--- a/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/constopt/ConstantTree.java	Tue Apr 14 11:36:54 2015 -0700
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/constopt/ConstantTree.java	Tue Apr 14 11:37:00 2015 -0700
@@ -161,7 +161,11 @@
     }
 
     public void markBlocks() {
-        stream(Flags.USAGE).forEach(block -> setDominatorPath(Flags.SUBTREE, block));
+        for (AbstractBlockBase<?> block : getBlocks()) {
+            if (get(Flags.USAGE, block)) {
+                setDominatorPath(Flags.SUBTREE, block);
+            }
+        }
     }
 
     public boolean isMarked(AbstractBlockBase<?> block) {
@@ -169,7 +173,12 @@
     }
 
     public boolean isLeafBlock(AbstractBlockBase<?> block) {
-        return block.getDominated().stream().noneMatch(this::isMarked);
+        for (AbstractBlockBase<?> dom : block.getDominated()) {
+            if (isMarked(dom)) {
+                return false;
+            }
+        }
+        return true;
     }
 
     public void setSolution(AbstractBlockBase<?> block) {