gas/flonum-copy.c

   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 (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 }