Function stbi__grow_buffer_unsafe

include/stb/stb_image.h:2075–2091

}

static void stbi__grow_buffer_unsafe(stbi__jpeg *j)
{
   do {
      unsigned int b = j->nomore ? 0 : stbi__get8(j->s);
      if (b == 0xff) {
         int c = stbi__get8(j->s);
         while (c == 0xff) c = stbi__get8(j->s); // consume fill bytes
         if (c != 0) {
            j->marker = (unsigned char) c;
            j->nomore = 1;
            return;
         }
      }
      j->code_buffer |= b << (24 - j->code_bits);
      j->code_bits += 8;
   } while (j->code_bits <= 24);
}

// (1 << n) - 1
static const stbi__uint32 stbi__bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535};