//# This file is a part of toml++ and is subject to the the terms of the MIT license.

//# Copyright (c) Mark Gillard <mark.gillard@outlook.com.au>

//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.

// SPDX-License-Identifier: MIT

#pragma once

//# {{

#include "preprocessor.hpp"

#if !TOML_IMPLEMENTATION

#error This is an implementation-only header.

#endif

//# }}

#include "unicode.hpp"

#include "simd.hpp"

#include "header_start.hpp"

TOML_IMPL_NAMESPACE_START

{

  TOML_PURE_GETTER

  TOML_EXTERNAL_LINKAGE

  bool is_ascii(const char* str, size_t len) noexcept

  {

    const char* const end = str + len;

#if TOML_HAS_SSE2 && (128 % CHAR_BIT) == 0

    {

      constexpr size_t chars_per_vector = 128u / CHAR_BIT;

      if (const size_t simdable = len - (len % chars_per_vector))

      {

        __m128i mask = _mm_setzero_si128();

        for (const char* const e = str + simdable; str < e; str += chars_per_vector)

        {

          const __m128i current_bytes = _mm_loadu_si128(reinterpret_cast<const __m128i*>(str));

          mask            = _mm_or_si128(mask, current_bytes);

        }

        const __m128i has_error = _mm_cmpgt_epi8(_mm_setzero_si128(), mask);

#if TOML_HAS_SSE4_1

        if (!_mm_testz_si128(has_error, has_error))

          return false;

#else

        if (_mm_movemask_epi8(_mm_cmpeq_epi8(has_error, _mm_setzero_si128())) != 0xFFFF)

          return false;

#endif

      }

    }

#endif

    for (; str < end; str++)

      if (static_cast<unsigned char>(*str) > 127u)

        return false;

    return true;

  }

}

TOML_IMPL_NAMESPACE_END;

#include "header_end.hpp"