[PATCH] D142166: [X86] Make `shouldExpandLogicAtomicRMWInIR` able to match both operands.

Fri Jan 20 10:55:05 PST 2023

goldstein.w.n added inline comments.

================
Comment at: llvm/test/CodeGen/X86/atomic-rm-bit-test-64.ll:1474
   %0 = atomicrmw xor ptr %v, i64 16 monotonic, align 8
-  %and = and i64 %0, 16
+  %and = and i64 16, %0
   %tobool.not = icmp eq i64 %and, 0
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RKSimon wrote:
> I'd expect DAG canonicalization to commute this in DAGCombiner::visitAND?
> I'd expect DAG canonicalization to commute this in DAGCombiner::visitAND?

The version that had assertions for canonical constant/non-constant operands did hit them so I expect there is some sequence where we go to `shouldExpandLogicAtomicRMWInIR` before canonicalization.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142166/new/

https://reviews.llvm.org/D142166