From 9be872b77ba83e579598a983ca71aab58ded4dc6 Mon Sep 17 00:00:00 2001 From: Zdenek Dvorak Date: Sun, 1 May 2005 10:08:14 +0200 Subject: re PR tree-optimization/18316 (Missed IV optimization) 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 --- gcc/tree-scalar-evolution.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'gcc/tree-scalar-evolution.c') diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index ca80893..c923409 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -2547,10 +2547,13 @@ scev_reset (void) } /* Checks whether OP behaves as a simple affine iv of LOOP in STMT and returns - its BASE and STEP if possible. */ + its BASE and STEP if possible. If ALLOW_NONCONSTANT_STEP is true, we + want STEP to be invariant in LOOP. Otherwise we require it to be an + integer constant. */ bool -simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step) +simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step, + bool allow_nonconstant_step) { basic_block bb = bb_for_stmt (stmt); tree type, ev; @@ -2579,8 +2582,15 @@ simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step) return false; *step = CHREC_RIGHT (ev); - if (TREE_CODE (*step) != INTEGER_CST) + if (allow_nonconstant_step) + { + if (tree_contains_chrecs (*step, NULL) + || chrec_contains_symbols_defined_in_loop (*step, loop->num)) + return false; + } + else if (TREE_CODE (*step) != INTEGER_CST) return false; + *base = CHREC_LEFT (ev); if (tree_contains_chrecs (*base, NULL) || chrec_contains_symbols_defined_in_loop (*base, loop->num)) -- cgit v1.1