diff options
Diffstat (limited to 'sysdeps/generic/memcpy.c')
-rw-r--r-- | sysdeps/generic/memcpy.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/sysdeps/generic/memcpy.c b/sysdeps/generic/memcpy.c new file mode 100644 index 0000000000..222d358224 --- /dev/null +++ b/sysdeps/generic/memcpy.c @@ -0,0 +1,55 @@ +/* memcpy -- copy memory to memory until the specified number of bytes + has been copied. Overlap is NOT handled correctly. + Copyright (C) 1991 Free Software Foundation, Inc. + Contributed by Torbjorn Granlund (tege@sics.se). + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <string.h> +#include <memcopy.h> + +PTR +DEFUN(memcpy, (dstpp, srcpp, len), + PTR dstpp AND CONST PTR srcpp AND size_t len) +{ + unsigned long int dstp = (long int) dstpp; + unsigned long int srcp = (long int) srcpp; + + /* Copy from the beginning to the end. */ + + /* If there not too few bytes to copy, use word copy. */ + if (len >= OP_T_THRES) + { + /* Copy just a few bytes to make DSTP aligned. */ + len -= (-dstp) % OPSIZ; + BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); + + /* Copy from SRCP to DSTP taking advantage of the known + alignment of DSTP. Number of bytes remaining is put + in the third argumnet, i.e. in LEN. This number may + vary from machine to machine. */ + + WORD_COPY_FWD (dstp, srcp, len, len); + + /* Fall out and copy the tail. */ + } + + /* There are just a few bytes to copy. Use byte memory operations. */ + BYTE_COPY_FWD (dstp, srcp, len); + + return dstpp; +} |