diff options
Diffstat (limited to 'llvm/lib/Analysis/LoopAccessAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/LoopAccessAnalysis.cpp | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp index 351e090..7ac51c3 100644 --- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp +++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp @@ -154,21 +154,19 @@ Value *llvm::stripIntegerCast(Value *V) { } const SCEV *llvm::replaceSymbolicStrideSCEV(PredicatedScalarEvolution &PSE, - const ValueToValueMap &PtrToStride, + const DenseMap<Value *, const SCEV *> &PtrToStride, Value *Ptr) { const SCEV *OrigSCEV = PSE.getSCEV(Ptr); // If there is an entry in the map return the SCEV of the pointer with the // symbolic stride replaced by one. - ValueToValueMap::const_iterator SI = PtrToStride.find(Ptr); + DenseMap<Value *, const SCEV *>::const_iterator SI = PtrToStride.find(Ptr); if (SI == PtrToStride.end()) // For a non-symbolic stride, just return the original expression. return OrigSCEV; - Value *StrideVal = stripIntegerCast(SI->second); - ScalarEvolution *SE = PSE.getSE(); - const SCEV *StrideSCEV = SE->getSCEV(StrideVal); + const SCEV *StrideSCEV = SI->second; assert(isa<SCEVUnknown>(StrideSCEV) && "shouldn't be in map"); const auto *CT = SE->getOne(StrideSCEV->getType()); @@ -658,7 +656,7 @@ public: /// the bounds of the pointer. bool createCheckForAccess(RuntimePointerChecking &RtCheck, MemAccessInfo Access, Type *AccessTy, - const ValueToValueMap &Strides, + const DenseMap<Value *, const SCEV *> &Strides, DenseMap<Value *, unsigned> &DepSetId, Loop *TheLoop, unsigned &RunningDepId, unsigned ASId, bool ShouldCheckStride, bool Assume); @@ -669,7 +667,7 @@ public: /// Returns true if we need no check or if we do and we can generate them /// (i.e. the pointers have computable bounds). bool canCheckPtrAtRT(RuntimePointerChecking &RtCheck, ScalarEvolution *SE, - Loop *TheLoop, const ValueToValueMap &Strides, + Loop *TheLoop, const DenseMap<Value *, const SCEV *> &Strides, Value *&UncomputablePtr, bool ShouldCheckWrap = false); /// Goes over all memory accesses, checks whether a RT check is needed @@ -764,7 +762,7 @@ static bool hasComputableBounds(PredicatedScalarEvolution &PSE, Value *Ptr, /// Check whether a pointer address cannot wrap. static bool isNoWrap(PredicatedScalarEvolution &PSE, - const ValueToValueMap &Strides, Value *Ptr, Type *AccessTy, + const DenseMap<Value *, const SCEV *> &Strides, Value *Ptr, Type *AccessTy, Loop *L) { const SCEV *PtrScev = PSE.getSCEV(Ptr); if (PSE.getSE()->isLoopInvariant(PtrScev, L)) @@ -957,7 +955,7 @@ static void findForkedSCEVs( static SmallVector<PointerIntPair<const SCEV *, 1, bool>> findForkedPointer(PredicatedScalarEvolution &PSE, - const ValueToValueMap &StridesMap, Value *Ptr, + const DenseMap<Value *, const SCEV *> &StridesMap, Value *Ptr, const Loop *L) { ScalarEvolution *SE = PSE.getSE(); assert(SE->isSCEVable(Ptr->getType()) && "Value is not SCEVable!"); @@ -982,7 +980,7 @@ findForkedPointer(PredicatedScalarEvolution &PSE, bool AccessAnalysis::createCheckForAccess(RuntimePointerChecking &RtCheck, MemAccessInfo Access, Type *AccessTy, - const ValueToValueMap &StridesMap, + const DenseMap<Value *, const SCEV *> &StridesMap, DenseMap<Value *, unsigned> &DepSetId, Loop *TheLoop, unsigned &RunningDepId, unsigned ASId, bool ShouldCheckWrap, @@ -1043,7 +1041,7 @@ bool AccessAnalysis::createCheckForAccess(RuntimePointerChecking &RtCheck, bool AccessAnalysis::canCheckPtrAtRT(RuntimePointerChecking &RtCheck, ScalarEvolution *SE, Loop *TheLoop, - const ValueToValueMap &StridesMap, + const DenseMap<Value *, const SCEV *> &StridesMap, Value *&UncomputablePtr, bool ShouldCheckWrap) { // Find pointers with computable bounds. We are going to use this information // to place a runtime bound check. @@ -1373,7 +1371,7 @@ static bool isNoWrapAddRec(Value *Ptr, const SCEVAddRecExpr *AR, std::optional<int64_t> llvm::getPtrStride(PredicatedScalarEvolution &PSE, Type *AccessTy, Value *Ptr, const Loop *Lp, - const ValueToValueMap &StridesMap, + const DenseMap<Value *, const SCEV *> &StridesMap, bool Assume, bool ShouldCheckWrap) { Type *Ty = Ptr->getType(); assert(Ty->isPointerTy() && "Unexpected non-ptr"); @@ -1822,7 +1820,7 @@ static bool areStridedAccessesIndependent(uint64_t Distance, uint64_t Stride, MemoryDepChecker::Dependence::DepType MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx, const MemAccessInfo &B, unsigned BIdx, - const ValueToValueMap &Strides) { + const DenseMap<Value *, const SCEV *> &Strides) { assert (AIdx < BIdx && "Must pass arguments in program order"); auto [APtr, AIsWrite] = A; @@ -2016,7 +2014,7 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx, bool MemoryDepChecker::areDepsSafe(DepCandidates &AccessSets, MemAccessInfoList &CheckDeps, - const ValueToValueMap &Strides) { + const DenseMap<Value *, const SCEV *> &Strides) { MaxSafeDepDistBytes = -1; SmallPtrSet<MemAccessInfo, 8> Visited; @@ -2691,6 +2689,12 @@ void LoopAccessInfo::collectStridedAccess(Value *MemAccess) { if (!Ptr) return; + // Note: getStrideFromPointer is a *profitability* heuristic. We + // could broaden the scope of values returned here - to anything + // which happens to be loop invariant and contributes to the + // computation of an interesting IV - but we chose not to as we + // don't have a cost model here, and broadening the scope exposes + // far too many unprofitable cases. Value *Stride = getStrideFromPointer(Ptr, PSE->getSE(), TheLoop); if (!Stride) return; @@ -2746,7 +2750,7 @@ void LoopAccessInfo::collectStridedAccess(Value *MemAccess) { } LLVM_DEBUG(dbgs() << "LAA: Found a strided access that we can version.\n"); - SymbolicStrides[Ptr] = Stride; + SymbolicStrides[Ptr] = StrideExpr; StrideSet.insert(Stride); } |