v8/src/win32-math.cc

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// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 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/)
#ifdef _MSC_VER
#undef V8_WIN32_LEAN_AND_MEAN
#define V8_WIN32_HEADERS_FULL
#include "win32-headers.h"
#include <limits.h> // Required for INT_MAX etc.
#include <math.h>
#include <float.h> // Required for DBL_MAX and on Win32 for finite()
#include "win32-math.h"
#include "checks.h"
namespace v8 {
// Test for finite value - usually defined in math.h
int isfinite(double x) {
return _finite(x);
}
} // namespace v8
// 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 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;
}
#endif // _MSC_VER