[llvm] [CmpInstAnalysis] Decompose icmp eq (and x, C) C2 (PR #136367)

[Yingwei Zheng via llvm-commits]

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@@ -97,9 +99,10 @@ llvm::decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate Pred,
   }
 
   DecomposedBitTest Result;
+
   switch (Pred) {
   default:
-    llvm_unreachable("Unexpected predicate");
+    return std::nullopt;
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dtcxzyw wrote:

It is still unreachable.

https://github.com/llvm/llvm-project/pull/136367