[PATCH] D105216: [ScalarEvolution] Fix overflow in computeBECount.

[Martin Storsjö via Phabricator via llvm-commits]

mstorsjo added a comment.

The case I'm observing is within this translation unit: https://martin.st/temp/gsmdec-preproc.c

There's some difference visible in the assembly generated by `clang -target aarch64-linux-gnu -c -O3 gsmdec-preproc.c`, I haven't exactly pinpointed what part of it is that breaks.

If you have access to aarch64 linux, the issue can be reproduced at runtime with these commands:

  git clone git://source.ffmpeg.org/ffmpeg
  cd ffmpeg
  ./configure --cc=clang --samples=/path/to/empty/dir
  make fate-rsync # sync data samples for running tests, into the path specified above
  make -j$(nproc) fate-g723_1-dec-1

The error in this case is in `libavformat/gsmdec.o`. There's also a couple other miscompilations in there, visible in `make fate-sub-vplayer` and `make fate-wmavoice-7k`, but I haven't pinpointed which translation unit those errors stem from.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D105216/new/

https://reviews.llvm.org/D105216