flonum-copy.c revision 78828 
1/* flonum_copy.c - copy a flonum
2   Copyright 1987, 1990, 1991, 1992, 1993, 2000
3   Free Software Foundation, Inc.
4
5   This file is part of GAS, the GNU Assembler.
6
7   GAS is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2, or (at your option)
10   any later version.
11
12   GAS is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with GAS; see the file COPYING.  If not, write to the Free
19   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20   02111-1307, USA.  */
21
22#include "as.h"
23
24void
25flonum_copy (in, out)
26     FLONUM_TYPE *in;
27     FLONUM_TYPE *out;
28{
29  unsigned int in_length;	/* 0 origin */
30  unsigned int out_length;	/* 0 origin */
31
32  out->sign = in->sign;
33  in_length = in->leader - in->low;
34
35  if (in->leader < in->low)
36    {
37      out->leader = out->low - 1;	/* 0.0 case */
38    }
39  else
40    {
41      out_length = out->high - out->low;
42      /* Assume no GAPS in packing of littlenums.
43	 I.e. sizeof(array) == sizeof(element) * number_of_elements.  */
44      if (in_length <= out_length)
45	{
46	  {
47	    /* For defensive programming, zero any high-order
48	       littlenums we don't need.  This is destroying evidence
49	       and wasting time, so why bother???  */
50	    if (in_length < out_length)
51	      {
52		memset ((char *) (out->low + in_length + 1), '\0',
53			out_length - in_length);
54	      }
55	  }
56	  memcpy ((void *) (out->low), (void *) (in->low),
57		  ((in_length + 1) * sizeof (LITTLENUM_TYPE)));
58	  out->exponent = in->exponent;
59	  out->leader = in->leader - in->low + out->low;
60	}
61      else
62	{
63	  int shorten;		/* 1-origin. Number of littlenums we drop.  */
64
65	  shorten = in_length - out_length;
66	  /* Assume out_length >= 0 ! */
67	  memcpy ((void *) (out->low), (void *) (in->low + shorten),
68		  ((out_length + 1) * sizeof (LITTLENUM_TYPE)));
69	  out->leader = out->high;
70	  out->exponent = in->exponent + shorten;
71	}
72    }				/* if any significant bits */
73}
74