/*- * Copyright (c) 2013 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Matt Thomas of 3am Software Foundry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <machine/asm.h> RCSID("$NetBSD: strlcat_naive.S,v 1.3 2013/08/22 19:25:00 matt Exp $") /* LINTSTUB: size_t strlcat(char *, const char *, size_t) */ ENTRY(strlcat) adds r3, r2, r0 /* point to just end of dst */ mov ip, r0 /* need to keep r0 for a while */ 1: cmp ip, r3 /* still within dst? */ beq 3f /* no, get length of src */ ldrb r2, [ip], #1 /* load next byte */ cmp r2, #0 /* was it a NUL? */ bne 1b /* no, get next byte */ sub r0, ip, r0 /* get actual length of dst */ subs r0, r0, #1 /* account for the trailing NUL */ subs r3, r3, #1 /* back up to last byte in dst */ sub ip, ip, #1 /* back up over the NUL */ 2: ldrb r2, [r1], #1 /* load next byte from append */ #if defined(__thumb__) && defined(_ARM_ARCH_T2) cbz r2, 5f /* was it a NUL? yes, end of append */ #else cmp r2, #0 /* was it a NUL? */ beq 5f /* yes, end of append */ #endif adds r0, r0, #1 /* count another byte */ cmp ip, r3 /* do we have enough room for it? */ #ifdef __thumb__ bge 2b strb r2, [ip], #1 /* yes, store it */ #else strblt r2, [ip], #1 /* yes, store it */ #endif b 2b /* get next byte from append */ 3: subs r0, r3, r0 /* move size to return value */ 4: ldrb r2, [r1], #1 /* load next byte from append */ #if defined(__thumb__) && defined(_ARM_ARCH_T2) cbz r2, 6f /* was it a NUL? yes, we're done */ #else RETc(eq) /* yes, we're done */ #endif adds r0, r0, #1 /* add one to return value */ b 4b /* get next byte from append */ 5: movs r2, #0 /* NUL */ strb r2, [ip] /* append final NUL */ 6: RET /* return */ END(strlcat) |