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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-exception7//8//===----------------------------------------------------------------------===//9 10// Copyright (c) Microsoft Corporation.11// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception12 13// Copyright 2018 Ulf Adams14// Copyright (c) Microsoft Corporation. All rights reserved.15 16// Boost Software License - Version 1.0 - August 17th, 200317 18// Permission is hereby granted, free of charge, to any person or organization19// obtaining a copy of the software and accompanying documentation covered by20// this license (the "Software") to use, reproduce, display, distribute,21// execute, and transmit the Software, and to prepare derivative works of the22// Software, and to permit third-parties to whom the Software is furnished to23// do so, all subject to the following:24 25// The copyright notices in the Software and this entire statement, including26// 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, and28// all derivative works of the Software, unless such copies or derivative29// works are solely in the form of machine-executable object code generated by30// a source language processor.31 32// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR33// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,34// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT35// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE36// 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 OTHER38// DEALINGS IN THE SOFTWARE.39 40#ifndef _LIBCPP_SRC_INCLUDE_RYU_RYU_H41#define _LIBCPP_SRC_INCLUDE_RYU_RYU_H42 43// Avoid formatting to keep the changes with the original code minimal.44// clang-format off45 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_BIT64#endif65 66_LIBCPP_BEGIN_NAMESPACE_STD67 68// https://github.com/ulfjack/ryu/tree/59661c3/ryu69 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_VER87 88template <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 98template <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 mode109 // _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 119template <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 mode130 // _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_BIT141#undef _LIBCPP_INTRINSIC128142 143_LIBCPP_END_NAMESPACE_STD144 145// clang-format on146 147#endif // _LIBCPP_SRC_INCLUDE_RYU_RYU_H148