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61 lines
2.0 KiB
C
61 lines
2.0 KiB
C
/* Copy memory to memory until the specified number of bytes
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has been copied. Overlap is NOT handled correctly.
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Copyright (C) 1991-2017 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, see
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<http://www.gnu.org/licenses/>. */
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#include <string.h>
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#include <memcopy.h>
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#undef memcpy
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void *
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memcpy (void *dstpp, const void *srcpp, size_t len)
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{
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unsigned long int dstp = (long int) dstpp;
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unsigned long int srcp = (long int) srcpp;
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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 manipulation,
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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 alignment of
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DSTP. Number of bytes remaining is put in the third argument,
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i.e. in LEN. This number may 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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return dstpp;
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}
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libc_hidden_builtin_def (memcpy)
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