When testing a new pull request for MARBL, I had TravisCI tests fail because changing the number of MARBL instances changed answers (it was bit-for-bit on my laptop). I traced the problem to a specific type of associate statement. Specifically, associate statements of the form
associate(col => mat_type(:)%a)
where a is a scalar element, results in col referring to contiguous memory being rather than having a proper stride to refer to each element a.
It looks like this issue was fixed by gfortran version 4.9, but setting up Travis to build with a newer gfortran while also linking to the netCDF library is non-trivial.
This version of the compiler has issues with Keith's bug (as seen by the last row in section 1) as well as a new bug that appears to be fixed in later versions (as seen by the last three entries in the second row).
$ gfortran --version
GNU Fortran (Ubuntu 4.8.5-4ubuntu8~14.04.2) 4.8.5
Copyright (C) 2015 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 10 20
pass associated column to function expecting dimension(:)
0 10 20
pass associated column to function expecting dimension(3)
0 10 20
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved.
$ gfortran-4.9 --version
GNU Fortran (Ubuntu 4.9.4-2ubuntu1~14.04.1) 4.9.4
Copyright (C) 2015 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved.
$ gfortran-5 --version
GNU Fortran (Ubuntu 5.5.0-12ubuntu1~14.04) 5.5.0 20171010
Copyright (C) 2015 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved.
$ gfortran-6 --version
GNU Fortran (Ubuntu 6.5.0-2ubuntu1~14.04.1) 6.5.0 20181026
Copyright (C) 2017 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved.
$ gfortran-7 --version
GNU Fortran (Ubuntu 7.4.0-1ubuntu1~14.04~ppa1) 7.4.0
Copyright (C) 2017 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved.
$ gfortran-8 --version
GNU Fortran (Ubuntu 8.3.0-16ubuntu3~14.04.2) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved. Given the date that the bug was closed, I would have expected all entries to be 0 1 2 with this version.
$ gfortran-9 --version
GNU Fortran (Ubuntu 9.1.0-2ubuntu2~14.04.2) 9.1.0
Copyright (C) 2019 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This version of the compiler has issues with Keith's bug but the problems seen in the second section with v4.8 have been resolved. Given the date that the bug was closed, I would have expected all entries to be 0 1 2 with this version as well.
$ gfortran --version
GNU Fortran (Homebrew GCC 9.2.0) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 10 20
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ ifort --version
ifort (IFORT) 16.0.2 20160204
Copyright (C) 1985-2016 Intel Corporation. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ ifort --version
ifort (IFORT) 17.0.4 20170411
Copyright (C) 1985-2017 Intel Corporation. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ ifort --version
ifort (IFORT) 18.0.3 20180410
Copyright (C) 1985-2018 Intel Corporation. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ pgf90 --version
pgf90 18.1-1 64-bit target on x86-64 Linux -tp nehalem
PGI Compilers and Tools
Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ pgf90 --version
pgf90 18.10-0 64-bit target on x86-64 Linux -tp nehalem
PGI Compilers and Tools
Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ pgf90 --version
pgf90 19.4-0 64-bit target on macOS -tp haswell
PGI Compilers and Tools
Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
This compiler behaves as expected
$ ./a.out
(1) Associate pointing to non-contiguous memory in a 3x3 matrix
print a column of a matrix
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2
(2) Associate pointing to scalar element in an array of derived type
print an array of derived-type elements
0 1 2
print the associate column
0 1 2
pass associated column to function expecting dimension(:)
0 1 2
pass associated column to function expecting dimension(3)
0 1 2