1/*
2 * File:         arch/blackfin/lib/memset.S
3 * Based on:
4 * Author:
5 *
6 * Created:
7 * Description:
8 *
9 * Modified:
10 *               Copyright 2004-2006 Analog Devices Inc.
11 *
12 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
28 */
29
30#include <linux/linkage.h>
31
32.align 2
33
34#ifdef CONFIG_MEMSET_L1
35.section .l1.text
36#else
37.text
38#endif
39
40/*
41 * C Library function MEMSET
42 * R0 = address (leave unchanged to form result)
43 * R1 = filler byte
44 * R2 = count
45 * Favours word aligned data.
46 */
47
48ENTRY(_memset)
49	P0 = R0 ;              /* P0 = address */
50	P2 = R2 ;              /* P2 = count   */
51	R3 = R0 + R2;          /* end          */
52	CC = R2 <= 7(IU);
53	IF CC JUMP  .Ltoo_small;
54	R1 = R1.B (Z);         /* R1 = fill char */
55	R2 =  3;
56	R2 = R0 & R2;          /* addr bottom two bits */
57	CC =  R2 == 0;             /* AZ set if zero.	*/
58	IF !CC JUMP  .Lforce_align ;  /* Jump if addr not aligned. */
59
60.Laligned:
61	P1 = P2 >> 2;          /* count = n/4        */
62	R2 = R1 <<  8;         /* create quad filler */
63	R2.L = R2.L + R1.L(NS);
64	R2.H = R2.L + R1.H(NS);
65	P2 = R3;
66
67	LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
68.Lquad_loop:
69	[P0++] = R2;
70
71	CC = P0 == P2;
72	IF !CC JUMP .Lbytes_left;
73	RTS;
74
75.Lbytes_left:
76	R2 = R3;                /* end point */
77	R3 = P0;                /* current position */
78	R2 = R2 - R3;           /* bytes left */
79	P2 = R2;
80
81.Ltoo_small:
82	CC = P2 == 0;           /* Check zero count */
83	IF CC JUMP .Lfinished;    /* Unusual */
84
85.Lbytes:
86	LSETUP (.Lbyte_loop , .Lbyte_loop) LC0=P2;
87.Lbyte_loop:
88	B[P0++] = R1;
89
90.Lfinished:
91	RTS;
92
93.Lforce_align:
94	CC = BITTST (R0, 0);  /* odd byte */
95	R0 = 4;
96	R0 = R0 - R2;
97	P1 = R0;
98	R0 = P0;		    /* Recover return address */
99	IF !CC JUMP .Lskip1;
100	B[P0++] = R1;
101.Lskip1:
102	CC = R2 <= 2;          /* 2 bytes */
103	P2 -= P1;              /* reduce count */
104	IF !CC JUMP .Laligned;
105	B[P0++] = R1;
106	B[P0++] = R1;
107	JUMP .Laligned;
108
109ENDPROC(_memset)
110