library/math_floor.c
/*
* $Id: math_floor.c,v 1.5 2006-01-08 12:04:23 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
* 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.
*
* - Neither the name of Olaf Barthel nor the names of 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.
*
*
* PowerPC math library based in part on work by Sun Microsystems
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
*/
#ifndef _MATH_HEADERS_H
#include "math_headers.h"
#endif /* _MATH_HEADERS_H */
/****************************************************************************/
#if defined(FLOATING_POINT_SUPPORT)
/****************************************************************************/
#if defined(IEEE_FLOATING_POINT_SUPPORT)
/****************************************************************************/
#if defined(__GNUC__)
/****************************************************************************/
#if defined(SMALL_DATA)
#define A4(x) "a4@(" #x ":W)"
#elif defined(SMALL_DATA32)
#define A4(x) "a4@(" #x ":L)"
#else
#define A4(x) #x
#endif /* SMALL_DATA */
/****************************************************************************/
extern double __floor(double x);
/****************************************************************************/
asm("
.text
.even
.globl _MathIeeeDoubBasBase
.globl ___floor
___floor:
movel a6,sp@-
movel "A4(_MathIeeeDoubBasBase)",a6
moveml sp@(8),d0/d1
jsr a6@(-90:W)
movel sp@+,a6
rts
");
/****************************************************************************/
#else
/****************************************************************************/
INLINE STATIC const double
__floor(double x)
{
double result;
result = IEEEDPFloor(x);
return(result);
}
/****************************************************************************/
#endif /* __GNUC__ */
/****************************************************************************/
#endif /* IEEE_FLOATING_POINT_SUPPORT */
/****************************************************************************/
#if defined(M68881_FLOATING_POINT_SUPPORT)
INLINE STATIC const double
__floor(double x)
{
int rounding_mode, round_down;
double result;
__asm __volatile ("fmove%.l fpcr,%0"
: "=dm" (rounding_mode)
: /* no inputs */ );
round_down = (rounding_mode & ~0x10) | 0x20;
__asm __volatile ("fmove%.l %0,fpcr"
: /* no outputs */
: "dmi" (round_down));
__asm __volatile ("fint%.x %1,%0"
: "=f" (result)
: "f" (x));
__asm __volatile ("fmove%.l %0,fpcr"
: /* no outputs */
: "dmi" (rounding_mode));
return(result);
}
#endif /* M68881_FLOATING_POINT_SUPPORT */
/****************************************************************************/
#if defined(PPC_FLOATING_POINT_SUPPORT)
static const double huge = 1.0e300;
INLINE STATIC double
__floor(double x)
{
int i0,i1,j0;
unsigned int i,j;
EXTRACT_WORDS(i0,i1,x);
j0 = ((i0>>20)&0x7ff)-0x3ff;
if(j0<20)
{
if(j0<0)
{
if(huge+x>0.0)
{
if(i0>=0)
{
i0=i1=0;
}
else if(((i0&0x7fffffff)|i1)!=0)
{
i0=0xbff00000;
i1=0;
}
}
}
else
{
i = (0x000fffff)>>j0;
if(((i0&i)|i1)==0)
return x;
if(huge+x>0.0)
{
if(i0<0)
i0 += (0x00100000)>>j0;
i0 &= (~i); i1=0;
}
}
}
else if (j0>51)
{
if(j0==0x400)
return x+x;
else
return x;
}
else
{
i = ((unsigned int)(0xffffffff))>>(j0-20);
if((i1&i)==0)
return x;
if(huge+x>0.0)
{
if(i0<0)
{
if(j0==20)
i0+=1;
else
{
j = i1+(1<<(52-j0));
if(j<i1)
i0 +=1;
i1=j;
}
}
i1 &= (~i);
}
}
INSERT_WORDS(x,i0,i1);
return x;
}
#endif /* PPC_FLOATING_POINT_SUPPORT */
/****************************************************************************/
double
floor(double x)
{
double result;
result = __floor(x);
return(result);
}
/****************************************************************************/
#endif /* FLOATING_POINT_SUPPORT */