[clang] [Clang] Add `__builtin_[ordered_]reduce_fadd` for ordered/unordered fp reductions (PR #176160)

[Sander de Smalen via cfe-commits]

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@@ -3628,6 +3630,44 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
     break;
   }
 
+  case Builtin::BI__builtin_reduce_addf:
+  case Builtin::BI__builtin_ordered_reduce_addf: {
+    if (checkArgCountRange(TheCall, 1, 2))
+      return ExprError();
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sdesmalen-arm wrote:

nit: I guess this needs to be `1` for `reduce_addf`, and `2` for `ordered_reduce_addf`?

https://github.com/llvm/llvm-project/pull/176160