[clang] [Clang] Add float type support to __builtin_reduce_add and __builtin_reduce_multipy (PR #120367)

[Farzon Lotfi via cfe-commits]

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@@ -1754,6 +1755,17 @@ static bool interp__builtin_vector_reduce(InterpState &S, CodePtr OpPC,
   PrimType ElemT = *S.getContext().classify(ElemType);
   unsigned NumElems = Arg.getNumElems();
 
+  if (ElemType->isRealFloatingType()) {
+    if (ID != Builtin::BI__builtin_reduce_add &&
+        ID != Builtin::BI__builtin_reduce_mul)
+      llvm_unreachable("Only reduce_add and reduce_mul are supported for "
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farzonl wrote:

@llvm-beanz I don't understand how this code could be removed by the compiler. the Code after an unreachable is in a different block. The unreachable is gated by the builtin check.

https://github.com/llvm/llvm-project/pull/120367