[all-commits] [llvm/llvm-project] 026fc9: [AMDGPU] Handle Additional Cases in tryFoldPhiAGPR

[Pierre van Houtryve via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 026fc9e9c41db6f20df275e7e405cadfecb1b6e6
      https://github.com/llvm/llvm-project/commit/026fc9e9c41db6f20df275e7e405cadfecb1b6e6
  Author: pvanhout <pierre.vanhoutryve at amd.com>
  Date:   2023-06-29 (Thu, 29 Jun 2023)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
    M llvm/test/CodeGen/AMDGPU/fold-agpr-phis.mir

  Log Message:
  -----------
  [AMDGPU] Handle Additional Cases in tryFoldPhiAGPR

 Sometimes PHI have different incoming values, such as:
 ```
%1:vgpr_256 = COPY %0:agpr_256
%2:vgpr_32 = COPY %1:vgpr_256.sub0
```

Those weren't handled, which could lead to massive performance issues if break-large-PHIs kicked in + AGPRs were used (MFMA)

Fixes SWDEV-407986

Reviewed By: #amdgpu, arsenm

Differential Revision: https://reviews.llvm.org/D153879