usr/src/lib/libc/vax/string/strsep.s

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
        .asciz "@(#)strsep.s    5.1 (Berkeley) %G%"
#endif /* LIBC_SCCS and not lint */

/*
 * Get next word from string *stringp, where words are
 * strings separated by characters from delim.
 *
 * Writes NULs into the string at *stringp to end tokens.
 * On return, *stringp points past the last NUL written (if there might
 * be further tokens), or is NULL (if there are definitely no more tokens).
 *
 * If *stringp is NULL, strtoken returns NULL.
 *
 * char *
 * strtoken(stringp, delim)
 *      register char **stringp;
 *      register char const *delim;
 */
#include "DEFS.h"

ENTRY(strsep, 0)
        tstl    *4(ap)          /* if (*stringp == NULL) */
        bneq    0f
        clrl    r0              #       return (NULL);
        ret

0:
        subl2   $32,sp          /* make room for 256 bit table */
        movc5   $0,(sp),$0,$32,(sp)
        movq    4(ap),r1        /* r1 = stringp, r2 = delim */

        /* turn on bit for each character in s2, including '\0' */
1:
        movzbl  (r2)+,r0
        bbss    r0,(sp),1b
        bneq    1b

        movl    (r1),r3         /* r3 = s = *stringp */
        movl    r3,r0           /* save return value */

        /* scan for delimiters */
2:
        movzbl  (r3)+,r2        /* c = *s++ */
        bbc     r2,(sp),2b      /* loop until c is in table */
        beql    3f
        clrb    -1(r3)          /* if c!='\0', s[-1] = 0 */
        movl    r3,(r1)         /* and *stringp = s */
        ret
3:
        clrl    (r1)            /* else *stringp = NULL */
        ret