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.
FastD2I(double x)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
FastI2D(int x)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
FastUI2D(unsigned x)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.
DoubleToUint32(double x)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