[all-commits] [llvm/llvm-project] a8e7be: RegisterCoalescer: Fix assert on remat to copy-to-...

[Matt Arsenault via All-commits]

  Branch: refs/heads/users/arsenm/issue120970/fix-assert-clobber-rematerialize-super-reg-def-at-subreg-extract
  Home:   https://github.com/llvm/llvm-project
  Commit: a8e7be5726bee76d95dae9e550c1ae4bd7f9da6d
      https://github.com/llvm/llvm-project/commit/a8e7be5726bee76d95dae9e550c1ae4bd7f9da6d
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2025-01-07 (Tue, 07 Jan 2025)

  Changed paths:
    M llvm/lib/CodeGen/RegisterCoalescer.cpp
    A llvm/test/CodeGen/AMDGPU/remat-physreg-copy-subreg-extract-already-live-at-def-issue120970.mir

  Log Message:
  -----------
  RegisterCoalescer: Fix assert on remat to copy-to-physreg with subregs

Do not try to rematerialize a super-register def used by a subregister
extract copy into a copy to a physical register if the other pieces of the
full physreg are live at the rematerialization point. It would insert the
super-register def at the rematerialization point, and assert since the
other half of the register was already live.

This is analagous to the undef subregister def handling above,
which handled the virtual register case.

Fixes #120970


  Commit: 9cef81d6c8a8f946d77b089ce0def7f913725bf1
      https://github.com/llvm/llvm-project/commit/9cef81d6c8a8f946d77b089ce0def7f913725bf1
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2025-01-07 (Tue, 07 Jan 2025)

  Changed paths:
    M llvm/lib/CodeGen/RegisterCoalescer.cpp

  Log Message:
  -----------
  Adjust comment


Compare: https://github.com/llvm/llvm-project/compare/fc0b6a774ac3...9cef81d6c8a8

To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications