https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115685
Bug ID: 115685
Summary: [OpenMP][5.1][OpenACC] Permit named constants
("PARAMETER") in firstprivate, shared and copyin
clauses
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: openacc, openmp, rejects-valid
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
CC: jakub at gcc dot gnu.org, tschwinge at gcc dot gnu.org
Target Milestone: ---
OpenMP 5.1 permits now named constants ("PARAMETER") in 'shared' and in
'firstprivate' clauses.
OpenACC 3.4 will permit it explicitly in 'firstprivate' and 'copyin' clauses (→
OpenACC, Issue 505), user code already used it for both arrays and scalars.
* * *
3 | !$omp parallel firstprivate(p) shared(q)
6 | !$omp target firstprivate(p)
Error: Object 'p' is not a variable at (1)
Error: Object 'q' is not a variable at (1)
Error: Object 'p' is not a variable at (1)
---- for: ----
integer, parameter :: p = 5, q= 7
!$omp parallel firstprivate(p) shared(q)
!$omp end parallel
!$omp target firstprivate(p)
!$omp end target
end
* * *
OpenACC (real-world use in the ICON code,
https://gitlab.dkrz.de/icon/icon-model/ ):
REAL(wp), PARAMETER :: zwdmin = 0.05_wp
!$ACC DECLARE COPYIN(zwdmin)
REAL(KIND=jprb), PARAMETER :: beta(2)= [0.7_jprb , 0.45_jprb ]
!$ACC DECLARE COPYIN(beta)
* * *
Wording in OpenMP (here TR12, but it was added in 5.1):
In "4.2.1 OpenMP Argument Lists":
[104:8] A variable list item is one of the following: […]
[104:11] * a named constant; […]
[104:18] A named constant as a list item can appear only in clauses where it is
explicitly allowed.
And in "6.1 Data-Sharing Attribute Rules" → "6.1.1 Variables Referenced in a
Construct":
[148:3–4] Certain variables and objects have predetermined data-sharing
attributes for the construct in which they are referenced […]
[150:16–17] * […] named constants are shared in constructs that are not
data-mapping constructs.
[150:18] * Named constants are firstprivate in target constructs.
[150:23–24] Variables with predetermined data-sharing attributes may not be
listed in data-sharing attribute clauses, except for the cases
listed below […]
[151:11] Named constants may be listed in a shared or firstprivate clause.
In 6.4.4 firstprivate Clause:
The list items that appear in a firstprivate clause may include named
constants.
(Same in 'shared' clauses, once the omission has been fixed; OpenMP, Issue
3995.)
