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 (c) 1987 Sun Microsystems, Inc. 24 */ 25 26#ident "%Z%%M% %I% %E% SMI" 27 28 .file "alloca.s" 29 30#include <sys/asm_linkage.h> 31 32 ! 33 ! o0: # bytes of space to allocate, already rounded to 0 mod 8 34 ! o1: %sp-relative offset of tmp area 35 ! o2: %sp-relative offset of end of tmp area 36 ! 37 ! we want to bump %sp by the requested size 38 ! then copy the tmp area to its new home 39 ! this is necessasy as we could theoretically 40 ! be in the middle of a compilicated expression. 41 ! 42 ENTRY(__builtin_alloca) 43 mov %sp, %o3 ! save current sp 44 sub %sp, %o0, %sp ! bump to new value 45 ! copy loop: should do nothing gracefully 46 b 2f 47 subcc %o2, %o1, %o5 ! number of bytes to move 481: 49 ld [%o3 + %o1], %o4 ! load from old temp area 50 st %o4, [%sp + %o1] ! store to new temp area 51 add %o1, 4, %o1 522: bg 1b 53 subcc %o5, 4, %o5 54 ! now return new %sp + end-of-temp 55 retl 56 add %sp, %o2, %o0 57 58 SET_SIZE(__builtin_alloca) 59