[all-commits] [llvm/llvm-project] 5a229a: [LoopVectorize] Don't create unnecessary vscale in...

[david-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5a229a6702e2e810c4f8ed29eb3b5af01afff2c7
      https://github.com/llvm/llvm-project/commit/5a229a6702e2e810c4f8ed29eb3b5af01afff2c7
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2021-04-22 (Thu, 22 Apr 2021)

  Changed paths:
    M llvm/lib/IR/IRBuilder.cpp
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/unittests/IR/IRBuilderTest.cpp

  Log Message:
  -----------
  [LoopVectorize] Don't create unnecessary vscale intrinsic calls

In quite a few cases in LoopVectorize.cpp we call createStepForVF
with a step value of 0, which leads to unnecessary generation of
llvm.vscale intrinsic calls. I've optimised IRBuilder::CreateVScale
and createStepForVF to return 0 when attempting to multiply
vscale by 0.

Differential Revision: https://reviews.llvm.org/D100763