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view usr/src/lib/libc/amd64/gen/memccpy.s @ 7298:b69e27387f74
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4758439 some files use "current date" sccs keywords
6560843 asm sources should not rely on .file "%M%" for naming STT_FILE symbols
6560958 Solaris:: perl modules should not use SCCS keywords in version information
6729074 webrev doesn't deal well with remote ssh hg parents
author | Mark J. Nelson <Mark.J.Nelson@Sun.COM> |
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date | Wed, 06 Aug 2008 16:29:39 -0600 |
parents | febeba71273d |
children |
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/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ .file "memccpy.s" #include <sys/asm_linkage.h> ANSI_PRAGMA_WEAK(memccpy,function) ENTRY(memccpy) /* (void *dst, void *src, uchar_t c, size_t) */ .loop: decq %rcx / decrement bytes to go jl .notfound movb (%rsi),%dh movb %dh,(%rdi) / move byte cmpb %dh,%dl / is it the byte sought? je .found / yes decq %rcx / decrement bytes to go jl .notfound movb 1(%rsi),%dh movb %dh,1(%rdi) / move byte cmpb %dh,%dl / is it the byte sought? je .found1 / yes decq %rcx / decrement bytes to go jl .notfound movb 2(%rsi),%dh movb %dh,2(%rdi) / move byte cmpb %dh,%dl / is it the byte sought? je .found2 / yes decq %rcx / decrement bytes to go jl .notfound movb 3(%rsi),%dh movb %dh,3(%rdi) / move byte addq $4,%rsi addq $4,%rdi cmpb %dh,%dl / is it the byte sought? jne .loop / no decq %rdi .found: incq %rdi / return pointer to next byte in dest movq %rdi,%rax ret .align 4 .found2: incq %rdi .found1: addq $2,%rdi / return pointer to next byte in dest movq %rdi,%rax ret .align 4 .notfound: xorl %eax,%eax / search fails ret SET_SIZE(memccpy)