mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-24 11:41:07 +00:00
126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/* Determine floating-point rounding mode within libc. Generic version.
|
|
Copyright (C) 2012-2017 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>
|
|
#include <stdlib.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 */
|