[AMDGPU] Fix a miscompile with S_ADD/S_SUB
The helper function isBoolSGPR is too aggressive when determining
when a v_cndmask can be skipped on a boolean value because the
function does not check the operands of and/or/xor.
This can be problematic for the Add/Sub combines that can leave
bits set even for inactive lanes leading to wrong results.
Fix this by inspecting the operands of and/or/xor recursively.
Differential Revision: https://reviews.llvm.org/D86878
GitOrigin-RevId: 08131c7439336e84b9df3e37b3aaeb76b8f60702
2 files changed
