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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* $Id: memcpy.S,v 1.3 2001/07/27 11:50:52 gniibe Exp $ |
3 | * | |
4 | * "memcpy" implementation of SuperH | |
5 | * | |
6 | * Copyright (C) 1999 Niibe Yutaka | |
7 | * | |
8 | */ | |
9 | ||
10 | /* | |
11 | * void *memcpy(void *dst, const void *src, size_t n); | |
12 | * No overlap between the memory of DST and of SRC are assumed. | |
13 | */ | |
14 | ||
15 | #include <linux/linkage.h> | |
16 | ENTRY(memcpy) | |
17 | tst r6,r6 | |
18 | bt/s 9f ! if n=0, do nothing | |
19 | mov r4,r0 | |
20 | sub r4,r5 ! From here, r5 has the distance to r0 | |
21 | add r6,r0 ! From here, r0 points the end of copying point | |
22 | mov #12,r1 | |
23 | cmp/gt r6,r1 | |
24 | bt/s 7f ! if it's too small, copy a byte at once | |
25 | add #-1,r5 | |
26 | add #1,r5 | |
27 | ! From here, r6 is free | |
28 | ! | |
29 | ! r4 --> [ ... ] DST [ ... ] SRC | |
30 | ! [ ... ] [ ... ] | |
31 | ! : : | |
32 | ! r0 --> [ ... ] r0+r5 --> [ ... ] | |
33 | ! | |
34 | ! | |
35 | mov r5,r1 | |
36 | mov #3,r2 | |
37 | and r2,r1 | |
38 | shll2 r1 | |
39 | mov r0,r3 ! Save the value on R0 to R3 | |
40 | mova jmptable,r0 | |
41 | add r1,r0 | |
42 | mov.l @r0,r1 | |
43 | jmp @r1 | |
44 | mov r3,r0 ! and back to R0 | |
45 | .balign 4 | |
46 | jmptable: | |
47 | .long case0 | |
48 | .long case1 | |
49 | .long case2 | |
50 | .long case3 | |
51 | ||
52 | ! copy a byte at once | |
53 | 7: mov r4,r2 | |
54 | add #1,r2 | |
55 | 8: | |
56 | cmp/hi r2,r0 | |
57 | mov.b @(r0,r5),r1 | |
58 | bt/s 8b ! while (r0>r2) | |
59 | mov.b r1,@-r0 | |
60 | 9: | |
61 | rts | |
62 | nop | |
63 | ||
64 | case0: | |
65 | ! | |
66 | ! GHIJ KLMN OPQR --> GHIJ KLMN OPQR | |
67 | ! | |
68 | ! First, align to long word boundary | |
69 | mov r0,r3 | |
70 | and r2,r3 | |
71 | tst r3,r3 | |
72 | bt/s 2f | |
73 | add #-4,r5 | |
74 | add #3,r5 | |
75 | 1: dt r3 | |
76 | mov.b @(r0,r5),r1 | |
77 | bf/s 1b | |
78 | mov.b r1,@-r0 | |
79 | ! | |
80 | add #-3,r5 | |
81 | 2: ! Second, copy a long word at once | |
82 | mov r4,r2 | |
83 | add #7,r2 | |
84 | 3: mov.l @(r0,r5),r1 | |
85 | cmp/hi r2,r0 | |
86 | bt/s 3b | |
87 | mov.l r1,@-r0 | |
88 | ! | |
89 | ! Third, copy a byte at once, if necessary | |
90 | cmp/eq r4,r0 | |
91 | bt/s 9b | |
92 | add #3,r5 | |
93 | bra 8b | |
94 | add #-6,r2 | |
95 | ||
96 | case1: | |
97 | ! | |
98 | ! GHIJ KLMN OPQR --> ...G HIJK LMNO PQR. | |
99 | ! | |
100 | ! First, align to long word boundary | |
101 | mov r0,r3 | |
102 | and r2,r3 | |
103 | tst r3,r3 | |
104 | bt/s 2f | |
105 | add #-1,r5 | |
106 | 1: dt r3 | |
107 | mov.b @(r0,r5),r1 | |
108 | bf/s 1b | |
109 | mov.b r1,@-r0 | |
110 | ! | |
111 | 2: ! Second, read a long word and write a long word at once | |
112 | mov.l @(r0,r5),r1 | |
113 | add #-4,r5 | |
114 | mov r4,r2 | |
115 | add #7,r2 | |
116 | ! | |
117 | #ifdef __LITTLE_ENDIAN__ | |
118 | 3: mov r1,r3 ! RQPO | |
119 | shll16 r3 | |
120 | shll8 r3 ! Oxxx | |
121 | mov.l @(r0,r5),r1 ! NMLK | |
122 | mov r1,r6 | |
123 | shlr8 r6 ! xNML | |
124 | or r6,r3 ! ONML | |
125 | cmp/hi r2,r0 | |
126 | bt/s 3b | |
127 | mov.l r3,@-r0 | |
128 | #else | |
129 | 3: mov r1,r3 ! OPQR | |
130 | shlr16 r3 | |
131 | shlr8 r3 ! xxxO | |
132 | mov.l @(r0,r5),r1 ! KLMN | |
133 | mov r1,r6 | |
134 | shll8 r6 ! LMNx | |
135 | or r6,r3 ! LMNO | |
136 | cmp/hi r2,r0 | |
137 | bt/s 3b | |
138 | mov.l r3,@-r0 | |
139 | #endif | |
140 | ! | |
141 | ! Third, copy a byte at once, if necessary | |
142 | cmp/eq r4,r0 | |
143 | bt/s 9b | |
144 | add #4,r5 | |
145 | bra 8b | |
146 | add #-6,r2 | |
147 | ||
148 | case2: | |
149 | ! | |
150 | ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR.. | |
151 | ! | |
152 | ! First, align to word boundary | |
153 | tst #1,r0 | |
154 | bt/s 2f | |
155 | add #-1,r5 | |
156 | mov.b @(r0,r5),r1 | |
157 | mov.b r1,@-r0 | |
158 | ! | |
159 | 2: ! Second, read a word and write a word at once | |
160 | add #-1,r5 | |
161 | mov r4,r2 | |
162 | add #3,r2 | |
163 | ! | |
164 | 3: mov.w @(r0,r5),r1 | |
165 | cmp/hi r2,r0 | |
166 | bt/s 3b | |
167 | mov.w r1,@-r0 | |
168 | ! | |
169 | ! Third, copy a byte at once, if necessary | |
170 | cmp/eq r4,r0 | |
171 | bt/s 9b | |
172 | add #1,r5 | |
173 | mov.b @(r0,r5),r1 | |
174 | rts | |
175 | mov.b r1,@-r0 | |
176 | ||
177 | case3: | |
178 | ! | |
179 | ! GHIJ KLMN OPQR --> .GHI JKLM NOPQ R... | |
180 | ! | |
181 | ! First, align to long word boundary | |
182 | mov r0,r3 | |
183 | and r2,r3 | |
184 | tst r3,r3 | |
185 | bt/s 2f | |
186 | add #-1,r5 | |
187 | 1: dt r3 | |
188 | mov.b @(r0,r5),r1 | |
189 | bf/s 1b | |
190 | mov.b r1,@-r0 | |
191 | ! | |
192 | 2: ! Second, read a long word and write a long word at once | |
193 | add #-2,r5 | |
194 | mov.l @(r0,r5),r1 | |
195 | add #-4,r5 | |
196 | mov r4,r2 | |
197 | add #7,r2 | |
198 | ! | |
199 | #ifdef __LITTLE_ENDIAN__ | |
200 | 3: mov r1,r3 ! RQPO | |
201 | shll8 r3 ! QPOx | |
202 | mov.l @(r0,r5),r1 ! NMLK | |
203 | mov r1,r6 | |
204 | shlr16 r6 | |
205 | shlr8 r6 ! xxxN | |
206 | or r6,r3 ! QPON | |
207 | cmp/hi r2,r0 | |
208 | bt/s 3b | |
209 | mov.l r3,@-r0 | |
210 | #else | |
211 | 3: mov r1,r3 ! OPQR | |
212 | shlr8 r3 ! xOPQ | |
213 | mov.l @(r0,r5),r1 ! KLMN | |
214 | mov r1,r6 | |
215 | shll16 r6 | |
216 | shll8 r6 ! Nxxx | |
217 | or r6,r3 ! NOPQ | |
218 | cmp/hi r2,r0 | |
219 | bt/s 3b | |
220 | mov.l r3,@-r0 | |
221 | #endif | |
222 | ! | |
223 | ! Third, copy a byte at once, if necessary | |
224 | cmp/eq r4,r0 | |
225 | bt/s 9b | |
226 | add #6,r5 | |
227 | bra 8b | |
228 | add #-6,r2 |