Re: [PATCH v3 1/2] rs6000: Add support for _mm_minpos_epu16

[Segher Boessenkool <segher@kernel.crashing.org>]

Hi!

On Thu, Jul 15, 2021 at 06:29:17PM -0500, Paul A. Clarke wrote:
> Add a naive implementation of the subject x86 intrinsic to
> ease porting.

> --- a/gcc/config/rs6000/smmintrin.h
> +++ b/gcc/config/rs6000/smmintrin.h
> @@ -172,4 +172,31 @@ _mm_test_mix_ones_zeros (__m128i __A, __m128i __mask)
>    return any_ones * any_zeros;
>  }
>  
> +/* Return horizontal packed word minimum and its index in bits [15:0]
> +   and bits [18:16] respectively.  */
> +__inline __m128i
> +__attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
> +_mm_minpos_epu16 (__m128i __A)
> +{
> +  union __u
> +    {
> +      __m128i __m;
> +      __v8hu __uh;
> +    };
> +  union __u __u = { .__m = __A }, __r = { .__m = {0} };
> +  unsigned short __ridx = 0;
> +  unsigned short __rmin = __u.__uh[__ridx];
> +  for (unsigned long __i = 1; __i < 8; __i++)
> +    {
> +      if (__u.__uh[__i] < __rmin)
> +	{
> +	  __rmin = __u.__uh[__i];
> +	  __ridx = __i;
> +	}
> +    }
> +  __r.__uh[0] = __rmin;
> +  __r.__uh[1] = __ridx;
> +  return __r.__m;
> +}

As before: does this work correctly on BE?  Was it tested there?

Okay for trunk if so.  Thanks!


Segher