diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.cpp | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index e6e0f6b..020eb61 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -3223,11 +3223,12 @@ static bool isInBoundsGep(Value *Ptr) { /// \brief Check whether the access through \p Ptr has a constant stride. static int isStridedPtr(ScalarEvolution *SE, DataLayout *DL, Value *Ptr, const Loop *Lp) { - const Type *PtrTy = Ptr->getType(); - assert(PtrTy->isPointerTy() && "Unexpected non ptr"); + const Type *Ty = Ptr->getType(); + assert(Ty->isPointerTy() && "Unexpected non ptr"); // Make sure that the pointer does not point to aggregate types. - if (cast<PointerType>(Ptr->getType())->getElementType()->isAggregateType()) { + const PointerType *PtrTy = cast<PointerType>(Ty); + if (PtrTy->getElementType()->isAggregateType()) { DEBUG(dbgs() << "LV: Bad stride - Not a pointer to a scalar type" << *Ptr << "\n"); return 0; @@ -3248,11 +3249,16 @@ static int isStridedPtr(ScalarEvolution *SE, DataLayout *DL, Value *Ptr, } // The address calculation must not wrap. Otherwise, a dependence could be - // inverted. An inbounds getelementptr that is a AddRec with a unit stride + // inverted. + // An inbounds getelementptr that is a AddRec with a unit stride // cannot wrap per definition. The unit stride requirement is checked later. + // An getelementptr without an inbounds attribute and unit stride would have + // 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 = AR->getNoWrapFlags(SCEV::NoWrapMask); - if (!IsNoWrapAddRec && !IsInBoundsGEP) { + bool IsInAddressSpaceZero = PtrTy->getAddressSpace() == 0; + if (!IsNoWrapAddRec && !IsInBoundsGEP && !IsInAddressSpaceZero) { DEBUG(dbgs() << "LV: Bad stride - Pointer may wrap in the address space " << *Ptr << " SCEV: " << *PtrScev << "\n"); return 0; @@ -3269,7 +3275,7 @@ static int isStridedPtr(ScalarEvolution *SE, DataLayout *DL, Value *Ptr, return 0; } - int64_t Size = DL->getTypeAllocSize(PtrTy->getPointerElementType()); + int64_t Size = DL->getTypeAllocSize(PtrTy->getElementType()); const APInt &APStepVal = C->getValue()->getValue(); // Huge step value - give up. @@ -3285,8 +3291,10 @@ static int isStridedPtr(ScalarEvolution *SE, DataLayout *DL, Value *Ptr, return 0; // If the SCEV could wrap but we have an inbounds gep with a unit stride we - // know we can't "wrap around the address space". - if (!IsNoWrapAddRec && IsInBoundsGEP && Stride != 1 && Stride != -1) + // 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) return 0; return Stride; |