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 1990 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27/* 28 * .seg "data" 29 * .asciz ident "%Z%%M% %I% %E% SMI" 30 */ 31! .seg "text" 32 33 .file "alloca.s" 34 35#include <sun4/asm_linkage.h> 36 37 ! 38 ! o0: # bytes of space to allocate, already rounded to 0 mod 8 39 ! o1: %sp-relative offset of tmp area 40 ! o2: %sp-relative offset of end of tmp area 41 ! 42 ! we want to bump %sp by the requested size 43 ! then copy the tmp area to its new home 44 ! this is necessasy as we could theoretically 45 ! be in the middle of a compilicated expression. 46 ! 47 ENTRY(__builtin_alloca) 48 mov %sp, %o3 ! save current sp 49 sub %sp, %o0, %sp ! bump to new value 50 ! copy loop: should do nothing gracefully 51 b 2f 52 subcc %o2, %o1, %o5 ! number of bytes to move 531: 54 ld [%o3 + %o1], %o4 ! load from old temp area 55 st %o4, [%sp + %o1] ! store to new temp area 56 add %o1, 4, %o1 572: bg 1b 58 subcc %o5, 4, %o5 59 ! now return new %sp + end-of-temp 60 retl 61 add %sp, %o2, %o0 62 SET_SIZE(__builtin_alloca) 63