lib/bcopy.c

   1 /* bcopy.c -- copy memory.
   2
   3    Copyright (C) 1992-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published
   7    by the Free Software Foundation, either version 3 of the License,
   8    or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  19
  20 #include <config.h>
  21
  22 #include <stddef.h>
  23
  24 /* Copy LENGTH bytes from SOURCE to DEST.  Does not null-terminate.  */
  25
  26 void
  27 bcopy (void const *source0, void *dest0, size_t length)
  28 {
  29   char const *source = source0;
  30   char *dest = dest0;
  31   if (source < dest)
  32     /* Moving from low mem to hi mem; start at end.  */
  33     for (source += length, dest += length; length; --length)
  34       *--dest = *--source;
  35   else if (source != dest)
  36     /* Moving from hi mem to low mem; start at beginning.  */
  37     for (; length; --length)
  38       *dest++ = *source++;
  39 }