]>
Commit | Line | Data |
---|---|---|
ebbad4cc | 1 | /* Copy memory to memory until the specified number of bytes |
28f540f4 | 2 | has been copied. Overlap is handled correctly. |
2b778ceb | 3 | Copyright (C) 1991-2021 Free Software Foundation, Inc. |
41bdb6e2 | 4 | This file is part of the GNU C Library. |
28f540f4 | 5 | |
6d52618b | 6 | The GNU C Library is free software; you can redistribute it and/or |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
28f540f4 | 10 | |
6d52618b UD |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
28f540f4 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
28f540f4 | 19 | |
28f540f4 RM |
20 | #include <string.h> |
21 | #include <memcopy.h> | |
22 | ||
23 | /* All this is so that bcopy.c can #include | |
24 | this file after defining some things. */ | |
25 | #ifndef a1 | |
26 | #define a1 dest /* First arg is DEST. */ | |
27 | #define a1const | |
28 | #define a2 src /* Second arg is SRC. */ | |
ebbad4cc | 29 | #define a2const const |
9a0a462c | 30 | #undef memmove |
28f540f4 RM |
31 | #endif |
32 | #if !defined(RETURN) || !defined(rettype) | |
33 | #define RETURN(s) return (s) /* Return DEST. */ | |
ebbad4cc | 34 | #define rettype void * |
28f540f4 RM |
35 | #endif |
36 | ||
6fb8cbcb L |
37 | #ifndef MEMMOVE |
38 | #define MEMMOVE memmove | |
39 | #endif | |
9a0a462c | 40 | |
28f540f4 | 41 | rettype |
85c2e611 | 42 | inhibit_loop_to_libcall |
9d46370c | 43 | MEMMOVE (a1const void *a1, a2const void *a2, size_t len) |
28f540f4 RM |
44 | { |
45 | unsigned long int dstp = (long int) dest; | |
46 | unsigned long int srcp = (long int) src; | |
47 | ||
48 | /* This test makes the forward copying code be used whenever possible. | |
49 | Reduces the working set. */ | |
50 | if (dstp - srcp >= len) /* *Unsigned* compare! */ | |
51 | { | |
52 | /* Copy from the beginning to the end. */ | |
53 | ||
19218757 MK |
54 | #if MEMCPY_OK_FOR_FWD_MEMMOVE |
55 | dest = memcpy (dest, src, len); | |
56 | #else | |
28f540f4 RM |
57 | /* If there not too few bytes to copy, use word copy. */ |
58 | if (len >= OP_T_THRES) | |
59 | { | |
60 | /* Copy just a few bytes to make DSTP aligned. */ | |
61 | len -= (-dstp) % OPSIZ; | |
62 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); | |
63 | ||
67a87b93 RM |
64 | /* Copy whole pages from SRCP to DSTP by virtual address |
65 | manipulation, as much as possible. */ | |
66 | ||
67 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); | |
68 | ||
28f540f4 RM |
69 | /* Copy from SRCP to DSTP taking advantage of the known |
70 | alignment of DSTP. Number of bytes remaining is put | |
6d52618b | 71 | in the third argument, i.e. in LEN. This number may |
28f540f4 RM |
72 | vary from machine to machine. */ |
73 | ||
74 | WORD_COPY_FWD (dstp, srcp, len, len); | |
75 | ||
76 | /* Fall out and copy the tail. */ | |
77 | } | |
78 | ||
79 | /* There are just a few bytes to copy. Use byte memory operations. */ | |
80 | BYTE_COPY_FWD (dstp, srcp, len); | |
19218757 | 81 | #endif /* MEMCPY_OK_FOR_FWD_MEMMOVE */ |
28f540f4 RM |
82 | } |
83 | else | |
84 | { | |
85 | /* Copy from the end to the beginning. */ | |
86 | srcp += len; | |
87 | dstp += len; | |
88 | ||
89 | /* If there not too few bytes to copy, use word copy. */ | |
90 | if (len >= OP_T_THRES) | |
91 | { | |
92 | /* Copy just a few bytes to make DSTP aligned. */ | |
93 | len -= dstp % OPSIZ; | |
94 | BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ); | |
95 | ||
96 | /* Copy from SRCP to DSTP taking advantage of the known | |
97 | alignment of DSTP. Number of bytes remaining is put | |
6d52618b | 98 | in the third argument, i.e. in LEN. This number may |
28f540f4 RM |
99 | vary from machine to machine. */ |
100 | ||
101 | WORD_COPY_BWD (dstp, srcp, len, len); | |
102 | ||
103 | /* Fall out and copy the tail. */ | |
104 | } | |
105 | ||
106 | /* There are just a few bytes to copy. Use byte memory operations. */ | |
107 | BYTE_COPY_BWD (dstp, srcp, len); | |
108 | } | |
109 | ||
ebbad4cc | 110 | RETURN (dest); |
28f540f4 | 111 | } |
85dd1003 UD |
112 | #ifndef memmove |
113 | libc_hidden_builtin_def (memmove) | |
114 | #endif |