Visible to Intel only — GUID: GUID-09D357EF-F6EA-4160-9A7A-CA9C7415B0B8
Visible to Intel only — GUID: GUID-09D357EF-F6EA-4160-9A7A-CA9C7415B0B8
GAP Message (Diagnostic ID 30526)
Message
To parallelize the loop at line %d, annotate the routine %s with %s.
Advice
If the loop contains a call to a function, the compiler cannot parallelize the loop without more information about the function being called.
However, if the function being called in the loop is an elemental function or a function specified with ATTRIBUTES CONCURRENCY_SAFE, then the call does not inhibit parallelization of the loop.
Example
Consider the following:
subroutine foo ()
integer, parameter :: N2 = 10000
real (8) :: A(N2), B(N2)
interface
function bar (k)
integer :: bar, k
end function bar
end interface
integer :: i
do i =1, N2
A(i) = B(i) * bar(N2)
end do
end subroutine foo
In this case, to parallelize the loop at line 11, declare the routine bar as elemental.
If you determine it is safe to do so, an alternative way you can modify the program code is as follows:
subroutine foo ()
integer, parameter :: N2 = 10000
real (8) :: A(N2), B(N2)
interface
function bar (k)
!dir$ attributes concurrency_safe : profitable :: bar
integer :: bar, k
end function bar
end interface
integer :: i
do i =1, N2
A(i) = B(i) * bar(N2)
end do
end subroutine foo
Verify
Confirm the routine satisfies the semantics of this annotation. A weaker annotation able to achieve a similar effect is ATTRIBUTES CONCURRENCY_SAFE(PROFITABLE).