Hi, Richard. Returning to accurate cost accumulation issue you found
recently. Here is the patch fixing it. You could try, if you want,
how MIPS will behave with it. The patch also more accurately
calculates ALLOCNO_CALL_FREQ which affects decision to spill allocno
in assign_hard_reg if it is more profitable.
2008-10-01 Vladimir Makarov <vmakarov@redhat.com>
* ira-int.h (ira_allocno): Add member updated_cover_class_cost.
(ALLOCNO_UPDATED_COVER_CLASS_COST): New.
(ira_fast_allocation): Remove the prototype.
* ira-color.c (update_copy_costs, allocno_cost_compare_func,
assign_hard_reg, calculate_allocno_spill_cost): Use updated costs.
(color_pass): Modify the updated costs.
(ira_color): Rename to color. Make it static.
(ira_fast_allocation): Rename to fast_allocation. Make it static.
(ira_color): New function.
* ira-conflicts.c (process_regs_for_copy): Propagate hard reg cost
change.
* ira-lives.c (last_call_num, allocno_saved_at_call): New
variables.
(set_allocno_live, clear_allocno_live, mark_ref_live,
mark_ref_dead): Invalidate corresponding element of
allocno_saved_at_call.
(process_bb_node_lives): Increment last_call_num. Setup
allocno_saved_at_call. Don't increase ALLOCNO_CALL_FREQ if the
allocno was already saved.
(ira_create_allocno_live_ranges): Initiate last_call_num and
allocno_saved_at_call.
* ira-build.c (ira_create_allocno): Initiate
ALLOCNO_UPDATED_COVER_CLASS_COST.
(create_cap_allocno, propagate_allocno_info,
remove_unnecessary_allocnos): Remove setting updated costs.
(ira_flattening): Set up ALLOCNO_UPDATED_COVER_CLASS_COST.
* ira.c (ira): Don't call ira_fast_allocation.
* ira-costs.c (setup_allocno_cover_class_and_costs): Don't set up
updated costs.