memset.S
1.69 KB
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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