re PR fortran/63570 ([F2018] Implement 13.7.137 RANDOM INIT (REPEATABLE, IMAGE DISTINCT))

2018-06-01  Steven G. Kargl  <kargl@gcc.gnu.org>

	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  <kargl@gcc.gnu.org>
 
	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  <kargl@gcc.gnu.org>

	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

5 files changed, 111 insertions, 3 deletions

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index c0b0f85..a220cc8 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,11 @@
+2018-06-01  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	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.
+
 2018-05-28  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libgfortran/85840
diff --git a/libgfortran/Makefile.am b/libgfortran/Makefile.am
index bf9dce4..5831631 100644
--- a/libgfortran/Makefile.am
+++ b/libgfortran/Makefile.am
@@ -915,7 +915,8 @@ $(gfor_built_specific_src) \
 $(gfor_built_specific2_src) \
 $(gfor_misc_specifics) \
 intrinsics/dprod_r8.f90 \
-intrinsics/f2c_specifics.F90
+intrinsics/f2c_specifics.F90 \
+intrinsics/random_init.f90
 
 # Turn on vectorization and loop unrolling for matmul.
 $(patsubst %.c,%.lo,$(notdir $(i_matmul_c))): AM_CFLAGS += -ffast-math -ftree-vectorize -funroll-loops --param max-unroll-times=4
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in
index 03c3968..b66a91b 100644
--- a/libgfortran/Makefile.in
+++ b/libgfortran/Makefile.in
@@ -408,7 +408,7 @@ am__objects_56 = _sign_i4.lo _sign_i8.lo _sign_i16.lo _sign_r4.lo \
 	_mod_r10.lo _mod_r16.lo
 am__objects_57 = misc_specifics.lo
 am__objects_58 = $(am__objects_55) $(am__objects_56) $(am__objects_57) \
-	dprod_r8.lo f2c_specifics.lo
+	dprod_r8.lo f2c_specifics.lo random_init.lo
 am__objects_59 = $(am__objects_3) $(am__objects_47) $(am__objects_49) \
 	$(am__objects_52) $(am__objects_53) $(am__objects_54) \
 	$(am__objects_58)
@@ -1374,7 +1374,8 @@ $(gfor_built_specific_src) \
 $(gfor_built_specific2_src) \
 $(gfor_misc_specifics) \
 intrinsics/dprod_r8.f90 \
-intrinsics/f2c_specifics.F90
+intrinsics/f2c_specifics.F90 \
+intrinsics/random_init.f90
 
 BUILT_SOURCES = $(gfor_built_src) $(gfor_built_specific_src) \
 	$(gfor_built_specific2_src) $(gfor_misc_specifics) \
@@ -6230,6 +6231,9 @@ selected_real_kind.lo: intrinsics/selected_real_kind.f90
 dprod_r8.lo: intrinsics/dprod_r8.f90
 	$(LIBTOOL)  --tag=FC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(FC) $(AM_FCFLAGS) $(FCFLAGS) -c -o dprod_r8.lo `test -f 'intrinsics/dprod_r8.f90' || echo '$(srcdir)/'`intrinsics/dprod_r8.f90
 
+random_init.lo: intrinsics/random_init.f90
+	$(LIBTOOL)  --tag=FC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(FC) $(AM_FCFLAGS) $(FCFLAGS) -c -o random_init.lo `test -f 'intrinsics/random_init.f90' || echo '$(srcdir)/'`intrinsics/random_init.f90
+
 mostlyclean-libtool:
 	-rm -f *.lo
 
diff --git a/libgfortran/gfortran.map b/libgfortran/gfortran.map
index 29af0dc..78f8d7e 100644
--- a/libgfortran/gfortran.map
+++ b/libgfortran/gfortran.map
@@ -799,6 +799,7 @@ GFORTRAN_8 {
     _gfortran_product_r4;
     _gfortran_product_r8;
     _gfortran_rand;
+    _gfortran_random_init;
     _gfortran_random_r10;
     _gfortran_random_r16;
     _gfortran_random_r4;
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 <kargl@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/>.
+!
+!
+! 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