https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92178
--- Comment #20 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Mikael Morin <mik...@gcc.gnu.org>: https://gcc.gnu.org/g:71e4d568b1264bca46d30c5fc4933f137d05ca24 commit r14-2520-g71e4d568b1264bca46d30c5fc4933f137d05ca24 Author: Mikael Morin <mik...@gcc.gnu.org> Date: Fri Jul 14 14:15:21 2023 +0200 fortran: Factor data references for scalar class argument wrapping [PR92178] In the case of a scalar actual arg passed to a polymorphic assumed-rank dummy with INTENT(OUT) attribute, avoid repeatedly evaluating the actual argument reference by saving a pointer to it. This is non-optimal, but may also be invalid, because the data reference may depend on its own content. In that case the expression can't be evaluated after the data has been deallocated. There are two ways redundant expressions are generated: - parmse.expr, which contains the actual argument expression, is reused to get or set subfields in gfc_conv_class_to_class. - gfc_conv_class_to_class, to get the virtual table pointer associated with the argument, generates a new expression from scratch starting with the frontend expression. The first part is fixed by saving parmse.expr to a pointer and using the pointer instead of the original expression. The second part is fixed by adding a separate field to gfc_se that is set to the class container expression when the expression to evaluate is polymorphic. This needs the same field in gfc_ss_info so that its value can be propagated to gfc_conv_class_to_class which is modified to use that value. Finally gfc_conv_procedure saves the expression in that field to a pointer in between to avoid the same problem as for the first part. PR fortran/92178 gcc/fortran/ChangeLog: * trans.h (struct gfc_se): New field class_container. (struct gfc_ss_info): Ditto. (gfc_evaluate_data_ref_now): New prototype. * trans.cc (gfc_evaluate_data_ref_now): Implement it. * trans-array.cc (gfc_conv_ss_descriptor): Copy class_container field from gfc_se struct to gfc_ss_info struct. (gfc_conv_expr_descriptor): Copy class_container field from gfc_ss_info struct to gfc_se struct. * trans-expr.cc (gfc_conv_class_to_class): Use class container set in class_container field if available. (gfc_conv_variable): Set class_container field on encountering class variables or components, clear it on encountering non-class components. (gfc_conv_procedure_call): Evaluate data ref to a pointer now, and replace later references by usage of the pointer. gcc/testsuite/ChangeLog: * gfortran.dg/intent_out_20.f90: New test.
