Retro68/gcc/libgfortran/ieee/ieee_helper.c
2017-10-07 02:16:47 +02:00

135 lines
3.9 KiB
C

/* Helper functions in C for IEEE modules
Copyright (C) 2013-2017 Free Software Foundation, Inc.
Contributed by Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
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/>. */
#include "libgfortran.h"
/* Prototypes. */
extern int ieee_class_helper_4 (GFC_REAL_4 *);
internal_proto(ieee_class_helper_4);
extern int ieee_class_helper_8 (GFC_REAL_8 *);
internal_proto(ieee_class_helper_8);
#ifdef HAVE_GFC_REAL_10
extern int ieee_class_helper_10 (GFC_REAL_10 *);
internal_proto(ieee_class_helper_10);
#endif
#ifdef HAVE_GFC_REAL_16
extern int ieee_class_helper_16 (GFC_REAL_16 *);
internal_proto(ieee_class_helper_16);
#endif
/* Enumeration of the possible floating-point types. These values
correspond to the hidden arguments of the IEEE_CLASS_TYPE
derived-type of IEEE_ARITHMETIC. */
enum { IEEE_OTHER_VALUE = 0, IEEE_SIGNALING_NAN, IEEE_QUIET_NAN,
IEEE_NEGATIVE_INF, IEEE_NEGATIVE_NORMAL, IEEE_NEGATIVE_DENORMAL,
IEEE_NEGATIVE_ZERO, IEEE_POSITIVE_ZERO, IEEE_POSITIVE_DENORMAL,
IEEE_POSITIVE_NORMAL, IEEE_POSITIVE_INF };
#define CLASSMACRO(TYPE) \
int ieee_class_helper_ ## TYPE (GFC_REAL_ ## TYPE *value) \
{ \
int res = __builtin_fpclassify (IEEE_QUIET_NAN, IEEE_POSITIVE_INF, \
IEEE_POSITIVE_NORMAL, \
IEEE_POSITIVE_DENORMAL, \
IEEE_POSITIVE_ZERO, *value); \
\
if (__builtin_signbit (*value)) \
{ \
if (res == IEEE_POSITIVE_NORMAL) \
return IEEE_NEGATIVE_NORMAL; \
else if (res == IEEE_POSITIVE_DENORMAL) \
return IEEE_NEGATIVE_DENORMAL; \
else if (res == IEEE_POSITIVE_ZERO) \
return IEEE_NEGATIVE_ZERO; \
else if (res == IEEE_POSITIVE_INF) \
return IEEE_NEGATIVE_INF; \
} \
\
if (res == IEEE_QUIET_NAN) \
{ \
/* TODO: Handle signaling NaNs */ \
return res; \
} \
\
return res; \
}
CLASSMACRO(4)
CLASSMACRO(8)
#ifdef HAVE_GFC_REAL_10
CLASSMACRO(10)
#endif
#ifdef HAVE_GFC_REAL_16
CLASSMACRO(16)
#endif
#define GFC_FPE_ALL (GFC_FPE_INVALID | GFC_FPE_DENORMAL | \
GFC_FPE_ZERO | GFC_FPE_OVERFLOW | \
GFC_FPE_UNDERFLOW | GFC_FPE_INEXACT)
/* Functions to save and restore floating-point state, clear and restore
exceptions on procedure entry/exit. The rules we follow are set
in Fortran 2008's 14.3 paragraph 3, note 14.4, 14.4 paragraph 4,
14.5 paragraph 2, and 14.6 paragraph 1. */
void ieee_procedure_entry (void *);
export_proto(ieee_procedure_entry);
void
ieee_procedure_entry (void *state)
{
/* Save the floating-point state in the space provided by the caller. */
get_fpu_state (state);
/* Clear the floating-point exceptions. */
set_fpu_except_flags (0, GFC_FPE_ALL);
}
void ieee_procedure_exit (void *);
export_proto(ieee_procedure_exit);
void
ieee_procedure_exit (void *state)
{
/* Get the flags currently signaling. */
int flags = get_fpu_except_flags ();
/* Restore the floating-point state we had on entry. */
set_fpu_state (state);
/* And re-raised the flags that were raised since entry. */
set_fpu_except_flags (flags, 0);
}