Merge branch 'linus' into sched/core
[linux-3.10.git] / arch / arm / lib / memmove.S
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
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
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]               )
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
77 6:              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
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
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
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
199 ENDPROC(memmove)