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 | #define fwd_align_merge(align) \ |
68 | do \ |
69 | { \ |
70 | a1 = ((op_t *) srcp)[1]; \ |
71 | a2 = ((op_t *) srcp)[2]; \ |
72 | ((op_t *) dstp)[0] = MERGE (a0, align*8, a1, (__WORDSIZE-align*8)); \ |
73 | ((op_t *) dstp)[1] = MERGE (a1, align*8, a2, (__WORDSIZE-align*8)); \ |
74 | a0 = a2; \ |
75 | srcp += 2 * OPSIZ; \ |
76 | dstp += 2 * OPSIZ; \ |
77 | len -= 2; \ |
78 | } \ |
79 | while (len != 0) |
80 | |
81 | #ifndef WORDCOPY_FWD_DEST_ALIGNED |
82 | # define WORDCOPY_FWD_DEST_ALIGNED _wordcopy_fwd_dest_aligned |
83 | #endif |
84 | |
85 | void |
86 | WORDCOPY_FWD_DEST_ALIGNED (long int dstp, long int srcp, size_t len) |
87 | { |
88 | op_t a0, a1, a2; |
89 | int sh_1, sh_2; |
90 | int align; |
91 | |
92 | /* Calculate how to shift a word read at the memory operation |
93 | aligned srcp to make it aligned for copy. */ |
94 | |
95 | align = srcp % OPSIZ; |
96 | sh_1 = 8 * (srcp % OPSIZ); |
97 | sh_2 = 8 * OPSIZ - sh_1; |
98 | |
99 | /* Make SRCP aligned by rounding it down to the beginning of the `op_t' |
100 | it points in the middle of. */ |
101 | srcp &= -OPSIZ; |
102 | a0 = ((op_t *) srcp)[0]; |
103 | |
104 | if (len & 1) |
105 | { |
106 | a1 = ((op_t *) srcp)[1]; |
107 | ((op_t *) dstp)[0] = MERGE (a0, sh_1, a1, sh_2); |
108 | |
109 | if (len == 1) |
110 | return; |
111 | |
112 | a0 = a1; |
113 | srcp += OPSIZ; |
114 | dstp += OPSIZ; |
115 | len -= 1; |
116 | } |
117 | |
118 | fwd_align_merge (align); |
119 | |
120 | } |
121 | |
122 | /* _wordcopy_bwd_aligned -- Copy block finishing right before |
123 | SRCP to block finishing right before DSTP with LEN `op_t' words |
124 | (not LEN bytes!). Both SRCP and DSTP should be aligned for memory |
125 | operations on `op_t's. */ |
126 | |
127 | #ifndef WORDCOPY_BWD_ALIGNED |
128 | # define WORDCOPY_BWD_ALIGNED _wordcopy_bwd_aligned |
129 | #endif |
130 | |
131 | void |
132 | WORDCOPY_BWD_ALIGNED (long int dstp, long int srcp, size_t len) |
133 | { |
134 | op_t a0, a1; |
135 | |
136 | if (len & 1) |
137 | { |
138 | srcp -= OPSIZ; |
139 | dstp -= OPSIZ; |
140 | ((op_t *) dstp)[0] = ((op_t *) srcp)[0]; |
141 | |
142 | if (len == 1) |
143 | return; |
144 | len -= 1; |
145 | } |
146 | |
147 | do |
148 | { |
149 | srcp -= 2 * OPSIZ; |
150 | dstp -= 2 * OPSIZ; |
151 | |
152 | a1 = ((op_t *) srcp)[1]; |
153 | a0 = ((op_t *) srcp)[0]; |
154 | ((op_t *) dstp)[1] = a1; |
155 | ((op_t *) dstp)[0] = a0; |
156 | |
157 | len -= 2; |
158 | } |
159 | while (len != 0); |
160 | } |
161 | |
162 | #define bwd_align_merge(align) \ |
163 | do \ |
164 | { \ |
165 | srcp -= 2 * OPSIZ; \ |
166 | dstp -= 2 * OPSIZ; \ |
167 | a1 = ((op_t *) srcp)[1]; \ |
168 | a0 = ((op_t *) srcp)[0]; \ |
169 | ((op_t *) dstp)[1] = MERGE (a1, align*8, a2, (__WORDSIZE-align*8)); \ |
170 | ((op_t *) dstp)[0] = MERGE (a0, align*8, a1, (__WORDSIZE-align*8)); \ |
171 | a2 = a0; \ |
172 | len -= 2; \ |
173 | } \ |
174 | while (len != 0) |
175 | |
176 | /* _wordcopy_bwd_dest_aligned -- Copy block finishing right |
177 | before SRCP to block finishing right before DSTP with LEN `op_t' |
178 | words (not LEN bytes!). DSTP should be aligned for memory |
179 | operations on `op_t', but SRCP must *not* be aligned. */ |
180 | |
181 | #ifndef WORDCOPY_BWD_DEST_ALIGNED |
182 | # define WORDCOPY_BWD_DEST_ALIGNED _wordcopy_bwd_dest_aligned |
183 | #endif |
184 | |
185 | void |
186 | WORDCOPY_BWD_DEST_ALIGNED (long int dstp, long int srcp, size_t len) |
187 | { |
188 | op_t a0, a1, a2; |
189 | int sh_1, sh_2; |
190 | int align; |
191 | |
192 | /* Calculate how to shift a word read at the memory operation |
193 | aligned srcp to make it aligned for copy. */ |
194 | |
195 | align = srcp % OPSIZ; |
196 | sh_1 = 8 * (srcp % OPSIZ); |
197 | sh_2 = 8 * OPSIZ - sh_1; |
198 | |
199 | /* Make srcp aligned by rounding it down to the beginning of the op_t |
200 | it points in the middle of. */ |
201 | srcp &= -OPSIZ; |
202 | a2 = ((op_t *) srcp)[0]; |
203 | |
204 | if (len & 1) |
205 | { |
206 | srcp -= OPSIZ; |
207 | dstp -= OPSIZ; |
208 | a1 = ((op_t *) srcp)[0]; |
209 | ((op_t *) dstp)[0] = MERGE (a1, sh_1, a2, sh_2); |
210 | |
211 | if (len == 1) |
212 | return; |
213 | |
214 | a2 = a1; |
215 | len -= 1; |
216 | } |
217 | |
218 | bwd_align_merge (align); |
219 | } |
220 | |