Re: [PATCH v3 06/11] OpenMP: Pointers and member mappings

[Jakub Jelinek <jakub@redhat.com>]

On Tue, Sep 13, 2022 at 02:03:16PM -0700, Julian Brown wrote:
> @@ -3440,6 +3437,50 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
>  		    {
>  		      if (pointer || (openacc && allocatable))
>  			{
> +			  gfc_omp_namelist *n2
> +			    = openacc ? NULL : clauses->lists[OMP_LIST_MAP];
> +
> +			  /* If the last reference is a pointer to a derived
> +			     type ("foo%dt_ptr"), check if any subcomponents
> +			     of the same derived type member are being mapped
> +			     elsewhere in the clause list ("foo%dt_ptr%x",
> +			     etc.).  If we have such subcomponent mappings,
> +			     we only create an ALLOC node for the pointer
> +			     itself, and inhibit mapping the whole derived
> +			     type.  */
> +
> +			  for (; n2 != NULL; n2 = n2->next)
> +			    {
> +			      if (n == n2 || !n2->expr)
> +				continue;
> +
> +			      int dep
> +				= gfc_dep_resolver (n->expr->ref, n2->expr->ref,
> +						    NULL, true);
> +			      if (dep == 0)
> +				continue;

Isn't this and the other loop quadratic compile time in number of clauses?
Could it be done linearly through some perhaps lazily built hash table or
something similar?

	Jakub