[all-commits] [llvm/llvm-project] 82a515: [LV] Fixing versioning-for-unit-stide of loops wit...

[azaks via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 82a5157ff1650e3366f7a9c619269766ad1d5e93
      https://github.com/llvm/llvm-project/commit/82a5157ff1650e3366f7a9c619269766ad1d5e93
  Author: Ayal Zaks <ayal.zaks at intel.com>
  Date:   2020-07-12 (Sun, 12 Jul 2020)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/optsize.ll

  Log Message:
  -----------
  [LV] Fixing versioning-for-unit-stide of loops with small trip count

This patch fixes D81345 and PR46652.

If a loop with a small trip count is compiled w/o -Os/-Oz, Loop Access Analysis
still generates runtime checks for unit strides that will version the loop.

In such cases, the loop vectorizer should either re-run the analysis or bail-out
from vectorizing the loop, as done prior to D81345. The latter is applied for
now as the former requires refactoring.

Differential Revision: https://reviews.llvm.org/D83470