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1394f032 BW |
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 | ||
48 | ENTRY(_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 | ||
51be24c3 | 109 | ENDPROC(_memset) |