1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 .file "strcpy.s" 28 29 /* 30 * strcpy(s1, s2) 31 * 32 * Copy string s2 to s1. s1 must be large enough. Return s1. 33 * 34 * Fast assembler language version of the following C-program strcpy 35 * which represents the `standard' for the C-library. 36 * 37 * char * 38 * strcpy(s1, s2) 39 * register char *s1; 40 * register const char *s2; 41 * { 42 * char *os1 = s1; 43 * 44 * while(*s1++ = *s2++) 45 * ; 46 * return(os1); 47 * } 48 * 49 */ 50 51 #include <sys/asm_linkage.h> 52 53 ! This implementation of strcpy works by first checking the 54 ! source alignment and copying byte, half byte, or word 55 ! quantities until the source ptr is aligned at an extended 56 ! word boundary. Once this has occurred, the string is copied, 57 ! checking for zero bytes, depending upon its dst ptr alignment. 58 ! (methods for xword, word, half-word, and byte copies are present) 59 60 ENTRY(strcpy) 61 62 .align 32 63 64 sub %o1, %o0, %o3 ! src - dst 65 andcc %o1, 7, %o4 ! dword aligned ? 66 bz,pn %ncc, .srcaligned ! yup 67 mov %o0, %o2 ! save dst 68 69 .chkbyte: 70 andcc %o1, 1, %g0 ! need to copy byte ? 71 bz,pn %ncc, .chkhalfword ! nope, maybe halfword 72 sub %g0, %o1, %g1 ! %g1<2:0> = # of unaligned bytes 73 ldub [%o2 + %o3], %o5 ! src[0] 74 tst %o5 ! src[0] == 0 ? 75 stb %o5, [%o2] ! dst[0] = src[0] 76 bz,pn %ncc, .done ! yup, done 77 inc %o2 ! src++, dst++ 78 79 .chkhalfword: 80 andcc %g1, 2, %g0 ! need to copy half-word ? 81 bz,pn %ncc, .chkword ! nope, maybe word 82 nop ! 83 lduh [%o2 + %o3], %o5 ! load src halfword 84 srl %o5, 8, %o4 ! extract first byte 85 tst %o4 ! first byte == 0 ? 86 bz,pn %ncc, .done ! yup, done 87 stb %o4, [%o2] ! store first byte 88 andcc %o5, 0xff, %g0 ! extract second byte 89 stb %o5, [%o2 + 1] ! store second byte 90 bz,pn %ncc, .done ! yup, 2nd byte zero, done 91 add %o2, 2, %o2 ! src += 2 92 93 .chkword: 94 andcc %g1, 4, %g0 ! need to copy word ? 95 bz,pn %ncc, .srcaligned ! nope 96 nop ! 97 lduw [%o2 + %o3], %o5 ! load src word 98 srl %o5, 24, %o4 ! extract first byte 99 tst %o4 ! is first byte zero ? 100 bz,pn %ncc, .done ! yup, done 101 stb %o4, [%o2] ! store first byte 102 srl %o5, 16, %o4 ! extract second byte 103 andcc %o4, 0xff, %g0 ! is second byte zero ? 104 bz,pn %ncc, .done ! yup, done 105 stb %o4, [%o2 + 1] ! store second byte 106 srl %o5, 8, %o4 ! extract third byte 107 andcc %o4, 0xff, %g0 ! third byte zero ? 108 bz,pn %ncc, .done ! yup, done 109 stb %o4, [%o2 + 2] ! store third byte 110 andcc %o5, 0xff, %g0 ! fourth byte zero ? 111 stb %o5, [%o2 + 3] ! store fourth byte 112 bz,pn %ncc, .done ! yup, fourth byte zero, done 113 add %o2, 4, %o2 ! src += 2 114 115 .srcaligned: 116 sethi %hi(0x01010101), %o4 ! Alan Mycroft's magic1 117 or %o4, %lo(0x01010101),%o4! finish loading magic1 118 sllx %o4, 32, %o1 ! spread magic1 119 and %o2, 3, %g4 ! dst<1:0> to examine offset 120 or %o4, %o1, %o4 ! to all 64 bits 121 cmp %g4, 1 ! dst offset of 1 or 5 122 sllx %o4, 7, %o5 ! Alan Mycroft's magic2 123 be,pn %ncc, .storebyte1241 ! store 1, 2, 4, 1 bytes 124 cmp %g4, 3 ! dst offset of 3 or 7 125 be,pn %ncc, .storebyte1421 ! store 1, 4, 2, 1 bytes 126 cmp %g4, 2 ! dst halfword aligned ? 127 be,pn %ncc, .storehalfword ! yup, store half-word wise 128 andcc %o2, 7, %g0 ! dst word aligned ? 129 bnz,pn %ncc, .storeword2 ! yup, store word wise 130 .empty 131 132 .storedword: 133 ldx [%o2 + %o3], %o1 ! src dword 134 add %o2, 8, %o2 ! src += 8, dst += 8 135 andn %o5, %o1, %g1 ! ~dword & 0x8080808080808080 136 sub %o1, %o4, %g4 ! dword - 0x0101010101010101 137 andcc %g4, %g1, %g0 ! ((dword - 0x0101010101010101) & ~dword & 0x8080808080808080) 138 bz,a,pt %ncc, .storedword ! no zero byte if magic expression == 0 139 stx %o1, [%o2 - 8] ! store word to dst (address pre-incremented) 140 141 .zerobyte: 142 orn %o4, %g0, %o4 ! 0xffffffffffffffff 143 sllx %o4, 56, %o4 ! 0xff00000000000000 144 srlx %o1, 56, %o3 ! %o3<7:0> = first byte 145 andcc %o1, %o4, %g0 ! first byte zero? 146 bz,pn %ncc, .done ! yup, done 147 stb %o3, [%o2 - 8] ! store first byte 148 srlx %o4, 8, %o4 ! 0x00ff000000000000 149 srlx %o1, 48, %o3 ! %o3<7:0> = second byte 150 andcc %o1, %o4, %g0 ! second byte zero? 151 bz,pn %ncc, .done ! yup, done 152 stb %o3, [%o2 - 7] ! store second byte 153 srlx %o4, 8, %o4 ! 0x0000ff0000000000 154 srlx %o1, 40, %o3 ! %o3<7:0> = third byte 155 andcc %o1, %o4, %g0 ! third byte zero? 156 bz,pn %ncc, .done ! yup, done 157 stb %o3, [%o2 - 6] ! store third byte 158 srlx %o4, 8, %o4 ! 0x000000ff00000000 159 srlx %o1, 32, %o3 ! %o3<7:0> = fourth byte 160 andcc %o1, %o4, %g0 ! fourth byte zero? 161 bz,pn %ncc, .done ! yup, done 162 stb %o3, [%o2 - 5] ! store fourth byte 163 srlx %o4, 8, %o4 ! 0x00000000ff000000 164 srlx %o1, 24, %o3 ! %o3<7:0> = fifth byte 165 andcc %o1, %o4, %g0 ! fifth byte zero? 166 bz,pn %ncc, .done ! yup, done 167 stb %o3, [%o2 - 4] ! store fifth byte 168 srlx %o4, 8, %o4 ! 0x0000000000ff0000 169 srlx %o1, 16, %o3 ! %o3<7:0> = sixth byte 170 andcc %o1, %o4, %g0 ! sixth byte zero? 171 bz,pn %ncc, .done ! yup, done 172 stb %o3, [%o2 - 3] ! store sixth byte 173 srlx %o4, 8, %o4 ! 0x000000000000ff00 174 andcc %o1, %o4, %g0 ! seventh byte zero? 175 srlx %o1, 8, %o3 ! %o3<7:0> = seventh byte 176 bz,pn %ncc, .done ! yup, done 177 stb %o3, [%o2 - 2] ! store seventh byte 178 stb %o1, [%o2 - 1] ! store eigth byte 179 .done: 180 retl ! done with leaf function 181 182 nop ! ensure following loop 16-byte aligned 183 184 .storebyte1421: 185 ldx [%o2 + %o3], %o1 ! x = src[] 186 add %o2, 8, %o2 ! src += 8, dst += 8 187 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 188 sub %o1, %o4, %g4 ! x - 0x0101010101010101 189 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) 190 bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases 191 srlx %o1, 56, %g1 ! %g1<7:0> = first byte; word aligned now 192 stb %g1, [%o2 - 8] ! store first byte 193 srlx %o1, 24, %g1 ! %g1<31:0> = bytes 2, 3, 4, 5 194 stw %g1, [%o2 - 7] ! store bytes 2, 3, 4, 5 195 srlx %o1, 8, %g1 ! %g1<15:0> = bytes 6, 7 196 sth %g1, [%o2 - 3] ! store bytes 6, 7 197 ba .storebyte1421 ! next dword 198 stb %o1, [%o2 - 1] ! store eigth byte 199 200 nop ! ensure following loop 16-byte aligned 201 nop ! ensure following loop 16-byte aligned 202 203 .storebyte1241: 204 ldx [%o2 + %o3], %o1 ! x = src[] 205 add %o2, 8, %o2 ! src += 8, dst += 8 206 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 207 sub %o1, %o4, %g4 ! x - 0x0101010101010101 208 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) 209 bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases 210 srlx %o1, 56, %g1 ! %g1<7:0> = first byte; word aligned now 211 stb %g1, [%o2 - 8] ! store first byte 212 srlx %o1, 40, %g1 ! %g1<15:0> = bytes 2, 3 213 sth %g1, [%o2 - 7] ! store bytes 2, 3 214 srlx %o1, 8, %g1 ! %g1<31:0> = bytes 4, 5, 6, 7 215 stw %g1, [%o2 - 5] ! store bytes 4, 5, 6, 7 216 ba .storebyte1241 ! next dword 217 stb %o1, [%o2 - 1] ! store eigth byte 218 219 nop ! ensure following loop 16-byte aligned 220 nop ! ensure following loop 16-byte aligned 221 222 .storehalfword: 223 ldx [%o2 + %o3], %o1 ! x = src[] 224 add %o2, 8, %o2 ! src += 8, dst += 8 225 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 226 sub %o1, %o4, %g4 ! x - 0x0101010101010101 227 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) 228 bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases 229 srlx %o1, 48, %g1 ! get first and second byte 230 sth %g1, [%o2 - 8] ! store first and second byte; word aligned now 231 srlx %o1, 16, %g1 ! %g1<31:0> = bytes 3, 4, 5, 6 232 stw %g1, [%o2 - 6] ! store bytes 3, 4, 5, 6 233 ba .storehalfword ! next word 234 sth %o1, [%o2 - 2] ! store seventh and eigth byte 235 236 .storeword: 237 ldx [%o2 + %o3], %o1 ! x = src[] 238 .storeword2: 239 add %o2, 8, %o2 ! src += 8, dst += 8 240 andn %o5, %o1, %g1 ! ~x & 0x0x8080808080808080 241 sub %o1, %o4, %g4 ! x - 0x0101010101010101 242 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) 243 bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases 244 srlx %o1, 32, %g1 ! get bytes 1,2,3,4 245 stw %g1, [%o2 - 8] ! store bytes 1,2,3,4 (address is pre-incremented) 246 ba .storeword ! no zero byte if magic expression == 0 247 stw %o1, [%o2 - 4] ! store bytes 5,6,7,8 248 249 nop ! padding, do not remove!!! 250 nop ! padding, do not remove!!! 251 SET_SIZE(strcpy) 252 253
Indexes created Sat Nov 28 14:09:03 UTC 2009
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