[all-commits] [llvm/llvm-project] 997ecb: [LoopVectorize] Add FastMathFlags to the select us...

[david-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 997ecb0036a56df1fe77fafb69393255aa995de2
      https://github.com/llvm/llvm-project/commit/997ecb0036a56df1fe77fafb69393255aa995de2
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2022-06-07 (Tue, 07 Jun 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/ARM/mve-reduction-predselect.ll
    M llvm/test/Transforms/LoopVectorize/ARM/mve-reduction-types.ll
    M llvm/test/Transforms/LoopVectorize/reduction-predselect.ll

  Log Message:
  -----------
  [LoopVectorize] Add FastMathFlags to the select used for reductions with tail-folding

Based on reviewer comments on https://reviews.llvm.org/D126692 I've
added FastMathFlags to the select instruction used when tail-folding
with reductions. These flags can then be used by InstCombine to
decide upon the most optimal floating point identity value for
fadd/fsub. Doing so unlocks further optimisations, such as folding
selects into masked loads.

Differential Revision: https://reviews.llvm.org/D126778