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, 7 insertions, 9 deletions

diff --git a/gcc/tree-eh.cc b/gcc/tree-eh.cc
index 41cf57d..425323f 100644
--- a/gcc/tree-eh.cc
+++ b/gcc/tree-eh.cc
@@ -2319,7 +2319,7 @@ redirect_eh_edge_1 (edge edge_in, basic_block new_bb, bool change_region)
   gcc_assert (old_lp_nr > 0);
   old_lp = get_eh_landing_pad_from_number (old_lp_nr);
 
-  throw_stmt = last_stmt (edge_in->src);
+  throw_stmt = *gsi_last_bb (edge_in->src);
   gcc_checking_assert (lookup_stmt_eh_lp (throw_stmt) == old_lp_nr);
 
   new_label = gimple_block_label (new_bb);
@@ -3515,11 +3515,9 @@ pass_lower_resx::execute (function *fun)
 
   FOR_EACH_BB_FN (bb, fun)
     {
-      gimple *last = last_stmt (bb);
-      if (last && is_gimple_resx (last))
+      if (gresx *last = safe_dyn_cast <gresx *> (*gsi_last_bb (bb)))
 	{
-	  dominance_invalidated |=
-	    lower_resx (bb, as_a <gresx *> (last), &mnt_map);
+	  dominance_invalidated |= lower_resx (bb, last, &mnt_map);
 	  any_rewritten = true;
 	}
     }
@@ -3944,7 +3942,7 @@ pass_lower_eh_dispatch::execute (function *fun)
 
   FOR_EACH_BB_FN (bb, fun)
     {
-      gimple *last = last_stmt (bb);
+      gimple *last = *gsi_last_bb (bb);
       if (last == NULL)
 	continue;
       if (gimple_code (last) == GIMPLE_EH_DISPATCH)
@@ -3979,7 +3977,7 @@ pass_lower_eh_dispatch::execute (function *fun)
       for (int i = 0; i < rpo_n; ++i)
 	{
 	  bb = BASIC_BLOCK_FOR_FN (fun, rpo[i]);
-	  gimple *last = last_stmt (bb);
+	  gimple *last = *gsi_last_bb (bb);
 	  if (last
 	      && gimple_code (last) == GIMPLE_RESX
 	      && !stmt_can_throw_external (fun, last))
@@ -4705,7 +4703,7 @@ cleanup_empty_eh (eh_landing_pad lp)
       for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
 	if (e->flags & EDGE_EH)
 	  {
-	    gimple *stmt = last_stmt (e->src);
+	    gimple *stmt = *gsi_last_bb (e->src);
 	    remove_stmt_from_eh_lp (stmt);
 	    remove_edge (e);
 	  }
@@ -4721,7 +4719,7 @@ cleanup_empty_eh (eh_landing_pad lp)
       for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
 	if (e->flags & EDGE_EH)
 	  {
-	    gimple *stmt = last_stmt (e->src);
+	    gimple *stmt = *gsi_last_bb (e->src);
 	    remove_stmt_from_eh_lp (stmt);
 	    add_stmt_to_eh_lp (stmt, new_lp_nr);
 	    remove_edge (e);