tree-ssa-loop-ivopts.c (strip_offset_1): New case.
* tree-ssa-loop-ivopts.c (strip_offset_1) <MULT_EXPR>: New case.
(force_expr_to_var_cost) <NEGATE_EXPR>: Likewise.
(ptr_difference_cost): Use affine combinations to compute it.
(difference_cost): Likewise.
(get_computation_cost_at): Compute more accurate cost for addresses
if the ratio is a multiplier allowed in addresses.
For non-addresses, consider that an additional offset or symbol is
added only once.