[clang] [Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - add MMX/SSE/AVX/AVX512 PMULHRSW intrinsics to be used in constexpr (PR #160636)

[Simon Pilgrim via cfe-commits]

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@@ -1351,7 +1354,7 @@ let Features = "avx512bitalg", Attributes = [NoThrow, Const, RequiredVectorWidth
   def vpshufbitqmb512_mask : X86Builtin<"unsigned long long int(_Vector<64, char>, _Vector<64, char>, unsigned long long int)">;
 }
 
-let Features = "avx512bw", Attributes = [NoThrow, Const, RequiredVectorWidth<512>] in {
+let Features = "avx512bw", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<512>] in {
   def pmulhrsw512 : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Vector<32, short>)">;
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RKSimon wrote:

move this with pmulhuw512 etc. below instead of creating a new block?

https://github.com/llvm/llvm-project/pull/160636