Re: [patch] for PR 18316 (updated)

[Richard Guenther <richard dot guenther at gmail dot com>]

On 4/22/05, Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> wrote:
> Hello, 
>
>         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.

build_fold_addr_expr?

>         (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.