minix/lib/libc/arch/arm/gen/flt_rounds.c
Lionel Sambuc f14fb60209 Libraries updates and cleanup
* Updating common/lib
 * Updating lib/csu
 * Updating lib/libc
 * Updating libexec/ld.elf_so
 * Corrected test on __minix in featuretest to actually follow the
   meaning of the comment.
 * Cleaned up _REENTRANT-related defintions.
 * Disabled -D_REENTRANT for libfetch
 * Removing some unneeded __NBSD_LIBC defines and tests

Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
2013-01-14 11:36:26 +01:00

82 lines
3 KiB
C

/* $NetBSD: flt_rounds.c,v 1.4 2012/03/21 20:04:57 he Exp $ */
/*
* Copyright (c) 1996 Mark Brinicombe
* 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 Mark Brinicombe
* 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/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: flt_rounds.c,v 1.4 2012/03/21 20:04:57 he Exp $");
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <ieeefp.h>
static const int map[] = {
1, /* round to nearest */
2, /* round to positive infinity */
3, /* round to negative infinity */
0 /* round to zero */
};
/*
* Return the current FP rounding mode
*
* Returns:
* 0 - round to zero
* 1 - round to nearest
* 2 - round to postive infinity
* 3 - round to negative infinity
*
* ok all we need to do is get the current FP rounding mode
* index our map table and return the appropriate value.
*
* HOWEVER:
* The ARM FPA codes the rounding mode into the actual FP instructions
* so there is no such thing as a global rounding mode.
* The default is round to nearest if rounding is not explicitly specified.
* FP instructions generated by GCC will not explicitly specify a rounding
* mode.
*
* So the best we can do it to return the rounding mode FP instructions
* use if rounding is not specified which is round to nearest.
*
* This could change in the future with new floating point emulators or
* soft float FP libraries.
*/
int __flt_rounds(void);
int
__flt_rounds(void)
{
return(map[fpgetround()]);
}