/* $NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $ */ /*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <machine/asm.h> #if defined(LIBC_SCCS) && !defined(lint) #if 0 RCSID("from: @(#)alloca.s 5.1 (Berkeley) 5/12/90") #else RCSID("$NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $") #endif #endif /* LIBC_SCCS and not lint */ /* like alloc, but automatic free in return */ ENTRY(alloca) movl (%sp),%a1 /* save return addr */ movl %sp,%d0 /* get current SP value */ subl 4(%sp),%d0 /* allocate requested space */ movql #-4,%d1 /* sign extend a mask */ andl %d1,%d0 /* longword align for efficiency */ addql #8,%d0 /* reuse space of call frame */ movl %d0,%sp /* set new SP value */ subql #4,%sp /* account for argument pop in caller */ #ifdef __SVR4_ABI__ moveal %d0,%a0 #endif jmp (%a1) /* funny return */ END(alloca) |