_setjmp.s

早期freebsd实现

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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	8.1 (Berkeley) 6/4/93"
#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,
 * The previous signal state is NOT restored.
 */

#include "DEFS.h"

ENTRY(_setjmp)
	movl	sp@(4),a0	/* save area pointer */
	clrl	a0@+		/* no old onstack */
	clrl	a0@+		/* no old sigmask */
	movl	sp,a0@+		/* save old SP */
	movl	a6,a0@+		/* save old FP */
	clrl	a0@+		/* no old AP */
	movl	sp@,a0@+	/* save old PC */
	clrl	a0@+		/* clear PS */
	moveml	#0x3CFC,a0@	/* save other non-scratch regs */
	clrl	d0		/* return zero */
	rts

ENTRY(_longjmp)
	movl	sp@(4),a0	/* save area pointer */
	addql	#8,a0		/* skip onstack/sigmask */
	tstl	a0@		/* ensure non-zero SP */
	jeq	botch		/* oops! */
	movl	sp@(8),d0	/* grab return value */
	jne	ok		/* non-zero ok */
	moveq	#1,d0		/* else make non-zero */
ok:
	movl	a0@+,sp		/* restore SP */
	movl	a0@+,a6		/* restore FP */
	addql	#4,a0		/* skip AP */
	movl	a0@+,sp@	/* restore PC */
	moveml	a0@(4),#0x3CFC	/* restore non-scratch regs */
	rts

botch:
	jsr	_longjmperror
	stop	#0