binutils-gdb/gas/flonum-copy.c

/* flonum_copy.c - copy a flonum
   Copyright (C) 1987, 1990, 1991 Free Software Foundation, Inc.
   
   This file is part of GAS, the GNU Assembler.
   
   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
   
   GAS 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 General Public License
   along with GAS; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "as.h"

#ifdef USG
#define bzero(s,n) memset(s,0,n)
#define bcopy(from,to,n) memcpy(to,from,n)
#endif

void
    flonum_copy (in, out)
FLONUM_TYPE *	in;
FLONUM_TYPE *	out;
{
	int			in_length;	/* 0 origin */
	int			out_length;	/* 0 origin */
	
	out -> sign = in -> sign;
	in_length = in  -> leader - in -> low;
	if (in_length < 0)
	    {
		    out -> leader = out -> low - 1; /* 0.0 case */
	    }
	else
	    {
		    out_length = out -> high - out -> low;
		    /*
		     * Assume no GAPS in packing of littlenums.
		     * I.e. sizeof(array) == sizeof(element) * number_of_elements.
		     */
		    if (in_length <= out_length)
			{
				{
					/*
					 * For defensive programming, zero any high-order littlenums we don't need.
					 * This is destroying evidence and wasting time, so why bother???
					 */
					if (in_length < out_length)
					    {
						    bzero ((char *)(out->low + in_length + 1), out_length - in_length);
					    }
				}
				bcopy ((char *)(in->low), (char *)(out->low), (int)((in_length + 1) * sizeof(LITTLENUM_TYPE)));
				out -> exponent = in -> exponent;
				out -> leader   = in -> leader - in -> low + out -> low;
			}
		    else
			{
				int	shorten;		/* 1-origin. Number of littlenums we drop. */
				
				shorten = in_length - out_length;
				/* Assume out_length >= 0 ! */
				bcopy ((char *)(in->low + shorten),(char *)( out->low), (int)((out_length + 1) * sizeof(LITTLENUM_TYPE)));
				out -> leader = out -> high;
				out -> exponent = in -> exponent + shorten;
			}
	    }				/* if any significant bits */
}

/* end of flonum_copy.c */