1 // Copyright 2006-2008 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 namespace v8 {
32 namespace internal {
33
34 // The fast double-to-int conversion routine does not guarantee
35 // rounding towards zero.
36 // The result is unspecified if x is infinite or NaN, or if the rounded
37 // integer value is outside the range of type int.
38 static inline int FastD2I(double x);
39
40
FastI2D(int x)41 static inline double FastI2D(int x) {
42 // There is no rounding involved in converting an integer to a
43 // double, so this code should compile to a few instructions without
44 // any FPU pipeline stalls.
45 return static_cast<double>(x);
46 }
47
48
FastUI2D(unsigned x)49 static inline double FastUI2D(unsigned x) {
50 // There is no rounding involved in converting an unsigned integer to a
51 // double, so this code should compile to a few instructions without
52 // any FPU pipeline stalls.
53 return static_cast<double>(x);
54 }
55
56
57 // This function should match the exact semantics of ECMA-262 9.4.
58 static inline double DoubleToInteger(double x);
59
60
61 // This function should match the exact semantics of ECMA-262 9.5.
62 static inline int32_t DoubleToInt32(double x);
63
64
65 // This function should match the exact semantics of ECMA-262 9.6.
DoubleToUint32(double x)66 static inline uint32_t DoubleToUint32(double x) {
67 return static_cast<uint32_t>(DoubleToInt32(x));
68 }
69
70
71 // Returns the value (0 .. 15) of a hexadecimal character c.
72 // If c is not a legal hexadecimal character, returns a value < 0.
73 int HexValue(uc32 c);
74
75
76 // Enumeration for allowing octals and ignoring junk when converting
77 // strings to numbers.
78 enum ConversionFlags {
79 NO_FLAGS = 0,
80 ALLOW_HEX = 1,
81 ALLOW_OCTALS = 2,
82 ALLOW_TRAILING_JUNK = 4
83 };
84
85
86 // Convert from Number object to C integer.
87 static inline int32_t NumberToInt32(Object* number);
88 static inline uint32_t NumberToUint32(Object* number);
89
90
91 // Converts a string into a double value according to ECMA-262 9.3.1
92 double StringToDouble(const char* str, int flags, double empty_string_val = 0);
93 double StringToDouble(String* str, int flags, double empty_string_val = 0);
94
95 // Converts a string into an integer.
96 int StringToInt(String* str, int index, int radix, double* value);
97 int StringToInt(const char* str, int index, int radix, double* value);
98
99 // Converts a double to a string value according to ECMA-262 9.8.1.
100 // The buffer should be large enough for any floating point number.
101 // 100 characters is enough.
102 const char* DoubleToCString(double value, Vector<char> buffer);
103
104 // Convert an int to a null-terminated string. The returned string is
105 // located inside the buffer, but not necessarily at the start.
106 const char* IntToCString(int n, Vector<char> buffer);
107
108 // Additional number to string conversions for the number type.
109 // The caller is responsible for calling free on the returned pointer.
110 char* DoubleToFixedCString(double value, int f);
111 char* DoubleToExponentialCString(double value, int f);
112 char* DoubleToPrecisionCString(double value, int f);
113 char* DoubleToRadixCString(double value, int radix);
114
115 } } // namespace v8::internal
116
117 #endif // V8_CONVERSIONS_H_
118