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/*
* Copyright (C) 2003, 2006 Apple Computer, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
*/
#include <math.h>
#include "global.h"
namespace KJS {
// This file exists because JavaScriptCore needs to define the NaN and Inf globals in a way
// that does not use a static initializer so we don't have a framework initialization routine.
// The trick is to define the NaN and Inf globals with a different type than the declaration.
// This trick works because the mangled name of the globals does not include the type, although
// I'm not sure that's guaranteed. There could be alignment issues with this, since arrays of
// characters don't necessarily need the same alignment doubles do, but for now it seems to work.
// It would be good to figure out a 100% clean way that still avoids code that runs at init time.
#if (defined(AVOID_STATIC_CONSTRUCTORS) && !AVOID_STATIC_CONSTRUCTORS)
KJS_EXPORT extern const double NaN = NAN;
KJS_EXPORT extern const double Inf = INFINITY;
#elif PLATFORM(DARWIN)
#if PLATFORM(BIG_ENDIAN)
KJS_EXPORT extern const unsigned char NaN[sizeof(double)] = { 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 };
KJS_EXPORT extern const unsigned char Inf[sizeof(double)] = { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 };
#elif PLATFORM(MIDDLE_ENDIAN)
KJS_EXPORT extern const unsigned char NaN[] = { 0, 0, 0xf8, 0x7f, 0, 0, 0, 0 };
KJS_EXPORT extern const unsigned char Inf[] = { 0, 0, 0xf0, 0x7f, 0, 0, 0, 0 };
#else
KJS_EXPORT extern const unsigned char NaN[sizeof(double)] = { 0, 0, 0, 0, 0, 0, 0xf8, 0x7f };
KJS_EXPORT extern const unsigned char Inf[sizeof(double)] = { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f };
#endif // PLATFORM(MIDDLE_ENDIAN)
#else // !PLATFORM(DARWIN)
// Note, we have to use union to ensure alignment. Otherwise, NaN_Bytes can start anywhere,
// while NaN_double has to be 4-byte aligned for 32-bits.
// With -fstrict-aliasing enabled, unions are the only safe way to do type masquerading.
static const union {
struct {
unsigned char NaN_Bytes[8];
unsigned char Inf_Bytes[8];
} bytes;
struct {
double NaN_Double;
double Inf_Double;
} doubles;
} NaNInf = { {
#if PLATFORM(BIG_ENDIAN)
{ 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 },
{ 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 }
#elif PLATFORM(MIDDLE_ENDIAN)
{ 0, 0, 0xf8, 0x7f, 0, 0, 0, 0 },
{ 0, 0, 0xf0, 0x7f, 0, 0, 0, 0 }
#else
{ 0, 0, 0, 0, 0, 0, 0xf8, 0x7f },
{ 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }
#endif
} } ;
KJS_EXPORT extern const double NaN = NaNInf.doubles.NaN_Double;
KJS_EXPORT extern const double Inf = NaNInf.doubles.Inf_Double;
#endif // !PLATFORM(DARWIN)
} // namespace KJS
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