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 46 int isnan(double x) { 47 return _isnan(x); 48 } 49 50 51 // Test for infinity - usually defined in math.h 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 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 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 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 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 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
