tree 0cc0132f5fc59bf232631002b86ca9a9ea9456d8
parent d6a3b5786ad5c454c79079e1e184a27b684a22c3
author Philip Reames <listmail@philipreames.com> 1550169554 +0000
committer Philip Reames <listmail@philipreames.com> 1550169554 +0000

Teach instcombine about remaining "idempotent" atomicrmw types

Expand on Quentin's r353471 patch which converts some atomicrmws into loads. Handle remaining operation types, and fix a slight bug. Atomic loads are required to have alignment. Since this was within the InstCombine fixed point, somewhere else in InstCombine was adding alignment before the verifier saw it, but still, we should fix.

Terminology wise, I'm using the "idempotent" naming that is used for the same operations in AtomicExpand and X86ISelLoweringInfo. Once this lands, I'll add similar tests for AtomicExpand, and move the pattern match function to a common location. In the review, there was seemingly consensus that "idempotent" was slightly incorrect for this context.  Once we setle on a better name, I'll update all uses at once.

Differential Revision: https://reviews.llvm.org/D58242


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354046 91177308-0d34-0410-b5e6-96231b3b80d8