More last_stmt removal

This adjusts more users of last_stmt where it is clear that debug
stmt skipping is unnecessary.  In most cases this also allowed
significant code simplification.

	gcc/c/
	* gimple-parser.cc (c_parser_parse_gimple_body): Avoid
	last_stmt.

	gcc/
	* gimple-range-path.cc (path_range_query::compute_outgoing_relations):
	Avoid last_stmt.
	* ipa-pure-const.cc (pass_nothrow::execute): Likewise.
	* predict.cc (apply_return_prediction): Likewise.
	* sese.cc (set_ifsese_condition): Likewise.  Simplify.
	* tree-cfg.cc (assert_unreachable_fallthru_edge_p): Avoid last_stmt.
	(make_edges_bb): Likewise.
	(make_cond_expr_edges): Likewise.
	(end_recording_case_labels): Likewise.
	(make_gimple_asm_edges): Likewise.
	(cleanup_dead_labels): Likewise.
	(group_case_labels): Likewise.
	(gimple_can_merge_blocks_p): Likewise.
	(gimple_merge_blocks): Likewise.
	(find_taken_edge): Likewise.  Also handle empty fallthru blocks.
	(gimple_duplicate_sese_tail): Avoid last_stmt.
	(find_loop_dist_alias): Likewise.
	(gimple_block_ends_with_condjump_p): Likewise.
	(gimple_purge_dead_eh_edges): Likewise.
	(gimple_purge_dead_abnormal_call_edges): Likewise.
	(pass_warn_function_return::execute): Likewise.
	(execute_fixup_cfg): Likewise.
	* tree-eh.cc (redirect_eh_edge_1): Likewise.
	(pass_lower_resx::execute): Likewise.
	(pass_lower_eh_dispatch::execute): Likewise.
	(cleanup_empty_eh): Likewise.
	* tree-if-conv.cc (if_convertible_bb_p): Likewise.
	(predicate_bbs): Likewise.
	(ifcvt_split_critical_edges): Likewise.
	* tree-loop-distribution.cc (create_edge_for_control_dependence):
	Likewise.
	(loop_distribution::transform_reduction_loop): Likewise.
	* tree-parloops.cc (transform_to_exit_first_loop_alt): Likewise.
	(try_transform_to_exit_first_loop_alt): Likewise.
	(transform_to_exit_first_loop): Likewise.
	(create_parallel_loop): Likewise.
	* tree-scalar-evolution.cc (get_loop_exit_condition): Likewise.
	* tree-ssa-dce.cc (mark_last_stmt_necessary): Likewise.
	(eliminate_unnecessary_stmts): Likewise.
	* tree-ssa-dom.cc
	(dom_opt_dom_walker::set_global_ranges_from_unreachable_edges):
	Likewise.
	* tree-ssa-ifcombine.cc (ifcombine_ifandif): Likewise.
	(pass_tree_ifcombine::execute): Likewise.
	* tree-ssa-loop-ch.cc (entry_loop_condition_is_static): Likewise.
	(should_duplicate_loop_header_p): Likewise.
	* tree-ssa-loop-ivcanon.cc (create_canonical_iv): Likewise.
	(tree_estimate_loop_size): Likewise.
	(try_unroll_loop_completely): Likewise.
	* tree-ssa-loop-ivopts.cc (tree_ssa_iv_optimize_loop): Likewise.
	* tree-ssa-loop-manip.cc (ip_normal_pos): Likewise.
	(canonicalize_loop_ivs): Likewise.
	* tree-ssa-loop-niter.cc (determine_value_range): Likewise.
	(bound_difference): Likewise.
	(number_of_iterations_popcount): Likewise.
	(number_of_iterations_cltz): Likewise.
	(number_of_iterations_cltz_complement): Likewise.
	(simplify_using_initial_conditions): Likewise.
	(number_of_iterations_exit_assumptions): Likewise.
	(loop_niter_by_eval): Likewise.
	(estimate_numbers_of_iterations): Likewise.

1 files changed, 2 insertions, 5 deletions

diff --git a/gcc/tree-ssa-loop-manip.cc b/gcc/tree-ssa-loop-manip.cc
index a52277a..909b705 100644
--- a/gcc/tree-ssa-loop-manip.cc
+++ b/gcc/tree-ssa-loop-manip.cc
@@ -768,7 +768,6 @@ ip_end_pos (class loop *loop)
 basic_block
 ip_normal_pos (class loop *loop)
 {
-  gimple *last;
   basic_block bb;
   edge exit;
 
@@ -776,9 +775,7 @@ ip_normal_pos (class loop *loop)
     return NULL;
 
   bb = single_pred (loop->latch);
-  last = last_stmt (bb);
-  if (!last
-      || gimple_code (last) != GIMPLE_COND)
+  if (!safe_is_a <gcond *> (*gsi_last_bb (bb)))
     return NULL;
 
   exit = EDGE_SUCC (bb, 0);
@@ -1588,7 +1585,7 @@ canonicalize_loop_ivs (class loop *loop, tree *nit, bool bump_in_latch)
 
   rewrite_all_phi_nodes_with_iv (loop, var_before);
 
-  stmt = as_a <gcond *> (last_stmt (exit->src));
+  stmt = as_a <gcond *> (*gsi_last_bb (exit->src));
   /* Make the loop exit if the control condition is not satisfied.  */
   if (exit->flags & EDGE_TRUE_VALUE)
     {