* tree-ssa-loop-ivopts.c (get_address_cost): Add address elements in
	right order.
	(force_var_cost): Determine cost of addition and multiplication more
	precisely.
	(get_computation_cost_at): Add cost for computing address elements to
	the final cost.

	* fold-const.c (fold): Attempt to use ptr_difference_const whenever
	one of the arguments of MINUS_EXPR is an address.
	(split_address_to_core_and_offset): New function.
	(ptr_difference_const): Handle case when one of the operands is a
	pointer.
	* tree-ssa-loop-ivopts.c (determine_base_object): Fold &*addr.
	(ptr_difference_cost): Pass addresses instead of objects to
	ptr_difference_const.

From-SVN: r90451