[PATCH] D136675: [MachineCSE] Allow PRE of instructions that read physical registers

[Martin Storsjö via Phabricator via llvm-commits]

mstorsjo added a comment.

Headsup, this caused miscompilations on arm for me.

To reproduce the issue, you can e.g. do this:

  git clone git://git.videolan.org/ffmpeg.git
  cd ffmpeg
  ./configure --arch=armv7 --cc="clang -target armv7-linux-gnueabihf .." --samples=$(pwd)/../samples
  make fate-rsync
  make -j$(nproc) fate-oma-demux

One preprocessed source file that differs in behaviour after this commit is this: https://martin.st/temp/id3v2-preproc.c Compiled with `clang -target armv7-linux-gnueabihf id3v2-preproc.c -c -o libavformat/id3v2.o -O2`.

Ok to revert until the issue has been resolved?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136675/new/

https://reviews.llvm.org/D136675