| 1 | /* Copy memory to memory until the specified number of bytes |
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| 2 | has been copied. Overlap is NOT handled correctly. |
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| 3 | Copyright (C) 1991-2022 Free Software Foundation, Inc. |
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| 4 | This file is part of the GNU C Library. |
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| 5 | |
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| 6 | The GNU C Library is free software; you can redistribute it and/or |
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| 7 | modify it under the terms of the GNU Lesser General Public |
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| 8 | License as published by the Free Software Foundation; either |
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| 9 | version 2.1 of the License, or (at your option) any later version. |
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| 10 | |
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| 11 | The GNU C Library is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | Lesser General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public |
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| 17 | License along with the GNU C Library; if not, see |
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| 18 | <https://www.gnu.org/licenses/>. */ |
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| 19 | |
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| 20 | #include <string.h> |
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| 21 | #include <memcopy.h> |
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| 22 | |
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| 23 | #ifndef MEMCPY |
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| 24 | # define MEMCPY memcpy |
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| 25 | #endif |
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| 26 | |
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| 27 | void * |
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| 28 | MEMCPY (void *dstpp, const void *srcpp, size_t len) |
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| 29 | { |
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| 30 | unsigned long int dstp = (long int) dstpp; |
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| 31 | unsigned long int srcp = (long int) srcpp; |
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| 32 | |
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| 33 | /* Copy from the beginning to the end. */ |
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| 34 | |
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| 35 | /* If there not too few bytes to copy, use word copy. */ |
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| 36 | if (len >= OP_T_THRES) |
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| 37 | { |
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| 38 | /* Copy just a few bytes to make DSTP aligned. */ |
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| 39 | len -= (-dstp) % OPSIZ; |
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| 40 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); |
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| 41 | |
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| 42 | /* Copy whole pages from SRCP to DSTP by virtual address manipulation, |
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| 43 | as much as possible. */ |
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| 44 | |
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| 45 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); |
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| 46 | |
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| 47 | /* Copy from SRCP to DSTP taking advantage of the known alignment of |
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| 48 | DSTP. Number of bytes remaining is put in the third argument, |
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| 49 | i.e. in LEN. This number may vary from machine to machine. */ |
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| 50 | |
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| 51 | WORD_COPY_FWD (dstp, srcp, len, len); |
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| 52 | |
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| 53 | /* Fall out and copy the tail. */ |
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| 54 | } |
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| 55 | |
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| 56 | /* There are just a few bytes to copy. Use byte memory operations. */ |
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| 57 | BYTE_COPY_FWD (dstp, srcp, len); |
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| 58 | |
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| 59 | return dstpp; |
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| 60 | } |
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| 61 | libc_hidden_builtin_def (MEMCPY) |
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| 62 | |
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