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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 #ifdef _MSC_VER
33 
34 #undef V8_WIN32_LEAN_AND_MEAN
35 #define V8_WIN32_HEADERS_FULL
36 #include "win32-headers.h"
37 #include <limits.h>        // Required for INT_MAX etc.
38 #include <math.h>
39 #include <float.h>         // Required for DBL_MAX and on Win32 for finite()
40 #include "win32-math.h"
41 
42 #include "checks.h"
43 
44 namespace v8 {
45 
46 // Test for finite value - usually defined in math.h
isfinite(double x)47 int isfinite(double x) {
48   return _finite(x);
49 }
50 
51 }  // namespace v8
52 
53 
54 // Test for a NaN (not a number) value - usually defined in math.h
isnan(double x)55 int isnan(double x) {
56   return _isnan(x);
57 }
58 
59 
60 // Test for infinity - usually defined in math.h
isinf(double x)61 int isinf(double x) {
62   return (_fpclass(x) & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0;
63 }
64 
65 
66 // Test if x is less than y and both nominal - usually defined in math.h
isless(double x,double y)67 int isless(double x, double y) {
68   return isnan(x) || isnan(y) ? 0 : x < y;
69 }
70 
71 
72 // Test if x is greater than y and both nominal - usually defined in math.h
isgreater(double x,double y)73 int isgreater(double x, double y) {
74   return isnan(x) || isnan(y) ? 0 : x > y;
75 }
76 
77 
78 // Classify floating point number - usually defined in math.h
fpclassify(double x)79 int fpclassify(double x) {
80   // Use the MS-specific _fpclass() for classification.
81   int flags = _fpclass(x);
82 
83   // Determine class. We cannot use a switch statement because
84   // the _FPCLASS_ constants are defined as flags.
85   if (flags & (_FPCLASS_PN | _FPCLASS_NN)) return FP_NORMAL;
86   if (flags & (_FPCLASS_PZ | _FPCLASS_NZ)) return FP_ZERO;
87   if (flags & (_FPCLASS_PD | _FPCLASS_ND)) return FP_SUBNORMAL;
88   if (flags & (_FPCLASS_PINF | _FPCLASS_NINF)) return FP_INFINITE;
89 
90   // All cases should be covered by the code above.
91   ASSERT(flags & (_FPCLASS_SNAN | _FPCLASS_QNAN));
92   return FP_NAN;
93 }
94 
95 
96 // Test sign - usually defined in math.h
signbit(double x)97 int signbit(double x) {
98   // We need to take care of the special case of both positive
99   // and negative versions of zero.
100   if (x == 0)
101     return _fpclass(x) & _FPCLASS_NZ;
102   else
103     return x < 0;
104 }
105 
106 #endif  // _MSC_VER
107