[AMDGPU] Implement SelectVOP3OpSel
Open
backend:AMDGPU
missed-optimization
- Dominant language
- LLVM
- Stars
- 40.5k
- Forks
- 18.7k
- PR merge metrics
- PR metrics pending
Description
AMDGPUDAGToDAGISel::SelectVOP3OpSel currently just says "FIXME: Handle op_sel". The effect of this is that non-packed 16-bit instructions like v_fma_f16 do not make use of op_sel to access the high half of a VGPR source. See test cases added by #219432.
Contributor guide
Research direction
Start at AMDGPUDAGToDAGISel::SelectVOP3OpSel and inspect the FIXME about handling op_sel. Review the test cases added by #219432 to understand the expected behavior for non-packed 16-bit instructions such as v_fma_f16. Done means those instructions can use op_sel to access the high half of a VGPR source and the relevant tests pass.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Active
- Clarity
- Mostly clear
- Newbie friendliness
- 68/100