[J-u-boot.git] / lib_blackfin / memset.S

/*
 * 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
Commit	Line	Data
3f0606ad	1	/*
155fd766	2	* File: memset.S
3f0606ad	3	*
155fd766 AL	4	* Copyright 2004-2007 Analog Devices Inc.
155fd766 AL	5	* Enter bugs at http://blackfin.uclinux.org/
3f0606ad AL	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, see the file COPYING, or write
	19	* to the Free Software Foundation, Inc.,
	20	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
3f0606ad AL	23	.align 2
	24
	25	/*
	26	* C Library function MEMSET
	27	* R0 = address (leave unchanged to form result)
	28	* R1 = filler byte
	29	* R2 = count
	30	* Favours word aligned data.
	31	*/
	32
	33	.globl _memset;
5b22163f	34	.type _memset, STT_FUNC;
3f0606ad AL	35	_memset:
	36	P0 = R0 ; /* P0 = address */
	37	P2 = R2 ; /* P2 = count */
	38	R3 = R0 + R2; /* end */
	39	CC = R2 <= 7(IU);
	40	IF CC JUMP .Ltoo_small;
	41	R1 = R1.B (Z); /* R1 = fill char */
	42	R2 = 3;
	43	R2 = R0 & R2; /* addr bottom two bits */
	44	CC = R2 == 0; /* AZ set if zero. */
	45	IF !CC JUMP .Lforce_align ; /* Jump if addr not aligned. */
	46
	47	.Laligned:
	48	P1 = P2 >> 2; /* count = n/4 */
	49	R2 = R1 << 8; /* create quad filler */
	50	R2.L = R2.L + R1.L(NS);
	51	R2.H = R2.L + R1.H(NS);
	52	P2 = R3;
	53
	54	LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
	55	.Lquad_loop:
	56	[P0++] = R2;
	57
	58	CC = P0 == P2;
	59	IF !CC JUMP .Lbytes_left;
	60	RTS;
	61
	62	.Lbytes_left:
	63	R2 = R3; /* end point */
	64	R3 = P0; /* current position */
	65	R2 = R2 - R3; /* bytes left */
	66	P2 = R2;
	67
	68	.Ltoo_small:
	69	CC = P2 == 0; /* Check zero count */
	70	IF CC JUMP .Lfinished; /* Unusual */
	71
	72	.Lbytes:
	73	LSETUP (.Lbyte_loop , .Lbyte_loop) LC0=P2;
	74	.Lbyte_loop:
	75	B[P0++] = R1;
	76
	77	.Lfinished:
	78	RTS;
	79
	80	.Lforce_align:
	81	CC = BITTST (R0, 0); /* odd byte */
	82	R0 = 4;
	83	R0 = R0 - R2;
	84	P1 = R0;
	85	R0 = P0; /* Recover return address */
	86	IF !CC JUMP .Lskip1;
	87	B[P0++] = R1;
	88	.Lskip1:
	89	CC = R2 <= 2; /* 2 bytes */
	90	P2 -= P1; /* reduce count */
	91	IF !CC JUMP .Laligned;
	92	B[P0++] = R1;
	93	B[P0++] = R1;
	94	JUMP .Laligned;
5b22163f MF	95
5b22163f MF	96	.size _memset, .-_memset