1/* $NetBSD: memccpy.S,v 1.4 2013/07/18 21:37:47 matt Exp $ */ 2 3/* 4 * Copyright (C) 1999 Scott Reynolds. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <machine/asm.h> 30 31#if defined(LIBC_SCCS) && !defined(lint) 32 RCSID("$NetBSD: memccpy.S,v 1.4 2013/07/18 21:37:47 matt Exp $") 33#endif /* LIBC_SCCS and not lint */ 34 35ENTRY(memccpy) 36 movl 16(%sp),%d0 | count 37 jeq Lmcbail | nothing to do 38 39 movl 4(%sp),%a0 | a0 = toaddr 40#ifndef __mcoldfire__ 41 subql #1,%d0 | prepare count for DBcc loop 42#endif 43 movl 8(%sp),%a1 | a1 = fromaddr 44 movl 12(%sp),%d1 | d1 = terminator 45 jeq Lmcloop | handle ASCII NUL specially 46 47 movl %d2,-(%sp) | save scratch register 48Lmcnzloop: 49 movb (%a1)+,%d2 | move a byte 50 movb %d2,(%a0)+ 51 cmpb %d2,%d1 | found the terminator? 52#ifndef __mcoldfire__ 53 dbeq %d0,Lmcnzloop | if not, keep transferring, 54#endif 55 jeq Lmcnzdone | otherwise done 56#ifdef __mcoldfire__ 57 subql #1,%d0 58 jne Lmcnzloop 59#else 60 clrw %d0 | check to see if more to do 61 subql #1,%d0 62 jcc Lmcnzloop | yes, keep going... 63#endif 64 65 movl (%sp)+,%d2 | restore scratch register 66 movql #0,%d0 | no terminator found, return NULL 67#ifdef __SVR4_ABI__ 68 movl %d0,%a0 | XXX maybe use lea to avoid stall? 69#endif 70 rts 71 72Lmcloop: 73 movb (%a1)+,(%a0)+ | move a byte; was it NUL? 74#ifndef __mcoldfire__ 75 dbeq %d0,Lmcloop | if not, keep transferring, 76#endif 77 jeq Lmcdone | otherwise done 78#ifdef __mcoldfire__ 79 subql #1,%d0 80 jne Lmcloop 81#else 82 clrw %d0 | check to see if more to do 83 subql #1,%d0 84 jcc Lmcloop | yes, keep going... 85#endif 86 | Note: %d0 is now -1! 87 movql #0,%d0 | no terminator found, return NULL 88Lmcbail: 89#ifdef __SVR4_ABI__ 90 movl %d0,%a0 | XXX maybe use lea to avoid stall? 91#endif 92 rts 93 94Lmcnzdone: 95 movl (%sp)+,%d2 | restore scratch register 96Lmcdone: 97 movl %a0,%d0 98 rts 99END(memccpy) 100