[all-commits] [llvm/llvm-project] faa4c4: [RegAlloc] Fix use-after-free in `RegAllocBase::cl...

[Shilei Tian via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: faa4c4c2dc804c31845d8f036345fac00e016f2d
      https://github.com/llvm/llvm-project/commit/faa4c4c2dc804c31845d8f036345fac00e016f2d
  Author: Shilei Tian <i at tianshilei.me>
  Date:   2025-08-01 (Fri, 01 Aug 2025)

  Changed paths:
    M llvm/lib/CodeGen/RegAllocBase.cpp
    A llvm/test/CodeGen/AMDGPU/use-after-free-after-cleanup-failed-vreg.ll

  Log Message:
  -----------
  [RegAlloc] Fix use-after-free in `RegAllocBase::cleanupFailedVReg` (#151435)

#128400 introduced a use-after-free bug in
`RegAllocBase::cleanupFailedVReg` when removing intervals from regunits.
The issue is from the `InterferenceCache` in `RAGreedy`, which holds
`LiveRange*`. The current `InterferenceCache` APIs make it difficult to
update it, and there isn't a straightforward way to do that.

Since #128400 already mentions it's not clear about the necessity of
removing intervals from regunits, this PR avoids the issue by simply
skipping that step.

Fixes SWDEV-527146.



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