Re: [Patch] Fortran/OpenMP: Fix depend-clause handling

[Jakub Jelinek <jakub@redhat.com>]

On Tue, Feb 15, 2022 at 11:26:12AM +0100, Tobias Burnus wrote:
> As found by Marcel, the 'depend' clause was differently handled in
> 'omp depobj(...) depend(...)' and in 'omp task depend(...)'.
> 
> The problem was that for a scalar pointer, depobj depended
> on the pointer address - while task depended on the pointer-target address.
> 
> If one now combines depobj and direct var dependency, the dependency
> is on different addresses, such that the dependency is not honored.
> Marcel's example is testsuite/libgomp.fortran/depend-4.f90.
> (Thanks for the report!)
> 
> 
> I think in the real world, the problem is not that big as most
> code either uses depobj or a variable and does not mix them. Likewise,
> using the address of a temporary variable (cf. below) will also usually
> work in terms of dependency.
> 
> 
> The attached patch does:
> - depend clause (as used by task etc):
>   For scalar allocatable/pointer, add another dereference
> 
> - For depobj (which handles the depend clause by itself)
>   - Fix array(element) handling by coping the depend-clause.
>     Before the result was 'D.123 = var; depobj = &D.123;'
>     which is really not intended.
>   - Several issues related to optional and allocatable/pointer.
> 
> OK for mainline? Does backporting to GCC 11 make sense?

Ok.  Dunno about backporting, perhaps later.

	Jakub