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      1 /*	$NetBSD: index.S,v 1.6 2020/09/29 02:58:51 msaitoh Exp $	*/
      2 /*
      3  * Copyright (c) 1980, 1993
      4  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
     15  *    may be used to endorse or promote products derived from this software
     16  *    without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*
     32  * Find the first occurrence of c in the string cp.
     33  * Return pointer to match or null pointer.
     34  *
     35  * char *
     36  * index(cp, c)
     37  *	char *cp, c;
     38  */
     39 #include "DEFS.h"
     40 
     41 #ifdef LIBC_SCCS
     42 RCSID("$NetBSD: index.S,v 1.6 2020/09/29 02:58:51 msaitoh Exp $")
     43 #endif
     44 
     45 /* Alas not quite twice as fast as the generic C version on a uvax2 */
     46 
     47 ENTRY(index, 0)
     48 	movq	4(%ap),%r0	# %r0 = cp; %r1 = c
     49 	tstb	%r1		# special case, looking for '\0'
     50 	jeql	3f
     51 1:
     52 	cmpb	(%r0),%r1
     53 	jeql	2f
     54 	tstb	(%r0)+
     55 	jneq	1b
     56 	clrl	%r0		# return NULL if no match
     57 2:
     58 	ret
     59 3:
     60 	tstb	(%r0)+
     61 	jneq	3b
     62 	decl	%r0
     63 	jbr	2b
     64 END(index)
     65