PR tree-optimization/18316
PR tree-optimization/19126
* tree.c (build_int_cst_type): Avoid shift by size of type.
* tree-scalar-evolution.c (simple_iv): Add allow_nonconstant_step
argument.
* tree-scalar-evolution.h (simple_iv): Declaration changed.
* tree-ssa-loop-ivopts.c (struct iv_cand): Add depends_on
field.
(dump_cand): Dump depends_on information.
(determine_biv_step): Add argument to simple_iv call.
(contains_abnormal_ssa_name_p): Handle case expr == NULL.
(find_bivs, find_givs_in_stmt_scev): Do not require step to be a
constant.
(add_candidate_1): Record depends_on for candidates.
(tree_int_cst_sign_bit, constant_multiple_of): New functions.
(get_computation_at, get_computation_cost_at, may_eliminate_iv):
Handle ivs with nonconstant step.
(iv_ca_set_remove_invariants, iv_ca_set_add_invariants): New functions.
(iv_ca_set_no_cp, iv_ca_set_cp): Handle cand->depends_on.
(create_new_iv): Unshare the step before passing it to create_iv.
(free_loop_data): Free cand->depends_on.
(build_addr_strip_iref): New function.
(find_interesting_uses_address): Use build_addr_strip_iref.
(strip_offset_1): Split the recursive part from strip_offset.
Strip constant offset component_refs and array_refs.
(strip_offset): Split the recursive part to strip_offset_1.
(add_address_candidates): Removed.
(add_derived_ivs_candidates): Do not use add_address_candidates.
(add_iv_value_candidates): Add candidates with stripped constant
offset. Consider all candidates with initial value 0 important.
(struct affine_tree_combination): New.
(aff_combination_const, aff_combination_elt, aff_combination_scale,
aff_combination_add_elt, aff_combination_add,
tree_to_aff_combination, add_elt_to_tree, aff_combination_to_tree,
fold_affine_sum): New functions.
(get_computation_at): Use fold_affine_sum.
* tree-ssa-loop-manip.c (create_iv): Handle ivs with nonconstant step.
* tree-ssa-loop-niter.c (number_of_iterations_exit): Add argument
to simple_iv call.
* gcc.dg/tree-ssa/loop-8.c: New test.
From-SVN: r99059
