1/*-
2 * Copyright (c) 2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <machine/asm.h>
28__FBSDID("$FreeBSD$");
29
30ENTRY(bzero, 2)
31
32	cmp.le	p6,p0=in1,r0			// bail if len <= 0
33(p6)	br.ret.spnt.few rp
34	;;
35	mov	r14=ar.lc			// save ar.lc
36
37	cmp.ltu	p6,p0=17,in1			// check for small
38(p6)	br.dptk.few 3f
39
401:	add	r15=-1,in1 ;;
41	mov	ar.lc=r15 ;;
422:	st1	[in0]=r0,1			// zero one byte
43	br.cloop.sptk.few 2b			// loop
44
45	;;
46	mov	ar.lc=r14			// done
47	br.ret.sptk.few rp
48
49	// Zero up to 8byte alignment
50
513:	tbit.nz	p6,p0=in0,0 ;;
52(p6)	st1	[in0]=r0,1
53(p6)	add	in1=-1,in1 ;;
54
55	tbit.nz	p6,p0=in0,1 ;;
56(p6)	st2	[in0]=r0,2
57(p6)	add	in1=-2,in1 ;;
58
59	tbit.nz	p6,p0=in0,2 ;;
60(p6)	st4	[in0]=r0,4
61(p6)	add	in1=-4,in1
62
63	;;
64	shr.u	r15=in1,3			// word count
65	extr.u	in1=in1,0,3 ;;			// trailing bytes
66	cmp.eq	p6,p0=r15,r0			// check for zero
67	cmp.ne	p7,p0=in1,r0
68(p6)	br.dpnt.few 1b				// zero last bytes
69
70	add	r15=-1,r15 ;;
71	mov	ar.lc=r15 ;;
724:	st8	[in0]=r0,8
73	br.cloop.sptk.few 4b
74
75(p7)	br.dpnt.few 1b				// zero last bytes
76
77	;;
78	mov	ar.lc=r14			// done
79	br.ret.sptk.few rp
80
81END(bzero)
82