--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/GraalCompiler.java	Wed May 09 10:43:05 2012 +0200
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/GraalCompiler.java	Wed May 09 12:10:35 2012 +0200
@@ -172,6 +172,9 @@
         new LoweringPhase(runtime).apply(graph);
         new CanonicalizerPhase(target, runtime, assumptions, true, null).apply(graph);
 
+        if (GraalOptions.CullFrameStates) {
+            new CullFrameStatesPhase().apply(graph);
+        }
         if (GraalOptions.Lower) {
             new FloatingReadPhase().apply(graph);
             if (GraalOptions.OptGVN) {

--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/GraalOptions.java	Wed May 09 10:43:05 2012 +0200
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/GraalOptions.java	Wed May 09 12:10:35 2012 +0200
@@ -164,6 +164,7 @@
 
     // Code generator settings
     public static boolean PropagateTypes                     = ____;
+    public static boolean CullFrameStates                    = true;
     public static boolean UseProfilingInformation            = true;
            static boolean RemoveNeverExecutedCode            = true;
            static boolean UseExceptionProbability            = true;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/CullFrameStatesPhase.java	Wed May 09 12:10:35 2012 +0200
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.graal.compiler.phases;
+
+import java.util.*;
+
+import com.oracle.graal.compiler.graph.*;
+import com.oracle.graal.debug.*;
+import com.oracle.graal.nodes.*;
+import com.oracle.graal.nodes.util.*;
+
+/**
+ * This phase culls unused FrameStates from the graph.
+ * It does a post order iteration over the graph, and
+ */
+public class CullFrameStatesPhase extends Phase {
+
+    private static final DebugMetric metricFrameStatesCulled = Debug.metric("FrameStatesCulled");
+    private static final DebugMetric metricMergesTraversed = Debug.metric("MergesTraversed");
+
+    @Override
+    protected void run(StructuredGraph graph) {
+        new CullFrameStates(graph.start(), new State(null)).apply();
+    }
+
+    public static class State implements MergeableState<State> {
+
+        private FrameState lastFrameState;
+
+        public State(FrameState lastFrameState) {
+            this.lastFrameState = lastFrameState;
+        }
+
+        @Override
+        public boolean merge(MergeNode merge, List<State> withStates) {
+            FrameState stateAfter = merge.stateAfter();
+            if (merge instanceof LoopBeginNode) {
+                if (stateAfter != null) {
+                    lastFrameState = stateAfter;
+                }
+                return true;
+            }
+            metricMergesTraversed.increment();
+            if (stateAfter != null) {
+                for (State other : withStates) {
+                    if (other.lastFrameState != lastFrameState) {
+                        lastFrameState = stateAfter;
+                        return true;
+                    }
+                }
+                metricFrameStatesCulled.increment();
+                merge.setStateAfter(null);
+                if (stateAfter.usages().isEmpty()) {
+                    GraphUtil.killWithUnusedFloatingInputs(stateAfter);
+                }
+            }
+            return true;
+        }
+
+        @Override
+        public void loopBegin(LoopBeginNode loopBegin) {
+        }
+
+        @Override
+        public void loopEnds(LoopBeginNode loopBegin, List<State> loopEndStates) {
+        }
+
+        @Override
+        public void afterSplit(FixedNode node) {
+        }
+
+        @Override
+        public State clone() {
+            return new State(lastFrameState);
+        }
+    }
+
+    public static class CullFrameStates extends PostOrderNodeIterator<State> {
+
+        public CullFrameStates(FixedNode start, State initialState) {
+            super(start, initialState);
+        }
+
+        @Override
+        protected void node(FixedNode node) {
+            if (node instanceof StateSplit) {
+                FrameState stateAfter = ((StateSplit) node).stateAfter();
+                if (stateAfter != null) {
+                    state.lastFrameState = stateAfter;
+                }
+            }
+        }
+    }
+
+}

--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/InliningPhase.java	Wed May 09 10:43:05 2012 +0200
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/InliningPhase.java	Wed May 09 12:10:35 2012 +0200
@@ -209,6 +209,9 @@
                 if (GraalOptions.Intrinsify) {
                     new IntrinsificationPhase(runtime).apply(newGraph);
                 }
+                if (GraalOptions.CullFrameStates) {
+                    new CullFrameStatesPhase().apply(newGraph);
+                }
                 if (GraalOptions.CacheGraphs && cache != null) {
                     cache.put(newGraph);
                 }