This is mp_mulul3.c in view mode; [Download] [Up]
/* Copyright (C) 1994 W. Schelter
This file is part of GNU Common Lisp, herein referred to as GCL
GCL is free software; you can redistribute it and/or modify it under
the terms of the GNU LIBRARY GENERAL PUBLIC LICENSE as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GCL 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 General Public License
for more details.
You should have received a copy of the GNU library general public
license along with GCL; see the file COPYING. If not, write to the
Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "include.h"
#include "arith.h"
/* ulong a,b,y;
(y = mulul3(a,b,&hiremainder), hiremainder:y == a*b) is TRUE.
*/
#ifdef USE_WORD_MULUL3
int mulul3(x,y,hiremainder)
ulong x,y,*hiremainder;
{
ulong xlo,xhi,ylo,yhi;
ulong z; TEMPVARS
xlo=x&65535;xhi=x>>16;ylo=y&65535;yhi=y>>16;
z=addll(xlo*yhi,xhi*ylo);
*hiremainder=(overflow)?xhi*yhi+65536+(z>>16):xhi*yhi+(z>>16);
z=addll(xlo*ylo,(z<<16));*hiremainder+=overflow;
return z;
}
#else
ulong
mulul3(a,b,h)
unsigned int a,b, *h;
{unsigned int temph,templ,ah,al,i;
ah=0;
al=0;
/* in case the shift by 32 does not zero an unsigned int..
we separate out the first step.*/
{if (b & 1)
{temph=0;templ=a;
lladd(temph,templ,ah,al);}
/* printf("\n%d b=%d a=%d (%d:%d)",i,b,a,ah,al); */
b=b>>1;
}
i=1;
while(b)
{if (b & 1)
{llshift(a,i,temph,templ);
lladd(temph,templ,ah,al);}
i++;b=b>>1;
}
*h=ah;
return al;
}
#endif
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.