26 12:47:37 +0000