Skip to content

Execution Tests: Prevent sinking in long vector derivative hlk #8054

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
alsepkow merged 2 commits into from
Jan 13, 2026
+4 −0
Merged

Execution Tests: Prevent sinking in long vector derivative hlk #8054

Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1673678
Prevent sinking in derivative hlk
alsepkow Jan 12, 2026
f800e6c
Use the return value of WaveReadLaneAt
alsepkow Jan 13, 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
4 changes: 4 additions & 0 deletions tools/clang/unittests/HLSLExec/ShaderOpArith.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4475,6 +4475,10 @@ void MSMain(uint GID : SV_GroupIndex,

vector<OUT_TYPE, NUM> Result = DERIVATIVE_FUNC(Vector);

// Prevents the above derivative call from being sunk into the if
// condition below. DXC Bug: https://github.com/microsoft/DirectXShaderCompiler/issues/8001
WaveReadLaneAt(Result, 3);

// For coarse derivatives, all lanes in the quad get the same result.
// But for fine derivatives, each lane gets a different result. To
// keep things generic we only store in the third lane as thats the
Expand Down