1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_CONVERSIONS_H_
#define V8_CONVERSIONS_H_
#include "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);
}
// The fast double-to-(unsigned-)int conversion routine does not guarantee
// rounding towards zero.
// For NaN and values outside the int range, return INT_MIN or INT_MAX.
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<int>(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 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) {
return static_cast<uint32_t>(DoubleToInt32(x));
}
// Enumeration for allowing octals and ignoring junk when converting
// strings to numbers.
enum ConversionFlags {
NO_FLAGS = 0,
ALLOW_HEX = 1,
ALLOW_OCTALS = 2,
ALLOW_TRAILING_JUNK = 4
};
// Converts a string into a double value according to ECMA-262 9.3.1
double StringToDouble(UnicodeCache* unicode_cache,
Vector<const char> 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);
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);
} } // namespace v8::internal
#endif // V8_CONVERSIONS_H_
|
