1 /* $NetBSD: memset.S,v 1.4 2003/10/14 07:51:45 scw Exp $ */
4 * Copyright 2003 Wasabi Systems, Inc.
7 * Written by Steve C. Woodford for Wasabi Systems, Inc.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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
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.
38 * Copyright (c) 1995 Mark Brinicombe.
39 * All rights reserved.
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
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.
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
69 #include <machine/asm.h>
70 __FBSDID("$FreeBSD$");
75 * memset: Sets a block of memory to the specified value
80 * r2 - number of bytes to write
86 /* LINTSTUB: Func: void bzero(void *, size_t) */
90 /* LINTSTUB: Func: void *memset(void *, int, size_t) */
92 and r3, r1, #0xff /* We deal with bytes */
95 cmp r1, #0x04 /* Do we have less than 4 bytes */
97 blt .Lmemset_lessthanfour
99 /* Ok first we will word align the address */
100 ands r2, ip, #0x03 /* Get the bottom two bits */
101 bne .Lmemset_wordunaligned /* The address is not word aligned */
103 /* We are now word aligned */
104 .Lmemset_wordaligned:
106 orr r3, r3, r3, lsl #8 /* Extend value to 16-bits */
109 tst ip, #0x04 /* Quad-align for armv5e */
114 orr r3, r3, r3, lsl #16 /* Extend value to 32-bits */
117 subne r1, r1, #0x04 /* Quad-align if necessary */
118 strne r3, [ip], #0x04
121 blt .Lmemset_loop4 /* If less than 16 then use words */
122 mov r2, r3 /* Duplicate data */
123 cmp r1, #0x80 /* If < 128 then skip the big loop */
126 /* Do 128 bytes at a time */
130 strdge r2, [ip], #0x08
131 strdge r2, [ip], #0x08
132 strdge r2, [ip], #0x08
133 strdge r2, [ip], #0x08
134 strdge r2, [ip], #0x08
135 strdge r2, [ip], #0x08
136 strdge r2, [ip], #0x08
137 strdge r2, [ip], #0x08
138 strdge r2, [ip], #0x08
139 strdge r2, [ip], #0x08
140 strdge r2, [ip], #0x08
141 strdge r2, [ip], #0x08
142 strdge r2, [ip], #0x08
143 strdge r2, [ip], #0x08
144 strdge r2, [ip], #0x08
145 strdge r2, [ip], #0x08
165 RETeq /* Zero length so just exit */
167 add r1, r1, #0x80 /* Adjust for extra sub */
169 /* Do 32 bytes at a time */
173 strdge r2, [ip], #0x08
174 strdge r2, [ip], #0x08
175 strdge r2, [ip], #0x08
176 strdge r2, [ip], #0x08
184 RETeq /* Zero length so just exit */
186 adds r1, r1, #0x10 /* Partially adjust for extra sub */
188 /* Deal with 16 bytes or more */
190 strdge r2, [ip], #0x08
191 strdge r2, [ip], #0x08
196 RETeq /* Zero length so just exit */
198 addlt r1, r1, #0x10 /* Possibly adjust for extra sub */
200 /* We have at least 4 bytes so copy as words */
203 strge r3, [ip], #0x04
205 RETeq /* Zero length so just exit */
208 /* Compensate for 64-bit alignment check */
216 strb r3, [ip], #0x01 /* Set 1 byte */
217 strbge r3, [ip], #0x01 /* Set another byte */
218 strbgt r3, [ip] /* and a third */
221 .Lmemset_wordunaligned:
223 strb r3, [ip], #0x01 /* Set 1 byte */
225 strbge r3, [ip], #0x01 /* Set another byte */
227 strbgt r3, [ip], #0x01 /* and a third */
228 cmp r1, #0x04 /* More than 4 bytes left? */
229 bge .Lmemset_wordaligned /* Yup */
231 .Lmemset_lessthanfour:
233 RETeq /* Zero length so exit */
234 strb r3, [ip], #0x01 /* Set 1 byte */
236 strbge r3, [ip], #0x01 /* Set another byte */
237 strbgt r3, [ip] /* and a third */