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ebbad4cc | 1 | /* Copy memory to memory until the specified number of bytes |
28f540f4 | 2 | has been copied. Overlap is handled correctly. |
688903eb | 3 | Copyright (C) 1991-2018 Free Software Foundation, Inc. |
41bdb6e2 | 4 | This file is part of the GNU C Library. |
28f540f4 RM |
5 | Contributed by Torbjorn Granlund (tege@sics.se). |
6 | ||
6d52618b | 7 | The GNU C Library is free software; you can redistribute it and/or |
41bdb6e2 AJ |
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. | |
28f540f4 | 11 | |
6d52618b UD |
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 | |
41bdb6e2 | 15 | Lesser General Public License for more details. |
28f540f4 | 16 | |
41bdb6e2 | 17 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ | |
28f540f4 | 20 | |
28f540f4 RM |
21 | #include <string.h> |
22 | #include <memcopy.h> | |
23 | ||
24 | /* All this is so that bcopy.c can #include | |
25 | this file after defining some things. */ | |
26 | #ifndef a1 | |
27 | #define a1 dest /* First arg is DEST. */ | |
28 | #define a1const | |
29 | #define a2 src /* Second arg is SRC. */ | |
ebbad4cc | 30 | #define a2const const |
9a0a462c | 31 | #undef memmove |
28f540f4 RM |
32 | #endif |
33 | #if !defined(RETURN) || !defined(rettype) | |
34 | #define RETURN(s) return (s) /* Return DEST. */ | |
ebbad4cc | 35 | #define rettype void * |
28f540f4 RM |
36 | #endif |
37 | ||
6fb8cbcb L |
38 | #ifndef MEMMOVE |
39 | #define MEMMOVE memmove | |
40 | #endif | |
9a0a462c | 41 | |
28f540f4 | 42 | rettype |
85c2e611 | 43 | inhibit_loop_to_libcall |
9d46370c | 44 | MEMMOVE (a1const void *a1, a2const void *a2, size_t len) |
28f540f4 RM |
45 | { |
46 | unsigned long int dstp = (long int) dest; | |
47 | unsigned long int srcp = (long int) src; | |
48 | ||
49 | /* This test makes the forward copying code be used whenever possible. | |
50 | Reduces the working set. */ | |
51 | if (dstp - srcp >= len) /* *Unsigned* compare! */ | |
52 | { | |
53 | /* Copy from the beginning to the end. */ | |
54 | ||
19218757 MK |
55 | #if MEMCPY_OK_FOR_FWD_MEMMOVE |
56 | dest = memcpy (dest, src, len); | |
57 | #else | |
28f540f4 RM |
58 | /* If there not too few bytes to copy, use word copy. */ |
59 | if (len >= OP_T_THRES) | |
60 | { | |
61 | /* Copy just a few bytes to make DSTP aligned. */ | |
62 | len -= (-dstp) % OPSIZ; | |
63 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); | |
64 | ||
67a87b93 RM |
65 | /* Copy whole pages from SRCP to DSTP by virtual address |
66 | manipulation, as much as possible. */ | |
67 | ||
68 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); | |
69 | ||
28f540f4 RM |
70 | /* Copy from SRCP to DSTP taking advantage of the known |
71 | alignment of DSTP. Number of bytes remaining is put | |
6d52618b | 72 | in the third argument, i.e. in LEN. This number may |
28f540f4 RM |
73 | vary from machine to machine. */ |
74 | ||
75 | WORD_COPY_FWD (dstp, srcp, len, len); | |
76 | ||
77 | /* Fall out and copy the tail. */ | |
78 | } | |
79 | ||
80 | /* There are just a few bytes to copy. Use byte memory operations. */ | |
81 | BYTE_COPY_FWD (dstp, srcp, len); | |
19218757 | 82 | #endif /* MEMCPY_OK_FOR_FWD_MEMMOVE */ |
28f540f4 RM |
83 | } |
84 | else | |
85 | { | |
86 | /* Copy from the end to the beginning. */ | |
87 | srcp += len; | |
88 | dstp += len; | |
89 | ||
90 | /* If there not too few bytes to copy, use word copy. */ | |
91 | if (len >= OP_T_THRES) | |
92 | { | |
93 | /* Copy just a few bytes to make DSTP aligned. */ | |
94 | len -= dstp % OPSIZ; | |
95 | BYTE_COPY_BWD (dstp, srcp, dstp % OPSIZ); | |
96 | ||
97 | /* Copy from SRCP to DSTP taking advantage of the known | |
98 | alignment of DSTP. Number of bytes remaining is put | |
6d52618b | 99 | in the third argument, i.e. in LEN. This number may |
28f540f4 RM |
100 | vary from machine to machine. */ |
101 | ||
102 | WORD_COPY_BWD (dstp, srcp, len, len); | |
103 | ||
104 | /* Fall out and copy the tail. */ | |
105 | } | |
106 | ||
107 | /* There are just a few bytes to copy. Use byte memory operations. */ | |
108 | BYTE_COPY_BWD (dstp, srcp, len); | |
109 | } | |
110 | ||
ebbad4cc | 111 | RETURN (dest); |
28f540f4 | 112 | } |
85dd1003 UD |
113 | #ifndef memmove |
114 | libc_hidden_builtin_def (memmove) | |
115 | #endif |