Merge branch 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-block.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 #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
30 ENTRY(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
52 1:              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]               )
70 2:      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
76 3:      PLD(    pld     [r1, #-128]             )
77 4:              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
84 5:              ands    ip, r2, #28
85                 rsb     ip, ip, #32
86                 addne   pc, pc, ip              @ C is always clear here
87                 b       7f
88 6:              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
110 7:              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
116 8:              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
125 9:              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
137 10:             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
157 11:             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
171 12:     PLD(    pld     [r1, #-128]             )
172 13:             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
202 14:             ands    ip, r2, #28
203                 beq     16f
204
205 15:             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
214 16:             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
223 17:             backward_copy_shift     push=16 pull=16
224
225 18:             backward_copy_shift     push=24 pull=8
226
227 ENDPROC(memmove)