| // Copyright 2011 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Extra POSIX/ANSI routines for Win32 when using Visual Studio C++. Please |
| // refer to The Open Group Base Specification for specification of the correct |
| // semantics for these functions. |
| // (http://www.opengroup.org/onlinepubs/000095399/) |
| #if defined(_MSC_VER) && (_MSC_VER < 1800) |
| |
| #include "win32-headers.h" |
| #include <limits.h> // Required for INT_MAX etc. |
| #include <float.h> // Required for DBL_MAX and on Win32 for finite() |
| #include <cmath> |
| #include "win32-math.h" |
| |
| #include "checks.h" |
| |
| |
| namespace std { |
| |
| // Test for a NaN (not a number) value - usually defined in math.h |
| int isnan(double x) { |
| return _isnan(x); |
| } |
| |
| |
| // Test for infinity - usually defined in math.h |
| int isinf(double x) { |
| return (_fpclass(x) & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0; |
| } |
| |
| |
| // Test for finite value - usually defined in math.h |
| int isfinite(double x) { |
| return _finite(x); |
| } |
| |
| |
| // Test if x is less than y and both nominal - usually defined in math.h |
| int isless(double x, double y) { |
| return isnan(x) || isnan(y) ? 0 : x < y; |
| } |
| |
| |
| // Test if x is greater than y and both nominal - usually defined in math.h |
| int isgreater(double x, double y) { |
| return isnan(x) || isnan(y) ? 0 : x > y; |
| } |
| |
| |
| // Classify floating point number - usually defined in math.h |
| int fpclassify(double x) { |
| // Use the MS-specific _fpclass() for classification. |
| int flags = _fpclass(x); |
| |
| // Determine class. We cannot use a switch statement because |
| // the _FPCLASS_ constants are defined as flags. |
| if (flags & (_FPCLASS_PN | _FPCLASS_NN)) return FP_NORMAL; |
| if (flags & (_FPCLASS_PZ | _FPCLASS_NZ)) return FP_ZERO; |
| if (flags & (_FPCLASS_PD | _FPCLASS_ND)) return FP_SUBNORMAL; |
| if (flags & (_FPCLASS_PINF | _FPCLASS_NINF)) return FP_INFINITE; |
| |
| // All cases should be covered by the code above. |
| ASSERT(flags & (_FPCLASS_SNAN | _FPCLASS_QNAN)); |
| return FP_NAN; |
| } |
| |
| |
| // Test sign - usually defined in math.h |
| int signbit(double x) { |
| // We need to take care of the special case of both positive |
| // and negative versions of zero. |
| if (x == 0) |
| return _fpclass(x) & _FPCLASS_NZ; |
| else |
| return x < 0; |
| } |
| |
| } // namespace std |
| |
| #endif // _MSC_VER |