[PATCH, rs6000] Fix _mm_extract_pi16 for big-endian

[Segher Boessenkool]

On Thu, Oct 25, 2018 at 01:41:15PM -0500, Paul Clarke wrote:
> For compatibility implementation of x86 vector intrinsic, _mm_extract_pi16,
> adjust shift value for big-endian mode.
> 
> Bootstrapped and tested on Linux POWER8 LE, POWER8 BE (64 & 32), and POWER7.

Does it fix existing testcases?

Okay for trunk in either case.  Thanks!  Also fine to backport to 8.


Segher


> 2018-10-25  Paul A. Clarke  <pc@us.ibm.com>
> 
> 	* config/rs6000/xmmintrin.h: Fix _mm_extract_pi16 for big-endian.
> 
> diff --git a/trunk/gcc/config/rs6000/xmmintrin.h b/trunk/gcc/config/rs6000/xmmintrin.h
> --- a/trunk/gcc/config/rs6000/xmmintrin.h	(revision 265238)
> +++ b/trunk/gcc/config/rs6000/xmmintrin.h	(working copy)
> @@ -1386,9 +1385,12 @@
>  extern __inline int __attribute__((__gnu_inline__, __always_inline__, __artificial__))
>  _mm_extract_pi16 (__m64 const __A, int const __N)
>  {
> -  const int shiftr = (__N & 3) * 16;
> +  unsigned int shiftr = __N & 3;
> +#ifdef __BIG_ENDIAN__
> +  shiftr = 3 - shiftr;
> +#endif
>  
> -  return ((__A >> shiftr) & 0xffff);
> +  return ((__A >> (shiftr * 16)) & 0xffff);
>  }
>  
>  extern __inline int __attribute__((__gnu_inline__, __always_inline__, __artificial__))