OpenMP* ORDERED directive executed by non-ordered loop

The OpenMP* ORDERED directive is only allowed in loops marked with the ORDERED clause.

The ORDERED directive is used to sequentially order the results of work done in parallel. The parallel loop that executes the ORDERED directive must be itself marked with the ORDERED clause. This diagnostic indicates that that constraint was (or may be) violated.

It is legal for a non-ordered loop to contain an ordered loop. The only loop that must be marked as ORDERED is the one whose body directly executes the ORDERED directive.

ID	Code Location	Description
1	OpenMP usage error	The location of the ORDERED directive
2	OpenMP declaration	The location of the loop that lacks the required ORDERED clause

Example


// Example A.24.1c from OpenMP 3.0 Specification
// Copyright (C) 1997-2008 OpenMP Architecture Review Board
#include <stdio>

void work(int k)
{
    #pragma ordered
    printf(" %d\n", k);
}

void a24(int lb; int ub; int stride)
{
    int i;
    #pragma omp parallel for ordered schedule(dynamic)
    for (i = lb; i < ub; i += stride) {
        work(i);
    }
}

int main(int argc, char **argv)
{
    a24(0, 100, 5);
    return 0;
}

Here is the same example in FORTRAN


! Example A.24.1f from OpenMP 3.0 Specification
! Copyright (C) 1997-2008 OpenMP Architecture Review Board
SUBROUTINE WORK(K)
    INTEGER K
!$OMP ORDERED
    WRITE(*,*) k
!$OMP END ORDERED

SUBROUTINE SUBA24(LB, UB, STRIDE)
    INTEGER LB, UB, STRIDE
    INTEGER I

!$OMP PARALLEL DO ORDERED SCHEDULE(DYNAMIC)
    DO I = LB, UB, STRIDE
        CALL WORK(I)
    END DO
!$OMP END PARALLEL DO

END SUBROUTINE SUBA24

PROGRAM A24
    CALL SUBA24(0, 100, 5)
END PROGRAM A24

Note

These examples, adapted from OpenMP 3.0 Specification, are covered by the following:

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