OLD | NEW |
1 // Copyright 2012 the V8 project authors. All rights reserved. | 1 // Copyright 2012 the V8 project authors. All rights reserved. |
2 // Redistribution and use in source and binary forms, with or without | 2 // Redistribution and use in source and binary forms, with or without |
3 // modification, are permitted provided that the following conditions are | 3 // modification, are permitted provided that the following conditions are |
4 // met: | 4 // met: |
5 // | 5 // |
6 // * Redistributions of source code must retain the above copyright | 6 // * Redistributions of source code must retain the above copyright |
7 // notice, this list of conditions and the following disclaimer. | 7 // notice, this list of conditions and the following disclaimer. |
8 // * Redistributions in binary form must reproduce the above | 8 // * Redistributions in binary form must reproduce the above |
9 // copyright notice, this list of conditions and the following | 9 // copyright notice, this list of conditions and the following |
10 // disclaimer in the documentation and/or other materials provided | 10 // disclaimer in the documentation and/or other materials provided |
(...skipping 110 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
121 // The input buffer has been trimmed. Therefore the last digit must be | 121 // The input buffer has been trimmed. Therefore the last digit must be |
122 // different from '0'. | 122 // different from '0'. |
123 ASSERT(buffer[buffer.length() - 1] != '0'); | 123 ASSERT(buffer[buffer.length() - 1] != '0'); |
124 // Set the last digit to be non-zero. This is sufficient to guarantee | 124 // Set the last digit to be non-zero. This is sufficient to guarantee |
125 // correct rounding. | 125 // correct rounding. |
126 significant_buffer[kMaxSignificantDecimalDigits - 1] = '1'; | 126 significant_buffer[kMaxSignificantDecimalDigits - 1] = '1'; |
127 *significant_exponent = | 127 *significant_exponent = |
128 exponent + (buffer.length() - kMaxSignificantDecimalDigits); | 128 exponent + (buffer.length() - kMaxSignificantDecimalDigits); |
129 } | 129 } |
130 | 130 |
| 131 |
131 // Reads digits from the buffer and converts them to a uint64. | 132 // Reads digits from the buffer and converts them to a uint64. |
132 // Reads in as many digits as fit into a uint64. | 133 // Reads in as many digits as fit into a uint64. |
133 // When the string starts with "1844674407370955161" no further digit is read. | 134 // When the string starts with "1844674407370955161" no further digit is read. |
134 // Since 2^64 = 18446744073709551616 it would still be possible read another | 135 // Since 2^64 = 18446744073709551616 it would still be possible read another |
135 // digit if it was less or equal than 6, but this would complicate the code. | 136 // digit if it was less or equal than 6, but this would complicate the code. |
136 static uint64_t ReadUint64(Vector<const char> buffer, | 137 static uint64_t ReadUint64(Vector<const char> buffer, |
137 int* number_of_read_digits) { | 138 int* number_of_read_digits) { |
138 uint64_t result = 0; | 139 uint64_t result = 0; |
139 int i = 0; | 140 int i = 0; |
140 while (i < buffer.length() && result <= (kMaxUint64 / 10 - 1)) { | 141 while (i < buffer.length() && result <= (kMaxUint64 / 10 - 1)) { |
(...skipping 27 matching lines...) Expand all Loading... |
168 int exponent = 0; | 169 int exponent = 0; |
169 *result = DiyFp(significand, exponent); | 170 *result = DiyFp(significand, exponent); |
170 *remaining_decimals = buffer.length() - read_digits; | 171 *remaining_decimals = buffer.length() - read_digits; |
171 } | 172 } |
172 } | 173 } |
173 | 174 |
174 | 175 |
175 static bool DoubleStrtod(Vector<const char> trimmed, | 176 static bool DoubleStrtod(Vector<const char> trimmed, |
176 int exponent, | 177 int exponent, |
177 double* result) { | 178 double* result) { |
178 #if (defined(V8_TARGET_ARCH_IA32) || defined(USE_SIMULATOR)) \ | 179 #if (V8_TARGET_ARCH_IA32 || defined(USE_SIMULATOR)) && !defined(_MSC_VER) |
179 && !defined(_MSC_VER) | |
180 // On x86 the floating-point stack can be 64 or 80 bits wide. If it is | 180 // On x86 the floating-point stack can be 64 or 80 bits wide. If it is |
181 // 80 bits wide (as is the case on Linux) then double-rounding occurs and the | 181 // 80 bits wide (as is the case on Linux) then double-rounding occurs and the |
182 // result is not accurate. | 182 // result is not accurate. |
183 // We know that Windows32 with MSVC, unlike with MinGW32, uses 64 bits and is | 183 // We know that Windows32 with MSVC, unlike with MinGW32, uses 64 bits and is |
184 // therefore accurate. | 184 // therefore accurate. |
185 // Note that the ARM and MIPS simulators are compiled for 32bits. They | 185 // Note that the ARM and MIPS simulators are compiled for 32bits. They |
186 // therefore exhibit the same problem. | 186 // therefore exhibit the same problem. |
187 return false; | 187 return false; |
188 #endif | 188 #endif |
189 if (trimmed.length() <= kMaxExactDoubleIntegerDecimalDigits) { | 189 if (trimmed.length() <= kMaxExactDoubleIntegerDecimalDigits) { |
(...skipping 243 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
433 | 433 |
434 double guess; | 434 double guess; |
435 if (DoubleStrtod(trimmed, exponent, &guess) || | 435 if (DoubleStrtod(trimmed, exponent, &guess) || |
436 DiyFpStrtod(trimmed, exponent, &guess)) { | 436 DiyFpStrtod(trimmed, exponent, &guess)) { |
437 return guess; | 437 return guess; |
438 } | 438 } |
439 return BignumStrtod(trimmed, exponent, guess); | 439 return BignumStrtod(trimmed, exponent, guess); |
440 } | 440 } |
441 | 441 |
442 } } // namespace v8::internal | 442 } } // namespace v8::internal |
OLD | NEW |