string split (line splitting)

str_split.c

static int*
str_split(const char *in, int siz, char delim) {
   int *eol = 0;
  __m128i msk = _mm_set1_epi8(0x80);
  __m128i sub = _mm_set1_epi8(0x01);
  __m128i neg = _mm_set1_epi64(-1LL);
  __m128i sep = _mm_set1_epi8(delim);
  __m128i endmsk = _mm_set1_epi32(-1);
  if (siz & 15) {
    endmsk = _mm_slli_si128(endmsk, 16 - (siz & 15))
  }
  for (int i = 0; i < siz; i += 16) {
    long long r[2];
    __m128i bmsk = (i + 16 < siz) ? _mm_set1_epi32(-1) : endmsk;
    __m128i v = _mm_and_si128(_mm_loadu_si128(in + i), bmsk);
    __m128i c = _mm_and_si128(_mm_xor_si128(v, neg), msk);
    __m128i x = _mm_and_si128(_mm_sub_epi8(_mm_xor_si128(v, sep), sub), c);
    _mm_storeu_si32(r, z);

    int p = 0;
    for (int j = 0; j < 2; ++j) {
      char *rb = (char*)(r + j);
      while ((p = ffsll(r[j]))) {
        int b = (p - 1) >> 3;
        dyn_add(eol, i + b + (j << 3));
        rb[b] = 0x0;
      }
    }
  }
  return eol;
}