* Makefile.in (tree-ssa-loop-ivopts.o): Add sbitmap.h dependency.
	* tree-ssa-loop-ivopts.c (struct iv_use): Change semantics of
	related_cands.
	(struct iv_ca, struct iv_ca_delta): New types.
	(tree_ssa_iv_optimize_init): Allocate important_candidates bitmap.
	(record_important_candidates): New.
	(find_iv_candidates): Call record_important_candidates.
	(alloc_use_cost_map): Derive size only from important candidates.
	(set_use_iv_cost, get_use_iv_cost): Use hash-like mechanism to speed
	up searches.
	(determine_use_iv_cost_generic, determine_use_iv_cost_address,
	determine_use_iv_cost_condition, determine_use_iv_cost_outer,
	determine_use_iv_cost): Return whether the use can be expressed by
	the candidate.
	(determine_use_iv_costs): Prune useless candidates from relate_cands
	bitmaps.
	(find_best_candidate, set_cost_up_to, set_cost): Removed.
	(cheaper_cost_pair, iv_ca_recount_cost, iv_ca_set_no_cp,
	iv_ca_set_cp, iv_ca_add_use, iv_ca_cost, iv_ca_has_deps,
	iv_ca_delta_add, iv_ca_cand_for_use, iv_ca_delta_commit,
	iv_ca_cand_used_p, iv_ca_delta_free, iv_ca_new, iv_ca_free,
	iv_ca_dump, iv_ca_extend, iv_ca_narrow): New functions.
	(try_add_cand_for, get_initial_solution, try_improve_iv_set,
	find_optimal_iv_set, create_new_ivs, tree_ssa_iv_optimize_loop):
	Use new iv set representation.
	(free_loop_data): clear important_candidates bitmap.
	(tree_ssa_iv_optimize_finalize): Free important_candidates bitmap.

From-SVN: r90306