[llvm] [WebAssembly] Lower fmuladd to madd and nmadd (PR #161355)

[Matt Arsenault via llvm-commits]

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@@ -514,6 +514,9 @@ enum NodeType {
   /// separately rounded operations.
   FMAD,
 
+  /// FMULADD - Performs a * b + c, with, or without, intermediate rounding.
+  FMULADD,
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arsenm wrote:

Can you add comment here explaining the use case here? Unless the underlying target directly has an fmuladd, nothing else should be using it and continue creating fma or the split sequence based on target preference 

https://github.com/llvm/llvm-project/pull/161355