[all-commits] [llvm/llvm-project] f91b6a: PowerPC: Fix VSX swap removal crash on an undef re...

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f91b6a0319fd900cb6e665fc8f8dcc5c1a801e4c
      https://github.com/llvm/llvm-project/commit/f91b6a0319fd900cb6e665fc8f8dcc5c1a801e4c
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2026-09-08 (Tue, 08 Sep 2026)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
    A llvm/test/CodeGen/PowerPC/vsx-swap-removal-undef.mir

  Log Message:
  -----------
  PowerPC: Fix VSX swap removal crash on an undef register (#216714)

formWebs walks each vector-register use and unions its equivalence class
with that of its defining instruction, which it requires to be present
in the swap map. A use of an undef register has no defining instruction, so
the web formation crashed. Treat it like a physical-register mention so the
web is conservatively rejected.

Found by AI while working on something else.

Co-authored-by: Claude (Opus 4.8) <noreply at anthropic.com>



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