1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 // Copyright (c) Microsoft Corporation. 11 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 12 13 14 // Copyright 2018 Ulf Adams 15 // Copyright (c) Microsoft Corporation. All rights reserved. 16 17 // Boost Software License - Version 1.0 - August 17th, 2003 18 19 // Permission is hereby granted, free of charge, to any person or organization 20 // obtaining a copy of the software and accompanying documentation covered by 21 // this license (the "Software") to use, reproduce, display, distribute, 22 // execute, and transmit the Software, and to prepare derivative works of the 23 // Software, and to permit third-parties to whom the Software is furnished to 24 // do so, all subject to the following: 25 26 // The copyright notices in the Software and this entire statement, including 27 // the above license grant, this restriction and the following disclaimer, 28 // must be included in all copies of the Software, in whole or in part, and 29 // all derivative works of the Software, unless such copies or derivative 30 // works are solely in the form of machine-executable object code generated by 31 // a source language processor. 32 33 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 34 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 35 // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT 36 // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE 37 // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, 38 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 39 // DEALINGS IN THE SOFTWARE. 40 41 #ifndef _LIBCPP_SRC_INCLUDE_RYU_RYU_H 42 #define _LIBCPP_SRC_INCLUDE_RYU_RYU_H 43 44 // Avoid formatting to keep the changes with the original code minimal. 45 // clang-format off 46 47 #include <__charconv/chars_format.h> 48 #include <__charconv/to_chars_result.h> 49 #include <__config> 50 #include <__system_error/errc.h> 51 #include <cstdint> 52 #include <cstring> 53 #include <type_traits> 54 55 #include "include/ryu/f2s.h" 56 #include "include/ryu/d2s.h" 57 #include "include/ryu/d2fixed.h" 58 59 #if defined(_MSC_VER) 60 #include <intrin.h> // for _umul128(), __shiftright128(), _BitScanForward{,64} 61 #endif // defined(_MSC_VER) 62 63 #if defined(_WIN64) || defined(_M_AMD64) || defined(__x86_64__) || defined(__aarch64__) 64 #define _LIBCPP_64_BIT 65 #endif 66 67 _LIBCPP_BEGIN_NAMESPACE_STD 68 69 // https://github.com/ulfjack/ryu/tree/59661c3/ryu 70 71 #if !defined(_MSC_VER) 72 _LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward64(unsigned long* __index, unsigned long long __mask) { 73 if (__mask == 0) { 74 return false; 75 } 76 *__index = __builtin_ctzll(__mask); 77 return true; 78 } 79 80 _LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward(unsigned long* __index, unsigned int __mask) { 81 if (__mask == 0) { 82 return false; 83 } 84 *__index = __builtin_ctz(__mask); 85 return true; 86 } 87 #endif // !_MSC_VER 88 89 template <class _Floating> 90 [[nodiscard]] to_chars_result _Floating_to_chars_ryu( 91 char* const _First, char* const _Last, const _Floating _Value, const chars_format _Fmt) noexcept { 92 if constexpr (_IsSame<_Floating, float>::value) { 93 return __f2s_buffered_n(_First, _Last, _Value, _Fmt); 94 } else { 95 return __d2s_buffered_n(_First, _Last, _Value, _Fmt); 96 } 97 } 98 99 template <class _Floating> 100 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_scientific_precision( 101 char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept { 102 103 // C11 7.21.6.1 "The fprintf function"/5: 104 // "A negative precision argument is taken as if the precision were omitted." 105 // /8: "e,E [...] if the precision is missing, it is taken as 6" 106 107 if (_Precision < 0) { 108 _Precision = 6; 109 } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode 110 // _Precision is ok. 111 } else { 112 // Avoid integer overflow. 113 // (This defensive check is slightly nonconformant; it can be carefully improved in the future.) 114 return {_Last, errc::value_too_large}; 115 } 116 117 return __d2exp_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision)); 118 } 119 120 template <class _Floating> 121 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_fixed_precision( 122 char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept { 123 124 // C11 7.21.6.1 "The fprintf function"/5: 125 // "A negative precision argument is taken as if the precision were omitted." 126 // /8: "f,F [...] If the precision is missing, it is taken as 6" 127 128 if (_Precision < 0) { 129 _Precision = 6; 130 } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode 131 // _Precision is ok. 132 } else { 133 // Avoid integer overflow. 134 // (This defensive check is slightly nonconformant; it can be carefully improved in the future.) 135 return {_Last, errc::value_too_large}; 136 } 137 138 return __d2fixed_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision)); 139 } 140 141 #undef _LIBCPP_64_BIT 142 #undef _LIBCPP_INTRINSIC128 143 144 _LIBCPP_END_NAMESPACE_STD 145 146 // clang-format on 147 148 #endif // _LIBCPP_SRC_INCLUDE_RYU_RYU_H 149