gnu/usr.bin/as/flonum-copy.c

/* flonum_copy.c - copy a flonum
   Copyright (C) 1987 Free Software Foundation, Inc.

This file is part of GAS, the GNU Assembler.

GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.

GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "flonum.h"
#ifdef USG
#define bzero(s,n) memset(s,0,n)
#define bcopy(from,to,n) memcpy(to,from,n)
#endif

void
flonum_copy (in, out)
     FLONUM_TYPE *      in;
     FLONUM_TYPE *      out;
{
  int                   in_length;      /* 0 origin */
  int                   out_length;     /* 0 origin */

  out -> sign = in -> sign;
  in_length = in  -> leader - in -> low;
  if (in_length < 0)
    {
      out -> leader = out -> low - 1; /* 0.0 case */
    }
  else
    {
      out_length = out -> high - out -> low;
      /*
       * Assume no GAPS in packing of littlenums.
       * I.e. sizeof(array) == sizeof(element) * number_of_elements.
       */
      if (in_length <= out_length)
        {
          {
            /*
             * For defensive programming, zero any high-order littlenums we don't need.
             * This is destroying evidence and wasting time, so why bother???
             */
            if (in_length < out_length)
              {
                bzero ((char *)(out->low + in_length + 1), out_length - in_length);
              }
          }
          bcopy ((char *)(in->low), (char *)(out->low), (int)((in_length + 1) * sizeof(LITTLENUM_TYPE)));
          out -> exponent = in -> exponent;
          out -> leader   = in -> leader - in -> low + out -> low;
        }
      else
        {
          int   shorten;                /* 1-origin. Number of littlenums we drop. */

          shorten = in_length - out_length;
          /* Assume out_length >= 0 ! */
          bcopy ((char *)(in->low + shorten),(char *)( out->low), (int)((out_length + 1) * sizeof(LITTLENUM_TYPE)));
          out -> leader = out -> high;
          out -> exponent = in -> exponent + shorten;
        }
    }                           /* if any significant bits */
}

/* end: flonum_copy.c */