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/* Internal libc stuff for floating point environment routines.
Copyright (C) 1997 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _FENV_LIBC_H
#define _FENV_LIBC_H 1
#include <fenv.h>
/* Transform a logical or of the FE_* bits to a bit pattern for the
appropriate sticky bits in the FPSCR. */
#define FE_to_sticky(excepts) \
(-(excepts & FE_INVALID) & FE_ALL_INVALID \
| (excepts) & (FE_ALL_EXCEPT & ~FE_INVALID | FE_ALL_INVALID))
/* The sticky bits in the FPSCR indicating exceptions have occurred. */
#define FPSCR_STICKY_BITS ((FE_ALL_EXCEPT | FE_ALL_INVALID) & ~FE_INVALID)
/* Equivalent to fegetenv, but returns a fenv_t instead of taking a
pointer. */
#define fegetenv_register() \
({ fenv_t env; asm ("mffs %0" : "=f" (env)); env; })
/* Equivalent to fesetenv, but takes a fenv_t instead of a pointer. */
#define fesetenv_register(env) \
({ double d = (env); asm ("mtfsf 0xff,%0" : : "f" (d)); })
/* This very handy macro:
- Sets the rounding mode to 'round to nearest';
- Sets the processor into IEEE mode; and
- Prevents exceptions from being raised for inexact results.
These things happen to be exactly what you need for typical elementary
functions. */
#define relax_fenv_state() asm ("mtfsfi 7,0")
typedef union
{
fenv_t fenv;
unsigned int l[2];
} fenv_union_t;
#endif /* fenv_libc.h */
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