kolibrios/programs/develop/open watcom/trunk/clib/fpu/cntrlfp.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
* DESCRIBE IT HERE!
*
****************************************************************************/
#include "variety.h"
#include <math.h>
#include <float.h>
#include "rtdata.h"
#if defined(__AXP__)
/*
* FPCR Trap Disable Flags
*/
#define FPCR_INEXACT 0x40000000
#define FPCR_UNDERFLOW 0x20000000
#define FPCR_OVERFLOW 0x00080000
#define FPCR_ZERODIVIDE 0x00040000
#define FPCR_INVALID 0x00020000
extern unsigned long _GetFPCR(void);
extern void _SetFPCR(unsigned long);
static unsigned int MapToCW(unsigned long fpcr)
{
unsigned int cw;
/*
* The rounding bits are identical but in the highword of the fpcr.
*/
cw = (fpcr >> 16) & ~(_MCW_RC);
if (fpcr & FPCR_INEXACT)
cw &= ~_EM_INEXACT;
if (fpcr & FPCR_ZERODIVIDE)
cw &= ~_EM_ZERODIVIDE;
if (fpcr & FPCR_OVERFLOW)
cw &= ~_EM_OVERFLOW;
if (fpcr & FPCR_UNDERFLOW)
cw &= ~_EM_UNDERFLOW;
if (fpcr & FPCR_INVALID)
cw &= ~_EM_INVALID;
return cw;
} /* MapToCW() */
static unsigned long MapFromCW(unsigned int cw)
{
unsigned long fpcr = 0L;
/*
* The rounding bits are identical but in the highword of the fpcr.
*/
fpcr = (cw & ~_MCW_RC) << 16;
if (!(cw & _EM_INEXACT))
fpcr |= FPCR_INEXACT;
if (!(cw & _EM_INVALID))
fpcr |= FPCR_INVALID;
if (!(cw & _EM_ZERODIVIDE))
fpcr |= FPCR_ZERODIVIDE;
if (!(cw & _EM_OVERFLOW))
fpcr |= FPCR_OVERFLOW;
if (!(cw & _EM_UNDERFLOW))
fpcr |= FPCR_UNDERFLOW;
return fpcr;
} /* MapFromCW() */
#endif
_WCRTLINK unsigned _controlfp(unsigned new, unsigned mask)
{
#if defined(_M_IX86)
return _control87(new, mask); /* JBS 99/09/16 */
#elif defined(__AXP__)
unsigned int cw;
cw = MapToCW(_GetFPCR());
if (mask)
{
cw = (cw & ~mask) | (new & mask);
_SetFPCR(MapFromCW(cw));
}
return cw;
#elif defined(__PPC__)
// No idea yet
return( 0 );
#elif defined(__MIPS__)
// No idea yet either
return( 0 );
#endif
} /* _controlfp() */