Skip to content

[ValueTracking] Allow getUnderlyingPointer to look through inttoptr/ptrtoint round trip casts #146432

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 2 commits into from
Closed

[ValueTracking] Allow getUnderlyingPointer to look through inttoptr/ptrtoint round trip casts #146432

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f716a09
[ValueTracking] Allow getUnderlyingPointer to look through inttoptr/p…
dakersnar Jun 30, 2025
0b0e08c
Pseudocode for alternate suggestion
dakersnar Jul 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions llvm/lib/Analysis/ValueTracking.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6661,6 +6661,10 @@ const Value *llvm::getUnderlyingObject(const Value *V, unsigned MaxLookup) {
if (!NewV->getType()->isPointerTy())
return V;
V = NewV;
} else if (Operator::getOpcode(V) == Instruction::IntToPtr &&
Operator::getOpcode(cast<Operator>(V)->getOperand(0)) ==
Instruction::PtrToInt) {
V = cast<Operator>(cast<Operator>(V)->getOperand(0))->getOperand(0);
} else if (auto *GA = dyn_cast<GlobalAlias>(V)) {
if (GA->isInterposable())
return V;
Expand Down
12 changes: 12 additions & 0 deletions llvm/unittests/Analysis/ValueTrackingTest.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3350,6 +3350,18 @@ TEST_F(ValueTrackingTest, ComputeConstantRange) {
}
}

TEST_F(ValueTrackingTest, GetUnderlyingObject) {
parseAssembly(R"(
@globalmem = external global i8
define void @test() {
%A = getelementptr i8, ptr @globalmem, i64 0
%A2 = getelementptr i8, ptr inttoptr (i32 ptrtoint (ptr @globalmem to i32) to ptr), i64 0
ret void
}
)");
EXPECT_EQ(getUnderlyingObject(A), getUnderlyingObject(A2));
}

struct FindAllocaForValueTestParams {
const char *IR;
bool AnyOffsetResult;
Expand Down
Loading