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| 1 | +//===------------------------- charconv.cpp -------------------------------===// |
| 2 | +// |
| 3 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | +// See https://llvm.org/LICENSE.txt for license information. |
| 5 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | +// |
| 7 | +//===----------------------------------------------------------------------===// |
| 8 | + |
| 9 | +#include "charconv" |
| 10 | +#include <string.h> |
| 11 | + |
| 12 | +_LIBCPP_BEGIN_NAMESPACE_STD |
| 13 | + |
| 14 | +namespace __itoa |
| 15 | +{ |
| 16 | + |
| 17 | +static constexpr char cDigitsLut[200] = { |
| 18 | + '0', '0', '0', '1', '0', '2', '0', '3', '0', '4', '0', '5', '0', '6', '0', |
| 19 | + '7', '0', '8', '0', '9', '1', '0', '1', '1', '1', '2', '1', '3', '1', '4', |
| 20 | + '1', '5', '1', '6', '1', '7', '1', '8', '1', '9', '2', '0', '2', '1', '2', |
| 21 | + '2', '2', '3', '2', '4', '2', '5', '2', '6', '2', '7', '2', '8', '2', '9', |
| 22 | + '3', '0', '3', '1', '3', '2', '3', '3', '3', '4', '3', '5', '3', '6', '3', |
| 23 | + '7', '3', '8', '3', '9', '4', '0', '4', '1', '4', '2', '4', '3', '4', '4', |
| 24 | + '4', '5', '4', '6', '4', '7', '4', '8', '4', '9', '5', '0', '5', '1', '5', |
| 25 | + '2', '5', '3', '5', '4', '5', '5', '5', '6', '5', '7', '5', '8', '5', '9', |
| 26 | + '6', '0', '6', '1', '6', '2', '6', '3', '6', '4', '6', '5', '6', '6', '6', |
| 27 | + '7', '6', '8', '6', '9', '7', '0', '7', '1', '7', '2', '7', '3', '7', '4', |
| 28 | + '7', '5', '7', '6', '7', '7', '7', '8', '7', '9', '8', '0', '8', '1', '8', |
| 29 | + '2', '8', '3', '8', '4', '8', '5', '8', '6', '8', '7', '8', '8', '8', '9', |
| 30 | + '9', '0', '9', '1', '9', '2', '9', '3', '9', '4', '9', '5', '9', '6', '9', |
| 31 | + '7', '9', '8', '9', '9'}; |
| 32 | + |
| 33 | +template <typename T> |
| 34 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 35 | +append1(char* buffer, T i) |
| 36 | +{ |
| 37 | + *buffer = '0' + static_cast<char>(i); |
| 38 | + return buffer + 1; |
| 39 | +} |
| 40 | + |
| 41 | +template <typename T> |
| 42 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 43 | +append2(char* buffer, T i) |
| 44 | +{ |
| 45 | + memcpy(buffer, &cDigitsLut[(i)*2], 2); |
| 46 | + return buffer + 2; |
| 47 | +} |
| 48 | + |
| 49 | +template <typename T> |
| 50 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 51 | +append3(char* buffer, T i) |
| 52 | +{ |
| 53 | + return append2(append1(buffer, (i) / 100), (i) % 100); |
| 54 | +} |
| 55 | + |
| 56 | +template <typename T> |
| 57 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 58 | +append4(char* buffer, T i) |
| 59 | +{ |
| 60 | + return append2(append2(buffer, (i) / 100), (i) % 100); |
| 61 | +} |
| 62 | + |
| 63 | +template <typename T> |
| 64 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 65 | +append2_no_zeros(char* buffer, T v) |
| 66 | +{ |
| 67 | + if (v < 10) |
| 68 | + return append1(buffer, v); |
| 69 | + else |
| 70 | + return append2(buffer, v); |
| 71 | +} |
| 72 | + |
| 73 | +template <typename T> |
| 74 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 75 | +append4_no_zeros(char* buffer, T v) |
| 76 | +{ |
| 77 | + if (v < 100) |
| 78 | + return append2_no_zeros(buffer, v); |
| 79 | + else if (v < 1000) |
| 80 | + return append3(buffer, v); |
| 81 | + else |
| 82 | + return append4(buffer, v); |
| 83 | +} |
| 84 | + |
| 85 | +template <typename T> |
| 86 | +inline _LIBCPP_INLINE_VISIBILITY char* |
| 87 | +append8_no_zeros(char* buffer, T v) |
| 88 | +{ |
| 89 | + if (v < 10000) |
| 90 | + { |
| 91 | + buffer = append4_no_zeros(buffer, v); |
| 92 | + } |
| 93 | + else |
| 94 | + { |
| 95 | + buffer = append4_no_zeros(buffer, v / 10000); |
| 96 | + buffer = append4(buffer, v % 10000); |
| 97 | + } |
| 98 | + return buffer; |
| 99 | +} |
| 100 | + |
| 101 | +char* |
| 102 | +__u32toa(uint32_t value, char* buffer) |
| 103 | +{ |
| 104 | + if (value < 100000000) |
| 105 | + { |
| 106 | + buffer = append8_no_zeros(buffer, value); |
| 107 | + } |
| 108 | + else |
| 109 | + { |
| 110 | + // value = aabbbbcccc in decimal |
| 111 | + const uint32_t a = value / 100000000; // 1 to 42 |
| 112 | + value %= 100000000; |
| 113 | + |
| 114 | + buffer = append2_no_zeros(buffer, a); |
| 115 | + buffer = append4(buffer, value / 10000); |
| 116 | + buffer = append4(buffer, value % 10000); |
| 117 | + } |
| 118 | + |
| 119 | + return buffer; |
| 120 | +} |
| 121 | + |
| 122 | +char* |
| 123 | +__u64toa(uint64_t value, char* buffer) |
| 124 | +{ |
| 125 | + if (value < 100000000) |
| 126 | + { |
| 127 | + uint32_t v = static_cast<uint32_t>(value); |
| 128 | + buffer = append8_no_zeros(buffer, v); |
| 129 | + } |
| 130 | + else if (value < 10000000000000000) |
| 131 | + { |
| 132 | + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); |
| 133 | + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); |
| 134 | + |
| 135 | + buffer = append8_no_zeros(buffer, v0); |
| 136 | + buffer = append4(buffer, v1 / 10000); |
| 137 | + buffer = append4(buffer, v1 % 10000); |
| 138 | + } |
| 139 | + else |
| 140 | + { |
| 141 | + const uint32_t a = |
| 142 | + static_cast<uint32_t>(value / 10000000000000000); // 1 to 1844 |
| 143 | + value %= 10000000000000000; |
| 144 | + |
| 145 | + buffer = append4_no_zeros(buffer, a); |
| 146 | + |
| 147 | + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); |
| 148 | + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); |
| 149 | + buffer = append4(buffer, v0 / 10000); |
| 150 | + buffer = append4(buffer, v0 % 10000); |
| 151 | + buffer = append4(buffer, v1 / 10000); |
| 152 | + buffer = append4(buffer, v1 % 10000); |
| 153 | + } |
| 154 | + |
| 155 | + return buffer; |
| 156 | +} |
| 157 | + |
| 158 | +} // namespace __itoa |
| 159 | + |
| 160 | +_LIBCPP_END_NAMESPACE_STD |
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