X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fcfopt.c;h=be03bfad64181658cfd6db7625f869410fb28301;hb=65220b7e75f02562c05ea53f2e31556e23ef9b11;hp=6fa73c7bfa20c2ae983c0e85166d16ab5796ba13;hpb=1ec30d95387eb392ba5a1adc7958ebd91383d59c;p=libfirm

diff --git a/ir/opt/cfopt.c b/ir/opt/cfopt.c
index 6fa73c7bf..be03bfad6 100644
--- a/ir/opt/cfopt.c
+++ b/ir/opt/cfopt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -62,6 +62,8 @@
 /* is empty if it contains only a Jmp node.                         */
 /* Blocks can only be removed if they are not needed for the        */
 /* semantics of Phi nodes.                                          */
+/* Further, we NEVER remove labeled blocks (even if we could move   */
+/* the label.                                                       */
 /*------------------------------------------------------------------*/
 
 /**
@@ -185,7 +187,6 @@ static void merge_blocks(ir_node *node, void *ctx) {
 	}
 }
 
-
 /**
  * Block walker removing control flow from dead block by
  * inspecting dominance info.
@@ -226,10 +227,14 @@ static void collect_nodes(ir_node *n, void *ctx) {
 	ir_op *op = get_irn_op(n);
 	merge_env *env = ctx;
 
-	if (op != op_Block) {
+	if (op == op_Block) {
+		/* mark the block as non-empty if it is labeled */
+		if (has_Block_label(n))
+			mark_Block_block_visited(n);
+	} else {
 		ir_node *b  = get_nodes_block(n);
 
-		if (op == op_Phi) {
+		if (op == op_Phi && get_irn_arity(n) > 0) {
 			/* Collect Phi nodes to compact ins along with block's ins. */
 			set_irn_link(n, get_irn_link(b));
 			set_irn_link(b, n);
@@ -308,7 +313,7 @@ static int test_whether_dispensable(ir_node *b, int pos) {
 		}
 
 		/* Seems to be empty. At least we detected this in collect_nodes. */
-		if (!get_irn_link(b)) {
+		if (get_irn_link(b) == NULL) {
 			/* There are no Phi nodes ==> all predecessors are dispensable. */
 			n_preds = get_Block_n_cfgpreds(pred);
 		} else {
@@ -772,7 +777,7 @@ void optimize_cf(ir_graph *irg) {
 
 	/* in rare cases a node may be kept alive more than once, use the visited flag to detect this */
 	inc_irg_visited(irg);
-	set_using_visited(irg);
+	set_using_irn_visited(irg);
 
 	/* fix the keep alive */
 	for (i = j = 0; i < n; i++) {
@@ -805,7 +810,7 @@ void optimize_cf(ir_graph *irg) {
 		env.changed = 1;
 	}
 
-	clear_using_visited(irg);
+	clear_using_irn_visited(irg);
 
 	if (env.phis_moved) {
 		/* Bad: when we moved Phi's, we might produce dead Phi nodes