re PR rtl-optimization/31360 (RTL loop invariant is not aggressive enough)

re PR rtl-optimization/31360 (RTL loop invariant is not aggressive enough)

	PR rtl-optimization/31360
	* cfgloopanal.c (target_small_cost, target_pres_cost): Removed.
	(target_reg_cost): New.
	(init_set_costs): Initialize target_reg_cost.  Add comments
	regarding the rationale of the costs.
	(global_cost_for_size): Renamed to...
	(estimate_reg_pressure_cost): ... and simplify.  Decrease importance
	of register pressure.
	* tree-ssa-loop-ivopts.c (ivopts_global_cost_for_size): Use
	estimate_reg_pressure_cost.  Add number of ivs.
	(determine_set_costs): Dump target_reg_cost.
	* loop-invariant.c (gain_for_invariant):  Use
	estimate_reg_pressure_cost.  Removed n_inv_uses argument.
	(best_gain_for_invariant, find_invariants_to_move): Remove
	n_inv_uses.
	* cfgloop.h (target_small_cost, target_pres_cost): Removed.
	(target_reg_cost): Declare.
	(global_cost_for_size): Declaration removed.
	(estimate_reg_pressure_cost): Declare.

	* gcc.dg/loop-7.c: New test.

From-SVN: r123919