[all-commits] [llvm/llvm-project] 9c49dc: [ConstantFold] Don't fold and/or i1 poison to pois...

[Juneyoung Lee via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 9c49dcc356eb4c59fc1353bbbaae6d3a56a656c1
      https://github.com/llvm/llvm-project/commit/9c49dcc356eb4c59fc1353bbbaae6d3a56a656c1
  Author: Juneyoung Lee <aqjune at gmail.com>
  Date:   2020-11-30 (Mon, 30 Nov 2020)

  Changed paths:
    M llvm/lib/IR/ConstantFold.cpp
    M llvm/test/Transforms/InstSimplify/ConstProp/poison.ll

  Log Message:
  -----------
  [ConstantFold] Don't fold and/or i1 poison to poison (NFC)

.. because it causes miscompilation when combined with select i1 -> and/or.

It is the select fold which is incorrect; but it is costly to disable the fold, so hack this one.

D92270