FailedChanges

Summary

  1. [AMDGPU] Remove unnecessary v_mov from a register to itself in WQM (details)
Commit 4a32cd11acd7c38f5e0b587d724935ab7a9938a6 by mjbedy
[AMDGPU] Remove unnecessary v_mov from a register to itself in WQM
lowering.
Summary:
- SI Whole Quad Mode phase is replacing WQM pseudo instructions with
v_mov instructions. While this is necessary for the special handling of
moving results out of WWM live ranges, it is not necessary for WQM live
ranges. The result is a v_mov from a register to itself after every WQM
operation. This change uses a COPY psuedo in these cases, which allows
the register allocator to coalesce the moves away.
Reviewers: tpr, dstuttard, foad, nhaehnle
Reviewed By: nhaehnle
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl,
dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71386
The file was modifiedllvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
The file was modifiedllvm/test/CodeGen/AMDGPU/wqm.mir
The file was modifiedllvm/test/CodeGen/AMDGPU/wqm.ll