X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firgopt.c;h=a4c454bda5d9760184731b7dce02efca95f6ca57;hb=6f068af98daa4725d60e5d23a8f98ec2841cfa44;hp=9c0612360b83b812672e0983b08c386bcb5d416d;hpb=15ad7ccd8dff64e1808e1d093d4a8d7cda5af33e;p=libfirm

diff --git a/ir/ir/irgopt.c b/ir/ir/irgopt.c
index 9c0612360..a4c454bda 100644
--- a/ir/ir/irgopt.c
+++ b/ir/ir/irgopt.c
@@ -100,19 +100,44 @@ void local_optimize_node(ir_node *n)
 	current_ir_graph = rem;
 }
 
+/**
+ * Enqueue all users of a node to a wait queue.
+ * Handles mode_T nodes.
+ */
+static void enqueue_users(ir_node *n, pdeq *waitq)
+{
+	const ir_edge_t *edge;
+
+	foreach_out_edge(n, edge) {
+		ir_node *succ = get_edge_src_irn(edge);
+
+		if (get_irn_link(succ) != waitq) {
+			pdeq_putr(waitq, succ);
+			set_irn_link(succ, waitq);
+		}
+		if (get_irn_mode(succ) == mode_T) {
+		/* A mode_T node has Proj's. Because most optimizations
+			run on the Proj's we have to enqueue them also. */
+			enqueue_users(succ, waitq);
+		}
+	}
+}
+
 /**
  * Block-Walker: uses dominance depth to mark dead blocks.
  */
 static void kill_dead_blocks(ir_node *block, void *env)
 {
-	(void) env;
+	pdeq *waitq = (pdeq*) env;
 
 	if (get_Block_dom_depth(block) < 0) {
 		/*
 		 * Note that the new dominance code correctly handles
 		 * the End block, i.e. it is always reachable from Start
 		 */
-		set_Block_dead(block);
+		ir_graph *irg = get_irn_irg(block);
+		enqueue_users(block, waitq);
+		exchange(block, new_r_Bad(irg, mode_BB));
 	}
 }
 
@@ -122,37 +147,11 @@ void local_optimize_graph(ir_graph *irg)
 	ir_graph *rem = current_ir_graph;
 	current_ir_graph = irg;
 
-	if (get_irg_dom_state(irg) == dom_consistent)
-		irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
-
 	do_local_optimize(get_irg_end(irg));
 
 	current_ir_graph = rem;
 }
 
-/**
- * Enqueue all users of a node to a wait queue.
- * Handles mode_T nodes.
- */
-static void enqueue_users(ir_node *n, pdeq *waitq)
-{
-	const ir_edge_t *edge;
-
-	foreach_out_edge(n, edge) {
-		ir_node *succ = get_edge_src_irn(edge);
-
-		if (get_irn_link(succ) != waitq) {
-			pdeq_putr(waitq, succ);
-			set_irn_link(succ, waitq);
-		}
-		if (get_irn_mode(succ) == mode_T) {
-		/* A mode_T node has Proj's. Because most optimizations
-			run on the Proj's we have to enqueue them also. */
-			enqueue_users(succ, waitq);
-		}
-	}
-}
-
 /**
  * Data flow optimization walker.
  * Optimizes all nodes and enqueue its users
@@ -184,14 +183,16 @@ int optimize_graph_df(ir_graph *irg)
 
 	state = edges_assure(irg);
 
-	if (get_opt_global_cse())
-		set_irg_pinned(irg, op_pin_state_floats);
-
 	/* Clean the value_table in irg for the CSE. */
 	new_identities(irg);
 
-	if (get_irg_dom_state(irg) == dom_consistent)
-		irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
+	if (get_opt_global_cse()) {
+		set_irg_pinned(irg, op_pin_state_floats);
+	}
+
+	/* The following enables unreachable code elimination (=Blocks may be
+	 * Bad). */
+	set_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK);
 
 	/* invalidate info */
 	set_irg_outs_inconsistent(irg);
@@ -207,12 +208,17 @@ int optimize_graph_df(ir_graph *irg)
 	 * so if it's not empty, the graph has been changed */
 	changed = !pdeq_empty(waitq);
 
-	/* finish the wait queue */
-	while (! pdeq_empty(waitq)) {
-		ir_node *n = (ir_node*)pdeq_getl(waitq);
-		if (! is_Bad(n))
+	do {
+		/* finish the wait queue */
+		while (! pdeq_empty(waitq)) {
+			ir_node *n = (ir_node*)pdeq_getl(waitq);
 			opt_walker(n, waitq);
-	}
+		}
+		/* kill newly generated unreachable code */
+		set_irg_outs_inconsistent(irg);
+		compute_doms(irg);
+		irg_block_walk_graph(irg, NULL, kill_dead_blocks, waitq);
+	} while (! pdeq_empty(waitq));
 
 	del_pdeq(waitq);
 
@@ -223,9 +229,11 @@ int optimize_graph_df(ir_graph *irg)
 
 	/* Finally kill BAD and doublets from the keep alives.
 	   Doing this AFTER edges where deactivated saves cycles */
-	end  = get_irg_end(irg);
+	end = get_irg_end(irg);
 	remove_End_Bads_and_doublets(end);
 
+	clear_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK);
+
 	current_ir_graph = rem;
 	return changed;
 }