[all-commits] [llvm/llvm-project] 47215e: [LV] Fix crash when target instruction for sinking...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 47215e1c6250298aa9db59b3b06f832fcd23be01
      https://github.com/llvm/llvm-project/commit/47215e1c6250298aa9db59b3b06f832fcd23be01
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2021-06-29 (Tue, 29 Jun 2021)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll

  Log Message:
  -----------
  [LV] Fix crash when target instruction for sinking is dead.

This patch fixes a crash when the target instruction for sinking is
dead. In that case, no recipe is created and trying to get the recipe
for it results in a crash. To ensure all sink targets are alive, find &
use the first previous alive instruction.

Note that the case where the sink source is dead is already handled.

Found by
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35320

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D104603