Re: [PATCH][x86] Match movss and movsd "blend" instructions

[Marc Glisse <marc dot glisse at inria dot fr>]

On Wed, 1 Aug 2018, Allan Sandfeld Jensen wrote:

>  extern __inline __m128d __attribute__((__gnu_inline__, __always_inline__, 
> __artificial__))
>  _mm_move_sd (__m128d __A, __m128d __B)
>  {
> -  return (__m128d) __builtin_ia32_movsd ((__v2df)__A, (__v2df)__B);
> +  return __extension__ (__m128d)(__v2df){__B[0],__A[1]};
>  }

If the goal is to have it represented as a VEC_PERM_EXPR internally, I 
wonder if we should be explicit and use __builtin_shuffle instead of 
relying on some forwprop pass to transform it. Maybe not, just asking. And 
the answer need not even be the same for _mm_move_sd and _mm_move_ss.

--
Marc Glisse