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  • /*
     * Copyright (C) 2004-2006 Atmel Corporation
     *
     * See file CREDITS for list of people who contributed to this
     * project.
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License as
     * published by the Free Software Foundation; either version 2 of
     * the License, or (at your option) any later version.
     *
     * 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, write to the Free Software
     * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     */
    
    	/*
    	 * r12:	void *b
    	 * r11:	int c
    	 * r10:	size_t len
    	 *
    	 * Returns b in r12
    	 */
    
    	.section .text.memset, "ax", @progbits
    
    
    	.global	memset
    	.type	memset, @function
    	.align	2
    memset:
    	mov	r9, r12
    	mov	r8, r12
    	or	r11, r11, r11 << 8
    	andl	r9, 3, COH
    	brne	1f
    
    2:	or	r11, r11, r11 << 16
    	sub	r10, 4
    	brlt	5f
    
    	/* Let's do some real work */
    4:	st.w	r8++, r11
    	sub	r10, 4
    	brge	4b
    
    	/*
    	 * When we get here, we've got less than 4 bytes to set. r10
    	 * might be negative.
    	 */
    5:	sub	r10, -4
    	reteq	r12
    
    	/* Fastpath ends here, exactly 32 bytes from memset */
    
    	/* Handle unaligned count or pointer */
    	bld	r10, 1
    	brcc	6f
    	st.b	r8++, r11
    	st.b	r8++, r11
    	bld	r10, 0
    	retcc	r12
    6:	st.b	r8++, r11
    	mov	pc, lr
    
    	/* Handle unaligned pointer */
    1:	sub	r10, 4
    	brlt	5b
    	add	r10, r9
    	lsl	r9, 1
    	add	pc, r9
    	st.b	r8++, r11
    	st.b	r8++, r11
    	st.b	r8++, r11
    	rjmp	2b
    
    	.size	memset, . - memset