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
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.
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.
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/)
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.
39 #include <float.h> // Required for DBL_MAX and on Win32 for finite()
40 #include "win32-math.h"
46 // Test for finite value - usually defined in math.h
47 int isfinite(double x) {
54 // Test for a NaN (not a number) value - usually defined in math.h
60 // Test for infinity - usually defined in math.h
62 return (_fpclass(x) & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0;
66 // Test if x is less than y and both nominal - usually defined in math.h
67 int isless(double x, double y) {
68 return isnan(x) || isnan(y) ? 0 : x < y;
72 // Test if x is greater than y and both nominal - usually defined in math.h
73 int isgreater(double x, double y) {
74 return isnan(x) || isnan(y) ? 0 : x > y;
78 // Classify floating point number - usually defined in math.h
79 int fpclassify(double x) {
80 // Use the MS-specific _fpclass() for classification.
81 int flags = _fpclass(x);
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;
90 // All cases should be covered by the code above.
91 ASSERT(flags & (_FPCLASS_SNAN | _FPCLASS_QNAN));
96 // Test sign - usually defined in math.h
97 int signbit(double x) {
98 // We need to take care of the special case of both positive
99 // and negative versions of zero.
101 return _fpclass(x) & _FPCLASS_NZ;