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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 by Michael Sevakis
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/****************************************************************************
* void memswap128(void *buf1, void *buf2, size_t len)
*/
.section .icode, "ax", %progbits
.align 2
.global memswap128
.type memswap128, %function
memswap128:
@ r0 = buf1
@ r1 = buf2
@ r2 = len
movs r2, r2, lsr #4 @ bytes => lines, len == 0?
moveq pc, lr @ not at least a line? leave
stmdb sp!, { r4-r10, lr } @ save registers and return address
.loop: @
ldmia r0, { r3-r6 } @ read four longwords from buf1
ldmia r1, { r7-r10 } @ read four longwords from buf2
stmia r0!, { r7-r10 } @ write buf2 data to buf1, buf1 += 16
stmia r1!, { r3-r6 } @ write buf1 data to buf2, buf2 += 16
subs r2, r2, #1 @ len -= 1, len > 0 ?
bhi .loop @ yes? keep exchanging
ldmia sp!, { r4-r10, pc } @ restore registers and return
.end:
.size memswap128, .end-memswap128
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