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 "memccpy.s" 28 29#include <sys/asm_linkage.h> 30 31 ANSI_PRAGMA_WEAK(memccpy,function) 32 33 ENTRY(memccpy) /* (void *dst, void *src, uchar_t c, size_t) */ 34.loop: 35 decq %rcx / decrement bytes to go 36 jl .notfound 37 movb (%rsi),%dh 38 movb %dh,(%rdi) / move byte 39 cmpb %dh,%dl / is it the byte sought? 40 je .found / yes 41 42 decq %rcx / decrement bytes to go 43 jl .notfound 44 movb 1(%rsi),%dh 45 movb %dh,1(%rdi) / move byte 46 cmpb %dh,%dl / is it the byte sought? 47 je .found1 / yes 48 49 decq %rcx / decrement bytes to go 50 jl .notfound 51 movb 2(%rsi),%dh 52 movb %dh,2(%rdi) / move byte 53 cmpb %dh,%dl / is it the byte sought? 54 je .found2 / yes 55 56 decq %rcx / decrement bytes to go 57 jl .notfound 58 movb 3(%rsi),%dh 59 movb %dh,3(%rdi) / move byte 60 addq $4,%rsi 61 addq $4,%rdi 62 cmpb %dh,%dl / is it the byte sought? 63 jne .loop / no 64 decq %rdi 65 66.found: 67 incq %rdi / return pointer to next byte in dest 68 movq %rdi,%rax 69 ret 70 71 .align 4 72.found2: 73 incq %rdi 74.found1: 75 addq $2,%rdi / return pointer to next byte in dest 76 movq %rdi,%rax 77 ret 78 79 .align 4 80.notfound: 81 xorl %eax,%eax / search fails 82 ret 83 SET_SIZE(memccpy) 84