[clang] [X86][RFC] Refactor the SSE intrinsics constexpr tests to simplify future expansion (PR #112578)

[Simon Pilgrim via cfe-commits]

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@@ -6,13 +6,23 @@
 
 #include <immintrin.h>
 
+#if defined(__cplusplus) && (__cplusplus >= 201103L)
+constexpr bool match_m128(__m128 v, float x, float y, float z, float w) {
+  return v[0] == x && v[1] == y && v[2] == z && v[3] == w;
+}
+#define TEST_CONSTEXPR(...) static_assert(__VA_ARGS__)
+#else
+#define TEST_CONSTEXPR(...)
+#endif
+
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RKSimon wrote:

Yes I think we should - I'm going to wait until I've found any more design issues but will move it into a common header soon.

https://github.com/llvm/llvm-project/pull/112578