1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)alloca.s 5.2 (Berkeley) 5/14/90 37 * $Id: alloca.S,v 1.3 1994/01/27 06:34:02 mycroft Exp $ 38 */ 39 40#if defined(LIBC_SCCS) 41 .text 42 .asciz "$Id: alloca.S,v 1.3 1994/01/27 06:34:02 mycroft Exp $" 43#endif 44 45/* like alloc, but automatic automatic free in return */ 46 47#include "DEFS.h" 48 49ENTRY(alloca) 50 popl %edx /* pop return addr */ 51 popl %eax /* pop amount to allocate */ 52 movl %esp,%ecx 53 addl $3,%eax /* round up to next word */ 54 andl $-4,%eax 55 subl %eax,%esp 56 movl %esp,%eax /* base of newly allocated space */ 57 pushl 8(%ecx) /* copy possible saved registers */ 58 pushl 4(%ecx) 59 pushl 0(%ecx) 60 pushl %eax /* dummy to pop at callsite */ 61 jmp %edx /* "return" */ 62