maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[Attributor] Handle special case when offset equals zero in nonnull deduction

This commit is contained in:
Hideto Ueno 2019-11-27 14:41:12 +00:00
parent cbfa237892
commit 0f4383faa7
2 changed files with 20 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
llvm/lib/Transforms/IPO/Attributor.cpp
View File

@ -308,15 +308,16 @@ static const Value *getPointerOperand(const Instruction *I) {
return nullptr;
}
static const Value *getBasePointerOfAccessPointerOperand(const Instruction *I,
int64_t &BytesOffset,
const DataLayout &DL) {
static const Value *
getBasePointerOfAccessPointerOperand(const Instruction *I, int64_t &BytesOffset,
const DataLayout &DL,
bool AllowNonInbounds = false) {
const Value *Ptr = getPointerOperand(I);
if (!Ptr)
return nullptr;
return GetPointerBaseWithConstantOffset(Ptr, BytesOffset, DL,
/*AllowNonInbounds*/ false);
AllowNonInbounds);
}
ChangeStatus AbstractAttribute::update(Attributor &A) {
@ -1702,8 +1703,7 @@ static int64_t getKnownNonNullAndDerefBytesForUse(
return 0;
}
if (auto *GEP = dyn_cast<GetElementPtrInst>(I))
if (GEP->hasAllZeroIndices() ||
(GEP->isInBounds() && GEP->hasAllConstantIndices())) {
if (GEP->hasAllConstantIndices()) {
TrackUse = true;
return 0;
}
@ -1718,6 +1718,18 @@ static int64_t getKnownNonNullAndDerefBytesForUse(
return std::max(int64_t(0), DerefBytes);
}
}
/// Corner case when an offset is 0.
if (const Value *Base = getBasePointerOfAccessPointerOperand(
I, Offset, DL, /*AllowNonInbounds*/ true)) {
if (Offset == 0 && Base == &AssociatedValue &&
getPointerOperand(I) == UseV) {
int64_t DerefBytes =
(int64_t)DL.getTypeStoreSize(PtrTy->getPointerElementType());
IsNonNull |= !NullPointerIsDefined;
return std::max(int64_t(0), DerefBytes);
}
}
if (const Value *Base =
GetPointerBaseWithConstantOffset(UseV, Offset, DL,
/*AllowNonInbounds*/ false)) {

6
llvm/test/Transforms/FunctionAttrs/align.ll
View File

@ -351,8 +351,7 @@ define i64 @test12-1(i32* align 4 %p) {
ret i64 %ret
}
; FXIME: %p should have nonnull
; ATTRIBUTOR: define i64 @test12-2(i32* nocapture nofree readonly align 16 %p)
; ATTRIBUTOR: define i64 @test12-2(i32* nocapture nofree nonnull readonly align 16 dereferenceable(8) %p)
define i64 @test12-2(i32* align 4 %p) {
%p-cast = bitcast i32* %p to i64*
%arrayidx0 = getelementptr i64, i64* %p-cast, i64 0
@ -370,8 +369,7 @@ define void @test12-3(i32* align 4 %p) {
ret void
}
; FXIME: %p should have nonnull
; ATTRIBUTOR: define void @test12-4(i32* nocapture nofree writeonly align 16 %p)
; ATTRIBUTOR: define void @test12-4(i32* nocapture nofree nonnull writeonly align 16 dereferenceable(8) %p)
define void @test12-4(i32* align 4 %p) {
%p-cast = bitcast i32* %p to i64*
%arrayidx0 = getelementptr i64, i64* %p-cast, i64 0