| //===------------------------- charconv.cpp -------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "charconv" |
| #include <string.h> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| namespace __itoa |
| { |
| |
| static constexpr char cDigitsLut[200] = { |
| '0', '0', '0', '1', '0', '2', '0', '3', '0', '4', '0', '5', '0', '6', '0', |
| '7', '0', '8', '0', '9', '1', '0', '1', '1', '1', '2', '1', '3', '1', '4', |
| '1', '5', '1', '6', '1', '7', '1', '8', '1', '9', '2', '0', '2', '1', '2', |
| '2', '2', '3', '2', '4', '2', '5', '2', '6', '2', '7', '2', '8', '2', '9', |
| '3', '0', '3', '1', '3', '2', '3', '3', '3', '4', '3', '5', '3', '6', '3', |
| '7', '3', '8', '3', '9', '4', '0', '4', '1', '4', '2', '4', '3', '4', '4', |
| '4', '5', '4', '6', '4', '7', '4', '8', '4', '9', '5', '0', '5', '1', '5', |
| '2', '5', '3', '5', '4', '5', '5', '5', '6', '5', '7', '5', '8', '5', '9', |
| '6', '0', '6', '1', '6', '2', '6', '3', '6', '4', '6', '5', '6', '6', '6', |
| '7', '6', '8', '6', '9', '7', '0', '7', '1', '7', '2', '7', '3', '7', '4', |
| '7', '5', '7', '6', '7', '7', '7', '8', '7', '9', '8', '0', '8', '1', '8', |
| '2', '8', '3', '8', '4', '8', '5', '8', '6', '8', '7', '8', '8', '8', '9', |
| '9', '0', '9', '1', '9', '2', '9', '3', '9', '4', '9', '5', '9', '6', '9', |
| '7', '9', '8', '9', '9'}; |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append1(char* buffer, T i) noexcept |
| { |
| *buffer = '0' + static_cast<char>(i); |
| return buffer + 1; |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append2(char* buffer, T i) noexcept |
| { |
| memcpy(buffer, &cDigitsLut[(i)*2], 2); |
| return buffer + 2; |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append3(char* buffer, T i) noexcept |
| { |
| return append2(append1(buffer, (i) / 100), (i) % 100); |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append4(char* buffer, T i) noexcept |
| { |
| return append2(append2(buffer, (i) / 100), (i) % 100); |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append2_no_zeros(char* buffer, T v) noexcept |
| { |
| if (v < 10) |
| return append1(buffer, v); |
| else |
| return append2(buffer, v); |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append4_no_zeros(char* buffer, T v) noexcept |
| { |
| if (v < 100) |
| return append2_no_zeros(buffer, v); |
| else if (v < 1000) |
| return append3(buffer, v); |
| else |
| return append4(buffer, v); |
| } |
| |
| template <typename T> |
| inline _LIBCPP_INLINE_VISIBILITY char* |
| append8_no_zeros(char* buffer, T v) noexcept |
| { |
| if (v < 10000) |
| { |
| buffer = append4_no_zeros(buffer, v); |
| } |
| else |
| { |
| buffer = append4_no_zeros(buffer, v / 10000); |
| buffer = append4(buffer, v % 10000); |
| } |
| return buffer; |
| } |
| |
| char* |
| __u32toa(uint32_t value, char* buffer) noexcept |
| { |
| if (value < 100000000) |
| { |
| buffer = append8_no_zeros(buffer, value); |
| } |
| else |
| { |
| // value = aabbbbcccc in decimal |
| const uint32_t a = value / 100000000; // 1 to 42 |
| value %= 100000000; |
| |
| buffer = append2_no_zeros(buffer, a); |
| buffer = append4(buffer, value / 10000); |
| buffer = append4(buffer, value % 10000); |
| } |
| |
| return buffer; |
| } |
| |
| char* |
| __u64toa(uint64_t value, char* buffer) noexcept |
| { |
| if (value < 100000000) |
| { |
| uint32_t v = static_cast<uint32_t>(value); |
| buffer = append8_no_zeros(buffer, v); |
| } |
| else if (value < 10000000000000000) |
| { |
| const uint32_t v0 = static_cast<uint32_t>(value / 100000000); |
| const uint32_t v1 = static_cast<uint32_t>(value % 100000000); |
| |
| buffer = append8_no_zeros(buffer, v0); |
| buffer = append4(buffer, v1 / 10000); |
| buffer = append4(buffer, v1 % 10000); |
| } |
| else |
| { |
| const uint32_t a = |
| static_cast<uint32_t>(value / 10000000000000000); // 1 to 1844 |
| value %= 10000000000000000; |
| |
| buffer = append4_no_zeros(buffer, a); |
| |
| const uint32_t v0 = static_cast<uint32_t>(value / 100000000); |
| const uint32_t v1 = static_cast<uint32_t>(value % 100000000); |
| buffer = append4(buffer, v0 / 10000); |
| buffer = append4(buffer, v0 % 10000); |
| buffer = append4(buffer, v1 / 10000); |
| buffer = append4(buffer, v1 % 10000); |
| } |
| |
| return buffer; |
| } |
| |
| } // namespace __itoa |
| |
| _LIBCPP_END_NAMESPACE_STD |