memset.S revision 1.1.54.1
1 /* $NetBSD: memset.S,v 1.1.54.1 2013/02/07 07:05:59 matt 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 71 #if defined(__ARM_EABI__) && !defined(BZER0) 72 STRONG_ALIAS(__aeabi_memset, memset) 73 #endif 74 75 /* 76 * memset: Sets a block of memory to the specified value 77 * 78 * On entry: 79 * r0 - dest address 80 * r1 - byte to write 81 * r2 - number of bytes to write 82 * 83 * On exit: 84 * r0 - dest address 85 */ 86 #ifdef _BZERO 87 /* LINTSTUB: Func: void bzero(void *, size_t) */ 88 ENTRY(bzero) 89 mov r3, #0x00 90 #else 91 /* LINTSTUB: Func: void *memset(void *, int, size_t) */ 92 ENTRY(memset) 93 and r3, r1, #0xff /* We deal with bytes */ 94 mov r1, r2 95 #endif 96 cmp r1, #0x04 /* Do we have less than 4 bytes */ 97 mov ip, r0 98 blt .Lmemset_lessthanfour 99 100 /* Ok first we will word align the address */ 101 ands r2, ip, #0x03 /* Get the bottom two bits */ 102 bne .Lmemset_wordunaligned /* The address is not word aligned */ 103 104 /* We are now word aligned */ 105 .Lmemset_wordaligned: 106 #ifndef _BZERO 107 orr r3, r3, r3, lsl #8 /* Extend value to 16-bits */ 108 #endif 109 #ifdef _ARM_ARCH_DWORD_OK 110 tst ip, #0x04 /* Quad-align for Xscale */ 111 #else 112 cmp r1, #0x10 113 #endif 114 #ifndef _BZERO 115 orr r3, r3, r3, lsl #16 /* Extend value to 32-bits */ 116 #endif 117 #ifdef _ARM_ARCH_DWORD_OK 118 subne r1, r1, #0x04 /* Quad-align if necessary */ 119 strne r3, [ip], #0x04 120 cmp r1, #0x10 121 #endif 122 blt .Lmemset_loop4 /* If less than 16 then use words */ 123 mov r2, r3 /* Duplicate data */ 124 cmp r1, #0x80 /* If < 128 then skip the big loop */ 125 blt .Lmemset_loop32 126 127 /* Do 128 bytes at a time */ 128 .Lmemset_loop128: 129 subs r1, r1, #0x80 130 #ifdef _ARM_ARCH_DWORD_OK 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 strged r2, [ip], #0x08 145 strged r2, [ip], #0x08 146 strged r2, [ip], #0x08 147 #else 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 stmgeia ip!, {r2-r3} 162 stmgeia ip!, {r2-r3} 163 stmgeia ip!, {r2-r3} 164 #endif 165 bgt .Lmemset_loop128 166 RETc(eq) /* Zero length so just exit */ 167 168 add r1, r1, #0x80 /* Adjust for extra sub */ 169 170 /* Do 32 bytes at a time */ 171 .Lmemset_loop32: 172 subs r1, r1, #0x20 173 #ifdef _ARM_ARCH_DWORD_OK 174 strged r2, [ip], #0x08 175 strged r2, [ip], #0x08 176 strged r2, [ip], #0x08 177 strged r2, [ip], #0x08 178 #else 179 stmgeia ip!, {r2-r3} 180 stmgeia ip!, {r2-r3} 181 stmgeia ip!, {r2-r3} 182 stmgeia ip!, {r2-r3} 183 #endif 184 bgt .Lmemset_loop32 185 RETc(eq) /* Zero length so just exit */ 186 187 adds r1, r1, #0x10 /* Partially adjust for extra sub */ 188 189 /* Deal with 16 bytes or more */ 190 #ifdef _ARM_ARCH_DWORD_OK 191 strged r2, [ip], #0x08 192 strged r2, [ip], #0x08 193 #else 194 stmgeia ip!, {r2-r3} 195 stmgeia ip!, {r2-r3} 196 #endif 197 RETc(eq) /* Zero length so just exit */ 198 199 addlt r1, r1, #0x10 /* Possibly adjust for extra sub */ 200 201 /* We have at least 4 bytes so copy as words */ 202 .Lmemset_loop4: 203 subs r1, r1, #0x04 204 strge r3, [ip], #0x04 205 bgt .Lmemset_loop4 206 RETc(eq) /* Zero length so just exit */ 207 208 #ifdef _ARM_ARCH_DWORD_OK 209 /* Compensate for 64-bit alignment check */ 210 adds r1, r1, #0x04 211 RETc(eq) 212 cmp r1, #2 213 #else 214 cmp r1, #-2 215 #endif 216 217 strb r3, [ip], #0x01 /* Set 1 byte */ 218 strgeb r3, [ip], #0x01 /* Set another byte */ 219 strgtb r3, [ip] /* and a third */ 220 RET /* Exit */ 221 222 .Lmemset_wordunaligned: 223 rsb r2, r2, #0x004 224 strb r3, [ip], #0x01 /* Set 1 byte */ 225 cmp r2, #0x02 226 strgeb r3, [ip], #0x01 /* Set another byte */ 227 sub r1, r1, r2 228 strgtb r3, [ip], #0x01 /* and a third */ 229 cmp r1, #0x04 /* More than 4 bytes left? */ 230 bge .Lmemset_wordaligned /* Yup */ 231 232 .Lmemset_lessthanfour: 233 cmp r1, #0x00 234 RETc(eq) /* Zero length so exit */ 235 strb r3, [ip], #0x01 /* Set 1 byte */ 236 cmp r1, #0x02 237 strgeb r3, [ip], #0x01 /* Set another byte */ 238 strgtb r3, [ip] /* and a third */ 239 RET /* Exit */ 240
Indexes created Tue Sep 23 07:09:52 GMT 2025