https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117297
Bug ID: 117297
Summary: late combine undoes too much
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: ak at gcc dot gnu.org
Target Milestone: ---
forked from PR117091
When the (admittedly extreme) test case from PR117091 is compiled with -O2
-fno-bit-tests -fno-jump-tables (to work around the switch scalability issues)
the compiler spends ~70% of the time in late combine doing
- 39.85% cc1 cc1 [.] temporarily_undo_changes(int)
◆
39.84% temporarily_undo_changes(int)
▒
rtl_ssa::insn_info::calculate_cost() const
▒
- rtl_ssa::changes_are_worthwhile(array_slice<rtl_ssa::insn_change*
const>, bool) ▒
- 31.12% (anonymous
namespace)::late_combine::combine_into_uses(rtl_ssa::insn_info*,
rtl_ssa::insn_info*) ▒
(anonymous namespace)::pass_late_combine::execute(function*)
▒
execute_one_pass(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
- 8.72% (anonymous namespace)::pass_late_combine::execute(function*)
▒
execute_one_pass(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
- 32.56% cc1 cc1 [.] redo_changes(int)
▒
32.56% rtl_ssa::insn_info::calculate_cost() const
▒
- rtl_ssa::changes_are_worthwhile(array_slice<rtl_ssa::insn_change*
const>, bool) ▒
- 25.50% (anonymous
namespace)::late_combine::combine_into_uses(rtl_ssa::insn_info*,
rtl_ssa::insn_info*) ▒
(anonymous namespace)::pass_late_combine::execute(function*)
▒
execute_one_pass(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒ - 7.06% (anonymous
namespace)::pass_late_combine::execute(function*)
▒ execute_one_pass(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
execute_pass_list_1(opt_pass*)
▒
