void skip_any_whitespace_sse42()

in src/detail/skip_chars_sse42.cpp [60:89]

• 25 lines of code
• 8 McCabe index (conditional complexity)

void skip_any_whitespace_sse42(decode_context &context) {
  const auto end = context.end;
  auto pos = context.position;

  for (; pos < end && json_unaligned_16(pos); ++pos) {
    if (!is_space(*pos)) {
      context.position = pos;
      return;
    }
  }

  alignas(16) static const char CHARS[16] = " \t\n\r";
  const auto chars = _mm_load_si128(reinterpret_cast<const __m128i *>(&CHARS[0]));

  for (; end - pos >= 16; pos += 16) {
    const auto chunk = _mm_load_si128(reinterpret_cast<const __m128i *>(pos));
    constexpr auto flags = _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_NEGATIVE_POLARITY | _SIDD_LEAST_SIGNIFICANT;
    const auto index = _mm_cmpestri(chars, 4, chunk, 16, flags);
    if (index != 16) {
      context.position = pos + index;
      return;
    }
  }

  while (pos < end && is_space(*pos)) {
    ++pos;
  }

  context.position = pos;
}