From ddd3e26e42b8d55989f9964c6ec6ee50b30b1802 Mon Sep 17 00:00:00 2001 From: "Steven G. Kargl" Date: Fri, 1 Jun 2018 17:05:02 +0000 Subject: re PR fortran/63570 ([F2018] Implement 13.7.137 RANDOM INIT (REPEATABLE, IMAGE DISTINCT)) 2018-06-01 Steven G. Kargl PR fortran/63570 * check.c (gfc_check_random_init): New function. Check arguments of RANDOM_INIT. * gfortran.h (GFC_ISYM_RANDOM_INIT): New enum token. * intrinsic.c (add_subroutines): Add RANDOM_INIT to list of subroutines. (gfc_check_intrinsic_standard): Introduce Fortran 2018 check. * intrinsic.h: Add prototypes for gfc_check_random_init and gfc_resolve_random_init * intrinsic.texi: Document new intrinsic subprogram. * iresolve.c (gfc_resolve_random_init): Resolve routine name. * trans-decl.c: Declare gfor_fndecl_random_init * trans-intrinsic.c (conv_intrinsic_random_init): New function. Translate call to RANDOM_INIT. (gfc_conv_intrinsic_subroutine): Call it. * trans.h: Declare gfor_fndecl_random_init 2018-06-01 Steven G. Kargl PR fortran/63570 * gfortran.dg/random_init_1.f90: New test. * gfortran.dg/random_init_2.f90: New test. * gfortran.dg/random_init_3.f90: New test. * gfortran.dg/random_init_4.f90: New test. * gfortran.dg/random_init_5.f90: New test. * gfortran.dg/random_init_6.f90: New test. 2018-06-01 Steven G. Kargl PR fortran/63570 * libgfortran/Makefile.am: Add random_init.f90 to build. * libgfortran/Makefile.in: Regenerated. * libgfortran/gfortran.map: Expose symbol for _gfortran_random_init. * libgfortran/intrinsics/random_init.f90: Implementation. From-SVN: r261075 --- libgfortran/intrinsics/random_init.f90 | 94 ++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 libgfortran/intrinsics/random_init.f90 (limited to 'libgfortran/intrinsics') diff --git a/libgfortran/intrinsics/random_init.f90 b/libgfortran/intrinsics/random_init.f90 new file mode 100644 index 0000000..edea0b8 --- /dev/null +++ b/libgfortran/intrinsics/random_init.f90 @@ -0,0 +1,94 @@ +! Copyright (C) 2018 Free Software Foundation, Inc. +! Contributed by Steven G. Kargl +! +! 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 +! . +! +! +! WARNING: This file should never be compiled with an option that changes +! default logical kind from 4 to some other value or changes default integer +! kind from from 4 to some other value. +! +! +! There are four combinations of repeatable and image_distinct. If a program +! is compiled without the -fcoarray= option or with -fcoarray=single, then +! execution of the compiled executable does not use image_distinct as it is +! irrelevant (although required). The behavior is as follows: +! +! call random_init(.true., .true.) +! +! The sequence of random numbers is repeatable within an instance of program +! execution. That is, calls to random_init(.true., .true.) during the +! execution will reset the sequence of RN to the same sequence. If the +! program is compiled with -fcoarray=lib and multiple images are instantiated, +! then each image accesses a repeatable distinct sequence of random numbers. +! There are no guarantees that multiple execution of the program will access +! the same sequence. +! +! call random_init(.false., .false.) +! call random_init(.false., .true.) +! +! The sequence of random numbers is determined from process-dependent seeds. +! On each execution of the executable, different seeds will be used. For +! -fcoarray=lib and multiple instantiated images, each image will use +! process-dependent seeds. In other words, the two calls have identical +! behavior. +! +! call random_init(.true., .false.) +! +! For a program compiled without the -fcoarray= option or with +! -fcoarray=single, a single image is instantiated when the executable is +! run. If the executable causes multiple images to be instantiated, then +! image_distinct=.false. in one image cannot affect the sequence of random +! numbers in another image. As gfortran gives each image its own independent +! PRNG, this condition is automatically satisfied. +! +impure subroutine _gfortran_random_init(repeatable, image_distinct, hidden) + + implicit none + + logical, value, intent(in) :: repeatable + logical, value, intent(in) :: image_distinct + integer, value, intent(in) :: hidden + + logical, save :: once = .true. + integer :: nseed + integer, save, allocatable :: seed(:) + + if (once) then + once = .false. + call random_seed(size=nseed) + allocate(seed(nseed)) + call random_seed(get=seed) + ! + ! To guarantee that seed is distinct on multiple images, add the hidden + ! argument (which is the image index). + ! + if (image_distinct) seed = seed + hidden + end if + + if (repeatable) then + call random_seed(put=seed); + else + call random_seed(); + end if + +end subroutine _gfortran_random_init -- cgit v1.1