diff options
Diffstat (limited to 'arch/blackfin/lib/memset.S')
| -rw-r--r-- | arch/blackfin/lib/memset.S | 96 | 
1 files changed, 96 insertions, 0 deletions
| diff --git a/arch/blackfin/lib/memset.S b/arch/blackfin/lib/memset.S new file mode 100644 index 000000000..26f63cdc9 --- /dev/null +++ b/arch/blackfin/lib/memset.S @@ -0,0 +1,96 @@ +/* + * File: memset.S + * + * Copyright 2004-2007 Analog Devices Inc. + * 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 + */ + +.align 2 + +/* + * C Library function MEMSET + * R0 = address (leave unchanged to form result) + * R1 = filler byte + * R2 = count + * Favours word aligned data. + */ + +.globl _memset; +.type _memset, STT_FUNC; +_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; + +.size _memset, .-_memset |