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/* FPU-related code for systems with GNU libc.
Copyright (C) 2005-2022 Free Software Foundation, Inc.
Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
This file is part of the GNU Fortran runtime library (libgfortran).
Libgfortran is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
Libgfortran 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 General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* FPU-related code for systems with the GNU libc, providing the
feenableexcept function in fenv.h to set individual exceptions
(there's nothing to do that in C99). */
#ifdef HAVE_FENV_H
#include <fenv.h>
#endif
/* Check we can actually store the FPU state in the allocated size. */
_Static_assert (sizeof(fenv_t) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
"GFC_FPE_STATE_BUFFER_SIZE is too small");
void set_fpu_trap_exceptions (int trap, int notrap)
{
int mode_set = 0, mode_clr = 0;
#ifdef FE_INVALID
if (trap & GFC_FPE_INVALID)
mode_set |= FE_INVALID;
if (notrap & GFC_FPE_INVALID)
mode_clr |= FE_INVALID;
#endif
/* Some glibc targets (like alpha) have FE_DENORMAL, but not many. */
#ifdef FE_DENORMAL
if (trap & GFC_FPE_DENORMAL)
mode_set |= FE_DENORMAL;
if (notrap & GFC_FPE_DENORMAL)
mode_clr |= FE_DENORMAL;
#endif
#ifdef FE_DIVBYZERO
if (trap & GFC_FPE_ZERO)
mode_set |= FE_DIVBYZERO;
if (notrap & GFC_FPE_ZERO)
mode_clr |= FE_DIVBYZERO;
#endif
#ifdef FE_OVERFLOW
if (trap & GFC_FPE_OVERFLOW)
mode_set |= FE_OVERFLOW;
if (notrap & GFC_FPE_OVERFLOW)
mode_clr |= FE_OVERFLOW;
#endif
#ifdef FE_UNDERFLOW
if (trap & GFC_FPE_UNDERFLOW)
mode_set |= FE_UNDERFLOW;
if (notrap & GFC_FPE_UNDERFLOW)
mode_clr |= FE_UNDERFLOW;
#endif
#ifdef FE_INEXACT
if (trap & GFC_FPE_INEXACT)
mode_set |= FE_INEXACT;
if (notrap & GFC_FPE_INEXACT)
mode_clr |= FE_INEXACT;
#endif
/* Clear stalled exception flags. */
feclearexcept (FE_ALL_EXCEPT);
feenableexcept (mode_set);
fedisableexcept (mode_clr);
}
int
get_fpu_trap_exceptions (void)
{
int exceptions = fegetexcept ();
int res = 0;
#ifdef FE_INVALID
if (exceptions & FE_INVALID) res |= GFC_FPE_INVALID;
#endif
#ifdef FE_DENORMAL
if (exceptions & FE_DENORMAL) res |= GFC_FPE_DENORMAL;
#endif
#ifdef FE_DIVBYZERO
if (exceptions & FE_DIVBYZERO) res |= GFC_FPE_ZERO;
#endif
#ifdef FE_OVERFLOW
if (exceptions & FE_OVERFLOW) res |= GFC_FPE_OVERFLOW;
#endif
#ifdef FE_UNDERFLOW
if (exceptions & FE_UNDERFLOW) res |= GFC_FPE_UNDERFLOW;
#endif
#ifdef FE_INEXACT
if (exceptions & FE_INEXACT) res |= GFC_FPE_INEXACT;
#endif
return res;
}
int
support_fpu_trap (int flag)
{
return support_fpu_flag (flag);
}
void set_fpu (void)
{
#ifndef FE_INVALID
if (options.fpe & GFC_FPE_INVALID)
estr_write ("Fortran runtime warning: IEEE 'invalid operation' "
"exception not supported.\n");
#endif
#ifndef FE_DENORMAL
if (options.fpe & GFC_FPE_DENORMAL)
estr_write ("Fortran runtime warning: Floating point 'denormal operand' "
"exception not supported.\n");
#endif
#ifndef FE_DIVBYZERO
if (options.fpe & GFC_FPE_ZERO)
estr_write ("Fortran runtime warning: IEEE 'division by zero' "
"exception not supported.\n");
#endif
#ifndef FE_OVERFLOW
if (options.fpe & GFC_FPE_OVERFLOW)
estr_write ("Fortran runtime warning: IEEE 'overflow' "
"exception not supported.\n");
#endif
#ifndef FE_UNDERFLOW
if (options.fpe & GFC_FPE_UNDERFLOW)
estr_write ("Fortran runtime warning: IEEE 'underflow' "
"exception not supported.\n");
#endif
#ifndef FE_INEXACT
if (options.fpe & GFC_FPE_INEXACT)
estr_write ("Fortran runtime warning: IEEE 'inexact' "
"exception not supported.\n");
#endif
set_fpu_trap_exceptions (options.fpe, 0);
}
int
get_fpu_except_flags (void)
{
int result, set_excepts;
result = 0;
set_excepts = fetestexcept (FE_ALL_EXCEPT);
#ifdef FE_INVALID
if (set_excepts & FE_INVALID)
result |= GFC_FPE_INVALID;
#endif
#ifdef FE_DIVBYZERO
if (set_excepts & FE_DIVBYZERO)
result |= GFC_FPE_ZERO;
#endif
#ifdef FE_OVERFLOW
if (set_excepts & FE_OVERFLOW)
result |= GFC_FPE_OVERFLOW;
#endif
#ifdef FE_UNDERFLOW
if (set_excepts & FE_UNDERFLOW)
result |= GFC_FPE_UNDERFLOW;
#endif
#ifdef FE_DENORMAL
if (set_excepts & FE_DENORMAL)
result |= GFC_FPE_DENORMAL;
#endif
#ifdef FE_INEXACT
if (set_excepts & FE_INEXACT)
result |= GFC_FPE_INEXACT;
#endif
return result;
}
void
set_fpu_except_flags (int set, int clear)
{
int exc_set = 0, exc_clr = 0;
#ifdef FE_INVALID
if (set & GFC_FPE_INVALID)
exc_set |= FE_INVALID;
else if (clear & GFC_FPE_INVALID)
exc_clr |= FE_INVALID;
#endif
#ifdef FE_DIVBYZERO
if (set & GFC_FPE_ZERO)
exc_set |= FE_DIVBYZERO;
else if (clear & GFC_FPE_ZERO)
exc_clr |= FE_DIVBYZERO;
#endif
#ifdef FE_OVERFLOW
if (set & GFC_FPE_OVERFLOW)
exc_set |= FE_OVERFLOW;
else if (clear & GFC_FPE_OVERFLOW)
exc_clr |= FE_OVERFLOW;
#endif
#ifdef FE_UNDERFLOW
if (set & GFC_FPE_UNDERFLOW)
exc_set |= FE_UNDERFLOW;
else if (clear & GFC_FPE_UNDERFLOW)
exc_clr |= FE_UNDERFLOW;
#endif
#ifdef FE_DENORMAL
if (set & GFC_FPE_DENORMAL)
exc_set |= FE_DENORMAL;
else if (clear & GFC_FPE_DENORMAL)
exc_clr |= FE_DENORMAL;
#endif
#ifdef FE_INEXACT
if (set & GFC_FPE_INEXACT)
exc_set |= FE_INEXACT;
else if (clear & GFC_FPE_INEXACT)
exc_clr |= FE_INEXACT;
#endif
feclearexcept (exc_clr);
feraiseexcept (exc_set);
}
int
support_fpu_flag (int flag)
{
if (flag & GFC_FPE_INVALID)
{
#ifndef FE_INVALID
return 0;
#endif
}
else if (flag & GFC_FPE_ZERO)
{
#ifndef FE_DIVBYZERO
return 0;
#endif
}
else if (flag & GFC_FPE_OVERFLOW)
{
#ifndef FE_OVERFLOW
return 0;
#endif
}
else if (flag & GFC_FPE_UNDERFLOW)
{
#ifndef FE_UNDERFLOW
return 0;
#endif
}
else if (flag & GFC_FPE_DENORMAL)
{
#ifndef FE_DENORMAL
return 0;
#endif
}
else if (flag & GFC_FPE_INEXACT)
{
#ifndef FE_INEXACT
return 0;
#endif
}
return 1;
}
int
get_fpu_rounding_mode (void)
{
int rnd_mode;
rnd_mode = fegetround ();
switch (rnd_mode)
{
#ifdef FE_TONEAREST
case FE_TONEAREST:
return GFC_FPE_TONEAREST;
#endif
#ifdef FE_UPWARD
case FE_UPWARD:
return GFC_FPE_UPWARD;
#endif
#ifdef FE_DOWNWARD
case FE_DOWNWARD:
return GFC_FPE_DOWNWARD;
#endif
#ifdef FE_TOWARDZERO
case FE_TOWARDZERO:
return GFC_FPE_TOWARDZERO;
#endif
default:
return 0; /* Should be unreachable. */
}
}
void
set_fpu_rounding_mode (int mode)
{
int rnd_mode;
switch (mode)
{
#ifdef FE_TONEAREST
case GFC_FPE_TONEAREST:
rnd_mode = FE_TONEAREST;
break;
#endif
#ifdef FE_UPWARD
case GFC_FPE_UPWARD:
rnd_mode = FE_UPWARD;
break;
#endif
#ifdef FE_DOWNWARD
case GFC_FPE_DOWNWARD:
rnd_mode = FE_DOWNWARD;
break;
#endif
#ifdef FE_TOWARDZERO
case GFC_FPE_TOWARDZERO:
rnd_mode = FE_TOWARDZERO;
break;
#endif
default:
return; /* Should be unreachable. */
}
fesetround (rnd_mode);
}
int
support_fpu_rounding_mode (int mode)
{
switch (mode)
{
case GFC_FPE_TONEAREST:
#ifdef FE_TONEAREST
return 1;
#else
return 0;
#endif
case GFC_FPE_UPWARD:
#ifdef FE_UPWARD
return 1;
#else
return 0;
#endif
case GFC_FPE_DOWNWARD:
#ifdef FE_DOWNWARD
return 1;
#else
return 0;
#endif
case GFC_FPE_TOWARDZERO:
#ifdef FE_TOWARDZERO
return 1;
#else
return 0;
#endif
default:
return 0; /* Should be unreachable. */
}
}
void
get_fpu_state (void *state)
{
fegetenv (state);
}
void
set_fpu_state (void *state)
{
fesetenv (state);
}
/* Underflow in glibc is currently only supported on alpha, through
the FE_MAP_UMZ macro and __ieee_set_fp_control() function call. */
int
support_fpu_underflow_control (int kind __attribute__((unused)))
{
#if defined(__alpha__) && defined(FE_MAP_UMZ)
return (kind == 4 || kind == 8) ? 1 : 0;
#else
return 0;
#endif
}
int
get_fpu_underflow_mode (void)
{
#if defined(__alpha__) && defined(FE_MAP_UMZ)
fenv_t state = __ieee_get_fp_control ();
/* Return 0 for abrupt underflow (flush to zero), 1 for gradual underflow. */
return (state & FE_MAP_UMZ) ? 0 : 1;
#else
return 0;
#endif
}
void
set_fpu_underflow_mode (int gradual __attribute__((unused)))
{
#if defined(__alpha__) && defined(FE_MAP_UMZ)
fenv_t state = __ieee_get_fp_control ();
if (gradual)
state &= ~FE_MAP_UMZ;
else
state |= FE_MAP_UMZ;
__ieee_set_fp_control (state);
#endif
}
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