void write_escaped_sse42()

in src/detail/escape_sse42.cpp [48:84]

• 32 lines of code
• 15 McCabe index (conditional complexity)

void write_escaped_sse42(
    encode_context &context,
    const char *begin,
    const char *end) {
  const auto buf = context.reserve(6 * (end - begin));  // 6 is the length of \u00xx
  auto out = buf;

  const __m128i ranges = _mm_setr_epi8(
    0x00, 0x1F,  // null byte & control characters
    0x22, 0x22,  // double quotation mark
    0x5C, 0x5C,  // reverse solidus (backslash)
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  );

  if (json_unaligned_2(begin) && (end - begin) >= 1) { write_escaped_1(out, begin); }
  if (json_unaligned_4(begin) && (end - begin) >= 2) { write_escaped_2(out, begin); }
  if (json_unaligned_8(begin) && (end - begin) >= 4) { write_escaped_4(out, begin); }
  if (json_unaligned_16(begin) && (end - begin) >= 8) { write_escaped_8(out, begin); }

  for (; end - begin >= 16; begin += 16) {
    const __m128i chunk = _mm_load_si128(reinterpret_cast<const __m128i *>(begin));
    const unsigned has_character_in_ranges = _mm_cmpestrc(ranges, 6, chunk, 16, _SIDD_CMP_RANGES);
    if (json_likely(!has_character_in_ranges)) {
      _mm_storeu_si128(reinterpret_cast<__m128i *>(out), chunk);
      out += 16;
    } else {
      write_escaped_16_sse42(out, chunk);
    }
  }

  if ((end - begin) >= 8) { write_escaped_8(out, begin); }
  if ((end - begin) >= 4) { write_escaped_4(out, begin); }
  if ((end - begin) >= 2) { write_escaped_2(out, begin); }
  if ((end - begin) >= 1) { write_escaped_1(out, begin); }

  context.advance(out - buf);
}