memset.S revision 1.1.50.1
1 /* $NetBSD: memset.S,v 1.1.50.1 2013/01/16 05:25:53 yamt 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 /* 72 * memset: Sets a block of memory to the specified value 73 * 74 * On entry: 75 * r0 - dest address 76 * r1 - byte to write 77 * r2 - number of bytes to write 78 * 79 * On exit: 80 * r0 - dest address 81 */ 82 #ifdef _BZERO 83 /* LINTSTUB: Func: void bzero(void *, size_t) */ 84 ENTRY(bzero) 85 mov r3, #0x00 86 #else 87 /* LINTSTUB: Func: void *memset(void *, int, size_t) */ 88 ENTRY(memset) 89 and r3, r1, #0xff /* We deal with bytes */ 90 mov r1, r2 91 #endif 92 cmp r1, #0x04 /* Do we have less than 4 bytes */ 93 mov ip, r0 94 blt .Lmemset_lessthanfour 95 96 /* Ok first we will word align the address */ 97 ands r2, ip, #0x03 /* Get the bottom two bits */ 98 bne .Lmemset_wordunaligned /* The address is not word aligned */ 99 100 /* We are now word aligned */ 101 .Lmemset_wordaligned: 102 #ifndef _BZERO 103 orr r3, r3, r3, lsl #8 /* Extend value to 16-bits */ 104 #endif 105 #ifdef _ARM_ARCH_DWORD_OK 106 tst ip, #0x04 /* Quad-align for Xscale */ 107 #else 108 cmp r1, #0x10 109 #endif 110 #ifndef _BZERO 111 orr r3, r3, r3, lsl #16 /* Extend value to 32-bits */ 112 #endif 113 #ifdef _ARM_ARCH_DWORD_OK 114 subne r1, r1, #0x04 /* Quad-align if necessary */ 115 strne r3, [ip], #0x04 116 cmp r1, #0x10 117 #endif 118 blt .Lmemset_loop4 /* If less than 16 then use words */ 119 mov r2, r3 /* Duplicate data */ 120 cmp r1, #0x80 /* If < 128 then skip the big loop */ 121 blt .Lmemset_loop32 122 123 /* Do 128 bytes at a time */ 124 .Lmemset_loop128: 125 subs r1, r1, #0x80 126 #ifdef _ARM_ARCH_DWORD_OK 127 strged r2, [ip], #0x08 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 #else 144 stmgeia ip!, {r2-r3} 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 #endif 161 bgt .Lmemset_loop128 162 RETc(eq) /* Zero length so just exit */ 163 164 add r1, r1, #0x80 /* Adjust for extra sub */ 165 166 /* Do 32 bytes at a time */ 167 .Lmemset_loop32: 168 subs r1, r1, #0x20 169 #ifdef _ARM_ARCH_DWORD_OK 170 strged r2, [ip], #0x08 171 strged r2, [ip], #0x08 172 strged r2, [ip], #0x08 173 strged r2, [ip], #0x08 174 #else 175 stmgeia ip!, {r2-r3} 176 stmgeia ip!, {r2-r3} 177 stmgeia ip!, {r2-r3} 178 stmgeia ip!, {r2-r3} 179 #endif 180 bgt .Lmemset_loop32 181 RETc(eq) /* Zero length so just exit */ 182 183 adds r1, r1, #0x10 /* Partially adjust for extra sub */ 184 185 /* Deal with 16 bytes or more */ 186 #ifdef _ARM_ARCH_DWORD_OK 187 strged r2, [ip], #0x08 188 strged r2, [ip], #0x08 189 #else 190 stmgeia ip!, {r2-r3} 191 stmgeia ip!, {r2-r3} 192 #endif 193 RETc(eq) /* Zero length so just exit */ 194 195 addlt r1, r1, #0x10 /* Possibly adjust for extra sub */ 196 197 /* We have at least 4 bytes so copy as words */ 198 .Lmemset_loop4: 199 subs r1, r1, #0x04 200 strge r3, [ip], #0x04 201 bgt .Lmemset_loop4 202 RETc(eq) /* Zero length so just exit */ 203 204 #ifdef _ARM_ARCH_DWORD_OK 205 /* Compensate for 64-bit alignment check */ 206 adds r1, r1, #0x04 207 RETc(eq) 208 cmp r1, #2 209 #else 210 cmp r1, #-2 211 #endif 212 213 strb r3, [ip], #0x01 /* Set 1 byte */ 214 strgeb r3, [ip], #0x01 /* Set another byte */ 215 strgtb r3, [ip] /* and a third */ 216 RET /* Exit */ 217 218 .Lmemset_wordunaligned: 219 rsb r2, r2, #0x004 220 strb r3, [ip], #0x01 /* Set 1 byte */ 221 cmp r2, #0x02 222 strgeb r3, [ip], #0x01 /* Set another byte */ 223 sub r1, r1, r2 224 strgtb r3, [ip], #0x01 /* and a third */ 225 cmp r1, #0x04 /* More than 4 bytes left? */ 226 bge .Lmemset_wordaligned /* Yup */ 227 228 .Lmemset_lessthanfour: 229 cmp r1, #0x00 230 RETc(eq) /* Zero length so exit */ 231 strb r3, [ip], #0x01 /* Set 1 byte */ 232 cmp r1, #0x02 233 strgeb r3, [ip], #0x01 /* Set another byte */ 234 strgtb r3, [ip] /* and a third */ 235 RET /* Exit */ 236
Indexes created Wed Sep 24 05:09:52 GMT 2025