xref: /titanic_50/usr/src/lib/libc/sparc/gen/lsub.s (revision 9a70fc3be3b1e966bf78825cdb8d509963a6f0a1)
17c478bd9Sstevel@tonic-gate/*
27c478bd9Sstevel@tonic-gate * CDDL HEADER START
37c478bd9Sstevel@tonic-gate *
47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the
57257d1b4Sraf * Common Development and Distribution License (the "License").
67257d1b4Sraf * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate *
87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate * and limitations under the License.
127c478bd9Sstevel@tonic-gate *
137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate *
197c478bd9Sstevel@tonic-gate * CDDL HEADER END
207c478bd9Sstevel@tonic-gate */
217257d1b4Sraf
227257d1b4Sraf/*
237257d1b4Sraf * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247257d1b4Sraf * Use is subject to license terms.
257257d1b4Sraf */
267257d1b4Sraf
277c478bd9Sstevel@tonic-gate/*	Copyright (c) 1988 AT&T	*/
287c478bd9Sstevel@tonic-gate/*	  All Rights Reserved	*/
297c478bd9Sstevel@tonic-gate
30*9a70fc3bSMark J. Nelson	.file	"lsub.s"
317c478bd9Sstevel@tonic-gate
327c478bd9Sstevel@tonic-gate/*
337c478bd9Sstevel@tonic-gate * Double long subtraction routine.  Ported from pdp 11/70 version
347c478bd9Sstevel@tonic-gate * with considerable effort.  All supplied comments were ported.
357c478bd9Sstevel@tonic-gate * Ported from m32 version to sparc. No comments about difficulty.
367c478bd9Sstevel@tonic-gate *
377c478bd9Sstevel@tonic-gate *	dl_t
387c478bd9Sstevel@tonic-gate *	lsub (lop, rop)
397c478bd9Sstevel@tonic-gate *		dl_t	lop;
407c478bd9Sstevel@tonic-gate *		dl_t	rop;
417c478bd9Sstevel@tonic-gate */
427c478bd9Sstevel@tonic-gate
437257d1b4Sraf#include "SYS.h"
447c478bd9Sstevel@tonic-gate
457c478bd9Sstevel@tonic-gate	ENTRY(lsub)
467c478bd9Sstevel@tonic-gate
477c478bd9Sstevel@tonic-gate	ld	[%o7+8],%o4		! Instruction at ret-addr should be a
487c478bd9Sstevel@tonic-gate	cmp     %o4,8			! 'unimp 8' indicating a valid call.
497c478bd9Sstevel@tonic-gate	be	1f			! if OK, go forward.
507c478bd9Sstevel@tonic-gate	nop				! delay instruction.
517c478bd9Sstevel@tonic-gate	jmp	%o7+8			! return
527c478bd9Sstevel@tonic-gate	nop				! delay instruction.
537c478bd9Sstevel@tonic-gate
547c478bd9Sstevel@tonic-gate1:
557c478bd9Sstevel@tonic-gate	ld	[%o0+0],%o2		! fetch lop.dl_hop
567c478bd9Sstevel@tonic-gate	ld	[%o0+4],%o3		! fetch lop.dl_lop
577c478bd9Sstevel@tonic-gate	ld	[%o1+0],%o4		! fetch rop.dl_hop
587c478bd9Sstevel@tonic-gate	ld	[%o1+4],%o5		! fetch rop.dl_lop
597c478bd9Sstevel@tonic-gate	subcc	%o3,%o5,%o3		! lop.dl_lop - rop.dl_lop (set carry)
607c478bd9Sstevel@tonic-gate	subxcc	%o2,%o4,%o2		! lop.dl_hop - rop.dl_hop - <carry>
617c478bd9Sstevel@tonic-gate	ld	[%sp+(16*4)],%o0	! address to store result into
627c478bd9Sstevel@tonic-gate	st	%o2,[%o0]		! store result.dl_hop
637c478bd9Sstevel@tonic-gate	jmp	%o7+12			! return
647c478bd9Sstevel@tonic-gate	st	%o3,[%o0+4]		! store result.dl_lop
657c478bd9Sstevel@tonic-gate
667c478bd9Sstevel@tonic-gate	SET_SIZE(lsub)
67