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#include <sys/asm_linkage.h> 32 33 ANSI_PRAGMA_WEAK(memccpy,function) 34 35 ENTRY(memccpy) /* (void *dst, void *src, uchar_t c, size_t) */ 36.loop: 37 decq %rcx / decrement bytes to go 38 jl .notfound 39 movb (%rsi),%dh 40 movb %dh,(%rdi) / move byte 41 cmpb %dh,%dl / is it the byte sought? 42 je .found / yes 43 44 decq %rcx / decrement bytes to go 45 jl .notfound 46 movb 1(%rsi),%dh 47 movb %dh,1(%rdi) / move byte 48 cmpb %dh,%dl / is it the byte sought? 49 je .found1 / yes 50 51 decq %rcx / decrement bytes to go 52 jl .notfound 53 movb 2(%rsi),%dh 54 movb %dh,2(%rdi) / move byte 55 cmpb %dh,%dl / is it the byte sought? 56 je .found2 / yes 57 58 decq %rcx / decrement bytes to go 59 jl .notfound 60 movb 3(%rsi),%dh 61 movb %dh,3(%rdi) / move byte 62 addq $4,%rsi 63 addq $4,%rdi 64 cmpb %dh,%dl / is it the byte sought? 65 jne .loop / no 66 decq %rdi 67 68.found: 69 incq %rdi / return pointer to next byte in dest 70 movq %rdi,%rax 71 ret 72 73 .align 4 74.found2: 75 incq %rdi 76.found1: 77 addq $2,%rdi / return pointer to next byte in dest 78 movq %rdi,%rax 79 ret 80 81 .align 4 82.notfound: 83 xorl %eax,%eax / search fails 84 ret 85 SET_SIZE(memccpy) 86