| Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 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 | |
| Mike Frysinger | 51be24c | 2007-06-11 15:31:30 +0800 | [diff] [blame] | 109 | ENDPROC(_memset) |