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Revert "Properly handle multi-element and dynamically sized allocas in getPointerDereferenceableBytes()" 

This reverts commit 217067d5179882de9deb60d2e866befea4c126e7.

Fails on llvm-clang-x86_64-expensive-checks-win

llvm-svn: 320945
This commit is contained in:
Bjorn Steinbrink 2017-12-17 15:16:58 +00:00
parent e880f262e5
commit 6f7bbf349f
3 changed files with 5 additions and 24 deletions
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2
llvm/include/llvm/IR/Value.h
View File

@ -570,7 +570,7 @@ public:
///
/// If CanBeNull is set by this function the pointer can either be null or be
/// dereferenceable up to the returned number of bytes.
uint64_t getPointerDereferenceableBytes(const DataLayout &DL,
unsigned getPointerDereferenceableBytes(const DataLayout &DL,
bool &CanBeNull) const;
/// \brief Returns an alignment of the pointer value.

10
llvm/lib/IR/Value.cpp
View File

@ -619,11 +619,11 @@ const Value *Value::stripInBoundsOffsets() const {
return stripPointerCastsAndOffsets<PSK_InBounds>(this);
}
uint64_t Value::getPointerDereferenceableBytes(const DataLayout &DL,
unsigned Value::getPointerDereferenceableBytes(const DataLayout &DL,
bool &CanBeNull) const {
assert(getType()->isPointerTy() && "must be pointer");
uint64_t DerefBytes = 0;
unsigned DerefBytes = 0;
CanBeNull = false;
if (const Argument *A = dyn_cast<Argument>(this)) {
DerefBytes = A->getDereferenceableBytes();
@ -655,10 +655,8 @@ uint64_t Value::getPointerDereferenceableBytes(const DataLayout &DL,
CanBeNull = true;
}
} else if (auto *AI = dyn_cast<AllocaInst>(this)) {
const ConstantInt *ArraySize = dyn_cast<ConstantInt>(AI->getArraySize());
if (ArraySize && AI->getAllocatedType()->isSized()) {
DerefBytes = DL.getTypeStoreSize(AI->getAllocatedType()) *
ArraySize->getZExtValue();
if (AI->getAllocatedType()->isSized()) {
DerefBytes = DL.getTypeStoreSize(AI->getAllocatedType());
CanBeNull = false;
}
} else if (auto *GV = dyn_cast<GlobalVariable>(this)) {

17
llvm/test/Analysis/ValueTracking/memory-dereferenceable.ll
View File

@ -36,23 +36,6 @@ entry:
%alloca = alloca i1
%load2 = load i1, i1* %alloca
; Load from empty array alloca
; CHECK-NOT: %empty_alloca
%empty_alloca = alloca i8, i64 0
%empty_load = load i8, i8* %empty_alloca
; Load from too small array alloca
; CHECK-NOT: %small_array_alloca
%small_array_alloca = alloca i8, i64 2
%saa_cast = bitcast i8* %small_array_alloca to i32*
%saa_load = load i32, i32* %saa_cast
; Load from array alloca
; CHECK: %big_array_alloca{{.*}}(unaligned)
%big_array_alloca = alloca i8, i64 4
%baa_cast = bitcast i8* %big_array_alloca to i32*
%baa_load = load i32, i32* %baa_cast
; CHECK: %dparam{{.*}}(aligned)
%load3 = load i32, i32 addrspace(1)* %dparam