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) 1998, by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27#ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31#include <sys/asm_linkage.h> 32#include <sys/stack.h> 33 34 ! 35 ! o0: # bytes of space to allocate, already rounded to 0 mod 8 36 ! o1: %sp-relative offset of tmp area 37 ! o2: %sp-relative offset of end of tmp area 38 ! 39 ! we want to bump %sp by the requested size 40 ! then copy the tmp area to its new home 41 ! this is necessary as we could theoretically 42 ! be in the middle of a complicated expression. 43 ! 44 ENTRY(__builtin_alloca) 45 add %sp, STACK_BIAS, %g1 ! save current sp + STACK_BIAS 46 sub %sp, %o0, %sp ! bump to new value 47 add %sp, STACK_BIAS, %g5 48 ! copy loop: should do nothing gracefully 49 b 2f 50 subcc %o2, %o1, %o5 ! number of bytes to move 511: 52 ldx [%g1 + %o1], %o4 ! load from old temp area 53 stx %o4, [%g5 + %o1] ! store to new temp area 54 add %o1, 8, %o1 552: bg,pt %xcc, 1b 56 subcc %o5, 8, %o5 57 ! now return new %sp + end-of-temp 58 add %sp, %o2, %o0 59 retl 60 add %o0, STACK_BIAS, %o0 61 SET_SIZE(__builtin_alloca) 62