Skip to content

[AMDGPU] Fix crash folding cos/sin table lookups on poison/undef vector lanes #216972

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

Merged
aobolensk merged 5 commits into from
Aug 18, 2026
+19 −2
Merged

[AMDGPU] Fix crash folding cos/sin table lookups on poison/undef vector lanes #216972

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
c9b0c94
[AMDGPU] Fix crash folding cos/sin table lookups on poison/undef vect…
aobolensk Aug 18, 2026
d8cc0b3
fix undef deprecator remark
aobolensk Aug 18, 2026
96ee16e
comment
aobolensk Aug 18, 2026
3bcea7b
Revert "comment"
aobolensk Aug 18, 2026
5aa3958
Merge branch 'main' into llvm-amdgpu-fix-tdofold-poison-lane
aobolensk Aug 18, 2026
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
8 changes: 6 additions & 2 deletions llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -844,8 +844,12 @@ bool AMDGPULibCalls::TDOFold(CallInst *CI, const FuncInfo &FInfo) {
SmallVector<APFloat, 4> Values;
Values.reserve(vecSize);
for (int eltNo = 0; eltNo < vecSize; ++eltNo) {
ConstantFP *eltval =
cast<ConstantFP>(CV->getAggregateElement((unsigned)eltNo));
// A lane may be undef or poison, in which case there is nothing to
// look up in the table.
ConstantFP *eltval = dyn_cast_or_null<ConstantFP>(
CV->getAggregateElement((unsigned)eltNo));
if (!eltval)
return false;
auto MatchingRow = llvm::find_if(tr, [eltval](const TableEntry &entry) {
return eltval->isExactlyValue(entry.input);
});
Expand Down
12 changes: 12 additions & 0 deletions llvm/test/CodeGen/AMDGPU/amdgpu-simplify-libcall-tdo-cos.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,18 @@ entry:
ret <2 x double> %c
}

; A lane that is not a ConstantFP has nothing to look up in the table.

@arsenm arsenm Aug 18, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Leave the comment, ignore the dumb bot

@aobolensk aobolensk Aug 18, 2026

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

ok, reverted

define <2 x float> @test_tdo_v2_f32_cos_poison_lane() {
; CHECK-LABEL: define <2 x float> @test_tdo_v2_f32_cos_poison_lane() {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[C:%.*]] = call <2 x float> @_Z3cosDv2_f(<2 x float> <float 0.000000e+00, float poison>)
; CHECK-NEXT: ret <2 x float> [[C]]
;
entry:
%c = call <2 x float> @_Z3cosDv2_f(<2 x float> <float 0.000000e+00, float poison>)
ret <2 x float> %c
}

declare float @_Z3cosf(float)
declare <2 x float> @_Z3cosDv2_f(<2 x float>)
declare half @_Z3cosDh(half)
Expand Down
Loading