[clang] [X86] Add MMX/SSE/AVX PHADD/SUB & HADDPS/D intrinsics to be used in constexpr (PR #156822)

[via cfe-commits]

================
@@ -110,19 +110,21 @@ let Attributes = [Const, NoThrow, RequiredVectorWidth<128>] in {
   }
 
   let Features = "sse3" in {
-    foreach Op = ["addsub", "hadd", "hsub"] in {
+    foreach Op = ["addsub"] in {
       def Op#ps : X86Builtin<"_Vector<4, float>(_Vector<4, float>, _Vector<4, float>)">;
       def Op#pd : X86Builtin<"_Vector<2, double>(_Vector<2, double>, _Vector<2, double>)">;
     }
   }
 
-  let Features = "ssse3" in {
-    foreach Op = ["phadd", "phsub"] in {
-      def Op#w128 : X86Builtin<"_Vector<8, short>(_Vector<8, short>, _Vector<8, short>)">;
-      def Op#sw128 : X86Builtin<"_Vector<8, short>(_Vector<8, short>, _Vector<8, short>)">;
-      def Op#d128 : X86Builtin<"_Vector<4, int>(_Vector<4, int>, _Vector<4, int>)">;
+  let Features = "sse3", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<128>] in {
+    foreach Op = ["hadd", "hsub"] in {
+      def Op#ps : X86Builtin<"_Vector<4, float>(_Vector<4, float>, _Vector<4, float>)">;
+      def Op#pd : X86Builtin<"_Vector<2, double>(_Vector<2, double>, _Vector<2, double>)">;
     }
+  }
 
+  let Features = "ssse3" in {
+    def pmaddubsw128 : X86Builtin<"_Vector<8, short>(_Vector<16, char>, _Vector<16, char>)">;
----------------
whytolearn wrote:

yes, my merge error 

https://github.com/llvm/llvm-project/pull/156822