1*84d9c625SLionel Sambuc/* $NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $ */ 22fe8fb19SBen Gras 32fe8fb19SBen Gras/*- 42fe8fb19SBen Gras * Copyright (c) 1990 The Regents of the University of California. 52fe8fb19SBen Gras * All rights reserved. 62fe8fb19SBen Gras * 72fe8fb19SBen Gras * This code is derived from software contributed to Berkeley by 82fe8fb19SBen Gras * the Systems Programming Group of the University of Utah Computer 92fe8fb19SBen Gras * Science Department. 102fe8fb19SBen Gras * 112fe8fb19SBen Gras * Redistribution and use in source and binary forms, with or without 122fe8fb19SBen Gras * modification, are permitted provided that the following conditions 132fe8fb19SBen Gras * are met: 142fe8fb19SBen Gras * 1. Redistributions of source code must retain the above copyright 152fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer. 162fe8fb19SBen Gras * 2. Redistributions in binary form must reproduce the above copyright 172fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer in the 182fe8fb19SBen Gras * documentation and/or other materials provided with the distribution. 192fe8fb19SBen Gras * 3. Neither the name of the University nor the names of its contributors 202fe8fb19SBen Gras * may be used to endorse or promote products derived from this software 212fe8fb19SBen Gras * without specific prior written permission. 222fe8fb19SBen Gras * 232fe8fb19SBen Gras * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 242fe8fb19SBen Gras * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 252fe8fb19SBen Gras * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 262fe8fb19SBen Gras * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 272fe8fb19SBen Gras * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 282fe8fb19SBen Gras * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 292fe8fb19SBen Gras * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 302fe8fb19SBen Gras * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 312fe8fb19SBen Gras * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 322fe8fb19SBen Gras * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 332fe8fb19SBen Gras * SUCH DAMAGE. 342fe8fb19SBen Gras */ 352fe8fb19SBen Gras 362fe8fb19SBen Gras#include <machine/asm.h> 372fe8fb19SBen Gras 382fe8fb19SBen Gras#if defined(LIBC_SCCS) && !defined(lint) 392fe8fb19SBen Gras#if 0 402fe8fb19SBen Gras RCSID("from: @(#)alloca.s 5.1 (Berkeley) 5/12/90") 412fe8fb19SBen Gras#else 42*84d9c625SLionel Sambuc RCSID("$NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $") 432fe8fb19SBen Gras#endif 442fe8fb19SBen Gras#endif /* LIBC_SCCS and not lint */ 452fe8fb19SBen Gras 462fe8fb19SBen Gras/* like alloc, but automatic free in return */ 472fe8fb19SBen Gras 482fe8fb19SBen GrasENTRY(alloca) 49*84d9c625SLionel Sambuc movl (%sp),%a1 /* save return addr */ 502fe8fb19SBen Gras movl %sp,%d0 /* get current SP value */ 51*84d9c625SLionel Sambuc subl 4(%sp),%d0 /* allocate requested space */ 52*84d9c625SLionel Sambuc movql #-4,%d1 /* sign extend a mask */ 53*84d9c625SLionel Sambuc andl %d1,%d0 /* longword align for efficiency */ 542fe8fb19SBen Gras addql #8,%d0 /* reuse space of call frame */ 552fe8fb19SBen Gras movl %d0,%sp /* set new SP value */ 56*84d9c625SLionel Sambuc subql #4,%sp /* account for argument pop in caller */ 572fe8fb19SBen Gras#ifdef __SVR4_ABI__ 582fe8fb19SBen Gras moveal %d0,%a0 592fe8fb19SBen Gras#endif 60*84d9c625SLionel Sambuc jmp (%a1) /* funny return */ 61*84d9c625SLionel SambucEND(alloca) 62