Mercurial > hg > truffle

changeset 5203:09e87f5b81e4

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix potential KillCFG problem Handle VirtualObjectField and VirtualObject better in killCFG
author Gilles Duboscq <duboscq@ssw.jku.at>
date Fri, 06 Apr 2012 15:44:15 +0200
parents 450af990078f
children 0a53ed842cb8
files graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/util/GraphUtil.java
diffstat 1 files changed, 16 insertions(+), 5 deletions(-) [+]
line wrap: on
line diff
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/util/GraphUtil.java	Fri Apr 06 15:23:58 2012 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/util/GraphUtil.java	Fri Apr 06 15:44:15 2012 +0200
@@ -27,8 +27,10 @@
 import java.util.*;
 
 import com.oracle.graal.graph.*;
+import com.oracle.graal.graph.iterators.*;
 import com.oracle.graal.nodes.*;
 import com.oracle.graal.nodes.calc.*;
+import com.oracle.graal.nodes.virtual.*;
 
 public class GraphUtil {
 
@@ -40,7 +42,11 @@
             killEnd(end);
         } else {
             // Normal control flow node.
-            for (Node successor : node.successors().snapshot()) {
+            /* We do not take a successor snapshot because this iterator supports concurrent modifications
+             * as long as they do not change the size of the successor list. Not tasking a snapshot allows
+             * us to see modifications to other branches that may happen while processing one branch.
+             */
+            for (Node successor : node.successors()) {
                 killCFG((FixedNode) successor);
             }
         }
@@ -50,6 +56,7 @@
     private static void killEnd(EndNode end) {
         MergeNode merge = end.merge();
         merge.removeEnd(end);
+        StructuredGraph graph = (StructuredGraph) end.graph();
         if (merge instanceof LoopBeginNode && merge.forwardEndCount() == 0) { //dead loop
             for (PhiNode phi : merge.phis().snapshot()) {
                 propagateKill(phi);
@@ -63,15 +70,19 @@
             killCFG(begin.next());
             begin.safeDelete();
         } else if (merge instanceof LoopBeginNode && ((LoopBeginNode) merge).loopEnds().isEmpty()) { // not a loop anymore
-            ((StructuredGraph) end.graph()).reduceDegenerateLoopBegin((LoopBeginNode) merge);
+            graph.reduceDegenerateLoopBegin((LoopBeginNode) merge);
         } else if (merge.phiPredecessorCount() == 1) { // not a merge anymore
-            ((StructuredGraph) end.graph()).reduceTrivialMerge(merge);
+            graph.reduceTrivialMerge(merge);
         }
     }
 
+    public static NodePredicate isFloatingNode() {
+        return isA(FloatingNode.class).or(CallTargetNode.class).or(FrameState.class).or(VirtualObjectFieldNode.class).or(VirtualObjectNode.class);
+    }
+
     public static void propagateKill(Node node) {
         if (node != null && node.isAlive()) {
-            List<Node> usagesSnapshot = node.usages().filter(isA(FloatingNode.class).or(CallTargetNode.class).or(FrameState.class)).snapshot();
+            List<Node> usagesSnapshot = node.usages().filter(isFloatingNode()).snapshot();
 
             // null out remaining usages
             node.replaceAtUsages(null);
@@ -91,7 +102,7 @@
     }
 
     public static void killUnusedFloatingInputs(Node node) {
-        List<Node> floatingInputs = node.inputs().filter(isA(FloatingNode.class).or(CallTargetNode.class).or(FrameState.class)).snapshot();
+        List<Node> floatingInputs = node.inputs().filter(isFloatingNode()).snapshot();
         node.safeDelete();
 
         for (Node in : floatingInputs) {