xref: /freebsd/lib/libc/i386/string/strcpy.S (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
12ceb2ce9SGarrett Wollman/*
22ceb2ce9SGarrett Wollman * Copyright (c) 1993 Winning Strategies, Inc.
32ceb2ce9SGarrett Wollman * All rights reserved.
42ceb2ce9SGarrett Wollman *
52ceb2ce9SGarrett Wollman * Redistribution and use in source and binary forms, with or without
62ceb2ce9SGarrett Wollman * modification, are permitted provided that the following conditions
72ceb2ce9SGarrett Wollman * are met:
82ceb2ce9SGarrett Wollman * 1. Redistributions of source code must retain the above copyright
92ceb2ce9SGarrett Wollman *    notice, this list of conditions and the following disclaimer.
102ceb2ce9SGarrett Wollman * 2. Redistributions in binary form must reproduce the above copyright
112ceb2ce9SGarrett Wollman *    notice, this list of conditions and the following disclaimer in the
122ceb2ce9SGarrett Wollman *    documentation and/or other materials provided with the distribution.
132ceb2ce9SGarrett Wollman * 3. All advertising materials mentioning features or use of this software
142ceb2ce9SGarrett Wollman *    must display the following acknowledgement:
152ceb2ce9SGarrett Wollman *      This product includes software developed by Winning Strategies, Inc.
162ceb2ce9SGarrett Wollman * 4. The name of the author may not be used to endorse or promote products
1721dc7d4fSJens Schweikhardt *    derived from this software without specific prior written permission
182ceb2ce9SGarrett Wollman *
192ceb2ce9SGarrett Wollman * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
202ceb2ce9SGarrett Wollman * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
212ceb2ce9SGarrett Wollman * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
222ceb2ce9SGarrett Wollman * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
232ceb2ce9SGarrett Wollman * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
242ceb2ce9SGarrett Wollman * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
252ceb2ce9SGarrett Wollman * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
262ceb2ce9SGarrett Wollman * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
272ceb2ce9SGarrett Wollman * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
282ceb2ce9SGarrett Wollman * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
292ceb2ce9SGarrett Wollman */
302ceb2ce9SGarrett Wollman
31e6d808aeSPeter Wemm#include <machine/asm.h>
322ceb2ce9SGarrett Wollman/*
332ceb2ce9SGarrett Wollman * strcpy (dst, src)
342ceb2ce9SGarrett Wollman *	copy the string src to dst.
352ceb2ce9SGarrett Wollman *
362ceb2ce9SGarrett Wollman * Written by:
372ceb2ce9SGarrett Wollman *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
382ceb2ce9SGarrett Wollman */
392ceb2ce9SGarrett Wollman
402ceb2ce9SGarrett Wollman/*
412ceb2ce9SGarrett Wollman * I've unrolled the loop eight times: large enough to make a
422ceb2ce9SGarrett Wollman * significant difference, and small enough not to totally trash the
4329ec6237SBill Fumerola * cache.
442ceb2ce9SGarrett Wollman */
452ceb2ce9SGarrett Wollman
462ceb2ce9SGarrett WollmanENTRY(strcpy)
472ceb2ce9SGarrett Wollman	movl	4(%esp),%ecx		/* dst address */
482ceb2ce9SGarrett Wollman	movl	8(%esp),%edx		/* src address */
492ceb2ce9SGarrett Wollman	pushl	%ecx			/* push dst address */
502ceb2ce9SGarrett Wollman
512ceb2ce9SGarrett Wollman	.align 2,0x90
522ceb2ce9SGarrett WollmanL1:	movb	(%edx),%al		/* unroll loop, but not too much */
532ceb2ce9SGarrett Wollman	movb	%al,(%ecx)
542ceb2ce9SGarrett Wollman	testb	%al,%al
552ceb2ce9SGarrett Wollman	je	L2
562ceb2ce9SGarrett Wollman	movb	1(%edx),%al
572ceb2ce9SGarrett Wollman	movb	%al,1(%ecx)
582ceb2ce9SGarrett Wollman	testb	%al,%al
592ceb2ce9SGarrett Wollman	je	L2
602ceb2ce9SGarrett Wollman	movb	2(%edx),%al
612ceb2ce9SGarrett Wollman	movb	%al,2(%ecx)
622ceb2ce9SGarrett Wollman	testb	%al,%al
632ceb2ce9SGarrett Wollman	je	L2
642ceb2ce9SGarrett Wollman	movb	3(%edx),%al
652ceb2ce9SGarrett Wollman	movb	%al,3(%ecx)
662ceb2ce9SGarrett Wollman	testb	%al,%al
672ceb2ce9SGarrett Wollman	je	L2
682ceb2ce9SGarrett Wollman	movb	4(%edx),%al
692ceb2ce9SGarrett Wollman	movb	%al,4(%ecx)
702ceb2ce9SGarrett Wollman	testb	%al,%al
712ceb2ce9SGarrett Wollman	je	L2
722ceb2ce9SGarrett Wollman	movb	5(%edx),%al
732ceb2ce9SGarrett Wollman	movb	%al,5(%ecx)
742ceb2ce9SGarrett Wollman	testb	%al,%al
752ceb2ce9SGarrett Wollman	je	L2
762ceb2ce9SGarrett Wollman	movb	6(%edx),%al
772ceb2ce9SGarrett Wollman	movb	%al,6(%ecx)
782ceb2ce9SGarrett Wollman	testb	%al,%al
792ceb2ce9SGarrett Wollman	je	L2
802ceb2ce9SGarrett Wollman	movb	7(%edx),%al
812ceb2ce9SGarrett Wollman	movb	%al,7(%ecx)
822ceb2ce9SGarrett Wollman	addl	$8,%edx
832ceb2ce9SGarrett Wollman	addl	$8,%ecx
842ceb2ce9SGarrett Wollman	testb	%al,%al
852ceb2ce9SGarrett Wollman	jne	L1
862ceb2ce9SGarrett WollmanL2:	popl	%eax			/* pop dst address */
872ceb2ce9SGarrett Wollman	ret
88ed820052SPeter WemmEND(strcpy)
89*93ab7586SKonstantin Belousov
90*93ab7586SKonstantin Belousov	.section .note.GNU-stack,"",%progbits
91