[people/ms/u-boot.git] / arch / blackfin / lib / memcpy.S

/*
 * File: memcpy.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

.globl _memcpy_ASM;
.type _memcpy_ASM, STT_FUNC;
_memcpy_ASM:
	CC = R2 <=  0;	/* length not positive?*/
	IF CC JUMP  .L_P1L2147483647;	/* Nothing to do */

	P0 = R0 ;	/* dst*/
	P1 = R1 ;	/* src*/
	P2 = R2 ;	/* length */

	/* check for overlapping data */
	CC = R1 < R0;	/* src < dst */
	IF !CC JUMP .Lno_overlap;
	R3 = R1 + R2;
	CC = R0 < R3;	/* and dst < src+len */
	IF CC JUMP .Lhas_overlap;

.Lno_overlap:
	/* Check for aligned data.*/

	R3 = R1 | R0;
	R0 = 0x3;
	R3 = R3 & R0;
	CC = R3;	/* low bits set on either address? */
	IF CC JUMP .Lnot_aligned;

	/* Both addresses are word-aligned, so we can copy
	at least part of the data using word copies.*/
	P2 = P2 >> 2;
	CC = P2 <= 2;
	IF !CC JUMP .Lmore_than_seven;
	/* less than eight bytes... */
	P2 = R2;
	LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
	R0 = R1;	/* setup src address for return */
.Lthree_start:
	R3 = B[P1++] (X);
.Lthree_end:
	B[P0++] = R3;

	RTS;

.Lmore_than_seven:
	/* There's at least eight bytes to copy. */
	P2 += -1;	/* because we unroll one iteration */
	LSETUP(.Lword_loop, .Lword_loop) LC0=P2;
	R0 = R1;
	I1 = P1;
	R3 = [I1++];
.Lword_loop:
	MNOP || [P0++] = R3 || R3 = [I1++];

	[P0++] = R3;
	/* Any remaining bytes to copy? */
	R3 = 0x3;
	R3 = R2 & R3;
	CC = R3 == 0;
	P1 = I1;	/* in case there's something left, */
	IF !CC JUMP .Lbytes_left;
	RTS;
.Lbytes_left:	P2 = R3;
.Lnot_aligned:
	/* From here, we're copying byte-by-byte. */
	LSETUP (.Lbyte_start , .Lbyte_end) LC0=P2;
	R0 = R1;	/* Save src address for return */
.Lbyte_start:
	R1 = B[P1++] (X);
.Lbyte_end:
	B[P0++] = R1;

.L_P1L2147483647:
	RTS;

.Lhas_overlap:
/* Need to reverse the copying, because the
 * dst would clobber the src.
 * Don't bother to work out alignment for
 * the reverse case.
 */
	R0 = R1;	/* save src for later. */
	P0 = P0 + P2;
	P0 += -1;
	P1 = P1 + P2;
	P1 += -1;
	LSETUP(.Lover_start, .Lover_end) LC0=P2;
.Lover_start:
	R1 = B[P1--] (X);
.Lover_end:
	B[P0--] = R1;

	RTS;

.size _memcpy_ASM, .-_memcpy_ASM
Commit	Line	Data
3f0606ad	1	/*
155fd766	2	* File: memcpy.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	*/
155fd766	22
3f0606ad AL	23	.align 2
	24
	25	.globl _memcpy_ASM;
5b22163f	26	.type _memcpy_ASM, STT_FUNC;
3f0606ad AL	27	_memcpy_ASM:
	28	CC = R2 <= 0; /* length not positive?*/
	29	IF CC JUMP .L_P1L2147483647; /* Nothing to do */
	30
	31	P0 = R0 ; /* dst*/
	32	P1 = R1 ; /* src*/
	33	P2 = R2 ; /* length */
	34
	35	/* check for overlapping data */
	36	CC = R1 < R0; /* src < dst */
	37	IF !CC JUMP .Lno_overlap;
	38	R3 = R1 + R2;
	39	CC = R0 < R3; /* and dst < src+len */
	40	IF CC JUMP .Lhas_overlap;
	41
	42	.Lno_overlap:
	43	/* Check for aligned data.*/
	44
	45	R3 = R1 \| R0;
	46	R0 = 0x3;
	47	R3 = R3 & R0;
	48	CC = R3; /* low bits set on either address? */
	49	IF CC JUMP .Lnot_aligned;
	50
	51	/* Both addresses are word-aligned, so we can copy
	52	at least part of the data using word copies.*/
	53	P2 = P2 >> 2;
	54	CC = P2 <= 2;
	55	IF !CC JUMP .Lmore_than_seven;
	56	/* less than eight bytes... */
	57	P2 = R2;
	58	LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
	59	R0 = R1; /* setup src address for return */
	60	.Lthree_start:
	61	R3 = B[P1++] (X);
	62	.Lthree_end:
	63	B[P0++] = R3;
	64
	65	RTS;
	66
	67	.Lmore_than_seven:
	68	/* There's at least eight bytes to copy. */
	69	P2 += -1; /* because we unroll one iteration */
	70	LSETUP(.Lword_loop, .Lword_loop) LC0=P2;
	71	R0 = R1;
	72	I1 = P1;
	73	R3 = [I1++];
	74	.Lword_loop:
	75	MNOP \|\| [P0++] = R3 \|\| R3 = [I1++];
	76
	77	[P0++] = R3;
	78	/* Any remaining bytes to copy? */
	79	R3 = 0x3;
	80	R3 = R2 & R3;
	81	CC = R3 == 0;
	82	P1 = I1; /* in case there's something left, */
	83	IF !CC JUMP .Lbytes_left;
	84	RTS;
	85	.Lbytes_left: P2 = R3;
	86	.Lnot_aligned:
	87	/* From here, we're copying byte-by-byte. */
	88	LSETUP (.Lbyte_start , .Lbyte_end) LC0=P2;
	89	R0 = R1; /* Save src address for return */
	90	.Lbyte_start:
91	R1 = B[P1++] (X);
92	.Lbyte_end:
93	B[P0++] = R1;
94
95	.L_P1L2147483647:
96	RTS;
97
98	.Lhas_overlap:
99	/* Need to reverse the copying, because the
100	* dst would clobber the src.
101	* Don't bother to work out alignment for
102	* the reverse case.
103	*/
104	R0 = R1; /* save src for later. */
105	P0 = P0 + P2;
106	P0 += -1;
107	P1 = P1 + P2;
108	P1 += -1;
109	LSETUP(.Lover_start, .Lover_end) LC0=P2;
110	.Lover_start:
111	R1 = B[P1--] (X);
112	.Lover_end:
113	B[P0--] = R1;
114
115	RTS;
5b22163f MF	116
5b22163f MF	117	.size _memcpy_ASM, .-_memcpy_ASM