[all-commits] [llvm/llvm-project] e5f4f3: [JumpThreading] Freeze undef/poison select conditi...

[Justin Lebar via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e5f4f31b3508dd06598051039268c27498472218
      https://github.com/llvm/llvm-project/commit/e5f4f31b3508dd06598051039268c27498472218
  Author: Justin Lebar <justin.lebar at gmail.com>
  Date:   2026-05-26 (Tue, 26 May 2026)

  Changed paths:
    M llvm/lib/Transforms/Scalar/JumpThreading.cpp
    M llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
    M llvm/test/Transforms/JumpThreading/select.ll
    M llvm/test/Transforms/JumpThreading/stale-loop-info-after-unfold-select.ll

  Log Message:
  -----------
  [JumpThreading] Freeze undef/poison select condition in unfoldSelectInstr (#199408)

When unfoldSelectInstr rewrites a select as a conditional branch, it
used SI->getCondition() directly, without freezing it first. A select
with an undef or poison condition does not immediately cause UB,
but branching on undef or poison does, so we need to freeze it.

This bug was found by a large run of Opus 4.7 looking for bugs in LLVM.



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