1 /* 2 * Copyright (c) 2021 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef ECMASCRIPT_BASE_NUMBER_HELPER_H 17 #define ECMASCRIPT_BASE_NUMBER_HELPER_H 18 19 #include <cstdint> 20 21 #include "ecmascript/ecma_string.h" 22 #include "ecmascript/js_tagged_value.h" 23 24 namespace panda::ecmascript::base { 25 constexpr double MIN_RADIX = 2; 26 constexpr double MAX_RADIX = 36; 27 constexpr double MIN_FRACTION = 0; 28 constexpr double MAX_FRACTION = 100; 29 30 // Coversion flags 31 static constexpr uint32_t NO_FLAGS = 0U; 32 static constexpr uint32_t ALLOW_BINARY = 1U << 0U; 33 static constexpr uint32_t ALLOW_OCTAL = 1U << 1U; 34 static constexpr uint32_t ALLOW_HEX = 1U << 2U; 35 static constexpr uint32_t IGNORE_TRAILING = 1U << 3U; 36 37 static constexpr uint32_t MAX_PRECISION = 16; 38 static constexpr uint8_t BINARY = 2; 39 static constexpr uint8_t OCTAL = 8; 40 static constexpr uint8_t DECIMAL = 10; 41 static constexpr uint8_t HEXADECIMAL = 16; 42 static constexpr double HALF = 0.5; 43 static constexpr double EPSILON = std::numeric_limits<double>::epsilon(); 44 static constexpr int64_t MAX_SAFE_INTEGER = 9007199254740991; 45 static constexpr double MAX_VALUE = std::numeric_limits<double>::max(); 46 static constexpr double MIN_VALUE = std::numeric_limits<double>::min(); 47 static constexpr double POSITIVE_INFINITY = std::numeric_limits<double>::infinity(); 48 static constexpr double NAN_VALUE = std::numeric_limits<double>::quiet_NaN(); 49 static constexpr uint64_t MAX_UINT64_VALUE = std::numeric_limits<uint64_t>::max(); 50 51 // Helper defines for double 52 static constexpr int DOUBLE_MAX_PRECISION = 17; 53 static constexpr int DOUBLE_EXPONENT_BIAS = 0x3FF; 54 static constexpr size_t DOUBLE_SIGNIFICAND_SIZE = 52; 55 static constexpr uint64_t DOUBLE_SIGN_MASK = 0x8000000000000000ULL; 56 static constexpr uint64_t DOUBLE_EXPONENT_MASK = 0x7FFULL << DOUBLE_SIGNIFICAND_SIZE; 57 static constexpr uint64_t DOUBLE_SIGNIFICAND_MASK = 0x000FFFFFFFFFFFFFULL; 58 static constexpr uint64_t DOUBLE_HIDDEN_BIT = 1ULL << DOUBLE_SIGNIFICAND_SIZE; 59 static constexpr int32_t MINUS_ZERO_LOBITS = static_cast<int32_t>(0); 60 static constexpr int32_t MINUS_ZERO_HIBITS = static_cast<int32_t>(1) << 31; 61 static constexpr int64_t MINUS_ZERO_BITS = (static_cast<uint64_t>(MINUS_ZERO_HIBITS) << 32) | MINUS_ZERO_LOBITS; 62 63 static constexpr size_t INT64_BITS = 64; 64 static constexpr size_t INT32_BITS = 32; 65 static constexpr size_t INT16_BITS = 16; 66 static constexpr size_t INT8_BITS = 8; 67 static constexpr size_t JS_DTOA_BUF_SIZE = 128; 68 69 // help defines for random 70 static constexpr int RIGHT12 = 12; 71 static constexpr int SECONDS_TO_SUBTLE = 1000000; 72 static constexpr int RIGHT27 = 27; 73 static constexpr int LEFT25 = 25; 74 static constexpr uint64_t GET_MULTIPLY = 0x2545F4914F6CDD1D; 75 // Exponent bits for double value between [1.0, 2.0) 76 static constexpr uint64_t EXPONENTBITS_RANGE_IN_ONE_AND_TWO = 0x3FF0000000000000; 77 78 class NumberHelper { 79 public: GetNaN()80 static inline JSTaggedType GetNaN() 81 { 82 return JSTaggedValue(NAN_VALUE).GetRawData(); 83 } 84 GetPositiveInfinity()85 static inline JSTaggedType GetPositiveInfinity() 86 { 87 return JSTaggedValue(POSITIVE_INFINITY).GetRawData(); 88 } 89 IsFinite(JSTaggedValue number)90 static bool IsFinite(JSTaggedValue number) 91 { 92 return number.IsInt() || (number.IsDouble() && std::isfinite(number.GetDouble())); 93 } IsNaN(JSTaggedValue number)94 static bool IsNaN(JSTaggedValue number) 95 { 96 return number.IsDouble() && std::isnan(number.GetDouble()); 97 } 98 static JSTaggedValue DoubleToString(JSThread *thread, double number, int radix); 99 static bool IsEmptyString(const uint8_t *start, const uint8_t *end); 100 static JSHandle<EcmaString> IntToEcmaString(const JSThread *thread, int number); 101 static JSHandle<EcmaString> NumberToString(const JSThread *thread, JSTaggedValue number); 102 static double TruncateDouble(double d); 103 static int64_t DoubleToInt64(double d); 104 static double StringToDouble(const uint8_t *start, const uint8_t *end, uint8_t radix, uint32_t flags = NO_FLAGS); 105 static int32_t DoubleToInt(double d, size_t bits); 106 static int32_t DoubleInRangeInt32(double d); 107 static JSTaggedValue DoubleToExponential(JSThread *thread, double number, int digit); 108 static JSTaggedValue DoubleToFixed(JSThread *thread, double number, int digit); 109 static JSTaggedValue DoubleToPrecision(JSThread *thread, double number, int digit); 110 static JSTaggedValue StringToDoubleWithRadix(const uint8_t *start, const uint8_t *end, int radix); 111 static CString IntToString(int number); 112 static CString IntegerToString(double number, int radix); 113 static JSTaggedValue StringToBigInt(JSThread *thread, JSHandle<JSTaggedValue> strVal); 114 115 private: 116 static char Carry(char current, int radix); 117 static double Strtod(const char *str, int exponent, uint8_t radix); 118 static CString DecimalsToString(double *numberInteger, double fraction, int radix, double delta); 119 static bool GotoNonspace(uint8_t **ptr, const uint8_t *end); 120 static void GetBase(double d, int digits, int *decpt, char *buf, char *bufTmp, int size); 121 static int GetMinmumDigits(double d, int *decpt, char *buf); 122 }; 123 124 // This class is used to generate 0~1 uniform distribution pseudo-random numbers. 125 // It uses a 64-bit seed which is current timestamp to generate state value. 126 // The value is used in xorshift64* random generator to generate result. 127 class RandomGenerator { 128 public: 129 static void InitRandom(); 130 static double NextDouble(); 131 static int32_t GenerateIdentityHash(); 132 static int32_t Next(int bits); 133 134 private: 135 static uint64_t XorShift64(uint64_t *pVal); 136 static double ToDouble(uint64_t state); 137 138 private: 139 static thread_local uint64_t randomState_; 140 }; 141 } // namespace panda::ecmascript::base 142 #endif // ECMASCRIPT_BASE_NUMBER_HELPER_H 143