[llvm] [InstCombine] Fold select of ordered fcmps of fabs over `isKnownNeverNaN`-selects to a single select (PR #192182)

[via llvm-commits]

================
@@ -3347,6 +3347,106 @@ static Instruction *foldSelectWithFCmpToFabs(SelectInst &SI,
   return ChangedFMF ? &SI : nullptr;
 }
 
+static bool matchIsNaNTest(FCmpInst *Cmp, Value *X, bool MatchIsNaN,
+                           InstCombinerImpl &IC) {
+  FCmpInst::Predicate ExpectedPred =
----------------
imkiva wrote:

Good point. I dropped the `uno` handling and now only match the canonical `isnotnan(X) ? X : Y` form.

https://github.com/llvm/llvm-project/pull/192182