[all-commits] [llvm/llvm-project] 839abd: [MachineLICM] Fix incorrect CSE on hoisted const l...

[Igor Kirillov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 839abdb0d293a87a8bf9a298c9d5c29845fd59b2
      https://github.com/llvm/llvm-project/commit/839abdb0d293a87a8bf9a298c9d5c29845fd59b2
  Author: Igor Kirillov <igor.kirillov at arm.com>
  Date:   2023-11-27 (Mon, 27 Nov 2023)

  Changed paths:
    M llvm/lib/CodeGen/MachineLICM.cpp
    M llvm/test/CodeGen/AArch64/machine-licm-hoist-load.ll

  Log Message:
  -----------
  [MachineLICM] Fix incorrect CSE on hoisted const load (#73007)

When hoisting an invariant load, we should not combine it with an
existing load through common subexpression elimination (CSE). This is
because there might be memory-changing instructions between the existing
load and the end of the block entering the loop.

Fixes https://github.com/llvm/llvm-project/issues/72855