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 .ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31#include <sys/asm_linkage.h> 32 33 ANSI_PRAGMA_WEAK(memmove,function) 34 ANSI_PRAGMA_WEAK(memcpy,function) 35 36#include "SYS.h" 37 38 ENTRY(memcpy) 39 movl %edi,%edx / save register variables 40 pushl %esi 41 movl 8(%esp),%edi / %edi = dest address 42 movl 12(%esp),%esi / %esi = source address 43 movl 16(%esp),%ecx / %ecx = length of string 44 movl %edi,%eax / return value from the call 45 46 shrl $2,%ecx / %ecx = number of words to move 47 rep ; smovl / move the words 48 49 movl 16(%esp),%ecx / %ecx = number of bytes to move 50 andl $0x3,%ecx / %ecx = number of bytes left to move 51 rep ; smovb / move the bytes 52 53 popl %esi / restore register variables 54 movl %edx,%edi 55 ret 56 SET_SIZE(memcpy) 57 58 59 ENTRY(memmove) 60 pushl %edi / save off %edi, %esi and move destination 61 movl 4+12(%esp),%ecx / get number of bytes to move 62 pushl %esi 63 testl %ecx,%ecx / if (n == 0) 64 je .CleanupReturn / return(s); 65 movl 8+ 4(%esp),%edi / destination buffer address 66 movl 8+ 8(%esp),%esi / source buffer address 67.Common: 68 movl $3,%eax / heavily used constant 69 cmpl %esi,%edi / if (source addr > dest addr) 70 leal -1(%esi,%ecx),%edx 71 jle .CopyRight / 72 cmpl %edx,%edi 73 jle .CopyLeft 74.CopyRight: 75 cmpl $8,%ecx / if (size < 8 bytes) 76 jbe .OneByteCopy / goto fast short copy loop 77.FourByteCopy: 78 movl %ecx,%edx / save count 79 movl %esi,%ecx / get source buffer 4 byte aligned 80 andl %eax,%ecx 81 jz .SkipAlignRight 82 subl %ecx,%edx 83 rep; smovb / do the byte part of copy 84.SkipAlignRight: 85 movl %edx,%ecx 86 shrl $2,%ecx 87 rep; smovl / do the long word part 88 movl %edx,%ecx / compute bytes left to move 89 andl %eax,%ecx / complete copy of remaining bytes 90 jz .CleanupReturn 91.OneByteCopy: 92 rep; smovb / do the byte part of copy 93.CleanupReturn: 94 popl %esi / } 95 popl %edi / restore registers 96 movl 4(%esp),%eax / set up return value 97.Return: 98 ret / return(dba); 99 100.CopyLeft: 101 std / reverse direction bit (RtoL) 102 cmpl $12,%ecx / if (size < 12) 103 ja .BigCopyLeft / { 104 movl %edx,%esi / src = src + size - 1 105 leal -1(%ecx,%edi),%edi / dst = dst + size - 1 106 rep; smovb / do the byte copy 107 cld / reset direction flag to LtoR 108 popl %esi / } 109 popl %edi / restore registers 110 movl 4(%esp),%eax / set up return value 111 ret / return(dba); 112.BigCopyLeft: / } else { 113 xchgl %edx,%ecx 114 movl %ecx,%esi / align source w/byte copy 115 leal -1(%edx,%edi),%edi 116 andl %eax,%ecx 117 jz .SkipAlignLeft 118 addl $1, %ecx / we need to insure that future 119 subl %ecx,%edx / copy is done on aligned boundary 120 rep; smovb 121.SkipAlignLeft: 122 movl %edx,%ecx 123 subl %eax,%esi 124 shrl $2,%ecx / do 4 byte copy RtoL 125 subl %eax,%edi 126 rep; smovl 127 andl %eax,%edx / do 1 byte copy whats left 128 jz .CleanupReturnLeft 129 movl %edx,%ecx 130 addl %eax,%esi / rep; smovl instruction will decrement 131 addl %eax,%edi / %edi, %esi by four after each copy 132 / adding 3 will restore pointers to byte 133 / before last double word copied 134 / which is where they are expected to 135 / be for the single byte copy code 136 rep; smovb 137.CleanupReturnLeft: 138 cld / reset direction flag to LtoR 139 popl %esi 140 popl %edi / restore registers 141 movl 4(%esp),%eax / set up return value 142 ret / return(dba); 143 SET_SIZE(memmove) 144