https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102596
Tobias Burnus <burnus at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
Keywords| |ice-on-valid-code
--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> ---
The problem is that gfc_omp_clause_default_ctor requires outer != NULL_TREE
(gcc_assert).
(C++ does ignore the last argument and C uses the hook_tree_tree_tree_tree_null
fallback.)
That is used in Fortran for:
/* Allocatable arrays and scalars in PRIVATE clauses need to be set to
"not currently allocated" allocation status if outer
array is "not currently allocated", otherwise should be allocated. */
But omp-low.cc has:
x = lang_hooks.decls.omp_clause_default_ctor
(c, unshare_expr (new_var),
cond ? NULL_TREE
: build_outer_var_ref (var, ctx));
Note the NULL_TREE.
My impression is that NULL_TREE is fine for reduction - and there is also code
like:
/* Reduction clause requires allocated ALLOCATABLE. */
if (OMP_CLAUSE_CODE (clause) != OMP_CLAUSE_REDUCTION
&& OMP_CLAUSE_CODE (clause) != OMP_CLAUSE_IN_REDUCTION
&& OMP_CLAUSE_CODE (clause) != OMP_CLAUSE_TASK_REDUCTION)
{
gfc_init_block (&cond_block);
...
tree tem = fold_convert (pvoid_type_node,
GFC_DESCRIPTOR_TYPE_P (type)
? gfc_conv_descriptor_data_get (outer) :
outer);/*...*/
cond = fold_build2_loc (input_location, NE_EXPR, logical_type_node,
tem, null_pointer_node);
However - there is other code which uses 'outer' like:
tree tem = gfc_walk_alloc_comps (outer, decl,
or
gfc_add_modify (&cond_block, decl, outer);
and those make use of 'outer'.
I don't quickly see whether outer is always required or it can be deduced in
this case.
(Does using OMP_CLAUSE_REDUCTION_PLACEHOLDER() make sense here?) — Or whether
some is-always-used case (→ 'cond' case) is needed as additional flag or
encoded in outer.
PS: I don't think it is a real regression as 'reduction(task:' wasn't supported
before.
