alloca.S revision 1.1
11.1Spaulus/*-
21.1Spaulus * Copyright (c) 1990 The Regents of the University of California.
31.1Spaulus * All rights reserved.
41.1Spaulus *
51.1Spaulus * This code is derived from software contributed to Berkeley by
61.1Spaulus * the Systems Programming Group of the University of Utah Computer
71.1Spaulus * Science Department.
81.1Spaulus *
91.1Spaulus * Redistribution and use in source and binary forms, with or without
101.1Spaulus * modification, are permitted provided that the following conditions
111.1Spaulus * are met:
121.1Spaulus * 1. Redistributions of source code must retain the above copyright
131.1Spaulus *    notice, this list of conditions and the following disclaimer.
141.1Spaulus * 2. Redistributions in binary form must reproduce the above copyright
151.1Spaulus *    notice, this list of conditions and the following disclaimer in the
161.1Spaulus *    documentation and/or other materials provided with the distribution.
171.1Spaulus * 3. All advertising materials mentioning features or use of this software
181.1Spaulus *    must display the following acknowledgement:
191.1Spaulus *	This product includes software developed by the University of
201.1Spaulus *	California, Berkeley and its contributors.
211.1Spaulus * 4. Neither the name of the University nor the names of its contributors
221.1Spaulus *    may be used to endorse or promote products derived from this software
231.1Spaulus *    without specific prior written permission.
241.1Spaulus *
251.1Spaulus * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
261.1Spaulus * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
271.1Spaulus * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
281.1Spaulus * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
291.1Spaulus * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
301.1Spaulus * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
311.1Spaulus * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
321.1Spaulus * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
331.1Spaulus * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
341.1Spaulus * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
351.1Spaulus * SUCH DAMAGE.
361.1Spaulus */
371.1Spaulus
381.1Spaulus#if defined(LIBC_SCCS) && !defined(lint)
391.1Spaulus	.text
401.1Spaulus	/*.asciz "from: @(#)alloca.s	5.1 (Berkeley) 5/12/90"*/
411.1Spaulus	.asciz "$Id: alloca.S,v 1.1 1993/11/25 23:36:50 paulus Exp $"
421.1Spaulus#endif /* LIBC_SCCS and not lint */
431.1Spaulus
441.1Spaulus/* like alloc, but automatic free in return */
451.1Spaulus
461.1Spaulus#include "DEFS.h"
471.1Spaulus
481.1SpaulusENTRY(alloca)
491.1Spaulus	movl	sp@,a0		/* save return addr */
501.1Spaulus	movl	sp,d0		/* get current SP value */
511.1Spaulus	subl	sp@(4),d0	/* allocate requested space */
521.1Spaulus	andb	#~3,d0		/* longword align for efficiency */
531.1Spaulus	addql	#8,d0		/* reuse space of call frame */
541.1Spaulus	movl	d0,sp		/* set new SP value */
551.1Spaulus	lea	sp@(-4),sp	/* account for argument pop in caller */
561.1Spaulus	jmp 	a0@		/* funny return */
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