xref: /freebsd/lib/libc/arm/string/memset.S (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1/*	$NetBSD: memset.S,v 1.4 2003/10/14 07:51:45 scw Exp $	*/
2
3/*
4 * Copyright 2003 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Steve C. Woodford for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *      This product includes software developed for the NetBSD Project by
20 *      Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37/*
38 * Copyright (c) 1995 Mark Brinicombe.
39 * All rights reserved.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 *    notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 *    notice, this list of conditions and the following disclaimer in the
48 *    documentation and/or other materials provided with the distribution.
49 * 3. All advertising materials mentioning features or use of this software
50 *    must display the following acknowledgement:
51 *	This product includes software developed by Mark Brinicombe.
52 * 4. The name of the company nor the name of the author may be used to
53 *    endorse or promote products derived from this software without specific
54 *    prior written permission.
55 *
56 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
57 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
58 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
59 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
60 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
61 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
62 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * SUCH DAMAGE.
67 */
68
69#include <machine/asm.h>
70__FBSDID("$FreeBSD$");
71
72/*
73 * memset: Sets a block of memory to the specified value
74 *
75 * On entry:
76 *   r0 - dest address
77 *   r1 - byte to write
78 *   r2 - number of bytes to write
79 *
80 * On exit:
81 *   r0 - dest address
82 */
83#ifdef _BZERO
84/* LINTSTUB: Func: void bzero(void *, size_t) */
85ENTRY(bzero)
86	mov	r3, #0x00
87#else
88/* LINTSTUB: Func: void *memset(void *, int, size_t) */
89ENTRY(memset)
90	and	r3, r1, #0xff		/* We deal with bytes */
91	mov	r1, r2
92#endif
93	cmp	r1, #0x04		/* Do we have less than 4 bytes */
94	mov	ip, r0
95	blt	.Lmemset_lessthanfour
96
97	/* Ok first we will word align the address */
98	ands	r2, ip, #0x03		/* Get the bottom two bits */
99	bne	.Lmemset_wordunaligned	/* The address is not word aligned */
100
101	/* We are now word aligned */
102.Lmemset_wordaligned:
103#ifndef _BZERO
104	orr	r3, r3, r3, lsl #8	/* Extend value to 16-bits */
105#endif
106#ifdef _ARM_ARCH_5E
107	tst	ip, #0x04		/* Quad-align for armv5e */
108#else
109	cmp	r1, #0x10
110#endif
111#ifndef _BZERO
112	orr	r3, r3, r3, lsl #16	/* Extend value to 32-bits */
113#endif
114#ifdef _ARM_ARCH_5E
115	subne	r1, r1, #0x04		/* Quad-align if necessary */
116	strne	r3, [ip], #0x04
117	cmp	r1, #0x10
118#endif
119	blt	.Lmemset_loop4		/* If less than 16 then use words */
120	mov	r2, r3			/* Duplicate data */
121	cmp	r1, #0x80		/* If < 128 then skip the big loop */
122	blt	.Lmemset_loop32
123
124	/* Do 128 bytes at a time */
125.Lmemset_loop128:
126	subs	r1, r1, #0x80
127#ifdef _ARM_ARCH_5E
128	strged	r2, [ip], #0x08
129	strged	r2, [ip], #0x08
130	strged	r2, [ip], #0x08
131	strged	r2, [ip], #0x08
132	strged	r2, [ip], #0x08
133	strged	r2, [ip], #0x08
134	strged	r2, [ip], #0x08
135	strged	r2, [ip], #0x08
136	strged	r2, [ip], #0x08
137	strged	r2, [ip], #0x08
138	strged	r2, [ip], #0x08
139	strged	r2, [ip], #0x08
140	strged	r2, [ip], #0x08
141	strged	r2, [ip], #0x08
142	strged	r2, [ip], #0x08
143	strged	r2, [ip], #0x08
144#else
145	stmgeia	ip!, {r2-r3}
146	stmgeia	ip!, {r2-r3}
147	stmgeia	ip!, {r2-r3}
148	stmgeia	ip!, {r2-r3}
149	stmgeia	ip!, {r2-r3}
150	stmgeia	ip!, {r2-r3}
151	stmgeia	ip!, {r2-r3}
152	stmgeia	ip!, {r2-r3}
153	stmgeia	ip!, {r2-r3}
154	stmgeia	ip!, {r2-r3}
155	stmgeia	ip!, {r2-r3}
156	stmgeia	ip!, {r2-r3}
157	stmgeia	ip!, {r2-r3}
158	stmgeia	ip!, {r2-r3}
159	stmgeia	ip!, {r2-r3}
160	stmgeia	ip!, {r2-r3}
161#endif
162	bgt	.Lmemset_loop128
163	RETeq			/* Zero length so just exit */
164
165	add	r1, r1, #0x80		/* Adjust for extra sub */
166
167	/* Do 32 bytes at a time */
168.Lmemset_loop32:
169	subs	r1, r1, #0x20
170#ifdef _ARM_ARCH_5E
171	strged	r2, [ip], #0x08
172	strged	r2, [ip], #0x08
173	strged	r2, [ip], #0x08
174	strged	r2, [ip], #0x08
175#else
176	stmgeia	ip!, {r2-r3}
177	stmgeia	ip!, {r2-r3}
178	stmgeia	ip!, {r2-r3}
179	stmgeia	ip!, {r2-r3}
180#endif
181	bgt	.Lmemset_loop32
182	RETeq			/* Zero length so just exit */
183
184	adds	r1, r1, #0x10		/* Partially adjust for extra sub */
185
186	/* Deal with 16 bytes or more */
187#ifdef _ARM_ARCH_5E
188	strged	r2, [ip], #0x08
189	strged	r2, [ip], #0x08
190#else
191	stmgeia	ip!, {r2-r3}
192	stmgeia	ip!, {r2-r3}
193#endif
194	RETeq			/* Zero length so just exit */
195
196	addlt	r1, r1, #0x10		/* Possibly adjust for extra sub */
197
198	/* We have at least 4 bytes so copy as words */
199.Lmemset_loop4:
200	subs	r1, r1, #0x04
201	strge	r3, [ip], #0x04
202	bgt	.Lmemset_loop4
203	RETeq			/* Zero length so just exit */
204
205#ifdef _ARM_ARCH_5E
206	/* Compensate for 64-bit alignment check */
207	adds	r1, r1, #0x04
208	RETeq
209	cmp	r1, #2
210#else
211	cmp	r1, #-2
212#endif
213
214	strb	r3, [ip], #0x01		/* Set 1 byte */
215	strgeb	r3, [ip], #0x01		/* Set another byte */
216	strgtb	r3, [ip]		/* and a third */
217	RET			/* Exit */
218
219.Lmemset_wordunaligned:
220	rsb	r2, r2, #0x004
221	strb	r3, [ip], #0x01		/* Set 1 byte */
222	cmp	r2, #0x02
223	strgeb	r3, [ip], #0x01		/* Set another byte */
224	sub	r1, r1, r2
225	strgtb	r3, [ip], #0x01		/* and a third */
226	cmp	r1, #0x04		/* More than 4 bytes left? */
227	bge	.Lmemset_wordaligned	/* Yup */
228
229.Lmemset_lessthanfour:
230	cmp	r1, #0x00
231	RETeq			/* Zero length so exit */
232	strb	r3, [ip], #0x01		/* Set 1 byte */
233	cmp	r1, #0x02
234	strgeb	r3, [ip], #0x01		/* Set another byte */
235	strgtb	r3, [ip]		/* and a third */
236	RET			/* Exit */
237