* tree-ssa-loop-niter.c (record_estimate): Add "upper" argument.
Update constant estimates of number of iterations.
(record_nonwrapping_iv): Add "upper" argument. "data_size_bounds_p"
argument renamed to "realistic".
(compute_estimated_nb_iterations): Removed.
(record_niter_bound): New function.
(idx_infer_loop_bounds): For possible but unlikely tail arrays,
call record_nonwrapping_iv with upper = false.
(infer_loop_bounds_from_signedness): Pass upper argument to
record_nonwrapping_iv.
(estimate_numbers_of_iterations_loop): Do not call
compute_estimated_nb_iterations. Record estimate based on profile
information. Initialize the constant estimates of number of
iterations.
* tree-data-ref.c (estimated_loop_iterations): Return the recorded
estimates.
* tree-ssa-loop-prefetch.c (loop_prefetch_arrays): Add dump when
number of iterations is too small.
* cfgloop.h (struct nb_iter_bound): Remove "realistic" field.
(EST_NOT_AVAILABLE): Removed.
(struct loop): Replace estimated_nb_iterations by any_upper_bound,
nb_iterations_upper_bound, any_estimate and nb_iterations_estimate
fields.