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/* $OpenBSD: flt_rounds.c,v 1.3 1996/11/13 21:20:11 niklas Exp $ */
/* $NetBSD: flt_rounds.c,v 1.1 1995/04/29 05:09:53 cgd Exp $ */
/*
* Copyright (c) 1995 Christopher G. Demetriou
* All rights reserved.
*
* 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 Christopher G. Demetriou
* for the NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char *rcsid = "$OpenBSD: flt_rounds.c,v 1.3 1996/11/13 21:20:11 niklas Exp $";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
static const int map[] = {
0, /* round to zero */
3, /* round to negative infinity */
1, /* round to nearest */
2 /* round to positive infinity */
};
int
__flt_rounds()
{
double fpcrval;
u_int64_t old;
__asm__("trapb");
__asm__("mf_fpcr %0" : "=f" (fpcrval));
__asm__("trapb");
old = *(u_int64_t *)&fpcrval;
return map[(old >> 58) & 0x3];
}
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