1 | /* _memcopy.c -- subroutines for memory copy functions. |
2 | Copyright (C) 1991-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | /* BE VERY CAREFUL IF YOU CHANGE THIS CODE...! */ |
20 | |
21 | #include <stddef.h> |
22 | #include <memcopy.h> |
23 | |
24 | /* _wordcopy_fwd_aligned -- Copy block beginning at SRCP to |
25 | block beginning at DSTP with LEN `op_t' words (not LEN bytes!). |
26 | Both SRCP and DSTP should be aligned for memory operations on `op_t's. */ |
27 | |
28 | #ifndef WORDCOPY_FWD_ALIGNED |
29 | # define WORDCOPY_FWD_ALIGNED _wordcopy_fwd_aligned |
30 | #endif |
31 | |
32 | void |
33 | WORDCOPY_FWD_ALIGNED (long int dstp, long int srcp, size_t len) |
34 | { |
35 | op_t a0, a1; |
36 | |
37 | if (len & 1) |
38 | { |
39 | ((op_t *) dstp)[0] = ((op_t *) srcp)[0]; |
40 | |
41 | if (len == 1) |
42 | return; |
43 | srcp += OPSIZ; |
44 | dstp += OPSIZ; |
45 | len -= 1; |
46 | } |
47 | |
48 | do |
49 | { |
50 | a0 = ((op_t *) srcp)[0]; |
51 | a1 = ((op_t *) srcp)[1]; |
52 | ((op_t *) dstp)[0] = a0; |
53 | ((op_t *) dstp)[1] = a1; |
54 | |
55 | srcp += 2 * OPSIZ; |
56 | dstp += 2 * OPSIZ; |
57 | len -= 2; |
58 | } |
59 | while (len != 0); |
60 | } |
61 | |
62 | /* _wordcopy_fwd_dest_aligned -- Copy block beginning at SRCP to |
63 | block beginning at DSTP with LEN `op_t' words (not LEN bytes!). |
64 | DSTP should be aligned for memory operations on `op_t's, but SRCP must |
65 | *not* be aligned. */ |
66 | |
67 | #ifndef WORDCOPY_FWD_DEST_ALIGNED |
68 | # define WORDCOPY_FWD_DEST_ALIGNED _wordcopy_fwd_dest_aligned |
69 | #endif |
70 | |
71 | void |
72 | WORDCOPY_FWD_DEST_ALIGNED (long int dstp, long int srcp, size_t len) |
73 | { |
74 | op_t a0, a1, a2; |
75 | int sh_1, sh_2; |
76 | |
77 | /* Calculate how to shift a word read at the memory operation |
78 | aligned srcp to make it aligned for copy. */ |
79 | |
80 | sh_1 = 8 * (srcp % OPSIZ); |
81 | sh_2 = 8 * OPSIZ - sh_1; |
82 | |
83 | /* Make SRCP aligned by rounding it down to the beginning of the `op_t' |
84 | it points in the middle of. */ |
85 | srcp &= -OPSIZ; |
86 | a0 = ((op_t *) srcp)[0]; |
87 | |
88 | if (len & 1) |
89 | { |
90 | a1 = ((op_t *) srcp)[1]; |
91 | ((op_t *) dstp)[0] = MERGE (a0, sh_1, a1, sh_2); |
92 | |
93 | if (len == 1) |
94 | return; |
95 | |
96 | a0 = a1; |
97 | srcp += OPSIZ; |
98 | dstp += OPSIZ; |
99 | len -= 1; |
100 | } |
101 | |
102 | do |
103 | { |
104 | a1 = ((op_t *) srcp)[1]; |
105 | a2 = ((op_t *) srcp)[2]; |
106 | ((op_t *) dstp)[0] = MERGE (a0, sh_1, a1, sh_2); |
107 | ((op_t *) dstp)[1] = MERGE (a1, sh_1, a2, sh_2); |
108 | a0 = a2; |
109 | |
110 | srcp += 2 * OPSIZ; |
111 | dstp += 2 * OPSIZ; |
112 | len -= 2; |
113 | } |
114 | while (len != 0); |
115 | } |
116 | |
117 | /* _wordcopy_bwd_aligned -- Copy block finishing right before |
118 | SRCP to block finishing right before DSTP with LEN `op_t' words |
119 | (not LEN bytes!). Both SRCP and DSTP should be aligned for memory |
120 | operations on `op_t's. */ |
121 | |
122 | #ifndef WORDCOPY_BWD_ALIGNED |
123 | # define WORDCOPY_BWD_ALIGNED _wordcopy_bwd_aligned |
124 | #endif |
125 | |
126 | void |
127 | WORDCOPY_BWD_ALIGNED (long int dstp, long int srcp, size_t len) |
128 | { |
129 | op_t a0, a1; |
130 | |
131 | if (len & 1) |
132 | { |
133 | srcp -= OPSIZ; |
134 | dstp -= OPSIZ; |
135 | ((op_t *) dstp)[0] = ((op_t *) srcp)[0]; |
136 | |
137 | if (len == 1) |
138 | return; |
139 | len -= 1; |
140 | } |
141 | |
142 | do |
143 | { |
144 | srcp -= 2 * OPSIZ; |
145 | dstp -= 2 * OPSIZ; |
146 | |
147 | a1 = ((op_t *) srcp)[1]; |
148 | a0 = ((op_t *) srcp)[0]; |
149 | ((op_t *) dstp)[1] = a1; |
150 | ((op_t *) dstp)[0] = a0; |
151 | |
152 | len -= 2; |
153 | } |
154 | while (len != 0); |
155 | } |
156 | |
157 | /* _wordcopy_bwd_dest_aligned -- Copy block finishing right |
158 | before SRCP to block finishing right before DSTP with LEN `op_t' |
159 | words (not LEN bytes!). DSTP should be aligned for memory |
160 | operations on `op_t', but SRCP must *not* be aligned. */ |
161 | |
162 | #ifndef WORDCOPY_BWD_DEST_ALIGNED |
163 | # define WORDCOPY_BWD_DEST_ALIGNED _wordcopy_bwd_dest_aligned |
164 | #endif |
165 | |
166 | void |
167 | WORDCOPY_BWD_DEST_ALIGNED (long int dstp, long int srcp, size_t len) |
168 | { |
169 | op_t a0, a1, a2; |
170 | int sh_1, sh_2; |
171 | |
172 | /* Calculate how to shift a word read at the memory operation |
173 | aligned srcp to make it aligned for copy. */ |
174 | |
175 | sh_1 = 8 * (srcp % OPSIZ); |
176 | sh_2 = 8 * OPSIZ - sh_1; |
177 | |
178 | /* Make srcp aligned by rounding it down to the beginning of the op_t |
179 | it points in the middle of. */ |
180 | srcp &= -OPSIZ; |
181 | a2 = ((op_t *) srcp)[0]; |
182 | |
183 | if (len & 1) |
184 | { |
185 | srcp -= OPSIZ; |
186 | dstp -= OPSIZ; |
187 | a1 = ((op_t *) srcp)[0]; |
188 | ((op_t *) dstp)[0] = MERGE (a1, sh_1, a2, sh_2); |
189 | |
190 | if (len == 1) |
191 | return; |
192 | |
193 | a2 = a1; |
194 | len -= 1; |
195 | } |
196 | |
197 | do |
198 | { |
199 | srcp -= 2 * OPSIZ; |
200 | dstp -= 2 * OPSIZ; |
201 | |
202 | a1 = ((op_t *) srcp)[1]; |
203 | a0 = ((op_t *) srcp)[0]; |
204 | ((op_t *) dstp)[1] = MERGE (a1, sh_1, a2, sh_2); |
205 | ((op_t *) dstp)[0] = MERGE (a0, sh_1, a1, sh_2); |
206 | a2 = a0; |
207 | |
208 | len -= 2; |
209 | } |
210 | while (len != 0); |
211 | } |
212 | |