freebsd-skq/lib/libc/arm/gen/flt_rounds.c
Andrew Turner cc0c9bba36 Implement __flt_rounds for ARMv6 hard-float. The fpscr register stores the
current rounding mode used by the VFP unit.
2014-03-22 12:28:21 +00:00

70 lines
2.1 KiB
C

/*-
* Copyright (c) 2012 Ian Lepore <freebsd@damnhippie.dyndns.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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>
__FBSDID("$FreeBSD$");
#include <fenv.h>
#include <float.h>
#ifndef __ARM_PCS_VFP
#include "softfloat-for-gcc.h"
#include "milieu.h"
#include "softfloat.h"
#endif
int
__flt_rounds(void)
{
int mode;
#ifndef __ARM_PCS_VFP
/*
* Translate our rounding modes to the unnamed
* manifest constants required by C99 et. al.
*/
mode = __softfloat_float_rounding_mode;
#else /* __ARM_PCS_VFP */
/*
* Read the floating-point status and control register
*/
__asm __volatile("vmrs %0, fpscr" : "=&r"(mode));
mode &= _ROUND_MASK;
#endif /* __ARM_PCS_VFP */
switch (mode) {
case FE_TOWARDZERO:
return (0);
case FE_TONEAREST:
return (1);
case FE_UPWARD:
return (2);
case FE_DOWNWARD:
return (3);
}
return (-1);
}