[PATCH] D57854: [InstCombine] Optimize `atomicrmw <op>, 0` into `load atomic` when possible

[JF Bastien via Phabricator via llvm-commits]

jfb accepted this revision.
jfb added a subscriber: reames.
jfb added a comment.
This revision is now accepted and ready to land.

One fix then this LGTM



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Comment at: lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp:39
+           Ordering != AtomicOrdering::Unordered &&
+           "AtomicRMWs don't make sense with Unordered or NotAtomic");
+    if (Ordering != AtomicOrdering::Acquire &&
----------------
Agreed NotAtomic is bonkers (`AtomicRMWInst::Init` disallows it), but Unordered might be sensible, @reames would know.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D57854/new/

https://reviews.llvm.org/D57854