58 lines
2.1 KiB
C
58 lines
2.1 KiB
C
/* $Id$ */
|
|
/* From: NetBSD: flt_rounds.c,v 1.2 1997/07/18 00:30:30 thorpej 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.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <machine/float.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];
|
|
}
|