| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copy memory to memory until the specified number of bytes |
| 2 | has been copied. Overlap is NOT handled correctly. |
| 3 | Copyright (C) 1991-2016 Free Software Foundation, Inc. |
| 4 | This file is part of the GNU C Library. |
| 5 | Contributed by Torbjorn Granlund (tege@sics.se). |
| 6 | |
| 7 | The GNU C Library is free software; you can redistribute it and/or |
| 8 | modify it under the terms of the GNU Lesser General Public |
| 9 | License as published by the Free Software Foundation; either |
| 10 | version 2.1 of the License, or (at your option) any later version. |
| 11 | |
| 12 | The GNU C Library is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | Lesser General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU Lesser General Public |
| 18 | License along with the GNU C Library; if not, see |
| 19 | <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include <string.h> |
| 22 | #include <memcopy.h> |
| 23 | |
| 24 | #undef memcpy |
| 25 | |
| 26 | void * |
| 27 | memcpy (void *dstpp, const void *srcpp, size_t len) |
| 28 | { |
| 29 | unsigned long int dstp = (long int) dstpp; |
| 30 | unsigned long int srcp = (long int) srcpp; |
| 31 | |
| 32 | /* Copy from the beginning to the end. */ |
| 33 | |
| 34 | /* If there not too few bytes to copy, use word copy. */ |
| 35 | if (len >= OP_T_THRES) |
| 36 | { |
| 37 | /* Copy just a few bytes to make DSTP aligned. */ |
| 38 | len -= (-dstp) % OPSIZ; |
| 39 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); |
| 40 | |
| 41 | /* Copy whole pages from SRCP to DSTP by virtual address manipulation, |
| 42 | as much as possible. */ |
| 43 | |
| 44 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); |
| 45 | |
| 46 | /* Copy from SRCP to DSTP taking advantage of the known alignment of |
| 47 | DSTP. Number of bytes remaining is put in the third argument, |
| 48 | i.e. in LEN. This number may vary from machine to machine. */ |
| 49 | |
| 50 | WORD_COPY_FWD (dstp, srcp, len, len); |
| 51 | |
| 52 | /* Fall out and copy the tail. */ |
| 53 | } |
| 54 | |
| 55 | /* There are just a few bytes to copy. Use byte memory operations. */ |
| 56 | BYTE_COPY_FWD (dstp, srcp, len); |
| 57 | |
| 58 | return dstpp; |
| 59 | } |
| 60 | libc_hidden_builtin_def (memcpy) |