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 <__debug> 51#include <__errc> 52#include <cstdint> 53#include <cstring> 54#include <type_traits> 55 56#include "include/ryu/f2s.h" 57#include "include/ryu/d2s.h" 58#include "include/ryu/d2fixed.h" 59 60#if defined(_MSC_VER) 61#include <intrin.h> // for _umul128(), __shiftright128(), _BitScanForward{,64} 62#endif // defined(_MSC_VER) 63 64#if defined(_WIN64) || defined(_M_AMD64) || defined(__x86_64__) || defined(__aarch64__) 65#define _LIBCPP_64_BIT 66#endif 67 68_LIBCPP_BEGIN_NAMESPACE_STD 69 70// https://github.com/ulfjack/ryu/tree/59661c3/ryu 71 72#if !defined(_MSC_VER) 73_LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward64(unsigned long* __index, unsigned long long __mask) { 74 if (__mask == 0) { 75 return false; 76 } 77 *__index = __builtin_ctzll(__mask); 78 return true; 79} 80 81_LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward(unsigned long* __index, unsigned int __mask) { 82 if (__mask == 0) { 83 return false; 84 } 85 *__index = __builtin_ctz(__mask); 86 return true; 87} 88#endif // !_MSC_VER 89 90template <class _Floating> 91[[nodiscard]] to_chars_result _Floating_to_chars_ryu( 92 char* const _First, char* const _Last, const _Floating _Value, const chars_format _Fmt) noexcept { 93 if constexpr (_IsSame<_Floating, float>::value) { 94 return __f2s_buffered_n(_First, _Last, _Value, _Fmt); 95 } else { 96 return __d2s_buffered_n(_First, _Last, _Value, _Fmt); 97 } 98} 99 100template <class _Floating> 101[[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_scientific_precision( 102 char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept { 103 104 // C11 7.21.6.1 "The fprintf function"/5: 105 // "A negative precision argument is taken as if the precision were omitted." 106 // /8: "e,E [...] if the precision is missing, it is taken as 6" 107 108 if (_Precision < 0) { 109 _Precision = 6; 110 } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode 111 // _Precision is ok. 112 } else { 113 // Avoid integer overflow. 114 // (This defensive check is slightly nonconformant; it can be carefully improved in the future.) 115 return {_Last, errc::value_too_large}; 116 } 117 118 return __d2exp_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision)); 119} 120 121template <class _Floating> 122[[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_fixed_precision( 123 char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept { 124 125 // C11 7.21.6.1 "The fprintf function"/5: 126 // "A negative precision argument is taken as if the precision were omitted." 127 // /8: "f,F [...] If the precision is missing, it is taken as 6" 128 129 if (_Precision < 0) { 130 _Precision = 6; 131 } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode 132 // _Precision is ok. 133 } else { 134 // Avoid integer overflow. 135 // (This defensive check is slightly nonconformant; it can be carefully improved in the future.) 136 return {_Last, errc::value_too_large}; 137 } 138 139 return __d2fixed_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision)); 140} 141 142#undef _LIBCPP_64_BIT 143#undef _LIBCPP_INTRINSIC128 144 145_LIBCPP_END_NAMESPACE_STD 146 147// clang-format on 148 149#endif // _LIBCPP_SRC_INCLUDE_RYU_RYU_H 150