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75494230 NP |
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 | ||
75494230 NP |
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 | ||
29 | ENTRY(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 | ||
46 | 1: subs r2, r2, #(28) | |
47 | stmfd sp!, {r5 - r8} | |
48 | blt 5f | |
49 | ||
2239aff6 | 50 | CALGN( ands ip, r0, #31 ) |
75494230 NP |
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 | |
4c4925c1 | 55 | CALGN( rsb ip, ip, #32 ) |
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56 | CALGN( add pc, r4, ip ) |
57 | ||
58 | PLD( pld [r1, #-4] ) | |
59 | 2: 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 | ||
65 | 3: PLD( pld [r1, #-128] ) | |
66 | 4: 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 | ||
73 | 5: ands ip, r2, #28 | |
74 | rsb ip, ip, #32 | |
75 | addne pc, pc, ip @ C is always clear here | |
76 | b 7f | |
fd522a8d | 77 | 6: W(nop) |
8b592783 CM |
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]! | |
75494230 NP |
85 | |
86 | add pc, pc, ip | |
87 | nop | |
fd522a8d | 88 | W(nop) |
8b592783 CM |
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]! | |
75494230 NP |
96 | |
97 | CALGN( bcs 2b ) | |
98 | ||
99 | 7: ldmfd sp!, {r5 - r8} | |
100 | ||
101 | 8: 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 | ||
110 | 9: 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 | ||
122 | 10: 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 | ||
2239aff6 | 134 | CALGN( ands ip, r0, #31 ) |
75494230 NP |
135 | CALGN( sbcnes r4, ip, r2 ) @ C is always set here |
136 | CALGN( subcc r2, r2, ip ) | |
137 | CALGN( bcc 15f ) | |
138 | ||
139 | 11: 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 | ||
148 | 12: PLD( pld [r1, #-128] ) | |
149 | 13: 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 | ||
175 | 14: ands ip, r2, #28 | |
176 | beq 16f | |
177 | ||
178 | 15: 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 | ||
187 | 16: add r1, r1, #(\pull / 8) | |
188 | b 8b | |
189 | ||
190 | .endm | |
191 | ||
192 | ||
193 | backward_copy_shift push=8 pull=24 | |
194 | ||
195 | 17: backward_copy_shift push=16 pull=16 | |
196 | ||
197 | 18: backward_copy_shift push=24 pull=8 | |
198 | ||
93ed3970 | 199 | ENDPROC(memmove) |