[all-commits] [llvm/llvm-project] db036e: [X86/Atomics] Correct a few transforms for new ato...

[Philip Reames via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: db036ee0a424374ae53e9ade2c1c4aa9424ef492
      https://github.com/llvm/llvm-project/commit/db036ee0a424374ae53e9ade2c1c4aa9424ef492
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2019-11-05 (Tue, 05 Nov 2019)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

  Log Message:
  -----------
  [X86/Atomics] Correct a few transforms for new atomic lowering

This is a partial fix for the issues described in commit message of 027aa27 (the revert of G24609).  Unfortunately, I can't provide test coverage for it on it's own as the only (known) wrong example is still wrong, but due to a separate issue.

These fixes are cases where when performing unrelated DAG combines, we were dropping the atomicity flags entirely.