https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109699
Bug ID: 109699
Summary: With OpenACC reallocating a fortran pointer on a user
type with allocatable fails.
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick.be...@univ-grenoble-alpes.fr
Target Milestone: ---
Created attachment 54970
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54970&action=edit
Test case to show the problem
With OpenACC reallocating a fortran pointer on a user type with allocatable
fails.
Type is:
type r2tab
double precision, dimension(:,:), allocatable :: val
integer :: dim1
integer :: dim2
end type r2tab
Variable in main to offload is:
type(r2tab), pointer :: tab=>null()
Gfortran 14.0 from master branch
commit 8d2793ef6b15dbdd347c854f663eb145af5ee593
Author: Marek Polacek <pola...@redhat.com>
Date: Thu Mar 9 18:43:34 2023 -0500
But also 12.2.1 20230302 [OG12]
Short test case attached to reproduce.
Compilation with gfortran 14 using:
gfortran -cpp -g -fopenacc testcase_begou.f90 -o testcase_begou
Execution output (wrong) with gfortran from master:
$ ./testcase_begou
=================================================
======================= 1 =======================
=================================================
=====>> ajoute: allocating on host and on device
=====>> ajoute OK
====> usage in main: set array to 1 on device
====> usage in main OK
Before update from the device, on host (should be 0): 0.000000
After update from device, on host shoud be 100: 100.000000
=====>> destroy datas on device and on host
=====>> destroy OK
=================================================
======================= 2 =======================
=================================================
=====>> ajoute: allocating on host and on device
=====>> ajoute OK
====> usage in main: set array to 2 on device
libgomp: cuStreamSynchronize error: an illegal memory access was encountered
With gfortran 12.2.1 the error message is a little bit more detailed (only
error message below, standard output is the same):
libgomp: cuStreamSynchronize error: an illegal memory access was encountered
libgomp: cuModuleGetFunction (__do_global_dtors__entry) error: an illegal
memory access was encountered
libgomp: device finalization failed
Hosts used with GNU compilers:
- AMD Epyc 7302 + Nvidia A100, CentOS8
- i7-12700H + Nvidia T600, Alma Linux8
Code works on :
- AMD Epyc 7302 + Nvidia A100, CentOS8 with Nvfortran 22.5-0:
nvfortran -acc=gpu,noautopar -gpu=cc80 -Mpreprocess testcase_begou.f90 -o
testcase_begou
- i7-12700H + Nvidia T600, Alma Linux8 with Nvfortran 23.3-0:
- nvfortran -acc=gpu,noautopar -gpu=cc75 -Mpreprocess testcase_begou.f90 -o
testcase_begou
- AMD EPYC 7542 + AMD MI 100 with Cray ftn 14.0.2:
- ftn -g -hacc -hnoomp -eF testcase_begou.f90 -o testcase_begou
Correct output is:
=================================================
======================= 1 =======================
=================================================
=====>> ajoute: allocating on host and on device
=====>> ajoute OK
====> usage in main: set array to 1 on device
====> usage in main OK
Before update from the device, on host (should be 0): 0.000000
After update from device, on host shoud be 100: 100.000000
=====>> destroy datas on device and on host
=====>> destroy OK
=================================================
======================= 2 =======================
=================================================
=====>> ajoute: allocating on host and on device
=====>> ajoute OK
====> usage in main: set array to 2 on device
====> usage in main OK
Before update from the device, on host (should be 0): 0.000000
After update from device, on host shoud be 800: 800.000000
=====>> destroy datas on device and on host
=====>> destroy OK
Thanks
Patrick
