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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / d8834a1323af72f6145bc81adadd75185ef6065f / . / arch / arm / lib / memcpy.S
blob: 40db90e5f45b5663a459e6d6865eb950d4c7adef [file] [log] [blame]
Matthias Weisserd8834a12011-03-10 21:36:32 +0000[diff] [blame^]1/*
2 * linux/arch/arm/lib/memcpy.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 28, 2005
6 * Copyright: 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 <asm/assembler.h>
14
15#define W(instr) instr
16
17#define LDR1W_SHIFT 0
18#define STR1W_SHIFT 0
19
20 .macro ldr1w ptr reg abort
21 W(ldr) \reg, [\ptr], #4
22 .endm
23
24 .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
25 ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
26 .endm
27
28 .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
29 ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
30 .endm
31
32 .macro ldr1b ptr reg cond=al abort
33 ldr\cond\()b \reg, [\ptr], #1
34 .endm
35
36 .macro str1w ptr reg abort
37 W(str) \reg, [\ptr], #4
38 .endm
39
40 .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
41 stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
42 .endm
43
44 .macro str1b ptr reg cond=al abort
45 str\cond\()b \reg, [\ptr], #1
46 .endm
47
48 .macro enter reg1 reg2
49 stmdb sp!, {r0, \reg1, \reg2}
50 .endm
51
52 .macro exit reg1 reg2
53 ldmfd sp!, {r0, \reg1, \reg2}
54 .endm
55
56 .text
57
58/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
59
60.globl memcpy
61memcpy:
62
63 enter r4, lr
64
65 subs r2, r2, #4
66 blt 8f
67 ands ip, r0, #3
68 PLD( pld [r1, #0] )
69 bne 9f
70 ands ip, r1, #3
71 bne 10f
72
731: subs r2, r2, #(28)
74 stmfd sp!, {r5 - r8}
75 blt 5f
76
77 CALGN( ands ip, r0, #31 )
78 CALGN( rsb r3, ip, #32 )
79 CALGN( sbcnes r4, r3, r2 ) @ C is always set here
80 CALGN( bcs 2f )
81 CALGN( adr r4, 6f )
82 CALGN( subs r2, r2, r3 ) @ C gets set
83 CALGN( add pc, r4, ip )
84
85 PLD( pld [r1, #0] )
862: PLD( subs r2, r2, #96 )
87 PLD( pld [r1, #28] )
88 PLD( blt 4f )
89 PLD( pld [r1, #60] )
90 PLD( pld [r1, #92] )
91
923: PLD( pld [r1, #124] )
934: ldr8w r1, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
94 subs r2, r2, #32
95 str8w r0, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
96 bge 3b
97 PLD( cmn r2, #96 )
98 PLD( bge 4b )
99
1005: ands ip, r2, #28
101 rsb ip, ip, #32
102#if LDR1W_SHIFT > 0
103 lsl ip, ip, #LDR1W_SHIFT
104#endif
105 addne pc, pc, ip @ C is always clear here
106 b 7f
1076:
108 .rept (1 << LDR1W_SHIFT)
109 W(nop)
110 .endr
111 ldr1w r1, r3, abort=20f
112 ldr1w r1, r4, abort=20f
113 ldr1w r1, r5, abort=20f
114 ldr1w r1, r6, abort=20f
115 ldr1w r1, r7, abort=20f
116 ldr1w r1, r8, abort=20f
117 ldr1w r1, lr, abort=20f
118
119#if LDR1W_SHIFT < STR1W_SHIFT
120 lsl ip, ip, #STR1W_SHIFT - LDR1W_SHIFT
121#elif LDR1W_SHIFT > STR1W_SHIFT
122 lsr ip, ip, #LDR1W_SHIFT - STR1W_SHIFT
123#endif
124 add pc, pc, ip
125 nop
126 .rept (1 << STR1W_SHIFT)
127 W(nop)
128 .endr
129 str1w r0, r3, abort=20f
130 str1w r0, r4, abort=20f
131 str1w r0, r5, abort=20f
132 str1w r0, r6, abort=20f
133 str1w r0, r7, abort=20f
134 str1w r0, r8, abort=20f
135 str1w r0, lr, abort=20f
136
137 CALGN( bcs 2b )
138
1397: ldmfd sp!, {r5 - r8}
140
1418: movs r2, r2, lsl #31
142 ldr1b r1, r3, ne, abort=21f
143 ldr1b r1, r4, cs, abort=21f
144 ldr1b r1, ip, cs, abort=21f
145 str1b r0, r3, ne, abort=21f
146 str1b r0, r4, cs, abort=21f
147 str1b r0, ip, cs, abort=21f
148
149 exit r4, pc
150
1519: rsb ip, ip, #4
152 cmp ip, #2
153 ldr1b r1, r3, gt, abort=21f
154 ldr1b r1, r4, ge, abort=21f
155 ldr1b r1, lr, abort=21f
156 str1b r0, r3, gt, abort=21f
157 str1b r0, r4, ge, abort=21f
158 subs r2, r2, ip
159 str1b r0, lr, abort=21f
160 blt 8b
161 ands ip, r1, #3
162 beq 1b
163
16410: bic r1, r1, #3
165 cmp ip, #2
166 ldr1w r1, lr, abort=21f
167 beq 17f
168 bgt 18f
169
170
171 .macro forward_copy_shift pull push
172
173 subs r2, r2, #28
174 blt 14f
175
176 CALGN( ands ip, r0, #31 )
177 CALGN( rsb ip, ip, #32 )
178 CALGN( sbcnes r4, ip, r2 ) @ C is always set here
179 CALGN( subcc r2, r2, ip )
180 CALGN( bcc 15f )
181
18211: stmfd sp!, {r5 - r9}
183
184 PLD( pld [r1, #0] )
185 PLD( subs r2, r2, #96 )
186 PLD( pld [r1, #28] )
187 PLD( blt 13f )
188 PLD( pld [r1, #60] )
189 PLD( pld [r1, #92] )
190
19112: PLD( pld [r1, #124] )
19213: ldr4w r1, r4, r5, r6, r7, abort=19f
193 mov r3, lr, pull #\pull
194 subs r2, r2, #32
195 ldr4w r1, r8, r9, ip, lr, abort=19f
196 orr r3, r3, r4, push #\push
197 mov r4, r4, pull #\pull
198 orr r4, r4, r5, push #\push
199 mov r5, r5, pull #\pull
200 orr r5, r5, r6, push #\push
201 mov r6, r6, pull #\pull
202 orr r6, r6, r7, push #\push
203 mov r7, r7, pull #\pull
204 orr r7, r7, r8, push #\push
205 mov r8, r8, pull #\pull
206 orr r8, r8, r9, push #\push
207 mov r9, r9, pull #\pull
208 orr r9, r9, ip, push #\push
209 mov ip, ip, pull #\pull
210 orr ip, ip, lr, push #\push
211 str8w r0, r3, r4, r5, r6, r7, r8, r9, ip, , abort=19f
212 bge 12b
213 PLD( cmn r2, #96 )
214 PLD( bge 13b )
215
216 ldmfd sp!, {r5 - r9}
217
21814: ands ip, r2, #28
219 beq 16f
220
22115: mov r3, lr, pull #\pull
222 ldr1w r1, lr, abort=21f
223 subs ip, ip, #4
224 orr r3, r3, lr, push #\push
225 str1w r0, r3, abort=21f
226 bgt 15b
227 CALGN( cmp r2, #0 )
228 CALGN( bge 11b )
229
23016: sub r1, r1, #(\push / 8)
231 b 8b
232
233 .endm
234
235
236 forward_copy_shift pull=8 push=24
237
23817: forward_copy_shift pull=16 push=16
239
24018: forward_copy_shift pull=24 push=8
241