[clang] [Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow MMX/SSE/AVX2 PSIGN intrinsics to be used in constexpr (PR #163685)

[Simon Pilgrim via cfe-commits]

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@@ -720,11 +717,10 @@ _mm_sign_epi32(__m128i __a, __m128i __b)
 ///    A 64-bit integer vector containing control bytes corresponding to
 ///    positions in the destination.
 /// \returns A 64-bit integer vector containing the resultant values.
-static __inline__ __m64 __DEFAULT_FN_ATTRS
-_mm_sign_pi8(__m64 __a, __m64 __b)
-{
-    return __trunc64(__builtin_ia32_psignb128((__v16qi)__anyext128(__a),
-                                              (__v16qi)__anyext128(__b)));
+static __inline__ __m64 __DEFAULT_FN_ATTRS_CONSTEXPR _mm_sign_pi8(__m64 __a,
+                                                                  __m64 __b) {
+  return __trunc64(__builtin_ia32_psignb128((__v16qi)__anyext128(__a),
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RKSimon wrote:

You will need to replace __anyext128 with __zext128 for the MMX variants of PSIGN

https://github.com/llvm/llvm-project/pull/163685