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/*
* File: arch/blackfin/lib/memmove.S
* Based on:
* Author:
*
* Created:
* Description:
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* 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, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/linkage.h>
.align 2
/*
* C Library function MEMMOVE
* R0 = To Address (leave unchanged to form result)
* R1 = From Address
* R2 = count
* Data may overlap
*/
ENTRY(_memmove)
I1 = P3;
P0 = R0; /* P0 = To address */
P3 = R1; /* P3 = From Address */
P2 = R2; /* P2 = count */
CC = P2 == 0; /* Check zero count*/
IF CC JUMP .Lfinished; /* very unlikely */
CC = R1 < R0 (IU); /* From < To */
IF !CC JUMP .Lno_overlap;
R3 = R1 + R2;
CC = R0 <= R3 (IU); /* (From+len) >= To */
IF CC JUMP .Loverlap;
.Lno_overlap:
R3 = 11;
CC = R2 <= R3;
IF CC JUMP .Lbytes;
R3 = R1 | R0; /* OR addresses together */
R3 <<= 30; /* check bottom two bits */
CC = AZ; /* AZ set if zero.*/
IF !CC JUMP .Lbytes; /* Jump if addrs not aligned.*/
I0 = P3;
P1 = P2 >> 2; /* count = n/4 */
P1 += -1;
R3 = 3;
R2 = R2 & R3; /* remainder */
P2 = R2; /* set remainder */
R1 = [I0++];
LSETUP (.Lquad_loop, .Lquad_loop) LC0=P1;
.Lquad_loop: MNOP || [P0++] = R1 || R1 = [I0++];
[P0++] = R1;
CC = P2 == 0; /* any remaining bytes? */
P3 = I0; /* Ammend P3 to updated ptr. */
IF !CC JUMP .Lbytes;
P3 = I1;
RTS;
.Lbytes: LSETUP (.Lbyte2_s, .Lbyte2_e) LC0=P2;
.Lbyte2_s: R1 = B[P3++](Z);
.Lbyte2_e: B[P0++] = R1;
.Lfinished: P3 = I1;
RTS;
.Loverlap:
P2 += -1;
P0 = P0 + P2;
P3 = P3 + P2;
R1 = B[P3--] (Z);
CC = P2 == 0;
IF CC JUMP .Lno_loop;
LSETUP (.Lol_s, .Lol_e) LC0 = P2;
.Lol_s: B[P0--] = R1;
.Lol_e: R1 = B[P3--] (Z);
.Lno_loop: B[P0] = R1;
P3 = I1;
RTS;
.size _memmove,.-_memmove
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