-rw-r--r-- 887 saferewrite-20211125/src/decode_256x2/avx/decode.c
#include <immintrin.h>
#include <stdint.h>
#include "crypto_decode.h"

#define COPY _mm256_set_epi64x(0x0303030303030303,0x0202020202020202,0x0101010101010101,0x0000000000000000)
#define MASK _mm256_set1_epi64x(0x8040201008040201)
#define MASK2 _mm256_set1_epi64x(0x0101010101010101)

void crypto_decode(void *v,const unsigned char *s)
{
  __m256i *r = v;
  int i;

  for (i = 0;i < 8;++i) {
    /* bytes s0 s1 s2 s3 */
    __m256i x = _mm256_set1_epi32(*(int32_t *) s);
    /* s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 s0 s1 s2 s3 */
    x = _mm256_shuffle_epi8(x,COPY);
    /* s0 s0 s0 s0 s0 s0 s0 s0 s1 s1 s1 s1 s1 s1 s1 s1 s2 s2 s2 s2 s2 s2 s2 s2 s3 s3 s3 s3 s3 s3 s3 s3 */
    x = _mm256_andnot_si256(x,MASK);
    x = _mm256_cmpeq_epi8(x,_mm256_setzero_si256());
    x &= MASK2;
    _mm256_storeu_si256(r,x);

    s += 4;
    r += 1;
  }
}