[clang] [X86] Allow PSHUFD/PSHUFLW/PSHUFW intrinsics in constexpr. (PR #161210)

[Simon Pilgrim via cfe-commits]

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@@ -2016,21 +2024,35 @@ let Features = "avx512f",
 
 let Features = "avx512bw", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<512>] in {
   def psrlv32hi : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Vector<32, short>)">;
+  def pshuflw512_mask  : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Constant int, _Vector<32, short>, unsigned int)">;
+  def pshuflw512_maskz : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Constant int, unsigned int)">;
+  def pshufhw512_mask  : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Constant int, _Vector<32, short>, unsigned int)">;
+  def pshufhw512_maskz : X86Builtin<"_Vector<32, short>(_Vector<32, short>, _Constant int, unsigned int)">;
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RKSimon wrote:

why did you add these?

https://github.com/llvm/llvm-project/pull/161210