[llvm] Revert "Avoid maxnum(sNaN, x) optimizations / folds (#170181)" (PR #184125)

[Phoebe Wang via llvm-commits]

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@@ -6744,27 +6743,29 @@ static MinMaxOptResult OptimizeConstMinMax(const Constant *RHSConst,
 
   // minnum(x, qnan) -> x
   // maxnum(x, qnan) -> x
+  // minnum(x, snan) -> qnan
+  // maxnum(x, snan) -> qnan
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phoebewang wrote:

Why don't simplify to x? Seems contradiction with rule in line 6761.

https://github.com/llvm/llvm-project/pull/184125