gas/flonum-copy.c

   1 /* flonum_copy.c - copy a flonum
   2    Copyright 1987, 1990, 1991, 1992, 1993, 2000, 2003
   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, 51 Franklin Street - Fifth Floor, Boston, MA
  20    02110-1301, 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 }