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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/avr32/lib/memcpy.S
10817 views
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/*

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 * Copyright (C) 2004-2006 Atmel Corporation

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 *

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 * This program is free software; you can redistribute it and/or modify

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 * it under the terms of the GNU General Public License version 2 as

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 * published by the Free Software Foundation.

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 */

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	/*

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	 * void *memcpy(void *to, const void *from, unsigned long n)

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	 *

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	 * This implementation does word-aligned loads in the main loop,

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	 * possibly sacrificing alignment of stores.

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	 *

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	 * Hopefully, in most cases, both "to" and "from" will be

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	 * word-aligned to begin with.

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	 */

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	.text

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	.global	memcpy

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	.type	memcpy, @function

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memcpy:

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	mov	r9, r11

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	andl	r9, 3, COH

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	brne	1f

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	/* At this point, "from" is word-aligned */

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2:	mov	r9, r12

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5:	sub	r10, 4

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	brlt	4f

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3:	ld.w	r8, r11++

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	sub	r10, 4

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	st.w	r12++, r8

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	brge	3b

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4:	neg	r10

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	reteq	r9

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	/* Handle unaligned count */

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	lsl	r10, 2

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	add	pc, pc, r10

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	retal	r9

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	/* Handle unaligned "from" pointer */

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1:	sub	r10, 4

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	movlt	r9, r12

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	brlt	4b

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	add	r10, r9

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	lsl	r9, 2

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	add	pc, pc, r9

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	ld.ub	r8, r11++

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	st.b	r12++, r8

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	mov	r8, r12

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	add	pc, pc, r9

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	sub	r8, 1

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	nop

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	sub	r8, 1

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	nop

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	sub	r8, 1

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	nop

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	mov	r9, r8

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	rjmp	5b

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