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