summary refs log tree commit diff
path: root/sysdeps/arm/memcpy.S
blob: 0602d992f0348194a77c3c5a622ea03d788bce30 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
/* Copyright (C) 2006-2015 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   Contributed by MontaVista Software, Inc. (written by Nicolas Pitre)

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library.  If not, see
   <http://www.gnu.org/licenses/>.  */

/* Thumb requires excessive IT insns here.  */
#define NO_THUMB
#include <sysdep.h>
#include <arm-features.h>

/*
 * Data preload for architectures that support it (ARM V5TE and above)
 */
#if (!defined (__ARM_ARCH_2__) && !defined (__ARM_ARCH_3__) \
     && !defined (__ARM_ARCH_3M__) && !defined (__ARM_ARCH_4__) \
     && !defined (__ARM_ARCH_4T__) && !defined (__ARM_ARCH_5__) \
     && !defined (__ARM_ARCH_5T__))
#define PLD(code...)    code
#else
#define PLD(code...)
#endif

/*
 * This can be used to enable code to cacheline align the source pointer.
 * Experiments on tested architectures (StrongARM and XScale) didn't show
 * this a worthwhile thing to do.  That might be different in the future.
 */
//#define CALGN(code...)        code
#define CALGN(code...)

/*
 * Endian independent macros for shifting bytes within registers.
 */
#ifndef __ARMEB__
#define PULL            lsr
#define PUSH            lsl
#else
#define PULL            lsl
#define PUSH            lsr
#endif

		.text
		.syntax unified

/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */

ENTRY(memcpy)

		push	{r0, r4, lr}
		cfi_adjust_cfa_offset (12)
		cfi_rel_offset (r4, 4)
		cfi_rel_offset (lr, 8)

		cfi_remember_state

		subs	r2, r2, #4
		blt	8f
		ands	ip, r0, #3
	PLD(	sfi_pld	r1, #0			)
		bne	9f
		ands	ip, r1, #3
		bne	10f

1:		subs	r2, r2, #(28)
		push	{r5 - r8}
		cfi_adjust_cfa_offset (16)
		cfi_rel_offset (r5, 0)
		cfi_rel_offset (r6, 4)
		cfi_rel_offset (r7, 8)
		cfi_rel_offset (r8, 12)
		blt	5f

	CALGN(	ands	ip, r1, #31		)
	CALGN(	rsb	r3, ip, #32		)
	CALGN(	sbcsne	r4, r3, r2		)  @ C is always set here
	CALGN(	bcs	2f			)
	CALGN(	adr	r4, 6f			)
	CALGN(	subs	r2, r2, r3		)  @ C gets set
#ifndef ARM_ALWAYS_BX
	CALGN(	add	pc, r4, ip, lsl	#(ARM_BX_ALIGN_LOG2 - 2))
#else
	CALGN(	add	r4, r4, ip, lsl	#(ARM_BX_ALIGN_LOG2 - 2))
	CALGN(	bx	r4			)
#endif

	PLD(	sfi_pld	r1, #0			)
2:	PLD(	subs	r2, r2, #96		)
	PLD(	sfi_pld	r1, #28			)
	PLD(	blt	4f			)
	PLD(	sfi_pld	r1, #60			)
	PLD(	sfi_pld	r1, #92			)

3:	PLD(	sfi_pld	r1, #124		)
4:		sfi_breg r1, \
		ldmia	\B!, {r3, r4, r5, r6, r7, r8, ip, lr}
		subs	r2, r2, #32
		sfi_breg r0, \
		stmia	\B!, {r3, r4, r5, r6, r7, r8, ip, lr}
		bge	3b
	PLD(	cmn	r2, #96			)
	PLD(	bge	4b			)

5:		ands	ip, r2, #28
		rsb	ip, ip, #32
#ifndef ARM_ALWAYS_BX
		/* C is always clear here.  */
		addne	pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
		b	7f
#else
		beq	7f
		push	{r10}
		cfi_adjust_cfa_offset (4)
		cfi_rel_offset (r10, 0)
		add	r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
		bx	r10
#endif
		.p2align ARM_BX_ALIGN_LOG2
6:		nop
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r3, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r4, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r5, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r6, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r7, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	r8, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r1, \
		ldr	lr, [\B], #4

#ifndef ARM_ALWAYS_BX
		add	pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
		nop
#else
		add	r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2)
		bx	r10
#endif
		.p2align ARM_BX_ALIGN_LOG2
		nop
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r3, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r4, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r5, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r6, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r7, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	r8, [\B], #4
		.p2align ARM_BX_ALIGN_LOG2
		sfi_breg r0, \
		str	lr, [\B], #4

#ifdef ARM_ALWAYS_BX
		pop	{r10}
		cfi_adjust_cfa_offset (-4)
		cfi_restore (r10)
#endif

	CALGN(	bcs	2b			)

7:		pop	{r5 - r8}
		cfi_adjust_cfa_offset (-16)
		cfi_restore (r5)
		cfi_restore (r6)
		cfi_restore (r7)
		cfi_restore (r8)

8:		movs	r2, r2, lsl #31
		sfi_breg r1, \
		ldrbne	r3, [\B], #1
		sfi_breg r1, \
		ldrbcs	r4, [\B], #1
		sfi_breg r1, \
		ldrbcs	ip, [\B]
		sfi_breg r0, \
		strbne	r3, [\B], #1
		sfi_breg r0, \
		strbcs	r4, [\B], #1
		sfi_breg r0, \
		strbcs	ip, [\B]

#if ((defined (__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)) \
     || defined (ARM_ALWAYS_BX))
		pop	{r0, r4, lr}
		cfi_adjust_cfa_offset (-12)
		cfi_restore (r4)
		cfi_restore (lr)
		bx      lr
#else
		pop	{r0, r4, pc}
#endif

		cfi_restore_state

9:		rsb	ip, ip, #4
		cmp	ip, #2
		sfi_breg r1, \
		ldrbgt	r3, [\B], #1
		sfi_breg r1, \
		ldrbge	r4, [\B], #1
		sfi_breg r1, \
		ldrb	lr, [\B], #1
		sfi_breg r0, \
		strbgt	r3, [\B], #1
		sfi_breg r0, \
		strbge	r4, [\B], #1
		subs	r2, r2, ip
		sfi_breg r0, \
		strb	lr, [\B], #1
		blt	8b
		ands	ip, r1, #3
		beq	1b

10:		bic	r1, r1, #3
		cmp	ip, #2
		sfi_breg r1, \
		ldr	lr, [\B], #4
		beq	17f
		bgt	18f


		.macro	forward_copy_shift pull push

		subs	r2, r2, #28
		blt	14f

	CALGN(	ands	ip, r1, #31		)
	CALGN(	rsb	ip, ip, #32		)
	CALGN(	sbcsne	r4, ip, r2		)  @ C is always set here
	CALGN(	subcc	r2, r2, ip		)
	CALGN(	bcc	15f			)

11:		push	{r5 - r8, r10}
		cfi_adjust_cfa_offset (20)
		cfi_rel_offset (r5, 0)
		cfi_rel_offset (r6, 4)
		cfi_rel_offset (r7, 8)
		cfi_rel_offset (r8, 12)
		cfi_rel_offset (r10, 16)

	PLD(	sfi_pld	r1, #0			)
	PLD(	subs	r2, r2, #96		)
	PLD(	sfi_pld	r1, #28			)
	PLD(	blt	13f			)
	PLD(	sfi_pld	r1, #60			)
	PLD(	sfi_pld	r1, #92			)

12:	PLD(	sfi_pld	r1, #124		)
13:		sfi_breg r1, \
		ldmia	\B!, {r4, r5, r6, r7}
		mov	r3, lr, PULL #\pull
		subs	r2, r2, #32
		sfi_breg r1, \
		ldmia	\B!, {r8, r10, ip, lr}
		orr	r3, r3, r4, PUSH #\push
		mov	r4, r4, PULL #\pull
		orr	r4, r4, r5, PUSH #\push
		mov	r5, r5, PULL #\pull
		orr	r5, r5, r6, PUSH #\push
		mov	r6, r6, PULL #\pull
		orr	r6, r6, r7, PUSH #\push
		mov	r7, r7, PULL #\pull
		orr	r7, r7, r8, PUSH #\push
		mov	r8, r8, PULL #\pull
		orr	r8, r8, r10, PUSH #\push
		mov	r10, r10, PULL #\pull
		orr	r10, r10, ip, PUSH #\push
		mov	ip, ip, PULL #\pull
		orr	ip, ip, lr, PUSH #\push
		sfi_breg r0, \
		stmia	\B!, {r3, r4, r5, r6, r7, r8, r10, ip}
		bge	12b
	PLD(	cmn	r2, #96			)
	PLD(	bge	13b			)

		pop	{r5 - r8, r10}
		cfi_adjust_cfa_offset (-20)
		cfi_restore (r5)
		cfi_restore (r6)
		cfi_restore (r7)
		cfi_restore (r8)
		cfi_restore (r10)

14:		ands	ip, r2, #28
		beq	16f

15:		mov	r3, lr, PULL #\pull
		sfi_breg r1, \
		ldr	lr, [\B], #4
		subs	ip, ip, #4
		orr	r3, r3, lr, PUSH #\push
		sfi_breg r0, \
		str	r3, [\B], #4
		bgt	15b
	CALGN(	cmp	r2, #0			)
	CALGN(	bge	11b			)

16:		sub	r1, r1, #(\push / 8)
		b	8b

		.endm


		forward_copy_shift	pull=8	push=24

17:		forward_copy_shift	pull=16	push=16

18:		forward_copy_shift	pull=24	push=8

END(memcpy)
libc_hidden_builtin_def (memcpy)