1/* $NetBSD: memccpy.S,v 1.1 2001/02/05 00:17:22 scottr 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 1.1 2001/02/05 00:17:22 scottr Exp $") 33#endif /* LIBC_SCCS and not lint */ 34 35ENTRY(memccpy) 36 movl %sp@(16),%d0 | count 37 jeq Lmcbail | nothing to do 38 39 movl %sp@(4),%a0 | a0 = toaddr 40 subql #1,%d0 | prepare count for DBcc loop 41 movl %sp@(8),%a1 | a1 = fromaddr 42 movl %sp@(12),%d1 | d1 = terminator 43 jeq Lmcloop | handle ASCII NUL specially 44 45 movl %d2,%sp@- | save scratch register 46Lmcnzloop: 47 movb %a1@+,%d2 | move a byte 48 movb %d2,%a0@+ 49 cmpb %d2,%d1 | found the terminator? 50 dbeq %d0,Lmcnzloop | if not, keep transferring, 51 jeq Lmcnzdone | otherwise done 52 clrw %d0 | check to see if more to do 53 subql #1,%d0 54 jcc Lmcnzloop | yes, keep going... 55 56 movl %sp@+,%d2 | restore scratch register 57 movql #0,%d0 | no terminator found, return NULL 58#ifdef __SVR4_ABI__ 59 movl %d0,%a0 | XXX maybe use lea to avoid stall? 60#endif 61 rts 62 63Lmcloop: 64 movb %a1@+,%a0@+ | move a byte; was it NUL? 65 dbeq %d0,Lmcloop | if not, keep transferring, 66 jeq Lmcdone | otherwise done 67 clrw %d0 | check to see if more to do 68 subql #1,%d0 69 jcc Lmcloop | yes, keep going... 70 | Note: %d0 is now -1! 71 movql #0,%d0 | no terminator found, return NULL 72Lmcbail: 73#ifdef __SVR4_ABI__ 74 movl %d0,%a0 | XXX maybe use lea to avoid stall? 75#endif 76 rts 77 78Lmcnzdone: 79 movl %sp@+,%d2 | restore scratch register 80Lmcdone: 81 movl %a0,%d0 82 rts 83