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 // Extra POSIX/ANSI routines for Win32 when using Visual Studio C++. Please
29 // refer to The Open Group Base Specification for specification of the correct
30 // semantics for these functions.
31 // (http://www.opengroup.org/onlinepubs/000095399/)
32 #if defined(_MSC_VER) && (_MSC_VER < 1800)
33
34 #include "win32-headers.h"
35 #include <limits.h> // Required for INT_MAX etc.
36 #include <float.h> // Required for DBL_MAX and on Win32 for finite()
37 #include <cmath>
38 #include "win32-math.h"
39
40 #include "checks.h"
41
42
43 namespace std {
44
45 // Test for a NaN (not a number) value - usually defined in math.h
isnan(double x)46 int isnan(double x) {
47 return _isnan(x);
48 }
49
50
51 // Test for infinity - usually defined in math.h
isinf(double x)52 int isinf(double x) {
53 return (_fpclass(x) & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0;
54 }
55
56
57 // Test for finite value - usually defined in math.h
isfinite(double x)58 int isfinite(double x) {
59 return _finite(x);
60 }
61
62
63 // Test if x is less than y and both nominal - usually defined in math.h
isless(double x,double y)64 int isless(double x, double y) {
65 return isnan(x) || isnan(y) ? 0 : x < y;
66 }
67
68
69 // Test if x is greater than y and both nominal - usually defined in math.h
isgreater(double x,double y)70 int isgreater(double x, double y) {
71 return isnan(x) || isnan(y) ? 0 : x > y;
72 }
73
74
75 // Classify floating point number - usually defined in math.h
fpclassify(double x)76 int fpclassify(double x) {
77 // Use the MS-specific _fpclass() for classification.
78 int flags = _fpclass(x);
79
80 // Determine class. We cannot use a switch statement because
81 // the _FPCLASS_ constants are defined as flags.
82 if (flags & (_FPCLASS_PN | _FPCLASS_NN)) return FP_NORMAL;
83 if (flags & (_FPCLASS_PZ | _FPCLASS_NZ)) return FP_ZERO;
84 if (flags & (_FPCLASS_PD | _FPCLASS_ND)) return FP_SUBNORMAL;
85 if (flags & (_FPCLASS_PINF | _FPCLASS_NINF)) return FP_INFINITE;
86
87 // All cases should be covered by the code above.
88 ASSERT(flags & (_FPCLASS_SNAN | _FPCLASS_QNAN));
89 return FP_NAN;
90 }
91
92
93 // Test sign - usually defined in math.h
signbit(double x)94 int signbit(double x) {
95 // We need to take care of the special case of both positive
96 // and negative versions of zero.
97 if (x == 0)
98 return _fpclass(x) & _FPCLASS_NZ;
99 else
100 return x < 0;
101 }
102
103 } // namespace std
104
105 #endif // _MSC_VER
106