99 lines
3.1 KiB
C
99 lines
3.1 KiB
C
/* Copy memory to memory until the specified number of bytes
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has been copied with error checking. Overlap is handled correctly.
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Copyright (C) 1991,1995,1996,1997,2003,2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Torbjorn Granlund (tege@sics.se).
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <string.h>
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#include <memcopy.h>
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#include <pagecopy.h>
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void *
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__memmove_chk (dest, src, len, destlen)
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void *dest;
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const void *src;
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size_t len;
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size_t destlen;
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{
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if (__builtin_expect (destlen < len, 0))
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__chk_fail ();
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unsigned long int dstp = (long int) dest;
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unsigned long int srcp = (long int) src;
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/* This test makes the forward copying code be used whenever possible.
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Reduces the working set. */
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if (dstp - srcp >= len) /* *Unsigned* compare! */
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{
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/* Copy from the beginning to the end. */
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/* If there not too few bytes to copy, use word copy. */
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if (len >= OP_T_THRES)
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{
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/* Copy just a few bytes to make DSTP aligned. */
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len -= (-dstp) % OPSIZ;
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BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
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/* Copy whole pages from SRCP to DSTP by virtual address
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manipulation, as much as possible. */
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PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
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/* Copy from SRCP to DSTP taking advantage of the known
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alignment of DSTP. Number of bytes remaining is put
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in the third argument, i.e. in LEN. This number may
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vary from machine to machine. */
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WORD_COPY_FWD (dstp, srcp, len, len);
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/* Fall out and copy the tail. */
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}
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/* There are just a few bytes to copy. Use byte memory operations. */
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BYTE_COPY_FWD (dstp, srcp, len);
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}
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else
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{
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/* Copy from the end to the beginning. */
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srcp += len;
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dstp += len;
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/* If there not too few bytes to copy, use word copy. */
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if (len >= OP_T_THRES)
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{
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/* Copy just a few bytes to make DSTP aligned. */
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len -= dstp % OPSIZ;
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BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ);
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/* Copy from SRCP to DSTP taking advantage of the known
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alignment of DSTP. Number of bytes remaining is put
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in the third argument, i.e. in LEN. This number may
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vary from machine to machine. */
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WORD_COPY_BWD (dstp, srcp, len, len);
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/* Fall out and copy the tail. */
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}
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/* There are just a few bytes to copy. Use byte memory operations. */
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BYTE_COPY_BWD (dstp, srcp, len);
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}
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return dest;
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}
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