https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94635
Bug ID: 94635
Summary: [OpenMP][Offloading] mapping with alloc/delete
followed by map(from/fromto fails
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Keywords: openmp, wrong-code
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
CC: jakub at gcc dot gnu.org
Target Milestone: ---
Based on an OpenMP test case from SOLLVE_VV,
https://github.com/SOLLVE/sollve_vv/
Namely, based on
tests/4.5/target_enter_exit_data/
test_target_enter_exit_data_allocate_array_alloc_delete.F90
The following test case works if one comments:
!$omp target enter data map(alloc: my1DPtr(:))
!$omp target exit data map(delete: my1DPtr(:))
Then it prints the expected
42 …
10 …
10 …
20 …
If one comments only the "map(delete:…)", it prints
42 …
10 …
0 … (should be: 10)
10 … (should be: 20)
And with alloc/delete enabled, it prints:
42 …
10 …
20 20 … 31911936 17 31907872 17 31907952 (should be: 10)
10 … (should be: 20)
In the 'target': when using "my1DArr = 99", the garbage values are replaced by
99, i.e. 20 20 … 99 99 … (twelf times 20 followed by eight times 99).
The testsuite first tests whether alloc/delete works – which does; only
re-using the alloc/delete space fails.
Test case:
----------
implicit none
INTEGER, PARAMETER :: N = 20
INTEGER, ALLOCATABLE, DIMENSION(:) :: my1DPtr
INTEGER, DIMENSION(N) :: my1DArr
allocate(my1DPtr(N))
!$omp target enter data map(alloc: my1DPtr(:))
!$omp target exit data map(delete: my1DPtr(:))
my1DPtr(:) = 10
my1DArr = 42
print *, my1DArr ! = 42, okay
print *, my1DPtr ! = 10, okay
!$omp target map(from: my1DArr) map(tofrom: my1DPtr(:))
my1DArr = my1DPtr
my1DPtr(:) = 20
!$omp end target
print *, my1DArr ! should be: 10 (not 0 or 20+garbage)
print *, my1DPtr ! should be: 20 (and not 10)
END
