| // Copyright 2011 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_CONVERSIONS_H_ |
| #define V8_CONVERSIONS_H_ |
| |
| #include <limits> |
| |
| #include "src/base/logging.h" |
| #include "src/handles.h" |
| #include "src/utils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class UnicodeCache; |
| |
| // Maximum number of significant digits in decimal representation. |
| // The longest possible double in decimal representation is |
| // (2^53 - 1) * 2 ^ -1074 that is (2 ^ 53 - 1) * 5 ^ 1074 / 10 ^ 1074 |
| // (768 digits). If we parse a number whose first digits are equal to a |
| // mean of 2 adjacent doubles (that could have up to 769 digits) the result |
| // must be rounded to the bigger one unless the tail consists of zeros, so |
| // we don't need to preserve all the digits. |
| const int kMaxSignificantDigits = 772; |
| |
| |
| inline bool isDigit(int x, int radix) { |
| return (x >= '0' && x <= '9' && x < '0' + radix) |
| || (radix > 10 && x >= 'a' && x < 'a' + radix - 10) |
| || (radix > 10 && x >= 'A' && x < 'A' + radix - 10); |
| } |
| |
| |
| inline bool isBinaryDigit(int x) { |
| return x == '0' || x == '1'; |
| } |
| |
| |
| // The fast double-to-(unsigned-)int conversion routine does not guarantee |
| // rounding towards zero. |
| // If x is NaN, the result is INT_MIN. Otherwise the result is the argument x, |
| // clamped to [INT_MIN, INT_MAX] and then rounded to an integer. |
| inline int FastD2IChecked(double x) { |
| if (!(x >= INT_MIN)) return INT_MIN; // Negation to catch NaNs. |
| if (x > INT_MAX) return INT_MAX; |
| return static_cast<int>(x); |
| } |
| |
| |
| // The fast double-to-(unsigned-)int conversion routine does not guarantee |
| // rounding towards zero. |
| // The result is unspecified if x is infinite or NaN, or if the rounded |
| // integer value is outside the range of type int. |
| inline int FastD2I(double x) { |
| return static_cast<int32_t>(x); |
| } |
| |
| inline unsigned int FastD2UI(double x); |
| |
| |
| inline double FastI2D(int x) { |
| // There is no rounding involved in converting an integer to a |
| // double, so this code should compile to a few instructions without |
| // any FPU pipeline stalls. |
| return static_cast<double>(x); |
| } |
| |
| |
| inline double FastUI2D(unsigned x) { |
| // There is no rounding involved in converting an unsigned integer to a |
| // double, so this code should compile to a few instructions without |
| // any FPU pipeline stalls. |
| return static_cast<double>(x); |
| } |
| |
| |
| // This function should match the exact semantics of ECMA-262 20.2.2.17. |
| inline float DoubleToFloat32(double x); |
| |
| |
| // This function should match the exact semantics of ECMA-262 9.4. |
| inline double DoubleToInteger(double x); |
| |
| |
| // This function should match the exact semantics of ECMA-262 9.5. |
| inline int32_t DoubleToInt32(double x); |
| |
| |
| // This function should match the exact semantics of ECMA-262 9.6. |
| inline uint32_t DoubleToUint32(double x); |
| |
| |
| // Enumeration for allowing octals and ignoring junk when converting |
| // strings to numbers. |
| enum ConversionFlags { |
| NO_FLAGS = 0, |
| ALLOW_HEX = 1, |
| ALLOW_OCTAL = 2, |
| ALLOW_IMPLICIT_OCTAL = 4, |
| ALLOW_BINARY = 8, |
| ALLOW_TRAILING_JUNK = 16 |
| }; |
| |
| |
| // Converts a string into a double value according to ECMA-262 9.3.1 |
| double StringToDouble(UnicodeCache* unicode_cache, |
| Vector<const uint8_t> str, |
| int flags, |
| double empty_string_val = 0); |
| double StringToDouble(UnicodeCache* unicode_cache, |
| Vector<const uc16> str, |
| int flags, |
| double empty_string_val = 0); |
| // This version expects a zero-terminated character array. |
| double StringToDouble(UnicodeCache* unicode_cache, |
| const char* str, |
| int flags, |
| double empty_string_val = 0); |
| |
| // Converts a string into an integer. |
| double StringToInt(UnicodeCache* unicode_cache, |
| Vector<const uint8_t> vector, |
| int radix); |
| |
| |
| double StringToInt(UnicodeCache* unicode_cache, |
| Vector<const uc16> vector, |
| int radix); |
| |
| const int kDoubleToCStringMinBufferSize = 100; |
| |
| // Converts a double to a string value according to ECMA-262 9.8.1. |
| // The buffer should be large enough for any floating point number. |
| // 100 characters is enough. |
| const char* DoubleToCString(double value, Vector<char> buffer); |
| |
| // Convert an int to a null-terminated string. The returned string is |
| // located inside the buffer, but not necessarily at the start. |
| const char* IntToCString(int n, Vector<char> buffer); |
| |
| // Additional number to string conversions for the number type. |
| // The caller is responsible for calling free on the returned pointer. |
| char* DoubleToFixedCString(double value, int f); |
| char* DoubleToExponentialCString(double value, int f); |
| char* DoubleToPrecisionCString(double value, int f); |
| char* DoubleToRadixCString(double value, int radix); |
| |
| |
| static inline bool IsMinusZero(double value) { |
| static const DoubleRepresentation minus_zero(-0.0); |
| return DoubleRepresentation(value) == minus_zero; |
| } |
| |
| |
| inline bool IsSmiDouble(double value); |
| |
| |
| // Integer32 is an integer that can be represented as a signed 32-bit |
| // integer. It has to be in the range [-2^31, 2^31 - 1]. |
| // We also have to check for negative 0 as it is not an Integer32. |
| inline bool IsInt32Double(double value); |
| |
| |
| // UInteger32 is an integer that can be represented as an unsigned 32-bit |
| // integer. It has to be in the range [0, 2^32 - 1]. |
| // We also have to check for negative 0 as it is not a UInteger32. |
| inline bool IsUint32Double(double value); |
| |
| |
| // Convert from Number object to C integer. |
| inline int32_t NumberToInt32(Object* number); |
| inline uint32_t NumberToUint32(Object* number); |
| inline int64_t NumberToInt64(Object* number); |
| |
| double StringToDouble(UnicodeCache* unicode_cache, Handle<String> string, |
| int flags, double empty_string_val = 0.0); |
| |
| |
| inline bool TryNumberToSize(Isolate* isolate, Object* number, size_t* result); |
| |
| |
| // Converts a number into size_t. |
| inline size_t NumberToSize(Isolate* isolate, Object* number); |
| |
| |
| // returns DoubleToString(StringToDouble(string)) == string |
| bool IsSpecialIndex(UnicodeCache* unicode_cache, String* string); |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_CONVERSIONS_H_ |