fpsetround.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
* 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) 1990, 1991 UNIX System Laboratories, Inc. */
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
#pragma weak _fpsetround = fpsetround
#include "lint.h"
#include <ieeefp.h>
#include "fp.h"
extern void _getmxcsr(int *), _putmxcsr(int);
fp_rnd
fpsetround(fp_rnd newrnd)
{
struct _cw87 cw;
fp_rnd oldrnd;
int mxcsr;
newrnd &= 0x3; /* mask off all ubt last 2 bits */
_getcw(&cw);
oldrnd = (fp_rnd)cw.rnd;
cw.rnd = newrnd;
_putcw(cw);
_getmxcsr(&mxcsr);
mxcsr = (mxcsr & ~0x6000) | ((int)newrnd << 13);
_putmxcsr(mxcsr);
return (oldrnd);
}