11.9Smatt/* $NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $ */ 21.2Sthorpej 31.1Spaulus/*- 41.1Spaulus * Copyright (c) 1990 The Regents of the University of California. 51.1Spaulus * All rights reserved. 61.1Spaulus * 71.1Spaulus * This code is derived from software contributed to Berkeley by 81.1Spaulus * the Systems Programming Group of the University of Utah Computer 91.1Spaulus * Science Department. 101.1Spaulus * 111.1Spaulus * Redistribution and use in source and binary forms, with or without 121.1Spaulus * modification, are permitted provided that the following conditions 131.1Spaulus * are met: 141.1Spaulus * 1. Redistributions of source code must retain the above copyright 151.1Spaulus * notice, this list of conditions and the following disclaimer. 161.1Spaulus * 2. Redistributions in binary form must reproduce the above copyright 171.1Spaulus * notice, this list of conditions and the following disclaimer in the 181.1Spaulus * documentation and/or other materials provided with the distribution. 191.6Sagc * 3. Neither the name of the University nor the names of its contributors 201.1Spaulus * may be used to endorse or promote products derived from this software 211.1Spaulus * without specific prior written permission. 221.1Spaulus * 231.1Spaulus * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 241.1Spaulus * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 251.1Spaulus * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 261.1Spaulus * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 271.1Spaulus * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 281.1Spaulus * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 291.1Spaulus * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 301.1Spaulus * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 311.1Spaulus * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 321.1Spaulus * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 331.1Spaulus * SUCH DAMAGE. 341.1Spaulus */ 351.1Spaulus 361.3Sthorpej#include <machine/asm.h> 371.2Sthorpej 381.1Spaulus#if defined(LIBC_SCCS) && !defined(lint) 391.2Sthorpej#if 0 401.2Sthorpej RCSID("from: @(#)alloca.s 5.1 (Berkeley) 5/12/90") 411.2Sthorpej#else 421.9Smatt RCSID("$NetBSD: alloca.S,v 1.9 2013/07/17 04:57:55 matt Exp $") 431.2Sthorpej#endif 441.1Spaulus#endif /* LIBC_SCCS and not lint */ 451.1Spaulus 461.1Spaulus/* like alloc, but automatic free in return */ 471.1Spaulus 481.1SpaulusENTRY(alloca) 491.7Smatt movl (%sp),%a1 /* save return addr */ 501.5Sthorpej movl %sp,%d0 /* get current SP value */ 511.7Smatt subl 4(%sp),%d0 /* allocate requested space */ 521.9Smatt movql #-4,%d1 /* sign extend a mask */ 531.9Smatt andl %d1,%d0 /* longword align for efficiency */ 541.5Sthorpej addql #8,%d0 /* reuse space of call frame */ 551.5Sthorpej movl %d0,%sp /* set new SP value */ 561.9Smatt subql #4,%sp /* account for argument pop in caller */ 571.4Skleink#ifdef __SVR4_ABI__ 581.5Sthorpej moveal %d0,%a0 591.4Skleink#endif 601.7Smatt jmp (%a1) /* funny return */ 611.8SmattEND(alloca) 62