Home | History | Annotate | Line # | Download | only in string 
      1 /* $NetBSD: strcat.S,v 1.1 2014/08/10 05:47:35 matt Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Matt Thomas of 3am Software Foundry.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <machine/asm.h>
     33 
     34 RCSID("$NetBSD: strcat.S,v 1.1 2014/08/10 05:47:35 matt Exp $")
     35 
     36 /*
     37  * Implementation of strcat using strlen/strcpy.
     38  */
     39 ENTRY(strcat)
     40 	stp	x29, x30, [sp, #-32]!	/* save fp, lr */
     41 	mov	x29, sp			/* init fp */
     42 	stp	x27, x28, [x29, #16]	/* save registers */
     43 
     44 	mov	x27, x0			/* save dst */
     45 	mov	x28, x1			/* save append */
     46 
     47 	bl	_C_LABEL(strlen)	/* find length of dst */
     48 
     49 	add	x0, x0, x27		/* add to dst pointer */
     50 	mov	x1, x28			/* fetch append */
     51 	bl	_C_LABEL(strcpy)	/* append string */
     52 
     53 	mov	x0, x27			/* restore dst as return value */
     54 	ldp	x27, x28, [x29, #16]	/* save registers */
     55 	ldp	x29, x30, [sp], #32	/* save fp, lr; pop stack */
     56 	ret
     57 END(strcat)
     58