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#pragma ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31/* 32 * memcpy(s1, s2, len) 33 * 34 * Copy s2 to s1, always copy n bytes. 35 * Note: this does not work for overlapped copies, bcopy() does 36 * 37 * Fast assembler language version of the following C-program for memcpy 38 * which represents the `standard' for the C-library. 39 * 40 * void * 41 * memcpy(void *s, const void *s0, size_t n) 42 * { 43 * if (n != 0) { 44 * char *s1 = s; 45 * const char *s2 = s0; 46 * do { 47 * *s1++ = *s2++; 48 * } while (--n != 0); 49 * } 50 * return (s); 51 * } 52 */ 53 54#include "SYS.h" 55 56 ANSI_PRAGMA_WEAK(memcpy,function) 57 58 ENTRY(memcpy) 59 st %o0, [%sp + 68] ! save des address for return val 60 cmp %o2, 17 ! for small counts copy bytes 61 bleu .dbytecp 62 andcc %o1, 3, %o5 ! is src word aligned 63 bz .aldst 64 cmp %o5, 2 ! is src half-word aligned 65 be .s2algn 66 cmp %o5, 3 ! src is byte aligned 67.s1algn:ldub [%o1], %o3 ! move 1 or 3 bytes to align it 68 inc 1, %o1 69 stb %o3, [%o0] ! move a byte to align src 70 inc 1, %o0 71 bne .s2algn 72 dec %o2 73 b .ald ! now go align dest 74 andcc %o0, 3, %o5 75 76.s2algn:lduh [%o1], %o3 ! know src is 2 byte alinged 77 inc 2, %o1 78 srl %o3, 8, %o4 79 stb %o4, [%o0] ! have to do bytes, 80 stb %o3, [%o0 + 1] ! don't know dst alingment 81 inc 2, %o0 82 dec 2, %o2 83 84.aldst: andcc %o0, 3, %o5 ! align the destination address 85.ald: bz .w4cp 86 cmp %o5, 2 87 bz .w2cp 88 cmp %o5, 3 89.w3cp: ld [%o1], %o4 90 inc 4, %o1 91 srl %o4, 24, %o5 92 stb %o5, [%o0] 93 bne .w1cp 94 inc %o0 95 dec 1, %o2 96 andn %o2, 3, %o3 ! o3 is aligned word count 97 dec 4, %o3 ! avoid reading beyond tail of src 98 sub %o1, %o0, %o1 ! o1 gets the difference 99 1001: sll %o4, 8, %g1 ! save residual bytes 101 ld [%o1+%o0], %o4 102 deccc 4, %o3 103 srl %o4, 24, %o5 ! merge with residual 104 or %o5, %g1, %g1 105 st %g1, [%o0] 106 bnz 1b 107 inc 4, %o0 108 sub %o1, 3, %o1 ! used one byte of last word read 109 and %o2, 3, %o2 110 b 7f 111 inc 4, %o2 112 113.w1cp: srl %o4, 8, %o5 114 sth %o5, [%o0] 115 inc 2, %o0 116 dec 3, %o2 117 andn %o2, 3, %o3 ! o3 is aligned word count 118 dec 4, %o3 ! avoid reading beyond tail of src 119 sub %o1, %o0, %o1 ! o1 gets the difference 120 1212: sll %o4, 24, %g1 ! save residual bytes 122 ld [%o1+%o0], %o4 123 deccc 4, %o3 124 srl %o4, 8, %o5 ! merge with residual 125 or %o5, %g1, %g1 126 st %g1, [%o0] 127 bnz 2b 128 inc 4, %o0 129 sub %o1, 1, %o1 ! used three bytes of last word read 130 and %o2, 3, %o2 131 b 7f 132 inc 4, %o2 133 134.w2cp: ld [%o1], %o4 135 inc 4, %o1 136 srl %o4, 16, %o5 137 sth %o5, [%o0] 138 inc 2, %o0 139 dec 2, %o2 140 andn %o2, 3, %o3 ! o3 is aligned word count 141 dec 4, %o3 ! avoid reading beyond tail of src 142 sub %o1, %o0, %o1 ! o1 gets the difference 143 1443: sll %o4, 16, %g1 ! save residual bytes 145 ld [%o1+%o0], %o4 146 deccc 4, %o3 147 srl %o4, 16, %o5 ! merge with residual 148 or %o5, %g1, %g1 149 st %g1, [%o0] 150 bnz 3b 151 inc 4, %o0 152 sub %o1, 2, %o1 ! used two bytes of last word read 153 and %o2, 3, %o2 154 b 7f 155 inc 4, %o2 156 157.w4cp: andn %o2, 3, %o3 ! o3 is aligned word count 158 sub %o1, %o0, %o1 ! o1 gets the difference 159 1601: ld [%o1+%o0], %o4 ! read from address 161 deccc 4, %o3 ! decrement count 162 st %o4, [%o0] ! write at destination address 163 bgu 1b 164 inc 4, %o0 ! increment to address 165 b 7f 166 and %o2, 3, %o2 ! number of leftover bytes, if any 167 168 ! 169 ! differenced byte copy, works with any alignment 170 ! 171.dbytecp: 172 b 7f 173 sub %o1, %o0, %o1 ! o1 gets the difference 174 1754: stb %o4, [%o0] ! write to address 176 inc %o0 ! inc to address 1777: deccc %o2 ! decrement count 178 bgeu,a 4b ! loop till done 179 ldub [%o1+%o0], %o4 ! read from address 180 retl 181 ld [%sp + 68], %o0 ! return s1, destination address 182 183 SET_SIZE(memcpy) 184