* gcse.c (struct bb_data): Add new fields, old_pressure, live_in
and backup.
(get_regno_pressure_class): Add prototype.
(update_bb_reg_pressure): New.
(should_hoist_expr_to_dom): Add new parameter from.
Monitor the change of reg pressure and use it to drive hoisting.
(hoist_code): Update LIVE and reg pressure information.
(calculate_bb_reg_pressure): Initialize live_in and backup.
* gcc.dg/hoist-register-pressure-3.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193425
138bc75d-0d04-0410-961f-
82ee72b054a4