[all-commits] [llvm/llvm-project] 1a9358: [LV] Relax over-strict assertion for reduction exi...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1a9358c090d0507be21c5e9b2d97a23ef1de8ab0
      https://github.com/llvm/llvm-project/commit/1a9358c090d0507be21c5e9b2d97a23ef1de8ab0
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2023-09-21 (Thu, 21 Sep 2023)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/select-reduction.ll

  Log Message:
  -----------
  [LV] Relax over-strict assertion for reduction exit value selects.

After f108c6c, (mul x, 1) is simplified to x, which can cause the select
for the final reduction value when tail-folding to use the reduction
value for both options. Relax the assertion to make sure this case is
allowed.

Note that the reduction is now redundant itself and could be further
simplified.

Fixes #66895.