18b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdoch// Copyright 2011 the V8 project authors. All rights reserved. 2b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Use of this source code is governed by a BSD-style license that can be 3b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// found in the LICENSE file. 4a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 5014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch#include "src/conversions.h" 6014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch 76ded16be15dd865a9b21ea304d5273c8be299c87Steve Block#include <limits.h> 8b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include <stdarg.h> 9b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include <cmath> 10b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 11b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/assert-scope.h" 12014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch#include "src/char-predicates-inl.h" 13014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch#include "src/codegen.h" 14b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/conversions-inl.h" 15b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/dtoa.h" 16b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/factory.h" 17b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/list-inl.h" 18b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/strtod.h" 19b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/utils.h" 20b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 21b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#ifndef _STLP_VENDOR_CSTD 22b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// STLPort doesn't import fpclassify into the std namespace. 23b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochusing std::fpclassify; 24b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#endif 25a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 26a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace v8 { 27a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blocknamespace internal { 28a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 29a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 30b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochnamespace { 31b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 32b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// C++-style iterator adaptor for StringCharacterStream 33b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// (unlike C++ iterators the end-marker has different type). 34b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass StringCharacterStreamIterator { 35b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch public: 36b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch class EndMarker {}; 37b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 38b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch explicit StringCharacterStreamIterator(StringCharacterStream* stream); 39b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 40b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch uint16_t operator*() const; 41b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch void operator++(); 42b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch bool operator==(EndMarker const&) const { return end_; } 43b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch bool operator!=(EndMarker const& m) const { return !end_; } 44b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 45b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch private: 46b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch StringCharacterStream* const stream_; 47b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch uint16_t current_; 48b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch bool end_; 49b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch}; 50b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 51b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 52b8a8cc1952d61a2f3a2568848933943a543b5d3eBen MurdochStringCharacterStreamIterator::StringCharacterStreamIterator( 53b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch StringCharacterStream* stream) : stream_(stream) { 54b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch ++(*this); 55b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 56b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 57b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochuint16_t StringCharacterStreamIterator::operator*() const { 58b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return current_; 59b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 60b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 61b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 62b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochvoid StringCharacterStreamIterator::operator++() { 63b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch end_ = !stream_->HasMore(); 64b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch if (!end_) { 65b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch current_ = stream_->GetNext(); 66b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch } 67b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 68b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} // End anonymous namespace. 69b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 70b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 718b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdochdouble StringToDouble(UnicodeCache* unicode_cache, 728b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdoch const char* str, int flags, double empty_string_val) { 73b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // We cast to const uint8_t* here to avoid instantiating the 74b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // InternalStringToDouble() template for const char* as well. 75b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch const uint8_t* start = reinterpret_cast<const uint8_t*>(str); 76b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch const uint8_t* end = start + StrLength(str); 77b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return InternalStringToDouble(unicode_cache, start, end, flags, 7844f0eee88ff00398ff7f715fab053374d808c90dSteve Block empty_string_val); 79a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 80a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 81a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 828b112d2025046f85ef7f6be087c6129c872ebad2Ben Murdochdouble StringToDouble(UnicodeCache* unicode_cache, 83b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Vector<const uint8_t> str, 8480d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen int flags, 8580d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen double empty_string_val) { 86b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // We cast to const uint8_t* here to avoid instantiating the 87b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // InternalStringToDouble() template for const char* as well. 88b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch const uint8_t* start = reinterpret_cast<const uint8_t*>(str.start()); 89b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch const uint8_t* end = start + str.length(); 90b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return InternalStringToDouble(unicode_cache, start, end, flags, 9144f0eee88ff00398ff7f715fab053374d808c90dSteve Block empty_string_val); 9280d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen} 9380d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen 94b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 95257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdochdouble StringToDouble(UnicodeCache* unicode_cache, 96257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch Vector<const uc16> str, 97257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch int flags, 98257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch double empty_string_val) { 99257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch const uc16* end = str.start() + str.length(); 100257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch return InternalStringToDouble(unicode_cache, str.start(), end, flags, 101257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch empty_string_val); 102257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch} 103257744e915dfc84d6d07a6b2accf8402d9ffc708Ben Murdoch 10480d68eab642096c1a48b6474d6ec33064b0ad1f5Kristian Monsen 105b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Converts a string into an integer. 106b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochdouble StringToInt(UnicodeCache* unicode_cache, 107b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Vector<const uint8_t> vector, 108b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch int radix) { 109b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return InternalStringToInt( 110b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch unicode_cache, vector.start(), vector.start() + vector.length(), radix); 111b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 112b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 113b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 114b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochdouble StringToInt(UnicodeCache* unicode_cache, 115b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Vector<const uc16> vector, 116b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch int radix) { 117b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return InternalStringToInt( 118b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch unicode_cache, vector.start(), vector.start() + vector.length(), radix); 119b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 120b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 121b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 122a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockconst char* DoubleToCString(double v, Vector<char> buffer) { 123a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block switch (fpclassify(v)) { 1241e0659c275bb392c045087af4f6b0d7565cb3d77Steve Block case FP_NAN: return "NaN"; 1251e0659c275bb392c045087af4f6b0d7565cb3d77Steve Block case FP_INFINITE: return (v < 0.0 ? "-Infinity" : "Infinity"); 1261e0659c275bb392c045087af4f6b0d7565cb3d77Steve Block case FP_ZERO: return "0"; 127a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block default: { 1283fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder builder(buffer.start(), buffer.length()); 129a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int decimal_point; 130a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int sign; 13125f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen const int kV8DtoaBufferCapacity = kBase10MaximalLength + 1; 1328a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang char decimal_rep[kV8DtoaBufferCapacity]; 1336ded16be15dd865a9b21ea304d5273c8be299c87Steve Block int length; 13425f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen 1358a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang DoubleToAscii(v, DTOA_SHORTEST, 0, 1368a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang Vector<char>(decimal_rep, kV8DtoaBufferCapacity), 1378a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang &sign, &length, &decimal_point); 138a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 139a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (sign) builder.AddCharacter('-'); 140a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 141a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (length <= decimal_point && decimal_point <= 21) { 142a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ECMA-262 section 9.8.1 step 6. 143a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep); 144a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', decimal_point - length); 145a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 146a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else if (0 < decimal_point && decimal_point <= 21) { 147a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ECMA-262 section 9.8.1 step 7. 148a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(decimal_rep, decimal_point); 149a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('.'); 150a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep + decimal_point); 151a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 152a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else if (decimal_point <= 0 && decimal_point > -6) { 153a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ECMA-262 section 9.8.1 step 8. 154a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString("0."); 155a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', -decimal_point); 156a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep); 157a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 158a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else { 159a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // ECMA-262 section 9.8.1 step 9 and 10 combined. 160a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter(decimal_rep[0]); 161a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (length != 1) { 162a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('.'); 163a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep + 1); 164a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 165a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('e'); 166a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter((decimal_point >= 0) ? '+' : '-'); 167a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int exponent = decimal_point - 1; 168a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (exponent < 0) exponent = -exponent; 1693fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch builder.AddDecimalInteger(exponent); 170a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 1711e0659c275bb392c045087af4f6b0d7565cb3d77Steve Block return builder.Finalize(); 172a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 173a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 174a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 175a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 176a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 177a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockconst char* IntToCString(int n, Vector<char> buffer) { 178a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative = false; 179a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (n < 0) { 180a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // We must not negate the most negative int. 181a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (n == kMinInt) return DoubleToCString(n, buffer); 182a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block negative = true; 183a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block n = -n; 184a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 185a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Build the string backwards from the least significant digit. 186a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int i = buffer.length(); 187a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block buffer[--i] = '\0'; 188a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block do { 189a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block buffer[--i] = '0' + (n % 10); 190a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block n /= 10; 191a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } while (n); 192a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (negative) buffer[--i] = '-'; 193a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return buffer.start() + i; 194a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 195a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 196a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 197a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockchar* DoubleToFixedCString(double value, int f) { 1983e5fa29ddb82551500b118e9bf37af3966277b70Teng-Hui Zhu const int kMaxDigitsBeforePoint = 21; 19925f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen const double kFirstNonFixed = 1e21; 20025f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen const int kMaxDigitsAfterPoint = 20; 201b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(f >= 0); 202b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(f <= kMaxDigitsAfterPoint); 203a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 204a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative = false; 205a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block double abs_value = value; 206a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (value < 0) { 207a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block abs_value = -value; 208a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block negative = true; 209a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 210a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 21125f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen // If abs_value has more than kMaxDigitsBeforePoint digits before the point 21225f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen // use the non-fixed conversion routine. 21325f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen if (abs_value >= kFirstNonFixed) { 214a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char arr[100]; 215b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Vector<char> buffer(arr, arraysize(arr)); 216a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return StrDup(DoubleToCString(value, buffer)); 217a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 218a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 219a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Find a sufficiently precise decimal representation of n. 220a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int decimal_point; 221a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int sign; 2223e5fa29ddb82551500b118e9bf37af3966277b70Teng-Hui Zhu // Add space for the '\0' byte. 22325f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen const int kDecimalRepCapacity = 2243e5fa29ddb82551500b118e9bf37af3966277b70Teng-Hui Zhu kMaxDigitsBeforePoint + kMaxDigitsAfterPoint + 1; 22525f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen char decimal_rep[kDecimalRepCapacity]; 22625f6136652d8341ed047e7fc1a450af5bd218ea9Kristian Monsen int decimal_rep_length; 2278a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang DoubleToAscii(value, DTOA_FIXED, f, 2288a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang Vector<char>(decimal_rep, kDecimalRepCapacity), 2298a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang &sign, &decimal_rep_length, &decimal_point); 230a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 231a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Create a representation that is padded with zeros if needed. 232a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int zero_prefix_length = 0; 233a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int zero_postfix_length = 0; 234a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 235a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_point <= 0) { 236a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block zero_prefix_length = -decimal_point + 1; 237a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block decimal_point = 1; 238a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 239a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 240a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (zero_prefix_length + decimal_rep_length < decimal_point + f) { 241a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block zero_postfix_length = decimal_point + f - decimal_rep_length - 242a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block zero_prefix_length; 243a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 244a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 245a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block unsigned rep_length = 246a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block zero_prefix_length + decimal_rep_length + zero_postfix_length; 2473fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder rep_builder(rep_length + 1); 248a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block rep_builder.AddPadding('0', zero_prefix_length); 249a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block rep_builder.AddString(decimal_rep); 250a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block rep_builder.AddPadding('0', zero_postfix_length); 251a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char* rep = rep_builder.Finalize(); 252a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 253a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Create the result string by appending a minus and putting in a 254a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // decimal point if needed. 255a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block unsigned result_size = decimal_point + f + 2; 2563fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder builder(result_size + 1); 257a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (negative) builder.AddCharacter('-'); 258a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(rep, decimal_point); 259a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (f > 0) { 260a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('.'); 261a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(rep + decimal_point, f); 262a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 263a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block DeleteArray(rep); 264a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return builder.Finalize(); 265a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 266a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 267a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 268a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockstatic char* CreateExponentialRepresentation(char* decimal_rep, 269a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int exponent, 270a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative, 271a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int significant_digits) { 272a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative_exponent = false; 273a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (exponent < 0) { 274a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block negative_exponent = true; 275a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block exponent = -exponent; 276a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 277a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 278a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Leave room in the result for appending a minus, for a period, the 279a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // letter 'e', a minus or a plus depending on the exponent, and a 280a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // three digit exponent. 281a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block unsigned result_size = significant_digits + 7; 2823fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder builder(result_size + 1); 283a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 284a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (negative) builder.AddCharacter('-'); 285a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter(decimal_rep[0]); 286a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (significant_digits != 1) { 287a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('.'); 288a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep + 1); 289d0582a6c46733687d045e4188a1bcd0123c758a1Steve Block int rep_length = StrLength(decimal_rep); 290d0582a6c46733687d045e4188a1bcd0123c758a1Steve Block builder.AddPadding('0', significant_digits - rep_length); 291a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 292a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 293a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('e'); 294a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter(negative_exponent ? '-' : '+'); 2953fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch builder.AddDecimalInteger(exponent); 296a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return builder.Finalize(); 297a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 298a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 299a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 300a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockchar* DoubleToExponentialCString(double value, int f) { 3010d5e116f6aee03185f237311a943491bb079a768Kristian Monsen const int kMaxDigitsAfterPoint = 20; 302a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // f might be -1 to signal that f was undefined in JavaScript. 303b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(f >= -1 && f <= kMaxDigitsAfterPoint); 304a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 305a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative = false; 306a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (value < 0) { 307a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block value = -value; 308a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block negative = true; 309a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 310a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 311a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Find a sufficiently precise decimal representation of n. 312a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int decimal_point; 313a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int sign; 3140d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // f corresponds to the digits after the point. There is always one digit 3150d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // before the point. The number of requested_digits equals hence f + 1. 3160d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // And we have to add one character for the null-terminator. 3170d5e116f6aee03185f237311a943491bb079a768Kristian Monsen const int kV8DtoaBufferCapacity = kMaxDigitsAfterPoint + 1 + 1; 3180d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // Make sure that the buffer is big enough, even if we fall back to the 3190d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // shortest representation (which happens when f equals -1). 320b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(kBase10MaximalLength <= kMaxDigitsAfterPoint + 1); 3218a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang char decimal_rep[kV8DtoaBufferCapacity]; 3220d5e116f6aee03185f237311a943491bb079a768Kristian Monsen int decimal_rep_length; 3230d5e116f6aee03185f237311a943491bb079a768Kristian Monsen 324a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (f == -1) { 3258a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang DoubleToAscii(value, DTOA_SHORTEST, 0, 3268a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang Vector<char>(decimal_rep, kV8DtoaBufferCapacity), 3278a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang &sign, &decimal_rep_length, &decimal_point); 3288a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang f = decimal_rep_length - 1; 329a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else { 3308a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang DoubleToAscii(value, DTOA_PRECISION, f + 1, 3318a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang Vector<char>(decimal_rep, kV8DtoaBufferCapacity), 3328a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang &sign, &decimal_rep_length, &decimal_point); 333a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 334b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(decimal_rep_length > 0); 335b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(decimal_rep_length <= f + 1); 336a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 337a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int exponent = decimal_point - 1; 338a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char* result = 339a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block CreateExponentialRepresentation(decimal_rep, exponent, negative, f+1); 340a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 341a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return result; 342a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 343a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 344a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 345a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockchar* DoubleToPrecisionCString(double value, int p) { 3460d5e116f6aee03185f237311a943491bb079a768Kristian Monsen const int kMinimalDigits = 1; 3470d5e116f6aee03185f237311a943491bb079a768Kristian Monsen const int kMaximalDigits = 21; 348b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(p >= kMinimalDigits && p <= kMaximalDigits); 3490d5e116f6aee03185f237311a943491bb079a768Kristian Monsen USE(kMinimalDigits); 350a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 351a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool negative = false; 352a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (value < 0) { 353a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block value = -value; 354a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block negative = true; 355a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 356a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 357a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Find a sufficiently precise decimal representation of n. 358a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int decimal_point; 359a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int sign; 3600d5e116f6aee03185f237311a943491bb079a768Kristian Monsen // Add one for the terminating null character. 3610d5e116f6aee03185f237311a943491bb079a768Kristian Monsen const int kV8DtoaBufferCapacity = kMaximalDigits + 1; 3628a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang char decimal_rep[kV8DtoaBufferCapacity]; 3630d5e116f6aee03185f237311a943491bb079a768Kristian Monsen int decimal_rep_length; 3640d5e116f6aee03185f237311a943491bb079a768Kristian Monsen 3658a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang DoubleToAscii(value, DTOA_PRECISION, p, 3668a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang Vector<char>(decimal_rep, kV8DtoaBufferCapacity), 3678a31eba00023874d4a1dcdc5f411cc4336776874Shimeng (Simon) Wang &sign, &decimal_rep_length, &decimal_point); 368b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(decimal_rep_length <= p); 369a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 370a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int exponent = decimal_point - 1; 371a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 372a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char* result = NULL; 373a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 374a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (exponent < -6 || exponent >= p) { 375a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block result = 376a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block CreateExponentialRepresentation(decimal_rep, exponent, negative, p); 377a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else { 378a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Use fixed notation. 379a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 380a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Leave room in the result for appending a minus, a period and in 381a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // the case where decimal_point is not positive for a zero in 382a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // front of the period. 383a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block unsigned result_size = (decimal_point <= 0) 384a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block ? -decimal_point + p + 3 385a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block : p + 2; 3863fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder builder(result_size + 1); 387a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (negative) builder.AddCharacter('-'); 388a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_point <= 0) { 389a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString("0."); 390a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', -decimal_point); 391a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddString(decimal_rep); 392a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', p - decimal_rep_length); 393a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } else { 394a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block const int m = Min(decimal_rep_length, decimal_point); 395a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(decimal_rep, m); 396a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', decimal_point - decimal_rep_length); 397a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_point < p) { 398a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddCharacter('.'); 399a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block const int extra = negative ? 2 : 1; 400a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_rep_length > decimal_point) { 401d0582a6c46733687d045e4188a1bcd0123c758a1Steve Block const int len = StrLength(decimal_rep + decimal_point); 402a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block const int n = Min(len, p - (builder.position() - extra)); 403a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(decimal_rep + decimal_point, n); 404a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 405a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddPadding('0', extra + (p - builder.position())); 406a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 407a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 408a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block result = builder.Finalize(); 409a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 410a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 411a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return result; 412a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 413a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 414a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 415a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Blockchar* DoubleToRadixCString(double value, int radix) { 416b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(radix >= 2 && radix <= 36); 417a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 418a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Character array used for conversion. 419a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const char chars[] = "0123456789abcdefghijklmnopqrstuvwxyz"; 420a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 421a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Buffer for the integer part of the result. 1024 chars is enough 422a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // for max integer value in radix 2. We need room for a sign too. 423a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block static const int kBufferSize = 1100; 424a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char integer_buffer[kBufferSize]; 425a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block integer_buffer[kBufferSize - 1] = '\0'; 426a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 427a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Buffer for the decimal part of the result. We only generate up 428a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // to kBufferSize - 1 chars for the decimal part. 429a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block char decimal_buffer[kBufferSize]; 430a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block decimal_buffer[kBufferSize - 1] = '\0'; 431a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 432a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Make sure the value is positive. 433a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block bool is_negative = value < 0.0; 434a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (is_negative) value = -value; 435a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 436a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Get the integer part and the decimal part. 437b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch double integer_part = std::floor(value); 438a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block double decimal_part = value - integer_part; 439a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 440a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Convert the integer part starting from the back. Always generate 441a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // at least one digit. 442a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int integer_pos = kBufferSize - 2; 443a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block do { 444014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch double remainder = modulo(integer_part, radix); 445b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch integer_buffer[integer_pos--] = chars[static_cast<int>(remainder)]; 446b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch integer_part -= remainder; 447a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block integer_part /= radix; 448a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } while (integer_part >= 1.0); 449a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Sanity check. 450b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DCHECK(integer_pos > 0); 451a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Add sign if needed. 452a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (is_negative) integer_buffer[integer_pos--] = '-'; 453a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 454a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Convert the decimal part. Repeatedly multiply by the radix to 455a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // generate the next char. Never generate more than kBufferSize - 1 456a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // chars. 457a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // 458a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // TODO(1093998): We will often generate a full decimal_buffer of 459a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // chars because hitting zero will often not happen. The right 460a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // solution would be to continue until the string representation can 461a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // be read back and yield the original value. To implement this 462a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // efficiently, we probably have to modify dtoa. 463a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int decimal_pos = 0; 464a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block while ((decimal_part > 0.0) && (decimal_pos < kBufferSize - 1)) { 465a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block decimal_part *= radix; 466a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block decimal_buffer[decimal_pos++] = 467b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch chars[static_cast<int>(std::floor(decimal_part))]; 468b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch decimal_part -= std::floor(decimal_part); 469a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block } 470a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block decimal_buffer[decimal_pos] = '\0'; 471a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 472a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Compute the result size. 473a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block int integer_part_size = kBufferSize - 2 - integer_pos; 474a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Make room for zero termination. 475a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block unsigned result_size = integer_part_size + decimal_pos; 476a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // If the number has a decimal part, leave room for the period. 477a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_pos > 0) result_size++; 478a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block // Allocate result and fill in the parts. 4793fb3ca8c7ca439d408449a395897395c0faae8d1Ben Murdoch SimpleStringBuilder builder(result_size + 1); 480a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(integer_buffer + integer_pos + 1, integer_part_size); 481a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block if (decimal_pos > 0) builder.AddCharacter('.'); 482a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block builder.AddSubstring(decimal_buffer, decimal_pos); 483a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block return builder.Finalize(); 484a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block} 485a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 486b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 487014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch// ES6 18.2.4 parseFloat(string) 488958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernierdouble StringToDouble(UnicodeCache* unicode_cache, Handle<String> string, 489958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier int flags, double empty_string_val) { 490958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier Handle<String> flattened = String::Flatten(string); 491958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier { 492958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier DisallowHeapAllocation no_gc; 493958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier String::FlatContent flat = flattened->GetFlatContent(); 494958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier DCHECK(flat.IsFlat()); 495958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier if (flat.IsOneByte()) { 496958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier return StringToDouble(unicode_cache, flat.ToOneByteVector(), flags, 497958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier empty_string_val); 498958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier } else { 499958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier return StringToDouble(unicode_cache, flat.ToUC16Vector(), flags, 500958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier empty_string_val); 501958fae7ec3f466955f8e5b50fa5b8d38b9e91675Emily Bernier } 502b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch } 503b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 504b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 505b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 506014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdochbool IsSpecialIndex(UnicodeCache* unicode_cache, String* string) { 507014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Max length of canonical double: -X.XXXXXXXXXXXXXXXXX-eXXX 508014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch const int kBufferSize = 24; 509014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch const int length = string->length(); 510014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (length == 0 || length > kBufferSize) return false; 511014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch uint16_t buffer[kBufferSize]; 512014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch String::WriteToFlat(string, buffer, 0, length); 513014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // If the first char is not a digit or a '-' or we can't match 'NaN' or 514014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // '(-)Infinity', bailout immediately. 515014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch int offset = 0; 516014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (!IsDecimalDigit(buffer[0])) { 517014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (buffer[0] == '-') { 518014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (length == 1) return false; // Just '-' is bad. 519014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (!IsDecimalDigit(buffer[1])) { 520014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (buffer[1] == 'I' && length == 9) { 521014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Allow matching of '-Infinity' below. 522014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } else { 523014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch return false; 524014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 525014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 526014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch offset++; 527014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } else if (buffer[0] == 'I' && length == 8) { 528014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Allow matching of 'Infinity' below. 529014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } else if (buffer[0] == 'N' && length == 3) { 530014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Match NaN. 531014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch return buffer[1] == 'a' && buffer[2] == 'N'; 532014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } else { 533014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch return false; 534014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 535014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 536014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Expected fast path: key is an integer. 537014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch static const int kRepresentableIntegerLength = 15; // (-)XXXXXXXXXXXXXXX 538014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (length - offset <= kRepresentableIntegerLength) { 539014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch const int initial_offset = offset; 540014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch bool matches = true; 541014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch for (; offset < length; offset++) { 542014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch matches &= IsDecimalDigit(buffer[offset]); 543014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 544014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (matches) { 545014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Match 0 and -0. 546014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (buffer[initial_offset] == '0') return initial_offset == length - 1; 547014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch return true; 548014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 549014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 550014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Slow path: test DoubleToString(StringToDouble(string)) == string. 551014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch Vector<const uint16_t> vector(buffer, length); 552014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch double d = StringToDouble(unicode_cache, vector, NO_FLAGS); 553014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (std::isnan(d)) return false; 554014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch // Compute reverse string. 555014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch char reverse_buffer[kBufferSize + 1]; // Result will be /0 terminated. 556014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch Vector<char> reverse_vector(reverse_buffer, arraysize(reverse_buffer)); 557014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch const char* reverse_string = DoubleToCString(d, reverse_vector); 558014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch for (int i = 0; i < length; ++i) { 559014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch if (static_cast<uint16_t>(reverse_string[i]) != buffer[i]) return false; 560014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch } 561014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch return true; 562014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch} 563014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch} // namespace internal 564014dc512cdd3e367bee49a713fdc5ed92584a3e5Ben Murdoch} // namespace v8 565