xref: /openbsd/gnu/usr.bin/binutils/gas/flonum-copy.c (revision 76d0caae)
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 
24 void
25 flonum_copy (FLONUM_TYPE *in, FLONUM_TYPE *out)
26 {
27   unsigned int in_length;	/* 0 origin */
28   unsigned int out_length;	/* 0 origin */
29 
30   out->sign = in->sign;
31   in_length = in->leader - in->low;
32 
33   if (in->leader < in->low)
34     {
35       out->leader = out->low - 1;	/* 0.0 case */
36     }
37   else
38     {
39       out_length = out->high - out->low;
40       /* Assume no GAPS in packing of littlenums.
41 	 I.e. sizeof(array) == sizeof(element) * number_of_elements.  */
42       if (in_length <= out_length)
43 	{
44 	  {
45 	    /* For defensive programming, zero any high-order
46 	       littlenums we don't need.  This is destroying evidence
47 	       and wasting time, so why bother???  */
48 	    if (in_length < out_length)
49 	      {
50 		memset ((char *) (out->low + in_length + 1), '\0',
51 			out_length - in_length);
52 	      }
53 	  }
54 	  memcpy ((void *) (out->low), (void *) (in->low),
55 		  ((in_length + 1) * sizeof (LITTLENUM_TYPE)));
56 	  out->exponent = in->exponent;
57 	  out->leader = in->leader - in->low + out->low;
58 	}
59       else
60 	{
61 	  int shorten;		/* 1-origin. Number of littlenums we drop.  */
62 
63 	  shorten = in_length - out_length;
64 	  /* Assume out_length >= 0 ! */
65 	  memcpy ((void *) (out->low), (void *) (in->low + shorten),
66 		  ((out_length + 1) * sizeof (LITTLENUM_TYPE)));
67 	  out->leader = out->high;
68 	  out->exponent = in->exponent + shorten;
69 	}
70     }				/* if any significant bits */
71 }
72