glibc/sysdeps/generic/get-rounding-mode.h

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/* Determine floating-point rounding mode within libc. Generic version.
Copyright (C) 2012-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _GET_ROUNDING_MODE_H
#define _GET_ROUNDING_MODE_H 1
#include <fpu_control.h>
/* Define values for FE_* modes not defined for this architecture. */
#ifdef FE_DOWNWARD
# define ORIG_FE_DOWNWARD FE_DOWNWARD
#else
# define ORIG_FE_DOWNWARD 0
#endif
#ifdef FE_TONEAREST
# define ORIG_FE_TONEAREST FE_TONEAREST
#else
# define ORIG_FE_TONEAREST 0
#endif
#ifdef FE_TOWARDZERO
# define ORIG_FE_TOWARDZERO FE_TOWARDZERO
#else
# define ORIG_FE_TOWARDZERO 0
#endif
#ifdef FE_UPWARD
# define ORIG_FE_UPWARD FE_UPWARD
#else
# define ORIG_FE_UPWARD 0
#endif
#define FE_CONSTRUCT_DISTINCT_VALUE(X, Y, Z) \
((((X) & 1) | ((Y) & 2) | ((Z) & 4)) ^ 7)
#ifndef FE_DOWNWARD
# define FE_DOWNWARD FE_CONSTRUCT_DISTINCT_VALUE (ORIG_FE_TONEAREST, \
ORIG_FE_TOWARDZERO, \
ORIG_FE_UPWARD)
#endif
#ifndef FE_TONEAREST
# define FE_TONEAREST FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
ORIG_FE_TOWARDZERO, \
ORIG_FE_UPWARD)
#endif
#ifndef FE_TOWARDZERO
# define FE_TOWARDZERO FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
FE_TONEAREST, \
ORIG_FE_UPWARD)
#endif
#ifndef FE_UPWARD
# define FE_UPWARD FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
FE_TONEAREST, \
FE_TOWARDZERO)
#endif
/* Return the floating-point rounding mode. */
static inline int
get_rounding_mode (void)
{
#if (defined _FPU_RC_DOWN \
|| defined _FPU_RC_NEAREST \
|| defined _FPU_RC_ZERO \
|| defined _FPU_RC_UP)
fpu_control_t fc;
const fpu_control_t mask = (0
# ifdef _FPU_RC_DOWN
| _FPU_RC_DOWN
# endif
# ifdef _FPU_RC_NEAREST
| _FPU_RC_NEAREST
# endif
# ifdef _FPU_RC_ZERO
| _FPU_RC_ZERO
# endif
# ifdef _FPU_RC_UP
| _FPU_RC_UP
# endif
);
_FPU_GETCW (fc);
switch (fc & mask)
{
# ifdef _FPU_RC_DOWN
case _FPU_RC_DOWN:
return FE_DOWNWARD;
# endif
# ifdef _FPU_RC_NEAREST
case _FPU_RC_NEAREST:
return FE_TONEAREST;
# endif
# ifdef _FPU_RC_ZERO
case _FPU_RC_ZERO:
return FE_TOWARDZERO;
# endif
# ifdef _FPU_RC_UP
case _FPU_RC_UP:
return FE_UPWARD;
# endif
default:
abort ();
}
#else
return FE_TONEAREST;
#endif
}
#endif /* get-rounding-mode.h */