https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88233
--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Mon Jul 8 17:35:12 2019 New Revision: 273240 URL: https://gcc.gnu.org/viewcvs?rev=273240&root=gcc&view=rev Log: subreg: Add -fsplit-wide-types-early (PR88233) Currently the second lower-subreg pass is run right before RA. This is much too late to be very useful. At least for targets that do not have RTL patterns for operations on multi-register modes it is a lot better to split patterns earlier, before combine and all related passes. This adds an option -fsplit-wide-types-early that does that, and enables it by default for rs6000. PR rtl-optimization/88233 * common.opt (fsplit-wide-types-early): New option. * common/config/rs6000/rs6000-common.c (rs6000_option_optimization_table): Add OPT_fsplit_wide_types_early for OPT_LEVELS_ALL. * doc/invoke.texi (Optimization Options): Add -fsplit-wide-types-early. * lower-subreg.c (pass_lower_subreg2::gate): Add test for flag_split_wide_types_early. (pass_data_lower_subreg3): New. (pass_lower_subreg3): New. (make_pass_lower_subreg3): New. * passes.def (pass_lower_subreg2): Move after the loop passes. (pass_lower_subreg3): New, inserted where pass_lower_subreg2 was. * tree-pass.h (make_pass_lower_subreg2): Move up, to its new place in the pass pipeline; its previous place is taken by ... (make_pass_lower_subreg3): ... this. Modified: trunk/gcc/ChangeLog trunk/gcc/common.opt trunk/gcc/common/config/rs6000/rs6000-common.c trunk/gcc/doc/invoke.texi trunk/gcc/lower-subreg.c trunk/gcc/passes.def trunk/gcc/tree-pass.h
