[llvm] [InstCombine] Canonicalize `icmp eq/ne (A ^ C), B` to `icmp eq/ne (A ^ B), C` (PR #67273)

[via llvm-commits]

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@@ -5437,6 +5437,15 @@ Instruction *InstCombinerImpl::foldICmpEquality(ICmpInst &I) {
         Pred, A,
         Builder.CreateIntrinsic(Op0->getType(), Intrinsic::fshl, {A, A, B}));
 
+  // Canonicalize:
+  // icmp eq/ne OneUse(A ^ Cst), B --> icmp eq/ne (A ^ B), Cst
+  Constant *Cst;
+  if (match(&I,
+            m_c_ICmp(PredUnused, m_OneUse(m_Xor(m_Value(A), m_Constant(Cst))),
+                     m_Value(B))))
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goldsteinn wrote:

Probably immconstant here.

https://github.com/llvm/llvm-project/pull/67273