https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87725
Bug ID: 87725
Summary: OpenMP 4.5 clause schedule(simd,monotonic:static) not
understood
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: as at cmplx dot uk
CC: jakub at gcc dot gnu.org
Target Milestone: ---
OpenMP 4.5 specifications say that
schedule clause can have 2 modifiers,
specifically this should be valid:
!$omp do schedule(simd,monotonic:static)
But gfortran9 rejects this with:
21 | !$omp do schedule(simd,monotonic:static, n/nthr )
| 1
Error: Unclassifiable OpenMP directive at (1)
Intel Fortran 18 does accept the above
construct with 2 schedule modifiers.
Using only a single modifier is accepted by gfortran9, i.e:
!$omp do schedule( simd:static )
!$omp do schedule( monotonic:static )
are both fine.
I guess this just hasn't been implemented yet?
A complete program:
use, intrinsic :: iso_fortran_env
use :: omp_lib
implicit none
integer :: i, val, tid, nthr, sum, part, n
write (*,*) "OMP version:", openmp_version
n = 2**30
sum = 0
!$omp parallel default( none ) &
!$omp private( tid, i, part, nthr ) &
!$omp shared( sum, n )
part = 0
nthr = omp_get_num_threads()
tid = omp_get_thread_num()
write (*,*) tid, nthr
! !$omp do schedule(simd,monotonic:static, n/nthr )
!$omp do schedule(simd:static, n/nthr )
! !$omp do schedule(monotonic:static, n/nthr )
do i=1,n
part = part + 1
end do
!$omp end do nowait
!$omp atomic
sum = sum + part
!$omp end atomic
!$omp end parallel
write (*,*) sum, ( sum .eq. n )
end
