unicode.inl

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// # 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 "header_start.hpp"
#include "simd.hpp"
#include "unicode.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"