[all-commits] [llvm/llvm-project] 43db79: [MSSAUpdater] Handle simplified accesses when upda...

[Nikita Popov via All-commits]

  Branch: refs/heads/release/18.x
  Home:   https://github.com/llvm/llvm-project
  Commit: 43db795259d91ddb3b12596e8aec3dddbd1fb583
      https://github.com/llvm/llvm-project/commit/43db795259d91ddb3b12596e8aec3dddbd1fb583
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2024-02-05 (Mon, 05 Feb 2024)

  Changed paths:
    M llvm/lib/Analysis/MemorySSAUpdater.cpp
    M llvm/test/Transforms/SimpleLoopUnswitch/memssa-readnone-access.ll

  Log Message:
  -----------
  [MSSAUpdater] Handle simplified accesses when updating phis (#78272)

This is a followup to #76819. After those changes, we can still run into
an assertion failure for a slight variation of the test case: When
fixing up MemoryPhis, we map the incoming access to the access of the
cloned instruction -- which may now no longer exist.

Fix this by reusing the getNewDefiningAccessForClone() helper, which
will look upwards for a new defining access in that case.

(cherry picked from commit a7a1b8b17e264fb0f2d2b4165cf9a7f5094b08b3)