gas/flonum-copy.c

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