1*84d9c625SLionel Sambuc/*- 2*84d9c625SLionel Sambuc * Copyright (c) 2013 The NetBSD Foundation, Inc. 3*84d9c625SLionel Sambuc * All rights reserved. 4*84d9c625SLionel Sambuc * 5*84d9c625SLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation 6*84d9c625SLionel Sambuc * by Matt Thomas of 3am Software Foundry. 7*84d9c625SLionel Sambuc * 8*84d9c625SLionel Sambuc * Redistribution and use in source and binary forms, with or without 9*84d9c625SLionel Sambuc * modification, are permitted provided that the following conditions 10*84d9c625SLionel Sambuc * are met: 11*84d9c625SLionel Sambuc * 1. Redistributions of source code must retain the above copyright 12*84d9c625SLionel Sambuc * notice, this list of conditions and the following disclaimer. 13*84d9c625SLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright 14*84d9c625SLionel Sambuc * notice, this list of conditions and the following disclaimer in the 15*84d9c625SLionel Sambuc * documentation and/or other materials provided with the distribution. 16*84d9c625SLionel Sambuc * 17*84d9c625SLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18*84d9c625SLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19*84d9c625SLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20*84d9c625SLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21*84d9c625SLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22*84d9c625SLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23*84d9c625SLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24*84d9c625SLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25*84d9c625SLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26*84d9c625SLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27*84d9c625SLionel Sambuc * POSSIBILITY OF SUCH DAMAGE. 28*84d9c625SLionel Sambuc */ 29*84d9c625SLionel Sambuc 30*84d9c625SLionel Sambuc#include <machine/asm.h> 31*84d9c625SLionel Sambuc 32*84d9c625SLionel SambucRCSID("$NetBSD: strcat_naive.S,v 1.3 2013/08/19 17:02:25 matt Exp $") 33*84d9c625SLionel Sambuc 34*84d9c625SLionel SambucENTRY(strcat) 35*84d9c625SLionel Sambuc mov ip, r0 /* need to preserve r0 */ 36*84d9c625SLionel Sambuc#if defined(__thumb__) 37*84d9c625SLionel Sambuc1: ldrb r2, [r0] /* load next byte */ 38*84d9c625SLionel Sambuc adds r0, r0, #1 /* advance */ 39*84d9c625SLionel Sambuc cmp r2, #0 /* was it a NUL? */ 40*84d9c625SLionel Sambuc bne 1b /* no, get next byte */ 41*84d9c625SLionel Sambuc subs r0, r0, #1 /* back up one to the NUL */ 42*84d9c625SLionel Sambuc subs r1, r1, r0 /* save one increment */ 43*84d9c625SLionel Sambuc2: ldrb r2, [r1, r0] /* load next byte from append */ 44*84d9c625SLionel Sambuc strb r2, [r0] /* store it */ 45*84d9c625SLionel Sambuc adds r0, r0, #1 /* advance */ 46*84d9c625SLionel Sambuc cmp r2, #0 /* was it a NUL? */ 47*84d9c625SLionel Sambuc bne 2b /* no, get next byte */ 48*84d9c625SLionel Sambuc mov r0, ip /* restore dst address */ 49*84d9c625SLionel Sambuc RET /* return */ 50*84d9c625SLionel Sambuc#else /* !__thumb__ */ 51*84d9c625SLionel Sambuc mov ip, r0 /* need to preserve r0 */ 52*84d9c625SLionel Sambuc1: ldrb r2, [ip], #1 /* load next byte */ 53*84d9c625SLionel Sambuc teq r2, #0 /* was it a NUL? */ 54*84d9c625SLionel Sambuc bne 1b /* no, get next byte */ 55*84d9c625SLionel Sambuc sub ip, ip, #1 /* back up one to the NUL */ 56*84d9c625SLionel Sambuc2: ldrb r2, [r1], #1 /* load next byte from append */ 57*84d9c625SLionel Sambuc strb r2, [ip], #1 /* store it */ 58*84d9c625SLionel Sambuc teq r2, #0 /* was it a NUL? */ 59*84d9c625SLionel Sambuc bne 2b /* no, get next byte */ 60*84d9c625SLionel Sambuc RET /* return */ 61*84d9c625SLionel Sambuc#endif 62*84d9c625SLionel SambucEND(strcat) 63