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kernel/linux-imx6_3.14.28/arch/arm64/lib/memmove.S 1.3 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Copyright (C) 2013 ARM Ltd.
   *
   * 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.
   *
   * This program 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/linkage.h>
  #include <asm/assembler.h>
  
  /*
   * Move a buffer from src to test (alignment handled by the hardware).
   * If dest <= src, call memcpy, otherwise copy in reverse order.
   *
   * Parameters:
   *	x0 - dest
   *	x1 - src
   *	x2 - n
   * Returns:
   *	x0 - dest
   */
  ENTRY(memmove)
  	cmp	x0, x1
  	b.ls	memcpy
  	add	x4, x0, x2
  	add	x1, x1, x2
  	subs	x2, x2, #8
  	b.mi	2f
  1:	ldr	x3, [x1, #-8]!
  	subs	x2, x2, #8
  	str	x3, [x4, #-8]!
  	b.pl	1b
  2:	adds	x2, x2, #4
  	b.mi	3f
  	ldr	w3, [x1, #-4]!
  	sub	x2, x2, #4
  	str	w3, [x4, #-4]!
  3:	adds	x2, x2, #2
  	b.mi	4f
  	ldrh	w3, [x1, #-2]!
  	sub	x2, x2, #2
  	strh	w3, [x4, #-2]!
  4:	adds	x2, x2, #1
  	b.mi	5f
  	ldrb	w3, [x1, #-1]
  	strb	w3, [x4, #-1]
  5:	ret
  ENDPROC(memmove)