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

[Phoebe Wang via cfe-commits]

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@@ -2539,9 +2536,8 @@ static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_sub_epi32(__m128i __a,
 ///    A 64-bit integer vector containing the subtrahend.
 /// \returns A 64-bit integer vector containing the difference of the values in
 ///    the operands.
-static __inline__ __m64 __DEFAULT_FN_ATTRS_MMX _mm_sub_si64(__m64 __a,
-                                                            __m64 __b) {
-  return (__m64)__builtin_ia32_psubq((__v1di)__a, (__v1di)__b);
+static __inline__ __m64 __DEFAULT_FN_ATTRS _mm_sub_si64(__m64 __a, __m64 __b) {
+  return (__m64)((unsigned long long)__a - (unsigned long long)__b);
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phoebewang wrote:

ditto.

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