xref: /titanic_41/usr/src/lib/libc/amd64/gen/alloca.s (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27	.ident	"%Z%%M%	%I%	%E% SMI"
28
29	.file	"%M%"
30
31#include "SYS.h"
32
33	ENTRY(__builtin_alloca)
34	popq	%rcx			/* grab our return address */
35	addq	$15, %rdi		/* round size up to multiple of 16 */
36	andq	$0xfffffffffffffff0, %rdi
37	subq	%rdi, %rsp		/* allocate requested space on stack */
38	movq	%rsp, %rax		/* pointer to new memory block */
39	jmp	*%rcx			/* return */
40	SET_SIZE(__builtin_alloca)
41