xref: /llvm-project/libcxx/src/include/ryu/ryu.h (revision 9783f28cbb155e4a8d49c12e1c60ce14dcfaf0c7)
1abb5dd6eSMark de Wever // -*- C++ -*-
2abb5dd6eSMark de Wever //===----------------------------------------------------------------------===//
3abb5dd6eSMark de Wever //
4abb5dd6eSMark de Wever // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5abb5dd6eSMark de Wever // See https://llvm.org/LICENSE.txt for license information.
6abb5dd6eSMark de Wever // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7abb5dd6eSMark de Wever //
8abb5dd6eSMark de Wever //===----------------------------------------------------------------------===//
9abb5dd6eSMark de Wever 
10abb5dd6eSMark de Wever // Copyright (c) Microsoft Corporation.
11abb5dd6eSMark de Wever // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
12abb5dd6eSMark de Wever 
13abb5dd6eSMark de Wever // Copyright 2018 Ulf Adams
14abb5dd6eSMark de Wever // Copyright (c) Microsoft Corporation. All rights reserved.
15abb5dd6eSMark de Wever 
16abb5dd6eSMark de Wever // Boost Software License - Version 1.0 - August 17th, 2003
17abb5dd6eSMark de Wever 
18abb5dd6eSMark de Wever // Permission is hereby granted, free of charge, to any person or organization
19abb5dd6eSMark de Wever // obtaining a copy of the software and accompanying documentation covered by
20abb5dd6eSMark de Wever // this license (the "Software") to use, reproduce, display, distribute,
21abb5dd6eSMark de Wever // execute, and transmit the Software, and to prepare derivative works of the
22abb5dd6eSMark de Wever // Software, and to permit third-parties to whom the Software is furnished to
23abb5dd6eSMark de Wever // do so, all subject to the following:
24abb5dd6eSMark de Wever 
25abb5dd6eSMark de Wever // The copyright notices in the Software and this entire statement, including
26abb5dd6eSMark de Wever // the above license grant, this restriction and the following disclaimer,
27abb5dd6eSMark de Wever // must be included in all copies of the Software, in whole or in part, and
28abb5dd6eSMark de Wever // all derivative works of the Software, unless such copies or derivative
29abb5dd6eSMark de Wever // works are solely in the form of machine-executable object code generated by
30abb5dd6eSMark de Wever // a source language processor.
31abb5dd6eSMark de Wever 
32abb5dd6eSMark de Wever // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
33abb5dd6eSMark de Wever // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
34abb5dd6eSMark de Wever // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
35abb5dd6eSMark de Wever // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
36abb5dd6eSMark de Wever // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
37abb5dd6eSMark de Wever // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
38abb5dd6eSMark de Wever // DEALINGS IN THE SOFTWARE.
39abb5dd6eSMark de Wever 
40abb5dd6eSMark de Wever #ifndef _LIBCPP_SRC_INCLUDE_RYU_RYU_H
41abb5dd6eSMark de Wever #define _LIBCPP_SRC_INCLUDE_RYU_RYU_H
42abb5dd6eSMark de Wever 
43abb5dd6eSMark de Wever // Avoid formatting to keep the changes with the original code minimal.
44abb5dd6eSMark de Wever // clang-format off
45abb5dd6eSMark de Wever 
46bbb0f2c7SArthur O'Dwyer #include <__charconv/chars_format.h>
47bbb0f2c7SArthur O'Dwyer #include <__charconv/to_chars_result.h>
48bbb0f2c7SArthur O'Dwyer #include <__config>
49*eb65912eSNikolas Klauser #include <__system_error/errc.h>
50bbb0f2c7SArthur O'Dwyer #include <cstdint>
51bbb0f2c7SArthur O'Dwyer #include <cstring>
52bbb0f2c7SArthur O'Dwyer #include <type_traits>
53bbb0f2c7SArthur O'Dwyer 
54abb5dd6eSMark de Wever #include "include/ryu/f2s.h"
55abb5dd6eSMark de Wever #include "include/ryu/d2s.h"
56abb5dd6eSMark de Wever #include "include/ryu/d2fixed.h"
57abb5dd6eSMark de Wever 
587b89360dSMartin Storsjö #if defined(_MSC_VER)
597b89360dSMartin Storsjö #include <intrin.h> // for _umul128(), __shiftright128(), _BitScanForward{,64}
607b89360dSMartin Storsjö #endif // defined(_MSC_VER)
61abb5dd6eSMark de Wever 
62abb5dd6eSMark de Wever #if defined(_WIN64) || defined(_M_AMD64) || defined(__x86_64__) ||  defined(__aarch64__)
63abb5dd6eSMark de Wever #define _LIBCPP_64_BIT
64abb5dd6eSMark de Wever #endif
65abb5dd6eSMark de Wever 
66abb5dd6eSMark de Wever _LIBCPP_BEGIN_NAMESPACE_STD
67abb5dd6eSMark de Wever 
68abb5dd6eSMark de Wever // https://github.com/ulfjack/ryu/tree/59661c3/ryu
69abb5dd6eSMark de Wever 
707b89360dSMartin Storsjö #if !defined(_MSC_VER)
_BitScanForward64(unsigned long * __index,unsigned long long __mask)71abb5dd6eSMark de Wever _LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward64(unsigned long* __index, unsigned long long __mask) {
72abb5dd6eSMark de Wever   if (__mask == 0) {
73abb5dd6eSMark de Wever     return false;
74abb5dd6eSMark de Wever   }
75abb5dd6eSMark de Wever   *__index = __builtin_ctzll(__mask);
76abb5dd6eSMark de Wever   return true;
77abb5dd6eSMark de Wever }
78abb5dd6eSMark de Wever 
_BitScanForward(unsigned long * __index,unsigned int __mask)79abb5dd6eSMark de Wever _LIBCPP_HIDE_FROM_ABI inline unsigned char _BitScanForward(unsigned long* __index, unsigned int __mask) {
80abb5dd6eSMark de Wever   if (__mask == 0) {
81abb5dd6eSMark de Wever     return false;
82abb5dd6eSMark de Wever   }
83abb5dd6eSMark de Wever   *__index = __builtin_ctz(__mask);
84abb5dd6eSMark de Wever   return true;
85abb5dd6eSMark de Wever }
867b89360dSMartin Storsjö #endif  // !_MSC_VER
87abb5dd6eSMark de Wever 
88abb5dd6eSMark de Wever template <class _Floating>
_Floating_to_chars_ryu(char * const _First,char * const _Last,const _Floating _Value,const chars_format _Fmt)89abb5dd6eSMark de Wever [[nodiscard]] to_chars_result _Floating_to_chars_ryu(
90abb5dd6eSMark de Wever     char* const _First, char* const _Last, const _Floating _Value, const chars_format _Fmt) noexcept {
91abb5dd6eSMark de Wever     if constexpr (_IsSame<_Floating, float>::value) {
92abb5dd6eSMark de Wever         return __f2s_buffered_n(_First, _Last, _Value, _Fmt);
93abb5dd6eSMark de Wever     } else {
94abb5dd6eSMark de Wever         return __d2s_buffered_n(_First, _Last, _Value, _Fmt);
95abb5dd6eSMark de Wever     }
96abb5dd6eSMark de Wever }
97abb5dd6eSMark de Wever 
98abb5dd6eSMark de Wever template <class _Floating>
_Floating_to_chars_scientific_precision(char * const _First,char * const _Last,const _Floating _Value,int _Precision)99abb5dd6eSMark de Wever [[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_scientific_precision(
100abb5dd6eSMark de Wever     char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept {
101abb5dd6eSMark de Wever 
102abb5dd6eSMark de Wever     // C11 7.21.6.1 "The fprintf function"/5:
103abb5dd6eSMark de Wever     // "A negative precision argument is taken as if the precision were omitted."
104abb5dd6eSMark de Wever     // /8: "e,E [...] if the precision is missing, it is taken as 6"
105abb5dd6eSMark de Wever 
106abb5dd6eSMark de Wever     if (_Precision < 0) {
107abb5dd6eSMark de Wever         _Precision = 6;
108abb5dd6eSMark de Wever     } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode
109abb5dd6eSMark de Wever         // _Precision is ok.
110abb5dd6eSMark de Wever     } else {
111abb5dd6eSMark de Wever         // Avoid integer overflow.
112abb5dd6eSMark de Wever         // (This defensive check is slightly nonconformant; it can be carefully improved in the future.)
113abb5dd6eSMark de Wever         return {_Last, errc::value_too_large};
114abb5dd6eSMark de Wever     }
115abb5dd6eSMark de Wever 
116abb5dd6eSMark de Wever     return __d2exp_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision));
117abb5dd6eSMark de Wever }
118abb5dd6eSMark de Wever 
119abb5dd6eSMark de Wever template <class _Floating>
_Floating_to_chars_fixed_precision(char * const _First,char * const _Last,const _Floating _Value,int _Precision)120abb5dd6eSMark de Wever [[nodiscard]] _LIBCPP_HIDE_FROM_ABI to_chars_result _Floating_to_chars_fixed_precision(
121abb5dd6eSMark de Wever     char* const _First, char* const _Last, const _Floating _Value, int _Precision) noexcept {
122abb5dd6eSMark de Wever 
123abb5dd6eSMark de Wever     // C11 7.21.6.1 "The fprintf function"/5:
124abb5dd6eSMark de Wever     // "A negative precision argument is taken as if the precision were omitted."
125abb5dd6eSMark de Wever     // /8: "f,F [...] If the precision is missing, it is taken as 6"
126abb5dd6eSMark de Wever 
127abb5dd6eSMark de Wever     if (_Precision < 0) {
128abb5dd6eSMark de Wever         _Precision = 6;
129abb5dd6eSMark de Wever     } else if (_Precision < 1'000'000'000) { // Match ' to fix compilation with GCC in C++11 mode
130abb5dd6eSMark de Wever         // _Precision is ok.
131abb5dd6eSMark de Wever     } else {
132abb5dd6eSMark de Wever         // Avoid integer overflow.
133abb5dd6eSMark de Wever         // (This defensive check is slightly nonconformant; it can be carefully improved in the future.)
134abb5dd6eSMark de Wever         return {_Last, errc::value_too_large};
135abb5dd6eSMark de Wever     }
136abb5dd6eSMark de Wever 
137abb5dd6eSMark de Wever     return __d2fixed_buffered_n(_First, _Last, _Value, static_cast<uint32_t>(_Precision));
138abb5dd6eSMark de Wever }
139abb5dd6eSMark de Wever 
140abb5dd6eSMark de Wever #undef _LIBCPP_64_BIT
141abb5dd6eSMark de Wever #undef _LIBCPP_INTRINSIC128
142abb5dd6eSMark de Wever 
143abb5dd6eSMark de Wever _LIBCPP_END_NAMESPACE_STD
144abb5dd6eSMark de Wever 
145abb5dd6eSMark de Wever // clang-format on
146abb5dd6eSMark de Wever 
147abb5dd6eSMark de Wever #endif // _LIBCPP_SRC_INCLUDE_RYU_RYU_H
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