* Makefile.in (tree-data-ref.o): Add langhooks.h dependency.
	* tree-ssa-loop-niter.c (derive_constant_upper_bound):  Follow
	ud-chains.  Handle AND_EXPR.
	(record_estimate): Record whether the estimate is realistic
	and whether it is derived from a loop exit.
	(record_nonwrapping_iv, idx_infer_loop_bounds, infer_loop_bounds_from_ref,
	infer_loop_bounds_from_array, infer_loop_bounds_from_signedness): New
	functions.
	(compute_estimated_nb_iterations): Take only realistic bounds into
	account.  Set estimate_state.  Use double_ints.
	(infer_loop_bounds_from_undefined): Call infer_loop_bounds_from_array
	and infer_loop_bounds_from_signedness.  Do not consider basic blocks
	that do not have to be always executed.
	(estimate_numbers_of_iterations_loop): Set estimate_state, and use it
	to determine whether to call infer_loop_bounds_from_undefined
	and compute_estimated_nb_iterations.
	(n_of_executions_at_most): Use double_ints.
	(free_numbers_of_iterations_estimates_loop): Set estimate_state.
	(substitute_in_loop_info): Do not replace in estimated_nb_iterations.
	* double-int.c (double_int_to_tree): Improve comment.
	(double_int_fits_to_tree_p): New function.
	* double-int.h (double_int_fits_to_tree_p): Declare.
	* tree-data-ref.c: Include langhooks.h.
	(estimate_niter_from_size_of_data, estimate_iters_using_array): Removed.
	(analyze_array_indexes): Do not call estimate_niter_from_size_of_data.
	(analyze_array): Do not pass estimate_only argument to
	analyze_array_indexes.
	(get_number_of_iters_for_loop): Build tree from the stored double_int
	value.
	(get_references_in_stmt, find_data_references_in_stmt): New functions.
	(find_data_references_in_loop): Use find_data_references_in_stmt.
	* tree-data-ref.h (struct data_ref_loc_d): New.
	(get_references_in_stmt): Declare.
	(estimate_iters_using_array): Declaration removed.
	* cfgloop.h (struct nb_iter_bound): Change type of bound to
	double_int.  Improve comments.  Add is_exit and realistic
	fields.
	(struct loop): Changed type of estimated_nb_iterations to double_int.
	Added estimate_state field.
	(record_estimate): Declaration removed.

From-SVN: r118729