[all-commits] [llvm/llvm-project] 47d10b: [instcombine] PRE freeze to only potentially posio...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 47d10b25f82d4df3a6953a12bbdea66ec1b5eaa4
      https://github.com/llvm/llvm-project/commit/47d10b25f82d4df3a6953a12bbdea66ec1b5eaa4
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2021-10-13 (Wed, 13 Oct 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
    M llvm/test/Transforms/InstCombine/freeze.ll

  Log Message:
  -----------
  [instcombine] PRE freeze to only potentially posion/undef operand of phi

This extends the foldOpIntoPhi code used when visiting a freeze user of a phi to allow any non-undef/poison operand as opposed to only non-undef/poison constants.  This lets us hoist a freeze in the increment of an IV into the preheader in many cases.

Differential Revision: https://reviews.llvm.org/D111744