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-rw-r--r--llvm/lib/Analysis/LoopAccessAnalysis.cpp61
1 files changed, 18 insertions, 43 deletions
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index f371feb8142..a2ab231a62d 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -773,7 +773,7 @@ static bool isInBoundsGep(Value *Ptr) {
/// \brief Return true if an AddRec pointer \p Ptr is unsigned non-wrapping,
/// i.e. monotonically increasing/decreasing.
static bool isNoWrapAddRec(Value *Ptr, const SCEVAddRecExpr *AR,
- PredicatedScalarEvolution &PSE, const Loop *L) {
+ ScalarEvolution *SE, const Loop *L) {
// FIXME: This should probably only return true for NUW.
if (AR->getNoWrapFlags(SCEV::NoWrapMask))
return true;
@@ -809,7 +809,7 @@ static bool isNoWrapAddRec(Value *Ptr, const SCEVAddRecExpr *AR,
// Assume constant for other the operand so that the AddRec can be
// easily found.
isa<ConstantInt>(OBO->getOperand(1))) {
- auto *OpScev = PSE.getSCEV(OBO->getOperand(0));
+ auto *OpScev = SE->getSCEV(OBO->getOperand(0));
if (auto *OpAR = dyn_cast<SCEVAddRecExpr>(OpScev))
return OpAR->getLoop() == L && OpAR->getNoWrapFlags(SCEV::FlagNSW);
@@ -820,35 +820,31 @@ static bool isNoWrapAddRec(Value *Ptr, const SCEVAddRecExpr *AR,
/// \brief Check whether the access through \p Ptr has a constant stride.
int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
- const Loop *Lp, const ValueToValueMap &StridesMap,
- bool Assume) {
+ const Loop *Lp, const ValueToValueMap &StridesMap) {
Type *Ty = Ptr->getType();
assert(Ty->isPointerTy() && "Unexpected non-ptr");
// Make sure that the pointer does not point to aggregate types.
auto *PtrTy = cast<PointerType>(Ty);
if (PtrTy->getElementType()->isAggregateType()) {
- DEBUG(dbgs() << "LAA: Bad stride - Not a pointer to a scalar type" << *Ptr
- << "\n");
+ DEBUG(dbgs() << "LAA: Bad stride - Not a pointer to a scalar type"
+ << *Ptr << "\n");
return 0;
}
const SCEV *PtrScev = replaceSymbolicStrideSCEV(PSE, StridesMap, Ptr);
const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev);
- if (Assume && !AR)
- AR = dyn_cast<SCEVAddRecExpr>(PSE.getAsAddRec(Ptr));
-
if (!AR) {
- DEBUG(dbgs() << "LAA: Bad stride - Not an AddRecExpr pointer " << *Ptr
- << " SCEV: " << *PtrScev << "\n");
+ DEBUG(dbgs() << "LAA: Bad stride - Not an AddRecExpr pointer "
+ << *Ptr << " SCEV: " << *PtrScev << "\n");
return 0;
}
// The accesss function must stride over the innermost loop.
if (Lp != AR->getLoop()) {
DEBUG(dbgs() << "LAA: Bad stride - Not striding over innermost loop " <<
- *Ptr << " SCEV: " << *AR << "\n");
+ *Ptr << " SCEV: " << *PtrScev << "\n");
return 0;
}
@@ -860,23 +856,12 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
// to access the pointer value "0" which is undefined behavior in address
// space 0, therefore we can also vectorize this case.
bool IsInBoundsGEP = isInBoundsGep(Ptr);
- bool IsNoWrapAddRec =
- PSE.hasNoOverflow(Ptr, SCEVWrapPredicate::IncrementNUSW) ||
- isNoWrapAddRec(Ptr, AR, PSE, Lp);
+ bool IsNoWrapAddRec = isNoWrapAddRec(Ptr, AR, PSE.getSE(), Lp);
bool IsInAddressSpaceZero = PtrTy->getAddressSpace() == 0;
if (!IsNoWrapAddRec && !IsInBoundsGEP && !IsInAddressSpaceZero) {
- if (Assume) {
- PSE.setNoOverflow(Ptr, SCEVWrapPredicate::IncrementNUSW);
- IsNoWrapAddRec = true;
- DEBUG(dbgs() << "LAA: Pointer may wrap in the address space:\n"
- << "LAA: Pointer: " << *Ptr << "\n"
- << "LAA: SCEV: " << *AR << "\n"
- << "LAA: Added an overflow assumption\n");
- } else {
- DEBUG(dbgs() << "LAA: Bad stride - Pointer may wrap in the address space "
- << *Ptr << " SCEV: " << *AR << "\n");
- return 0;
- }
+ DEBUG(dbgs() << "LAA: Bad stride - Pointer may wrap in the address space "
+ << *Ptr << " SCEV: " << *PtrScev << "\n");
+ return 0;
}
// Check the step is constant.
@@ -886,7 +871,7 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
const SCEVConstant *C = dyn_cast<SCEVConstant>(Step);
if (!C) {
DEBUG(dbgs() << "LAA: Bad stride - Not a constant strided " << *Ptr <<
- " SCEV: " << *AR << "\n");
+ " SCEV: " << *PtrScev << "\n");
return 0;
}
@@ -910,18 +895,8 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
// know we can't "wrap around the address space". In case of address space
// zero we know that this won't happen without triggering undefined behavior.
if (!IsNoWrapAddRec && (IsInBoundsGEP || IsInAddressSpaceZero) &&
- Stride != 1 && Stride != -1) {
- if (Assume) {
- // We can avoid this case by adding a run-time check.
- DEBUG(dbgs() << "LAA: Non unit strided pointer which is not either "
- << "inbouds or in address space 0 may wrap:\n"
- << "LAA: Pointer: " << *Ptr << "\n"
- << "LAA: SCEV: " << *AR << "\n"
- << "LAA: Added an overflow assumption\n");
- PSE.setNoOverflow(Ptr, SCEVWrapPredicate::IncrementNUSW);
- } else
- return 0;
- }
+ Stride != 1 && Stride != -1)
+ return 0;
return Stride;
}
@@ -1148,8 +1123,8 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx,
const SCEV *AScev = replaceSymbolicStrideSCEV(PSE, Strides, APtr);
const SCEV *BScev = replaceSymbolicStrideSCEV(PSE, Strides, BPtr);
- int StrideAPtr = isStridedPtr(PSE, APtr, InnermostLoop, Strides, true);
- int StrideBPtr = isStridedPtr(PSE, BPtr, InnermostLoop, Strides, true);
+ int StrideAPtr = isStridedPtr(PSE, APtr, InnermostLoop, Strides);
+ int StrideBPtr = isStridedPtr(PSE, BPtr, InnermostLoop, Strides);
const SCEV *Src = AScev;
const SCEV *Sink = BScev;
@@ -1849,7 +1824,7 @@ LoopAccessInfo::LoopAccessInfo(Loop *L, ScalarEvolution *SE,
const TargetLibraryInfo *TLI, AliasAnalysis *AA,
DominatorTree *DT, LoopInfo *LI,
const ValueToValueMap &Strides)
- : PSE(*SE, *L), PtrRtChecking(SE), DepChecker(PSE, L), TheLoop(L), DL(DL),
+ : PSE(*SE), PtrRtChecking(SE), DepChecker(PSE, L), TheLoop(L), DL(DL),
TLI(TLI), AA(AA), DT(DT), LI(LI), NumLoads(0), NumStores(0),
MaxSafeDepDistBytes(-1U), CanVecMem(false),
StoreToLoopInvariantAddress(false) {
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