Dear All, After submitting the patch, I did something that I should have done a long time ago: some timing tests :-)
I used actual_array_offset_1.f90, which is based on Arjen Markus's implementation of quicksort using unlimited polymorphic entities as carriers of the objects to be sorted. With 10^5 elements in the array and -O3, without the patch, the execution time is 49ms. With the patch it climbs to 315ms Dominique repeated the test with 10^7 elements and got 4.4s before the patch and 46.5 after. In light of this, I withdraw the submission and will concentrate on making the pointer version work in all circumstances with submodules. Best regards Paul On 27 September 2016 at 10:27, Paul Richard Thomas <paul.richard.tho...@gmail.com> wrote: > Dear All, > > The first attempts at fixing this bug were posted to the PR in > February of this year. Since then, real life has intervened and I have > not been able to get back to it until now. > > The first patch used the address of the vtable to perform the > switching in SELECT_TYPE. Unfortunately, it failed in submodule_6.f90 > and I have not been able to find a way to fix this without breaking > the ABI and having to bump up the module version number. > > The second patch uses a string for the switching, which comprises a > concatenation of the type name and the module or procedure name. > Clearly, there is a performance penalty associated with this. My > recent efforts have been focussed on making this version detect > incoming selectors and associates that are use associated with > libraries that were compiled before this patch was applied and the > result is this submission. By the way, I was unable to find a way of > testing this feature as part of the testsuite but have done so 'by > hand'. > > If the performance penalty is considered to be a show stopper, I could > develop further the version based on the vtable addresses but will > have to postpone any further work on this for a few weeks. > > Otherwise, this patch does bootstrap and regtest on FC21/x86_64 - OK for > trunk? > > Cheers > > Paul > > 2016-09-27 Paul Thomas <pa...@gcc.gnu.org> > > PR fortran/69834 > * class.c (get_unique_type_string): Add an extra argument > 'icase' that defaults to false but, when true, switches the > order of type name and module or procedure name. > (get_unique_hashed_string): New argument 'icase' switches > bewteen the old form and a new one in which the string length > is limited to GFC_MAX_SYMBOL_LEN and, in case of this limit > being exceeded, the hash string is followed by as much of the > composite name as possible. > (gfc_case_name): New function. > (gfc_find_derived_vtab): Add '_name' field to vtable. This is > initialized by 'get_unique_type_string' with 'icase' true. > (find_intrinsic_vtab): Ditto with initialization performed by a > call to 'gfc_case_name'. > * gfortran.h : Add macro 'gfc_add_name_component' and prototype > for 'gfc_case_name'. > * resolve.c (vtable_old_style): New function to determine if a > use associated vtable is missing the '_name' field. > (resolve_select_type): Call 'vtable_old_style' to determine if > any of the derived types or vtables come from a library that > was compiled before this patch. If this is the case, the old > form of SELECT TYPE is activated, in which the cases are set by > the hash value. Otherwise, the 'unique_type_string' is used. > > 2016-09-27 Paul Thomas <pa...@gcc.gnu.org> > > PR fortran/69834 > * gfortran.dg/finalize_21.f90: Remove semi colon from the tree > scan. > * gfortran.dg/select_type_36.f03: New test. > * gfortran.dg/select_type_37.f03: New test. -- The difference between genius and stupidity is; genius has its limits. Albert Einstein
