[all-commits] [llvm/llvm-project] b40fde: [InstCombine] fold fdiv with pow divisor (PR49147)

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b40fde062c306584d88243de11175187e754ce3b
      https://github.com/llvm/llvm-project/commit/b40fde062c306584d88243de11175187e754ce3b
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-02-14 (Sun, 14 Feb 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
    M llvm/test/Transforms/InstCombine/fdiv.ll

  Log Message:
  -----------
  [InstCombine] fold fdiv with pow divisor (PR49147)

This is unusual in the general (non-reciprocal) case because we need
an extra instruction, but that should be better for general FP
reassociation and codegen. We conservatively check for "arcp" FMF
here as we do with existing fdiv folds, but it is not strictly
necessary to have that.

This is part of solving:
https://llvm.org/PR49147
(The powi variant potentially has a different constraint.)

Differential Revision: https://reviews.llvm.org/D96648