https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93264
rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rsandifo at gcc dot gnu.org
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org>
---
(In reply to Richard Biener from comment #3)
> In general it's a bad idea to try go "back" to CFG layout mode and the fix is
> to not do that. Which probably means scheduling pass_sms earlier and indeed
> then best before pass_partition_blocks. I don't see any reason to _not_ do
> this, the current pipeline is
>
> NEXT_PASS (pass_partition_blocks);
> NEXT_PASS (pass_outof_cfg_layout_mode);
> NEXT_PASS (pass_split_all_insns);
> NEXT_PASS (pass_lower_subreg3);
> NEXT_PASS (pass_df_initialize_no_opt);
> NEXT_PASS (pass_stack_ptr_mod);
> NEXT_PASS (pass_mode_switching);
> NEXT_PASS (pass_match_asm_constraints);
> NEXT_PASS (pass_sms);
> NEXT_PASS (pass_live_range_shrinkage);
> NEXT_PASS (pass_sched);
> NEXT_PASS (pass_early_remat);
> NEXT_PASS (pass_ira);
> NEXT_PASS (pass_reload);
> NEXT_PASS (pass_postreload);
> PUSH_INSERT_PASSES_WITHIN (pass_postreload)
>
> and while I understand sms wants to run as close to RA as possible the
> passes between its current position and partitioning should not mess
> with the schedule (mode switching might insert code I think).
Yeah, it ought to be better to do mode switching first. But I think
the more important ones are:
NEXT_PASS (pass_split_all_insns);
NEXT_PASS (pass_lower_subreg3);
Scheduling should happen on the split form of insns rather than the
unsplit form. lower_subreg should also improve "schedulability".
