commit 5c802fd2ca4f5fcf920c93a9786e802a0054ab72
author Philip Reames <listmail@philipreames.com> Fri Feb 15 21:23:51 2019 +0000
committer Philip Reames <listmail@philipreames.com> Fri Feb 15 21:23:51 2019 +0000
tree 324a190152438692333cd304a98e0a61d39524db
parent 92fd2811692730d1d60466be26c949fd42e2bb74

[InstCombine] Convert atomicrmws to xchg or store where legal

Implement two more transforms of atomicrmw:
1) We can convert an atomicrmw which produces a known value in memory into an xchg instead.
2) We can convert an atomicrmw xchg w/o users into a store for some orderings.

Differential Revision: https://reviews.llvm.org/D58290



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354170 91177308-0d34-0410-b5e6-96231b3b80d8