2.2 Fortran 95 OpenMP Validation

You can obtain a static, interprocedural validation of a Fortran 95 program’s OpenMP directives by using the f95 compiler’s global program checking feature. Enable OpenMP checking by compiling with the -XlistMP flag. (Diagnostic messages from -XlistMP appear in a separate file created with the name of the source file and a .lst extension). The compiler will diagnose the following violations and parallelization inhibitors:

• Violations in the specifications of parallel directives, including improper nesting.

• Parallelization inhibitors due to data usage, detected by interprocedural dependence analysis.

• Parallelization inhibitors detected by interprocedural pointer analysis.

For example, compiling a source file ord.f with -XlistMP produces a diagnostic file ord.lst:

FILE  "ord.f"
     1  !$OMP PARALLEL
     2  !$OMP DO ORDERED
     3                  do i=1,100
     4                          call work(i)
     5                  end do
     6  !$OMP END DO
     7  !$OMP END PARALLEL
     8
     9  !$OMP PARALLEL
    10  !$OMP DO
    11                  do i=1,100
    12                          call work(i)
    13                  end do
    14  !$OMP END DO
    15  !$OMP END PARALLEL
    16                  end
    17                  subroutine work(k)
    18  !$OMP ORDERED
         ^
**** ERR-OMP:  It is illegal for an ORDERED directive to bind to a
DO directive (ord.f, line 10, column 2) that does not have the
ORDERED clause specified.
    19                  write(*,*) k
    20  !$OMP END ORDERED
    21                  return
    22                  end

In this example, the ORDERED directive in subroutine WORK receives a diagnostic that refers to the second DO directive because it lacks an ORDERED clause.