runtime/JSValue.cpp

   1 /*
   2  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
   3  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
   4  *  Copyright (C) 2003, 2007, 2008 Apple Inc. All rights reserved.
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Library General Public
   8  *  License as published by the Free Software Foundation; either
   9  *  version 2 of the License, or (at your option) any later version.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Library General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Library General Public License
  17  *  along with this library; see the file COPYING.LIB.  If not, write to
  18  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  *  Boston, MA 02110-1301, USA.
  20  *
  21  */
  22
  23 #include "config.h"
  24 #include "JSValue.h"
  25
  26 #include "JSFunction.h"
  27 #include <wtf/MathExtras.h>
  28
  29 namespace JSC {
  30
  31 static const double D32 = 4294967296.0;
  32
  33 // ECMA 9.4
  34 double JSValuePtr::toInteger(ExecState* exec) const
  35 {
  36     if (isInt32Fast())
  37         return getInt32Fast();
  38     double d = toNumber(exec);
  39     return isnan(d) ? 0.0 : trunc(d);
  40 }
  41
  42 double JSValuePtr::toIntegerPreserveNaN(ExecState* exec) const
  43 {
  44     if (isInt32Fast())
  45         return getInt32Fast();
  46     return trunc(toNumber(exec));
  47 }
  48
  49 int32_t toInt32SlowCase(double d, bool& ok)
  50 {
  51     ok = true;
  52
  53     if (d >= -D32 / 2 && d < D32 / 2)
  54         return static_cast<int32_t>(d);
  55
  56     if (isnan(d) || isinf(d)) {
  57         ok = false;
  58         return 0;
  59     }
  60
  61     double d32 = fmod(trunc(d), D32);
  62     if (d32 >= D32 / 2)
  63         d32 -= D32;
  64     else if (d32 < -D32 / 2)
  65         d32 += D32;
  66     return static_cast<int32_t>(d32);
  67 }
  68
  69 uint32_t toUInt32SlowCase(double d, bool& ok)
  70 {
  71     ok = true;
  72
  73     if (d >= 0.0 && d < D32)
  74         return static_cast<uint32_t>(d);
  75
  76     if (isnan(d) || isinf(d)) {
  77         ok = false;
  78         return 0;
  79     }
  80
  81     double d32 = fmod(trunc(d), D32);
  82     if (d32 < 0)
  83         d32 += D32;
  84     return static_cast<uint32_t>(d32);
  85 }
  86
  87 } // namespace JSC