[llvm] [InstSimplify] Add constant folding support for `ucmp`/`scmp` intrinsics (PR #93730)

[Nikita Popov via llvm-commits]

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@@ -2764,6 +2766,33 @@ static Constant *ConstantFoldIntrinsicCall2(Intrinsic::ID IntrinsicID, Type *Ty,
                   ? *C0
                   : *C1);
 
+    case Intrinsic::scmp:
+    case Intrinsic::ucmp:
+      if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
+        return PoisonValue::get(Ty);
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nikic wrote:

Missing test coverage for the poison cases.

https://github.com/llvm/llvm-project/pull/93730