grammar/detail/charset.hpp

0001 //
0002 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // Official repository: https://github.com/boostorg/url
0008 //
0009
0010 #ifndef BOOST_URL_GRAMMAR_DETAIL_CHARSET_HPP
0011 #define BOOST_URL_GRAMMAR_DETAIL_CHARSET_HPP
0012
0013 #include <boost/core/bit.hpp>
0014 #include <type_traits>
0015
0016 #ifdef BOOST_URL_USE_SSE2
0017 # include <emmintrin.h>
0018 # include <xmmintrin.h>
0019 # ifdef _MSC_VER
0020 #  include <intrin.h>
0021 # endif
0022 #endif
0023
0024 #ifdef _MSC_VER
0025 #pragma warning(push)
0026 #pragma warning(disable: 4127) // conditional expression is constant
0027 #endif
0028
0029 namespace boost {
0030 namespace urls {
0031 namespace grammar {
0032 namespace detail {
0033
0034 template<class T, class = void>
0035 struct has_find_if : std::false_type {};
0036
0037 template<class T>
0038 struct has_find_if<T, void_t<
0039     decltype(
0040     std::declval<char const*&>() =
0041         std::declval<T const&>().find_if(
0042             std::declval<char const*>(),
0043             std::declval<char const*>())
0044             )>> : std::true_type
0045 {
0046 };
0047
0048 template<class T, class = void>
0049 struct has_find_if_not : std::false_type {};
0050
0051 template<class T>
0052 struct has_find_if_not<T, void_t<
0053     decltype(
0054     std::declval<char const*&>() =
0055         std::declval<T const&>().find_if_not(
0056             std::declval<char const*>(),
0057             std::declval<char const*>())
0058             )>> : std::true_type
0059 {
0060 };
0061
0062 template<class Pred>
0063 char const*
0064 find_if(
0065     char const* first,
0066     char const* const last,
0067     Pred const& pred,
0068     std::false_type) noexcept
0069 {
0070     while(first != last)
0071     {
0072         if(pred(*first))
0073             break;
0074         ++first;
0075     }
0076     return first;
0077 }
0078
0079 template<class Pred>
0080 char const*
0081 find_if(
0082     char const* first,
0083     char const* const last,
0084     Pred const& pred,
0085     std::true_type) noexcept
0086 {
0087     return pred.find_if(
0088         first, last);
0089 }
0090
0091 template<class Pred>
0092 char const*
0093 find_if_not(
0094     char const* first,
0095     char const* const last,
0096     Pred const& pred,
0097     std::false_type) noexcept
0098 {
0099     while(first != last)
0100     {
0101         if(! pred(*first))
0102             break;
0103         ++first;
0104     }
0105     return first;
0106 }
0107
0108 template<class Pred>
0109 char const*
0110 find_if_not(
0111     char const* first,
0112     char const* const last,
0113     Pred const& pred,
0114     std::true_type) noexcept
0115 {
0116     return pred.find_if_not(
0117         first, last);
0118 }
0119
0120 #ifdef BOOST_URL_USE_SSE2
0121
0122 // by Peter Dimov
0123 template<class Pred>
0124 char const*
0125 find_if_pred(
0126     Pred const& pred,
0127     char const* first,
0128     char const* last ) noexcept
0129 {
0130     while( last - first >= 16 )
0131     {
0132         unsigned char r[ 16 ] = {};
0133         for( int i = 0; i < 16; ++i )
0134             r[ i ] = pred( first[ i ] )? 0xFF: 0x00;
0135         __m128i r2 = _mm_loadu_si128( (__m128i const*)r );
0136         unsigned r3 = _mm_movemask_epi8( r2 );
0137         if( r3 )
0138             return first + boost::core::countr_zero( r3 );
0139         first += 16;
0140     }
0141     while(
0142         first != last &&
0143         ! pred(*first))
0144     {
0145         ++first;
0146     }
0147     return first;
0148 }
0149
0150 // by Peter Dimov
0151 template<class Pred>
0152 char const*
0153 find_if_not_pred(
0154     Pred const& pred,
0155     char const* first,
0156     char const* last ) noexcept
0157 {
0158     while( last - first >= 16 )
0159     {
0160         unsigned char r[ 16 ] = {};
0161         for( int i = 0; i < 16; ++i )
0162             r[ i ] = pred( first[ i ] )? 0x00: 0xFF;
0163         __m128i r2 = _mm_loadu_si128( (__m128i const*)r );
0164         unsigned r3 = _mm_movemask_epi8( r2 );
0165         if( r3 )
0166             return first + boost::core::countr_zero( r3 );
0167         first += 16;
0168     }
0169     while(
0170         first != last &&
0171         pred(*first))
0172     {
0173         ++first;
0174     }
0175     return first;
0176 }
0177
0178 #endif
0179
0180 } // detail
0181 } // grammar
0182 } // urls
0183 } // boost
0184
0185 #ifdef _MSC_VER
0186 #pragma warning(pop)
0187 #endif
0188
0189 #endif