1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_CONVERSIONS_H_ 29 #define V8_CONVERSIONS_H_ 30 31 #include "scanner-base.h" 32 33 namespace v8 { 34 namespace internal { 35 36 37 // The fast double-to-(unsigned-)int conversion routine does not guarantee 38 // rounding towards zero. 39 // The result is unspecified if x is infinite or NaN, or if the rounded 40 // integer value is outside the range of type int. 41 static inline int FastD2I(double x) { 42 // The static_cast convertion from double to int used to be slow, but 43 // as new benchmarks show, now it is much faster than lrint(). 44 return static_cast<int>(x); 45 } 46 47 static inline unsigned int FastD2UI(double x); 48 49 50 static inline double FastI2D(int x) { 51 // There is no rounding involved in converting an integer to a 52 // double, so this code should compile to a few instructions without 53 // any FPU pipeline stalls. 54 return static_cast<double>(x); 55 } 56 57 58 static inline double FastUI2D(unsigned x) { 59 // There is no rounding involved in converting an unsigned integer to a 60 // double, so this code should compile to a few instructions without 61 // any FPU pipeline stalls. 62 return static_cast<double>(x); 63 } 64 65 66 // This function should match the exact semantics of ECMA-262 9.4. 67 static inline double DoubleToInteger(double x); 68 69 70 // This function should match the exact semantics of ECMA-262 9.5. 71 static inline int32_t DoubleToInt32(double x); 72 73 74 // This function should match the exact semantics of ECMA-262 9.6. 75 static inline uint32_t DoubleToUint32(double x) { 76 return static_cast<uint32_t>(DoubleToInt32(x)); 77 } 78 79 80 // Enumeration for allowing octals and ignoring junk when converting 81 // strings to numbers. 82 enum ConversionFlags { 83 NO_FLAGS = 0, 84 ALLOW_HEX = 1, 85 ALLOW_OCTALS = 2, 86 ALLOW_TRAILING_JUNK = 4 87 }; 88 89 90 // Convert from Number object to C integer. 91 static inline int32_t NumberToInt32(Object* number); 92 static inline uint32_t NumberToUint32(Object* number); 93 94 95 // Converts a string into a double value according to ECMA-262 9.3.1 96 double StringToDouble(UnicodeCache* unicode_cache, 97 String* str, 98 int flags, 99 double empty_string_val = 0); 100 double StringToDouble(UnicodeCache* unicode_cache, 101 Vector<const char> str, 102 int flags, 103 double empty_string_val = 0); 104 // This version expects a zero-terminated character array. 105 double StringToDouble(UnicodeCache* unicode_cache, 106 const char* str, 107 int flags, 108 double empty_string_val = 0); 109 110 // Converts a string into an integer. 111 double StringToInt(UnicodeCache* unicode_cache, String* str, int radix); 112 113 // Converts a double to a string value according to ECMA-262 9.8.1. 114 // The buffer should be large enough for any floating point number. 115 // 100 characters is enough. 116 const char* DoubleToCString(double value, Vector<char> buffer); 117 118 // Convert an int to a null-terminated string. The returned string is 119 // located inside the buffer, but not necessarily at the start. 120 const char* IntToCString(int n, Vector<char> buffer); 121 122 // Additional number to string conversions for the number type. 123 // The caller is responsible for calling free on the returned pointer. 124 char* DoubleToFixedCString(double value, int f); 125 char* DoubleToExponentialCString(double value, int f); 126 char* DoubleToPrecisionCString(double value, int f); 127 char* DoubleToRadixCString(double value, int radix); 128 129 } } // namespace v8::internal 130 131 #endif // V8_CONVERSIONS_H_ 132
