/* * File: arch/blackfin/lib/memset.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 #ifdef CONFIG_MEMSET_L1 .section .l1.text #else .text #endif /* * C Library function MEMSET * R0 = address (leave unchanged to form result) * R1 = filler byte * R2 = count * Favours word aligned data. */ ENTRY(_memset) P0 = R0 ; /* P0 = address */ P2 = R2 ; /* P2 = count */ R3 = R0 + R2; /* end */ CC = R2 <= 7(IU); IF CC JUMP .Ltoo_small; R1 = R1.B (Z); /* R1 = fill char */ R2 = 3; R2 = R0 & R2; /* addr bottom two bits */ CC = R2 == 0; /* AZ set if zero. */ IF !CC JUMP .Lforce_align ; /* Jump if addr not aligned. */ .Laligned: P1 = P2 >> 2; /* count = n/4 */ R2 = R1 << 8; /* create quad filler */ R2.L = R2.L + R1.L(NS); R2.H = R2.L + R1.H(NS); P2 = R3; LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1; .Lquad_loop: [P0++] = R2; CC = P0 == P2; IF !CC JUMP .Lbytes_left; RTS; .Lbytes_left: R2 = R3; /* end point */ R3 = P0; /* current position */ R2 = R2 - R3; /* bytes left */ P2 = R2; .Ltoo_small: CC = P2 == 0; /* Check zero count */ IF CC JUMP .Lfinished; /* Unusual */ .Lbytes: LSETUP (.Lbyte_loop , .Lbyte_loop) LC0=P2; .Lbyte_loop: B[P0++] = R1; .Lfinished: RTS; .Lforce_align: CC = BITTST (R0, 0); /* odd byte */ R0 = 4; R0 = R0 - R2; P1 = R0; R0 = P0; /* Recover return address */ IF !CC JUMP .Lskip1; B[P0++] = R1; .Lskip1: CC = R2 <= 2; /* 2 bytes */ P2 -= P1; /* reduce count */ IF !CC JUMP .Laligned; B[P0++] = R1; B[P0++] = R1; JUMP .Laligned; ENDPROC(_memset)