lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Taken from generic/memmove.c; trivially modified to work with |
| 2 | arch-specific memcopy.h for Cris. |
| 3 | |
| 4 | Copy memory to memory until the specified number of bytes |
| 5 | has been copied. Overlap is handled correctly. |
| 6 | Copyright (C) 1991, 1995, 1996, 1997, 2003 Free Software Foundation, Inc. |
| 7 | This file is part of the GNU C Library. |
| 8 | Contributed by Torbjorn Granlund (tege@sics.se). |
| 9 | |
| 10 | The GNU C Library is free software; you can redistribute it and/or |
| 11 | modify it under the terms of the GNU Lesser General Public |
| 12 | License as published by the Free Software Foundation; either |
| 13 | version 2.1 of the License, or (at your option) any later version. |
| 14 | |
| 15 | The GNU C Library is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 18 | Lesser General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU Lesser General Public |
| 21 | License along with the GNU C Library; if not, write to the Free |
| 22 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 23 | 02111-1307 USA. */ |
| 24 | |
| 25 | #include <string.h> |
| 26 | |
| 27 | #include "memcopy.h" |
| 28 | #include "../generic/pagecopy.h" |
| 29 | |
| 30 | void *memmove (void *dest, const void *src, size_t len) |
| 31 | { |
| 32 | unsigned long int dstp = (long int) dest; |
| 33 | unsigned long int srcp = (long int) src; |
| 34 | |
| 35 | /* This test makes the forward copying code be used whenever possible. |
| 36 | Reduces the working set. */ |
| 37 | if (dstp - srcp >= len) /* *Unsigned* compare! */ |
| 38 | { |
| 39 | #if 1 |
| 40 | #warning REMINDER: Cris arch-opt memmove assumes memcpy does forward copying! |
| 41 | memcpy(dest, src, len); |
| 42 | #else |
| 43 | /* Copy from the beginning to the end. */ |
| 44 | |
| 45 | /* If there not too few bytes to copy, use word copy. */ |
| 46 | if (len >= OP_T_THRES) |
| 47 | { |
| 48 | /* Copy just a few bytes to make DSTP aligned. */ |
| 49 | len -= (-dstp) % OPSIZ; |
| 50 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); |
| 51 | |
| 52 | /* Copy whole pages from SRCP to DSTP by virtual address |
| 53 | manipulation, as much as possible. */ |
| 54 | |
| 55 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); |
| 56 | |
| 57 | /* Copy from SRCP to DSTP taking advantage of the known |
| 58 | alignment of DSTP. Number of bytes remaining is put |
| 59 | in the third argument, i.e. in LEN. This number may |
| 60 | vary from machine to machine. */ |
| 61 | |
| 62 | WORD_COPY_FWD (dstp, srcp, len, len); |
| 63 | |
| 64 | /* Fall out and copy the tail. */ |
| 65 | } |
| 66 | |
| 67 | /* There are just a few bytes to copy. Use byte memory operations. */ |
| 68 | BYTE_COPY_FWD (dstp, srcp, len); |
| 69 | #endif |
| 70 | } |
| 71 | else |
| 72 | { |
| 73 | /* Copy from the end to the beginning. */ |
| 74 | srcp += len; |
| 75 | dstp += len; |
| 76 | |
| 77 | /* If there not too few bytes to copy, use word copy. */ |
| 78 | if (len >= OP_T_THRES) |
| 79 | { |
| 80 | /* Copy just a few bytes to make DSTP aligned. */ |
| 81 | len -= dstp % OPSIZ; |
| 82 | BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ); |
| 83 | |
| 84 | /* Copy from SRCP to DSTP taking advantage of the known |
| 85 | alignment of DSTP. Number of bytes remaining is put |
| 86 | in the third argument, i.e. in LEN. This number may |
| 87 | vary from machine to machine. */ |
| 88 | |
| 89 | WORD_COPY_BWD (dstp, srcp, len, len); |
| 90 | |
| 91 | /* Fall out and copy the tail. */ |
| 92 | } |
| 93 | |
| 94 | /* There are just a few bytes to copy. Use byte memory operations. */ |
| 95 | BYTE_COPY_BWD (dstp, srcp, len); |
| 96 | } |
| 97 | |
| 98 | return (dest); |
| 99 | } |
| 100 | libc_hidden_def(memmove) |