* tree-data-ref.c: Rename DDR_SIZE_VECT to DDR_NB_LOOPS.
	(subscript_dependence_tester_1): Declared.
	(print_dir_vectors, print_dist_vectors): New.
	(debug_data_dependence_relation): New.
	(dump_data_dependence_relation): Print more details.
	(initialize_data_dependence_relation): Initialize DDR_LOOP_NEST.
	(analyze_subscript_affine_affine): Don't ICE when gcd_alpha_beta is 0.
	(save_dist_v, save_dir_v, add_outer_distances,
	build_classic_dist_vector_1): New.
	(build_classic_dist_vector): Rewrite to work on DDR_LOOP_NEST.
	Don't test for lambda_vector_lexico_pos.
	(same_access_functions, add_multivariate_self_dist,
	add_other_self_distances, dir_from_dist): New.
	(build_classic_dir_vector): Replace implementation almost identical to 
	build_classic_dist_vector with a walk of DDR_DIST_VECTS with a call to
	dir_from_dist.
	(subscript_dependence_tester_1): New.
	(subscript_dependence_tester): Handle the lexicographically negative
	distance vectors by recomputing the dependence relation.
	(compute_affine_dependence): Remove parameter loop_nest_depth.
	(compute_self_dependence): Don't call compute_subscript_distance.
	(compute_all_dependences): Remove parameters nb_loops, loop_nest_depth.
	Add a parameter for the loop_nest.
	(find_loop_nest_1, find_loop_nest): New.
	(compute_data_dependences_for_loop): Compute the loop nest, and give
	up if the nest is not well formed.
	* tree-data-ref.h (loop_p): New.
	(struct data_dependence_relation): Replace size_vect field with 
	loop_nest, a vec of loops.
	(DDR_SIZE_VECT): Renamed DDR_NB_LOOPS.
	(DDR_LOOP_NEST): New.
	(print_dir_vectors, print_dist_vectors,
	debug_data_dependence_relation): Declared.
	(index_in_loop_nest): New.
	* tree-vect-analyze.c (vect_analyze_data_ref_dependence): Use
	DDR_LOOP_NEST and index_in_loop_nest to determine the dependence
	distance.

From-SVN: r112399