usr/src/lib/libc/vax/gen/setjmp.s

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
        .asciz "@(#)setjmp.s    5.9 (Berkeley) 6/1/90"
#endif /* LIBC_SCCS and not lint */

/*
 * C library -- setjmp, longjmp
 *
 *      longjmp(a,v)
 * will generate a "return(v)" from
 * the last call to
 *      setjmp(a)
 * by restoring registers from the stack,
 * and a struct sigcontext, see <signal.h>
 */

#include "DEFS.h"

ENTRY(setjmp, R6)
        movl    4(ap),r6                # construct sigcontext
        subl2   $8,sp                   # space for current struct sigstack
        pushl   sp                      # get current values
        pushl   $0                      # no new values
        calls   $3,_sigstack            # pop args plus signal stack value
        movl    (sp)+,(r6)+             # save onsigstack status of caller
        pushl   $0
        calls   $1,_sigblock            # get signal mask
        movl    r0,(r6)+                # save signal mask of caller
        movl    (ap),r0
        moval   4(ap)[r0],(r6)+         # save sp of caller
        movl    12(fp),(r6)+            # save frame pointer of caller
        movl    8(fp),(r6)+             # save argument pointer of caller
        movl    16(fp),(r6)+            # save pc of caller
        movpsl  (r6)                    # save psl of caller
        movw    4(fp),(r6)
        clrl    r0
        ret

ENTRY(longjmp, 0)
        movl    8(ap),r0                # return(v)
        movl    4(ap),r1                # fetch buffer
        tstl    12(r1)
        beql    botch
loop:
        cmpl    12(r1),fp               # are we there yet?
        beql    done
        blssu   botch
        moval   20(fp),r2
        blbc    6(fp),1f                # was r0 saved?
        movl    r0,(r2)+
1:
        bbc     $1,6(fp),2f             # was r1 saved?
        movl    r1,(r2)
2:
        movl    $loop,16(fp)
        ret                             # pop another frame

done:
        pushl   r1                      # pointer to sigcontext
        calls   $1,_sigreturn           # restore previous context
                                        # we should never return
botch:
        calls   $0,_longjmperror
        halt