1 /* 2 * Copyright (C) 2012 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 /** 32 * Imported from: 33 * https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/platform/Decimal.h 34 * Check UPSTREAM-GIT-SHA for the commit ID of the last update from Blink core. 35 */ 36 37 #ifndef Decimal_h 38 #define Decimal_h 39 40 #include "mozilla/Assertions.h" 41 #include <stdint.h> 42 #include "mozilla/Types.h" 43 44 #include <string> 45 46 #ifndef ASSERT 47 #define DEFINED_ASSERT_FOR_DECIMAL_H 1 48 #define ASSERT MOZ_ASSERT 49 #endif 50 51 #define PLATFORM_EXPORT 52 53 // To use USING_FAST_MALLOC we'd need: 54 // https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/wtf/Allocator.h 55 // Since we don't allocate Decimal objects, no need. 56 #define USING_FAST_MALLOC(type) \ 57 void ignore_this_dummy_method() = delete 58 59 #define DISALLOW_NEW() \ 60 private: \ 61 void* operator new(size_t) = delete; \ 62 void* operator new(size_t, void*) = delete; \ 63 public: 64 65 namespace blink { 66 67 namespace DecimalPrivate { 68 class SpecialValueHandler; 69 } 70 71 // This class represents decimal base floating point number. 72 // 73 // FIXME: Once all C++ compiler support decimal type, we should replace this 74 // class to compiler supported one. See below URI for current status of decimal 75 // type for C++: // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1977.html 76 class PLATFORM_EXPORT Decimal { 77 USING_FAST_MALLOC(Decimal); 78 public: 79 enum Sign { 80 Positive, 81 Negative, 82 }; 83 84 // You should not use EncodedData other than unit testing. 85 class EncodedData { 86 DISALLOW_NEW(); 87 // For accessing FormatClass. 88 friend class Decimal; 89 friend class DecimalPrivate::SpecialValueHandler; 90 public: 91 EncodedData(Sign, int exponent, uint64_t coefficient); 92 93 bool operator==(const EncodedData&) const; 94 bool operator!=(const EncodedData& another) const { return !operator==(another); } 95 coefficient()96 uint64_t coefficient() const { return m_coefficient; } 97 int countDigits() const; exponent()98 int exponent() const { return m_exponent; } isFinite()99 bool isFinite() const { return !isSpecial(); } isInfinity()100 bool isInfinity() const { return m_formatClass == ClassInfinity; } isNaN()101 bool isNaN() const { return m_formatClass == ClassNaN; } isSpecial()102 bool isSpecial() const { return m_formatClass == ClassInfinity || m_formatClass == ClassNaN; } isZero()103 bool isZero() const { return m_formatClass == ClassZero; } sign()104 Sign sign() const { return m_sign; } setSign(Sign sign)105 void setSign(Sign sign) { m_sign = sign; } 106 107 private: 108 enum FormatClass { 109 ClassInfinity, 110 ClassNormal, 111 ClassNaN, 112 ClassZero, 113 }; 114 115 EncodedData(Sign, FormatClass); formatClass()116 FormatClass formatClass() const { return m_formatClass; } 117 118 uint64_t m_coefficient; 119 int16_t m_exponent; 120 FormatClass m_formatClass; 121 Sign m_sign; 122 }; 123 124 MFBT_API explicit Decimal(int32_t = 0); 125 MFBT_API Decimal(Sign, int exponent, uint64_t coefficient); 126 MFBT_API Decimal(const Decimal&); 127 128 MFBT_API Decimal& operator=(const Decimal&); 129 MFBT_API Decimal& operator+=(const Decimal&); 130 MFBT_API Decimal& operator-=(const Decimal&); 131 MFBT_API Decimal& operator*=(const Decimal&); 132 MFBT_API Decimal& operator/=(const Decimal&); 133 134 MFBT_API Decimal operator-() const; 135 136 MFBT_API bool operator==(const Decimal&) const; 137 MFBT_API bool operator!=(const Decimal&) const; 138 MFBT_API bool operator<(const Decimal&) const; 139 MFBT_API bool operator<=(const Decimal&) const; 140 MFBT_API bool operator>(const Decimal&) const; 141 MFBT_API bool operator>=(const Decimal&) const; 142 143 MFBT_API Decimal operator+(const Decimal&) const; 144 MFBT_API Decimal operator-(const Decimal&) const; 145 MFBT_API Decimal operator*(const Decimal&) const; 146 MFBT_API Decimal operator/(const Decimal&) const; 147 exponent()148 int exponent() const 149 { 150 ASSERT(isFinite()); 151 return m_data.exponent(); 152 } 153 isFinite()154 bool isFinite() const { return m_data.isFinite(); } isInfinity()155 bool isInfinity() const { return m_data.isInfinity(); } isNaN()156 bool isNaN() const { return m_data.isNaN(); } isNegative()157 bool isNegative() const { return sign() == Negative; } isPositive()158 bool isPositive() const { return sign() == Positive; } isSpecial()159 bool isSpecial() const { return m_data.isSpecial(); } isZero()160 bool isZero() const { return m_data.isZero(); } 161 162 MFBT_API Decimal abs() const; 163 MFBT_API Decimal ceil() const; 164 MFBT_API Decimal floor() const; 165 MFBT_API Decimal remainder(const Decimal&) const; 166 MFBT_API Decimal round() const; 167 168 MFBT_API double toDouble() const; 169 // Note: toString method supports infinity and nan but fromString not. 170 MFBT_API std::string toString() const; 171 MFBT_API bool toString(char* strBuf, size_t bufLength) const; 172 173 static MFBT_API Decimal fromDouble(double); 174 // fromString supports following syntax EBNF: 175 // number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)? 176 // | sign? '.' digit+ (exponent-marker sign? digit+)? 177 // sign ::= '+' | '-' 178 // exponent-marker ::= 'e' | 'E' 179 // digit ::= '0' | '1' | ... | '9' 180 // Note: fromString doesn't support "infinity" and "nan". 181 static MFBT_API Decimal fromString(const std::string& aValue); 182 static MFBT_API Decimal infinity(Sign); 183 static MFBT_API Decimal nan(); 184 static MFBT_API Decimal zero(Sign); 185 186 // You should not use below methods. We expose them for unit testing. 187 MFBT_API explicit Decimal(const EncodedData&); value()188 const EncodedData& value() const { return m_data; } 189 190 private: 191 struct AlignedOperands { 192 uint64_t lhsCoefficient; 193 uint64_t rhsCoefficient; 194 int exponent; 195 }; 196 197 MFBT_API explicit Decimal(double); 198 MFBT_API Decimal compareTo(const Decimal&) const; 199 200 static MFBT_API AlignedOperands alignOperands(const Decimal& lhs, const Decimal& rhs); invertSign(Sign sign)201 static inline Sign invertSign(Sign sign) { return sign == Negative ? Positive : Negative; } 202 sign()203 Sign sign() const { return m_data.sign(); } 204 205 EncodedData m_data; 206 }; 207 208 } // namespace blink 209 210 namespace mozilla { 211 typedef blink::Decimal Decimal; 212 } // namespace mozilla 213 214 #undef USING_FAST_MALLOC 215 216 #ifdef DEFINED_ASSERT_FOR_DECIMAL_H 217 #undef DEFINED_ASSERT_FOR_DECIMAL_H 218 #undef ASSERT 219 #endif 220 221 #endif // Decimal_h 222