[clang] [clang] Restrict use of scalar types in vector builtins (PR #119423)

[Eli Friedman via cfe-commits]

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@@ -14585,11 +14585,18 @@ void Sema::CheckAddressOfPackedMember(Expr *rhs) {
                      _2, _3, _4));
 }
 
+static ExprResult UsualUnaryConversionsNoPromoteInt(Sema &S, Expr *E) {
+  // Don't promote integer types
+  if (QualType Ty = E->getType(); S.getASTContext().isPromotableIntegerType(Ty))
+    return S.DefaultFunctionArrayLvalueConversion(E);
+  return S.UsualUnaryConversions(E);
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efriedma-quic wrote:

It's a little weird that the resulting type can be larger than what integer promotion would produce (without this patch, `struct S { long l : 4; }; S s; static_assert(sizeof(__builtin_elementwise_abs(s.l)) == 4);`).  But maybe that's fine.

https://github.com/llvm/llvm-project/pull/119423