1/* $NetBSD: alloca.S,v 1.5 2013/08/17 01:07:45 matt Exp $ */ 2 3/* 4 * Copyright (c) 1995 Mark Brinicombe 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Mark Brinicombe 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35/* like alloc, but automatic automatic free in return */ 36 37#include <machine/asm.h> 38 39ENTRY(alloca) 40 adds r0, r0, #7 /* round up to next 8 byte alignment */ 41#if !defined(__thumb__) || defined(_ARM_ARCH_T2) 42 bics r0, r0, #7 43 sub sp, sp, r0 /* Adjust the stack pointer */ 44 mov r0, sp /* r0 = base of new space */ 45#else 46 lsrs r0, r0, #3 47 lsls r0, r0, #3 48 mov r1, sp 49 subs r0, r1, r0 /* Adjust the stack pointer */ 50 mov sp, r0 /* r0 = base of new space */ 51#endif 52 RET 53END(alloca) 54