[clang] [HLSL] Implement the dst HLSL Function (PR #133828)

[via cfe-commits]

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@@ -35,6 +35,12 @@ length_vec_impl(vector<T, N> X) {
 #endif
 }
 
+template <typename T>
+constexpr vector<T, 4> dst_impl(vector<T, 4> Src0, vector<T, 4> Src1) {
+  vector<T, 4> Dest = {1, Src0[1] * Src1[1], Src0[2], Src1[3]};
+  return Dest;
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metkarpoonam wrote:

Thank you for the suggestion. This change eliminates one store and one load instruction, and also removes the need for an additional variable, resulting in more efficient code.

https://github.com/llvm/llvm-project/pull/133828