[clang] [llvm] Clang: convert `__m64` intrinsics to unconditionally use SSE2 instead of MMX. (PR #96540)

[Phoebe Wang via cfe-commits]

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@@ -811,10 +843,11 @@ _mm_slli_pi32(__m64 __m, int __count)
 ///    A 64-bit integer vector interpreted as a single 64-bit integer.
 /// \returns A 64-bit integer vector containing the left-shifted value. If
 ///     \a __count is greater or equal to 64, the result is set to 0.
-static __inline__ __m64 __DEFAULT_FN_ATTRS
+static __inline__ __m64 __DEFAULT_FN_ATTRS_SSE2
 _mm_sll_si64(__m64 __m, __m64 __count)
 {
-    return (__m64)__builtin_ia32_psllq((__v1di)__m, __count);
+    return __trunc64(__builtin_ia32_psllq128((__v2di)__anyext128(__m),
+                                             __anyext128(__count)));
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phoebewang wrote:

Missing `(__v2di)`?

https://github.com/llvm/llvm-project/pull/96540