alpha/gen/fpsetround.c

1.10    perry /* $NetBSD: fpsetround.c,v 1.10 2005/12/24 23:10:08 perry Exp $ */
 1.1      cgd
 1.1      cgd /*
 1.1      cgd  * Copyright (c) 1995 Christopher G. Demetriou
 1.1      cgd  * All rights reserved.
 1.3      cgd  *
 1.1      cgd  * Redistribution and use in source and binary forms, with or without
 1.1      cgd  * modification, are permitted provided that the following conditions
 1.1      cgd  * are met:
 1.1      cgd  * 1. Redistributions of source code must retain the above copyright
 1.1      cgd  *    notice, this list of conditions and the following disclaimer.
 1.1      cgd  * 2. Redistributions in binary form must reproduce the above copyright
 1.1      cgd  *    notice, this list of conditions and the following disclaimer in the
 1.1      cgd  *    documentation and/or other materials provided with the distribution.
 1.1      cgd  * 3. All advertising materials mentioning features or use of this software
 1.1      cgd  *    must display the following acknowledgement:
 1.3      cgd  *          This product includes software developed for the
 1.7     salo  *          NetBSD Project.  See http://www.NetBSD.org/ for
 1.3      cgd  *          information about NetBSD.
 1.1      cgd  * 4. The name of the author may not be used to endorse or promote products
 1.3      cgd  *    derived from this software without specific prior written permission.
 1.3      cgd  *
 1.1      cgd  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 1.1      cgd  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 1.1      cgd  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 1.1      cgd  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 1.1      cgd  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 1.1      cgd  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 1.1      cgd  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 1.1      cgd  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 1.1      cgd  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 1.1      cgd  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 1.3      cgd  *
 1.3      cgd  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
 1.1      cgd  */
 1.1      cgd
 1.6  thorpej #include <sys/cdefs.h>
 1.9    lukem #if defined(LIBC_SCCS) && !defined(lint)
1.10    perry __RCSID("$NetBSD: fpsetround.c,v 1.10 2005/12/24 23:10:08 perry Exp $");
 1.9    lukem #endif /* LIBC_SCCS and not lint */
 1.6  thorpej
 1.6  thorpej #include "namespace.h"
 1.6  thorpej
 1.1      cgd #include <sys/types.h>
 1.1      cgd #include <ieeefp.h>
 1.6  thorpej
 1.6  thorpej #ifdef __weak_alias
 1.6  thorpej __weak_alias(fpsetround,_fpsetround)
 1.6  thorpej #endif
 1.1      cgd
 1.1      cgd fp_rnd
 1.1      cgd fpsetround(rnd_dir)
 1.1      cgd 	fp_rnd rnd_dir;
 1.1      cgd {
 1.1      cgd 	double fpcrval;
 1.1      cgd 	u_int64_t old, new;
 1.1      cgd
1.10    perry 	__asm("excb");
1.10    perry 	__asm("mf_fpcr %0" : "=f" (fpcrval));
 1.8      mrg 	old = *(u_int64_t *)(void *)&fpcrval;
 1.1      cgd
 1.1      cgd 	new = old & ~(long)0x0c00000000000000;
 1.1      cgd 	new = (long)rnd_dir << 58;
 1.8      mrg 	*(u_int64_t *)(void *)&fpcrval = new;
 1.1      cgd
1.10    perry 	__asm("mt_fpcr %0" : : "f" (fpcrval));
1.10    perry 	__asm("excb");
 1.1      cgd
 1.1      cgd 	return ((old >> 58) & 0x3);
 1.1      cgd }