/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
.file "lsub.s"
/*
* Double long subtraction routine. Ported from pdp 11/70 version
* with considerable effort. All supplied comments were ported.
* Ported from m32 version to sparc. No comments about difficulty.
*
* dl_t
* lsub (lop, rop)
* dl_t lop;
* dl_t rop;
*/
#include "SYS.h"
ENTRY(lsub)
ld [%o7+8],%o4 ! Instruction at ret-addr should be a
cmp %o4,8 ! 'unimp 8' indicating a valid call.
be 1f ! if OK, go forward.
nop ! delay instruction.
jmp %o7+8 ! return
nop ! delay instruction.
1:
ld [%o0+0],%o2 ! fetch lop.dl_hop
ld [%o0+4],%o3 ! fetch lop.dl_lop
ld [%o1+0],%o4 ! fetch rop.dl_hop
ld [%o1+4],%o5 ! fetch rop.dl_lop
subcc %o3,%o5,%o3 ! lop.dl_lop - rop.dl_lop (set carry)
subxcc %o2,%o4,%o2 ! lop.dl_hop - rop.dl_hop - <carry>
ld [%sp+(16*4)],%o0 ! address to store result into
st %o2,[%o0] ! store result.dl_hop
jmp %o7+12 ! return
st %o3,[%o0+4] ! store result.dl_lop
SET_SIZE(lsub)