X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fcfopt.c;h=b455993b55875f7bb8bbbeed69db3784dd53d8f4;hb=1d523ad26cd541494c1e6cd8dc4b0736f0adc2cf;hp=7ed73c20d0cd15b83d8e5b62cf697461cbd39e9e;hpb=f8cc15664f571aa7ef89d6f6bc8d5bd2b8ca7d53;p=libfirm

diff --git a/ir/opt/cfopt.c b/ir/opt/cfopt.c
index 7ed73c20d..b455993b5 100644
--- a/ir/opt/cfopt.c
+++ b/ir/opt/cfopt.c
@@ -114,7 +114,7 @@ static void collect_nodes(ir_node *n, void *ctx)
 		ir_node *block = get_nodes_block(n);
 		add_Block_phi(block, n);
 	} else if (is_Block(n)) {
-		if (has_Block_entity(n)) {
+		if (get_Block_entity(n) != NULL) {
 			/* block with a jump label attached cannot be removed. */
 			set_Block_removable(n, false);
 		}
@@ -234,6 +234,26 @@ non_dispensable:
 	return 1;
 }
 
+/**
+ * This method merges blocks. A block is applicable to be merged, if it
+ * has only one predecessor with an unconditional jump to this block;
+ * and if this block does not contain any phis.
+ */
+static void merge_blocks(ir_node *b, void *env)
+{
+	(void) env;
+
+	if (get_Block_n_cfgpreds(b) == 1) {
+		ir_node* pred = get_Block_cfgpred(b, 0);
+		if (is_Jmp(pred)) {
+			ir_node* pred_block = get_nodes_block(pred);
+			if (get_Block_phis(b) == NULL) {
+				exchange(b, pred_block);
+			}
+		}
+	}
+}
+
 /**
  * This method removes empty blocks.  A block is empty if it only contains Phi
  * and Jmp nodes.
@@ -861,7 +881,7 @@ static ir_graph_state_t do_cfopt(ir_graph *irg)
 	 * blocks, which it finds in a linked list computed before.
 	 * */
 	assure_doms(irg);
-	irg_block_walk_graph(irg, optimize_blocks, NULL, &env);
+	irg_block_walk_graph(irg, optimize_blocks, merge_blocks, &env);
 
 	new_end = optimize_in_place(end);
 	if (new_end != end) {