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// Copyright 2006-2008 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.
#ifndef V8_CONVERSIONS_INL_H_
#define V8_CONVERSIONS_INL_H_
#include <math.h>
#include <float.h> // required for DBL_MAX and on Win32 for finite()
#include <stdarg.h>
// ----------------------------------------------------------------------------
// Extra POSIX/ANSI functions for Win32/MSVC.
#include "conversions.h"
#include "platform.h"
namespace v8 {
namespace internal {
// The fast double-to-int conversion routine does not guarantee
// rounding towards zero.
static inline int FastD2I(double x) {
#ifdef __USE_ISOC99
// The ISO C99 standard defines the lrint() function which rounds a
// double to an integer according to the current rounding direction.
return lrint(x);
#else
// This is incredibly slow on Intel x86. The reason is that rounding
// towards zero is implied by the C standard. This means that the
// status register of the FPU has to be changed with the 'fldcw'
// instruction. This completely stalls the pipeline and takes many
// hundreds of clock cycles.
return static_cast<int>(x);
#endif
}
static inline double DoubleToInteger(double x) {
if (isnan(x)) return 0;
if (!isfinite(x) || x == 0) return x;
return (x >= 0) ? floor(x) : ceil(x);
}
int32_t NumberToInt32(Object* number) {
if (number->IsSmi()) return Smi::cast(number)->value();
return DoubleToInt32(number->Number());
}
uint32_t NumberToUint32(Object* number) {
if (number->IsSmi()) return Smi::cast(number)->value();
return DoubleToUint32(number->Number());
}
int32_t DoubleToInt32(double x) {
int32_t i = FastD2I(x);
if (FastI2D(i) == x) return i;
static const double two32 = 4294967296.0;
static const double two31 = 2147483648.0;
if (!isfinite(x) || x == 0) return 0;
if (x < 0 || x >= two32) x = fmod(x, two32);
x = (x >= 0) ? floor(x) : ceil(x) + two32;
return (int32_t) ((x >= two31) ? x - two32 : x);
}
} } // namespace v8::internal
#endif // V8_CONVERSIONS_INL_H_
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