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1/*
2 * linux/arch/arm/lib/memmove.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 28, 2005
6 * Copyright: (C) MontaVista Software Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15
16 .text
17
18/*
19 * Prototype: void *memmove(void *dest, const void *src, size_t n);
20 *
21 * Note:
22 *
23 * If the memory regions don't overlap, we simply branch to memcpy which is
24 * normally a bit faster. Otherwise the copy is done going downwards. This
25 * is a transposition of the code from copy_template.S but with the copy
26 * occurring in the opposite direction.
27 */
28
29ENTRY(memmove)
30
31 subs ip, r0, r1
32 cmphi r2, ip
33 bls memcpy
34
35 stmfd sp!, {r0, r4, lr}
36 add r1, r1, r2
37 add r0, r0, r2
38 subs r2, r2, #4
39 blt 8f
40 ands ip, r0, #3
41 PLD( pld [r1, #-4] )
42 bne 9f
43 ands ip, r1, #3
44 bne 10f
45
461: subs r2, r2, #(28)
47 stmfd sp!, {r5 - r8}
48 blt 5f
49
50 CALGN( ands ip, r0, #31 )
51 CALGN( sbcnes r4, ip, r2 ) @ C is always set here
52 CALGN( bcs 2f )
53 CALGN( adr r4, 6f )
54 CALGN( subs r2, r2, ip ) @ C is set here
55 CALGN( rsb ip, ip, #32 )
56 CALGN( add pc, r4, ip )
57
58 PLD( pld [r1, #-4] )
592: PLD( subs r2, r2, #96 )
60 PLD( pld [r1, #-32] )
61 PLD( blt 4f )
62 PLD( pld [r1, #-64] )
63 PLD( pld [r1, #-96] )
64
653: PLD( pld [r1, #-128] )
664: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
67 subs r2, r2, #32
68 stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
69 bge 3b
70 PLD( cmn r2, #96 )
71 PLD( bge 4b )
72
735: ands ip, r2, #28
74 rsb ip, ip, #32
75 addne pc, pc, ip @ C is always clear here
76 b 7f
776: W(nop)
78 W(ldr) r3, [r1, #-4]!
79 W(ldr) r4, [r1, #-4]!
80 W(ldr) r5, [r1, #-4]!
81 W(ldr) r6, [r1, #-4]!
82 W(ldr) r7, [r1, #-4]!
83 W(ldr) r8, [r1, #-4]!
84 W(ldr) lr, [r1, #-4]!
85
86 add pc, pc, ip
87 nop
88 W(nop)
89 W(str) r3, [r0, #-4]!
90 W(str) r4, [r0, #-4]!
91 W(str) r5, [r0, #-4]!
92 W(str) r6, [r0, #-4]!
93 W(str) r7, [r0, #-4]!
94 W(str) r8, [r0, #-4]!
95 W(str) lr, [r0, #-4]!
96
97 CALGN( bcs 2b )
98
997: ldmfd sp!, {r5 - r8}
100
1018: movs r2, r2, lsl #31
102 ldrneb r3, [r1, #-1]!
103 ldrcsb r4, [r1, #-1]!
104 ldrcsb ip, [r1, #-1]
105 strneb r3, [r0, #-1]!
106 strcsb r4, [r0, #-1]!
107 strcsb ip, [r0, #-1]
108 ldmfd sp!, {r0, r4, pc}
109
1109: cmp ip, #2
111 ldrgtb r3, [r1, #-1]!
112 ldrgeb r4, [r1, #-1]!
113 ldrb lr, [r1, #-1]!
114 strgtb r3, [r0, #-1]!
115 strgeb r4, [r0, #-1]!
116 subs r2, r2, ip
117 strb lr, [r0, #-1]!
118 blt 8b
119 ands ip, r1, #3
120 beq 1b
121
12210: bic r1, r1, #3
123 cmp ip, #2
124 ldr r3, [r1, #0]
125 beq 17f
126 blt 18f
127
128
129 .macro backward_copy_shift push pull
130
131 subs r2, r2, #28
132 blt 14f
133
134 CALGN( ands ip, r0, #31 )
135 CALGN( sbcnes r4, ip, r2 ) @ C is always set here
136 CALGN( subcc r2, r2, ip )
137 CALGN( bcc 15f )
138
13911: stmfd sp!, {r5 - r9}
140
141 PLD( pld [r1, #-4] )
142 PLD( subs r2, r2, #96 )
143 PLD( pld [r1, #-32] )
144 PLD( blt 13f )
145 PLD( pld [r1, #-64] )
146 PLD( pld [r1, #-96] )
147
14812: PLD( pld [r1, #-128] )
14913: ldmdb r1!, {r7, r8, r9, ip}
150 mov lr, r3, push #\push
151 subs r2, r2, #32
152 ldmdb r1!, {r3, r4, r5, r6}
153 orr lr, lr, ip, pull #\pull
154 mov ip, ip, push #\push
155 orr ip, ip, r9, pull #\pull
156 mov r9, r9, push #\push
157 orr r9, r9, r8, pull #\pull
158 mov r8, r8, push #\push
159 orr r8, r8, r7, pull #\pull
160 mov r7, r7, push #\push
161 orr r7, r7, r6, pull #\pull
162 mov r6, r6, push #\push
163 orr r6, r6, r5, pull #\pull
164 mov r5, r5, push #\push
165 orr r5, r5, r4, pull #\pull
166 mov r4, r4, push #\push
167 orr r4, r4, r3, pull #\pull
168 stmdb r0!, {r4 - r9, ip, lr}
169 bge 12b
170 PLD( cmn r2, #96 )
171 PLD( bge 13b )
172
173 ldmfd sp!, {r5 - r9}
174
17514: ands ip, r2, #28
176 beq 16f
177
17815: mov lr, r3, push #\push
179 ldr r3, [r1, #-4]!
180 subs ip, ip, #4
181 orr lr, lr, r3, pull #\pull
182 str lr, [r0, #-4]!
183 bgt 15b
184 CALGN( cmp r2, #0 )
185 CALGN( bge 11b )
186
18716: add r1, r1, #(\pull / 8)
188 b 8b
189
190 .endm
191
192
193 backward_copy_shift push=8 pull=24
194
19517: backward_copy_shift push=16 pull=16
196
19718: backward_copy_shift push=24 pull=8
198
199ENDPROC(memmove)
1/*
2 * linux/arch/arm/lib/memmove.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 28, 2005
6 * Copyright: (C) MontaVista Software Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/unwind.h>
16
17 .text
18
19/*
20 * Prototype: void *memmove(void *dest, const void *src, size_t n);
21 *
22 * Note:
23 *
24 * If the memory regions don't overlap, we simply branch to memcpy which is
25 * normally a bit faster. Otherwise the copy is done going downwards. This
26 * is a transposition of the code from copy_template.S but with the copy
27 * occurring in the opposite direction.
28 */
29
30ENTRY(memmove)
31 UNWIND( .fnstart )
32
33 subs ip, r0, r1
34 cmphi r2, ip
35 bls memcpy
36
37 stmfd sp!, {r0, r4, lr}
38 UNWIND( .fnend )
39
40 UNWIND( .fnstart )
41 UNWIND( .save {r0, r4, lr} ) @ in first stmfd block
42 add r1, r1, r2
43 add r0, r0, r2
44 subs r2, r2, #4
45 blt 8f
46 ands ip, r0, #3
47 PLD( pld [r1, #-4] )
48 bne 9f
49 ands ip, r1, #3
50 bne 10f
51
521: subs r2, r2, #(28)
53 stmfd sp!, {r5 - r8}
54 UNWIND( .fnend )
55
56 UNWIND( .fnstart )
57 UNWIND( .save {r0, r4, lr} )
58 UNWIND( .save {r5 - r8} ) @ in second stmfd block
59 blt 5f
60
61 CALGN( ands ip, r0, #31 )
62 CALGN( sbcnes r4, ip, r2 ) @ C is always set here
63 CALGN( bcs 2f )
64 CALGN( adr r4, 6f )
65 CALGN( subs r2, r2, ip ) @ C is set here
66 CALGN( rsb ip, ip, #32 )
67 CALGN( add pc, r4, ip )
68
69 PLD( pld [r1, #-4] )
702: PLD( subs r2, r2, #96 )
71 PLD( pld [r1, #-32] )
72 PLD( blt 4f )
73 PLD( pld [r1, #-64] )
74 PLD( pld [r1, #-96] )
75
763: PLD( pld [r1, #-128] )
774: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr}
78 subs r2, r2, #32
79 stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr}
80 bge 3b
81 PLD( cmn r2, #96 )
82 PLD( bge 4b )
83
845: ands ip, r2, #28
85 rsb ip, ip, #32
86 addne pc, pc, ip @ C is always clear here
87 b 7f
886: W(nop)
89 W(ldr) r3, [r1, #-4]!
90 W(ldr) r4, [r1, #-4]!
91 W(ldr) r5, [r1, #-4]!
92 W(ldr) r6, [r1, #-4]!
93 W(ldr) r7, [r1, #-4]!
94 W(ldr) r8, [r1, #-4]!
95 W(ldr) lr, [r1, #-4]!
96
97 add pc, pc, ip
98 nop
99 W(nop)
100 W(str) r3, [r0, #-4]!
101 W(str) r4, [r0, #-4]!
102 W(str) r5, [r0, #-4]!
103 W(str) r6, [r0, #-4]!
104 W(str) r7, [r0, #-4]!
105 W(str) r8, [r0, #-4]!
106 W(str) lr, [r0, #-4]!
107
108 CALGN( bcs 2b )
109
1107: ldmfd sp!, {r5 - r8}
111 UNWIND( .fnend ) @ end of second stmfd block
112
113 UNWIND( .fnstart )
114 UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
115
1168: movs r2, r2, lsl #31
117 ldrneb r3, [r1, #-1]!
118 ldrcsb r4, [r1, #-1]!
119 ldrcsb ip, [r1, #-1]
120 strneb r3, [r0, #-1]!
121 strcsb r4, [r0, #-1]!
122 strcsb ip, [r0, #-1]
123 ldmfd sp!, {r0, r4, pc}
124
1259: cmp ip, #2
126 ldrgtb r3, [r1, #-1]!
127 ldrgeb r4, [r1, #-1]!
128 ldrb lr, [r1, #-1]!
129 strgtb r3, [r0, #-1]!
130 strgeb r4, [r0, #-1]!
131 subs r2, r2, ip
132 strb lr, [r0, #-1]!
133 blt 8b
134 ands ip, r1, #3
135 beq 1b
136
13710: bic r1, r1, #3
138 cmp ip, #2
139 ldr r3, [r1, #0]
140 beq 17f
141 blt 18f
142 UNWIND( .fnend )
143
144
145 .macro backward_copy_shift push pull
146
147 UNWIND( .fnstart )
148 UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
149 subs r2, r2, #28
150 blt 14f
151
152 CALGN( ands ip, r0, #31 )
153 CALGN( sbcnes r4, ip, r2 ) @ C is always set here
154 CALGN( subcc r2, r2, ip )
155 CALGN( bcc 15f )
156
15711: stmfd sp!, {r5 - r9}
158 UNWIND( .fnend )
159
160 UNWIND( .fnstart )
161 UNWIND( .save {r0, r4, lr} )
162 UNWIND( .save {r5 - r9} ) @ in new second stmfd block
163
164 PLD( pld [r1, #-4] )
165 PLD( subs r2, r2, #96 )
166 PLD( pld [r1, #-32] )
167 PLD( blt 13f )
168 PLD( pld [r1, #-64] )
169 PLD( pld [r1, #-96] )
170
17112: PLD( pld [r1, #-128] )
17213: ldmdb r1!, {r7, r8, r9, ip}
173 mov lr, r3, lspush #\push
174 subs r2, r2, #32
175 ldmdb r1!, {r3, r4, r5, r6}
176 orr lr, lr, ip, lspull #\pull
177 mov ip, ip, lspush #\push
178 orr ip, ip, r9, lspull #\pull
179 mov r9, r9, lspush #\push
180 orr r9, r9, r8, lspull #\pull
181 mov r8, r8, lspush #\push
182 orr r8, r8, r7, lspull #\pull
183 mov r7, r7, lspush #\push
184 orr r7, r7, r6, lspull #\pull
185 mov r6, r6, lspush #\push
186 orr r6, r6, r5, lspull #\pull
187 mov r5, r5, lspush #\push
188 orr r5, r5, r4, lspull #\pull
189 mov r4, r4, lspush #\push
190 orr r4, r4, r3, lspull #\pull
191 stmdb r0!, {r4 - r9, ip, lr}
192 bge 12b
193 PLD( cmn r2, #96 )
194 PLD( bge 13b )
195
196 ldmfd sp!, {r5 - r9}
197 UNWIND( .fnend ) @ end of the second stmfd block
198
199 UNWIND( .fnstart )
200 UNWIND( .save {r0, r4, lr} ) @ still in first stmfd block
201
20214: ands ip, r2, #28
203 beq 16f
204
20515: mov lr, r3, lspush #\push
206 ldr r3, [r1, #-4]!
207 subs ip, ip, #4
208 orr lr, lr, r3, lspull #\pull
209 str lr, [r0, #-4]!
210 bgt 15b
211 CALGN( cmp r2, #0 )
212 CALGN( bge 11b )
213
21416: add r1, r1, #(\pull / 8)
215 b 8b
216 UNWIND( .fnend )
217
218 .endm
219
220
221 backward_copy_shift push=8 pull=24
222
22317: backward_copy_shift push=16 pull=16
224
22518: backward_copy_shift push=24 pull=8
226
227ENDPROC(memmove)