[llvm] [InstCombine] Support DemandElts in SimplifyDemandedFPClass (PR #174176)

[Matt Arsenault via llvm-commits]

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@@ -211,6 +211,15 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
         Depth);
   }
 
+  KnownFPClass computeKnownFPClass(Value *Val, const APInt &DemandedElts,
+                                   FastMathFlags FMF,
+                                   FPClassTest Interested = fcAllFlags,
+                                   const Instruction *CtxI = nullptr,
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arsenm wrote:

Yes, ComputKnownFPClass does, but it would help if it looked more like SimplifyDemandedBits

https://github.com/llvm/llvm-project/pull/174176