4.4BSD/usr/src/sys/tahoe/math/Ksubf.s

/*-
 * Copyright (c) 1985 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Computer Consoles Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)Ksubf.s	7.1 (Berkeley) 12/6/90
 */

#include "../tahoe/SYS.h"

/*
 * _Ksubf(acc_most,acc_least,op_most,op_least,hfs)
 *
 * subf(d1,d2)
 * {
 * 	return(d1+(-d2));
 * }
 */
	.text
ENTRY(Ksubf, 0)
	tstl	4(fp)	# handle (a-b) where a and/or b = 0.0
	jneq	next
	movl	$0,r1
	movl	12(fp),r0
	lnd	r0
	std	r0
	ret
next:
	tstl	12(fp)
	jneq	doit
	movl	$0,r1
	movl	4(fp),r0
	ret
doit:
	lnd	12(fp)	# note: -(0) = 0 by definition!
	pushl	20(fp)	# hfs
	pushd	
	pushl	8(fp)
	pushl	4(fp)	# acc
	callf	$24,_Kaddf
	ret