[all-commits] [llvm/llvm-project] cb2cb2: [InstCombine] Avoid deleting volatile memcpys.

[Patrick Walton via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cb2cb2d201811d95d4f35337817faea05654d8f0
      https://github.com/llvm/llvm-project/commit/cb2cb2d201811d95d4f35337817faea05654d8f0
  Author: Patrick Walton <pcwalton at fb.com>
  Date:   2022-10-30 (Sun, 30 Oct 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
    M llvm/test/Transforms/InstCombine/memcpy-from-global.ll

  Log Message:
  -----------
  [InstCombine] Avoid deleting volatile memcpys.

InstCombine can replace memcpy to an alloca with a pointer directly to the
source in certain cases. Unfortunately, it also did so for volatile memcpys.
This patch makes it stop doing that.

This was discovered in D136822.

Differential Revision: https://reviews.llvm.org/D137031