gas/flonum-copy.c

   1 /* flonum_copy.c - copy a flonum
   2    Copyright (C) 1987-2020 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 3, 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, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 #include "as.h"
  22
  23 void
  24 flonum_copy (FLONUM_TYPE *in, FLONUM_TYPE *out)
  25 {
  26   unsigned int in_length;       /* 0 origin */
  27   unsigned int out_length;      /* 0 origin */
  28
  29   out->sign = in->sign;
  30   in_length = in->leader - in->low;
  31
  32   if (in->leader < in->low)
  33     {
  34       out->leader = out->low - 1;       /* 0.0 case */
  35     }
  36   else
  37     {
  38       out_length = out->high - out->low;
  39       /* Assume no GAPS in packing of littlenums.
  40          I.e. sizeof(array) == sizeof(element) * number_of_elements.  */
  41       if (in_length <= out_length)
  42         {
  43           {
  44             /* For defensive programming, zero any high-order
  45                littlenums we don't need.  This is destroying evidence
  46                and wasting time, so why bother???  */
  47             if (in_length < out_length)
  48               {
  49                 memset ((char *) (out->low + in_length + 1), '\0',
  50                         out_length - in_length);
  51               }
  52           }
  53           memcpy ((void *) (out->low), (void *) (in->low),
  54                   ((in_length + 1) * sizeof (LITTLENUM_TYPE)));
  55           out->exponent = in->exponent;
  56           out->leader = in->leader - in->low + out->low;
  57         }
  58       else
  59         {
  60           int shorten;          /* 1-origin. Number of littlenums we drop.  */
  61
  62           shorten = in_length - out_length;
  63           /* Assume out_length >= 0 ! */
  64           memcpy ((void *) (out->low), (void *) (in->low + shorten),
  65                   ((out_length + 1) * sizeof (LITTLENUM_TYPE)));
  66           out->leader = out->high;
  67           out->exponent = in->exponent + shorten;
  68         }
  69     }                           /* if any significant bits */
  70 }