gcc/libgfortran/ieee/ieee_exceptions.F90
2024-01-03 12:19:35 +01:00

306 lines
8.9 KiB
Fortran

! Implementation of the IEEE_EXCEPTIONS standard intrinsic module
! Copyright (C) 2013-2024 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 "config.h"
#include "kinds.inc"
#include "c99_protos.inc"
#include "fpu-target.inc"
module IEEE_EXCEPTIONS
implicit none
private
! Derived types and named constants
type, public :: IEEE_FLAG_TYPE
private
integer :: hidden
end type
type(IEEE_FLAG_TYPE), parameter, public :: &
IEEE_INVALID = IEEE_FLAG_TYPE(GFC_FPE_INVALID), &
IEEE_OVERFLOW = IEEE_FLAG_TYPE(GFC_FPE_OVERFLOW), &
IEEE_DIVIDE_BY_ZERO = IEEE_FLAG_TYPE(GFC_FPE_ZERO), &
IEEE_UNDERFLOW = IEEE_FLAG_TYPE(GFC_FPE_UNDERFLOW), &
IEEE_INEXACT = IEEE_FLAG_TYPE(GFC_FPE_INEXACT)
type(IEEE_FLAG_TYPE), parameter, public :: &
IEEE_USUAL(3) = [ IEEE_OVERFLOW, IEEE_DIVIDE_BY_ZERO, IEEE_INVALID ], &
IEEE_ALL(5) = [ IEEE_USUAL, IEEE_UNDERFLOW, IEEE_INEXACT ]
type, public :: IEEE_STATUS_TYPE
private
character(len=GFC_FPE_STATE_BUFFER_SIZE) :: hidden
end type
type, public :: IEEE_MODES_TYPE
private
integer :: rounding
integer :: underflow
integer :: halting
end type
interface IEEE_SUPPORT_FLAG
module procedure IEEE_SUPPORT_FLAG_4, &
IEEE_SUPPORT_FLAG_8, &
#ifdef HAVE_GFC_REAL_10
IEEE_SUPPORT_FLAG_10, &
#endif
#ifdef HAVE_GFC_REAL_16
IEEE_SUPPORT_FLAG_16, &
#endif
IEEE_SUPPORT_FLAG_NOARG
end interface IEEE_SUPPORT_FLAG
public :: IEEE_SUPPORT_FLAG, IEEE_SUPPORT_HALTING
public :: IEEE_SET_HALTING_MODE, IEEE_GET_HALTING_MODE
public :: IEEE_SET_FLAG, IEEE_GET_FLAG
public :: IEEE_SET_STATUS, IEEE_GET_STATUS
public :: IEEE_SET_MODES, IEEE_GET_MODES
contains
! Fortran 2018: Saving and restoring floating-point modes
! (rounding modes, underflow mode, and halting mode)
!
! For now, we only have one rounding mode for all kinds.
! Some targets could optimize getting/setting all modes at once, but for now
! we make three calls. This code must be kept in sync with:
! - IEEE_{GET,SET}_ROUNDING_MODE
! - IEEE_{GET,SET}_UNDERFLOW_MODE
! - IEEE_{GET,SET}_HALTING_MODE
subroutine IEEE_GET_MODES (MODES)
implicit none
type(IEEE_MODES_TYPE), intent(out) :: MODES
interface
integer function helper_rounding() &
bind(c, name="_gfortrani_get_fpu_rounding_mode")
end function
integer function helper_underflow() &
bind(c, name="_gfortrani_get_fpu_underflow_mode")
end function
pure integer function helper_halting() &
bind(c, name="_gfortrani_get_fpu_trap_exceptions")
end function
end interface
MODES%rounding = helper_rounding()
MODES%underflow = helper_underflow()
MODES%halting = helper_halting()
end subroutine
subroutine IEEE_SET_MODES (MODES)
implicit none
type(IEEE_MODES_TYPE), intent(in) :: MODES
interface
subroutine helper_rounding(val) &
bind(c, name="_gfortrani_set_fpu_rounding_mode")
integer, value :: val
end subroutine
subroutine helper_underflow(val) &
bind(c, name="_gfortrani_set_fpu_underflow_mode")
integer, value :: val
end subroutine
pure subroutine helper_halting(trap, notrap) &
bind(c, name="_gfortrani_set_fpu_trap_exceptions")
integer, intent(in), value :: trap, notrap
end subroutine
end interface
call helper_rounding(MODES%rounding)
call helper_underflow(MODES%underflow)
call helper_halting(MODES%halting, NOT(MODES%halting))
end subroutine
! Saving and restoring floating-point status
subroutine IEEE_GET_STATUS (STATUS_VALUE)
implicit none
type(IEEE_STATUS_TYPE), intent(out) :: STATUS_VALUE
interface
subroutine helper(ptr) &
bind(c, name="_gfortrani_get_fpu_state")
use, intrinsic :: iso_c_binding, only : c_char
character(kind=c_char) :: ptr(*)
end subroutine
end interface
call helper(STATUS_VALUE%hidden)
end subroutine
subroutine IEEE_SET_STATUS (STATUS_VALUE)
implicit none
type(IEEE_STATUS_TYPE), intent(in) :: STATUS_VALUE
interface
subroutine helper(ptr) &
bind(c, name="_gfortrani_set_fpu_state")
use, intrinsic :: iso_c_binding, only : c_char
character(kind=c_char) :: ptr(*)
end subroutine
end interface
call helper(STATUS_VALUE%hidden)
end subroutine
! Getting and setting flags
elemental subroutine IEEE_GET_FLAG (FLAG, FLAG_VALUE)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
logical, intent(out) :: FLAG_VALUE
interface
pure integer function helper() &
bind(c, name="_gfortrani_get_fpu_except_flags")
end function
end interface
FLAG_VALUE = (IAND(helper(), FLAG%hidden) /= 0)
end subroutine
elemental subroutine IEEE_SET_FLAG (FLAG, FLAG_VALUE)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
logical, intent(in) :: FLAG_VALUE
interface
pure subroutine helper(set, clear) &
bind(c, name="_gfortrani_set_fpu_except_flags")
integer, intent(in), value :: set, clear
end subroutine
end interface
if (FLAG_VALUE) then
call helper(FLAG%hidden, 0)
else
call helper(0, FLAG%hidden)
end if
end subroutine
! Querying and changing the halting mode
elemental subroutine IEEE_GET_HALTING_MODE (FLAG, HALTING)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
logical, intent(out) :: HALTING
interface
pure integer function helper() &
bind(c, name="_gfortrani_get_fpu_trap_exceptions")
end function
end interface
HALTING = (IAND(helper(), FLAG%hidden) /= 0)
end subroutine
elemental subroutine IEEE_SET_HALTING_MODE (FLAG, HALTING)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
logical, intent(in) :: HALTING
interface
pure subroutine helper(trap, notrap) &
bind(c, name="_gfortrani_set_fpu_trap_exceptions")
integer, intent(in), value :: trap, notrap
end subroutine
end interface
if (HALTING) then
call helper(FLAG%hidden, 0)
else
call helper(0, FLAG%hidden)
end if
end subroutine
! Querying support
pure logical function IEEE_SUPPORT_HALTING (FLAG)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
interface
pure integer function helper(flag) &
bind(c, name="_gfortrani_support_fpu_trap")
integer, intent(in), value :: flag
end function
end interface
IEEE_SUPPORT_HALTING = (helper(FLAG%hidden) /= 0)
end function
pure logical function IEEE_SUPPORT_FLAG_NOARG (FLAG)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
interface
pure integer function helper(flag) &
bind(c, name="_gfortrani_support_fpu_flag")
integer, intent(in), value :: flag
end function
end interface
IEEE_SUPPORT_FLAG_NOARG = (helper(FLAG%hidden) /= 0)
end function
pure logical function IEEE_SUPPORT_FLAG_4 (FLAG, X) result(res)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
real(kind=4), intent(in) :: X
res = IEEE_SUPPORT_FLAG_NOARG(FLAG)
end function
pure logical function IEEE_SUPPORT_FLAG_8 (FLAG, X) result(res)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
real(kind=8), intent(in) :: X
res = IEEE_SUPPORT_FLAG_NOARG(FLAG)
end function
#ifdef HAVE_GFC_REAL_10
pure logical function IEEE_SUPPORT_FLAG_10 (FLAG, X) result(res)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
real(kind=10), intent(in) :: X
res = IEEE_SUPPORT_FLAG_NOARG(FLAG)
end function
#endif
#ifdef HAVE_GFC_REAL_16
pure logical function IEEE_SUPPORT_FLAG_16 (FLAG, X) result(res)
implicit none
type(IEEE_FLAG_TYPE), intent(in) :: FLAG
real(kind=16), intent(in) :: X
res = IEEE_SUPPORT_FLAG_NOARG(FLAG)
end function
#endif
end module IEEE_EXCEPTIONS