[clang] [clang][FMV] Do not omit explicit default target_version attribute. (PR #96628)

[Alexandros Lamprineas via cfe-commits]

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@@ -11465,6 +11465,10 @@ static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD) {
   // otherwise it is treated as a normal function.
   if (TA && !TA->isDefaultVersion())
     return false;
+  // The target_version attribute only causes Multiversioning if this
+  // declaration is NOT the default version.
+  if (TVA && TVA->isDefaultVersion())
+    return false;
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labrinea wrote:

Hmm, we can't write it this way I am affraid because the function used both for target and target_version attributes. If TA is not null and TVA is null we are early exiting while we shouldn't.

https://github.com/llvm/llvm-project/pull/96628