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kernel/linux-imx6_3.14.28/arch/avr32/lib/memcpy.S 1.24 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Copyright (C) 2004-2006 Atmel Corporation
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  	/*
  	 * void *memcpy(void *to, const void *from, unsigned long n)
  	 *
  	 * This implementation does word-aligned loads in the main loop,
  	 * possibly sacrificing alignment of stores.
  	 *
  	 * Hopefully, in most cases, both "to" and "from" will be
  	 * word-aligned to begin with.
  	 */
  	.text
  	.global	memcpy
  	.type	memcpy, @function
  memcpy:
  	mov	r9, r11
  	andl	r9, 3, COH
  	brne	1f
  
  	/* At this point, "from" is word-aligned */
  2:	mov	r9, r12
  5:	sub	r10, 4
  	brlt	4f
  
  3:	ld.w	r8, r11++
  	sub	r10, 4
  	st.w	r12++, r8
  	brge	3b
  
  4:	neg	r10
  	reteq	r9
  
  	/* Handle unaligned count */
  	lsl	r10, 2
  	add	pc, pc, r10
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	retal	r9
  
  	/* Handle unaligned "from" pointer */
  1:	sub	r10, 4
  	movlt	r9, r12
  	brlt	4b
  	add	r10, r9
  	lsl	r9, 2
  	add	pc, pc, r9
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	ld.ub	r8, r11++
  	st.b	r12++, r8
  	mov	r8, r12
  	add	pc, pc, r9
  	sub	r8, 1
  	nop
  	sub	r8, 1
  	nop
  	sub	r8, 1
  	nop
  	mov	r9, r8
  	rjmp	5b