| //===----------------------------------------------------------------------===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| // Copyright (c) Microsoft Corporation. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // Copyright 2018 Ulf Adams | |
| // Copyright (c) Microsoft Corporation. All rights reserved. | |
| // Boost Software License - Version 1.0 - August 17th, 2003 | |
| // Permission is hereby granted, free of charge, to any person or organization | |
| // obtaining a copy of the software and accompanying documentation covered by | |
| // this license (the "Software") to use, reproduce, display, distribute, | |
| // execute, and transmit the Software, and to prepare derivative works of the | |
| // Software, and to permit third-parties to whom the Software is furnished to | |
| // do so, all subject to the following: | |
| // The copyright notices in the Software and this entire statement, including | |
| // the above license grant, this restriction and the following disclaimer, | |
| // must be included in all copies of the Software, in whole or in part, and | |
| // all derivative works of the Software, unless such copies or derivative | |
| // works are solely in the form of machine-executable object code generated by | |
| // a source language processor. | |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT | |
| // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE | |
| // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, | |
| // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER | |
| // DEALINGS IN THE SOFTWARE. | |
| // Avoid formatting to keep the changes with the original code minimal. | |
| // clang-format off | |
| _LIBCPP_BEGIN_NAMESPACE_STD | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __decimalLength9(const uint32_t __v) { | |
| // Function precondition: __v is not a 10-digit number. | |
| // (f2s: 9 digits are sufficient for round-tripping.) | |
| // (d2fixed: We print 9-digit blocks.) | |
| _LIBCPP_ASSERT_INTERNAL(__v < 1000000000, ""); | |
| if (__v >= 100000000) { return 9; } | |
| if (__v >= 10000000) { return 8; } | |
| if (__v >= 1000000) { return 7; } | |
| if (__v >= 100000) { return 6; } | |
| if (__v >= 10000) { return 5; } | |
| if (__v >= 1000) { return 4; } | |
| if (__v >= 100) { return 3; } | |
| if (__v >= 10) { return 2; } | |
| return 1; | |
| } | |
| // Returns __e == 0 ? 1 : ceil(log_2(5^__e)). | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline int32_t __pow5bits(const int32_t __e) { | |
| // This approximation works up to the point that the multiplication overflows at __e = 3529. | |
| // If the multiplication were done in 64 bits, it would fail at 5^4004 which is just greater | |
| // than 2^9297. | |
| _LIBCPP_ASSERT_INTERNAL(__e >= 0, ""); | |
| _LIBCPP_ASSERT_INTERNAL(__e <= 3528, ""); | |
| return static_cast<int32_t>(((static_cast<uint32_t>(__e) * 1217359) >> 19) + 1); | |
| } | |
| // Returns floor(log_10(2^__e)). | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __log10Pow2(const int32_t __e) { | |
| // The first value this approximation fails for is 2^1651 which is just greater than 10^297. | |
| _LIBCPP_ASSERT_INTERNAL(__e >= 0, ""); | |
| _LIBCPP_ASSERT_INTERNAL(__e <= 1650, ""); | |
| return (static_cast<uint32_t>(__e) * 78913) >> 18; | |
| } | |
| // Returns floor(log_10(5^__e)). | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __log10Pow5(const int32_t __e) { | |
| // The first value this approximation fails for is 5^2621 which is just greater than 10^1832. | |
| _LIBCPP_ASSERT_INTERNAL(__e >= 0, ""); | |
| _LIBCPP_ASSERT_INTERNAL(__e <= 2620, ""); | |
| return (static_cast<uint32_t>(__e) * 732923) >> 20; | |
| } | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __float_to_bits(const float __f) { | |
| uint32_t __bits = 0; | |
| std::memcpy(&__bits, &__f, sizeof(float)); | |
| return __bits; | |
| } | |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __double_to_bits(const double __d) { | |
| uint64_t __bits = 0; | |
| std::memcpy(&__bits, &__d, sizeof(double)); | |
| return __bits; | |
| } | |
| _LIBCPP_END_NAMESPACE_STD | |
| // clang-format on | |