[llvm] [InstSimplify] fold uno/ord comparison if fpclass is always NaN (PR #97763)

[Yingwei Zheng via llvm-commits]

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@@ -4117,9 +4117,14 @@ static Value *simplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
   // This catches the 2 variable input case, constants are handled below as a
   // class-like compare.
   if (Pred == FCmpInst::FCMP_ORD || Pred == FCmpInst::FCMP_UNO) {
-    if (FMF.noNaNs() || (isKnownNeverNaN(RHS, /*Depth=*/0, Q) &&
-                         isKnownNeverNaN(LHS, /*Depth=*/0, Q)))
+    KnownFPClass RHSClass = computeKnownFPClass(RHS, fcAllFlags, 0, Q);
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dtcxzyw wrote:

```suggestion
    KnownFPClass RHSClass = computeKnownFPClass(RHS, fcAllFlags, /*Depth=*/0, Q);
```

https://github.com/llvm/llvm-project/pull/97763