[Bug target/92492] [AVX512F] Icc generate much better code for loop vectorization

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92492

--- Comment #1 from Hongtao.liu <crazylht at gmail dot com> ---
Much more simple case, exclude disturb of point alias and unknown loop count
cat test.c:

typedef unsigned char uint8_t;

static inline uint8_t x264_clip_uint8( int x )
{
  return x&(~63) ? (-x)>>7 : x;
}


void mc_weight( uint8_t *__restrict dst, uint8_t *__restrict src)
{
        for( int x = 0; x < 16; x++ )
            dst[x] = x264_clip_uint8(src[x]);
}

Refer to https://godbolt.org/z/YJXWRD 

Gcc failed to vectorize loop, icc succeed.