--- a/graal/GraalCompiler/src/com/sun/c1x/gen/LIRGenerator.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/gen/LIRGenerator.java	Thu May 05 16:07:00 2011 +0200
@@ -465,7 +465,7 @@
         CiValue resultOperand = resultOperandFor(x.kind);
         CiCallingConvention cc = compilation.frameMap().getCallingConvention(x.signature(), JavaCall);
         List<CiValue> pointerSlots = new ArrayList<CiValue>(2);
-        List<CiValue> argList = visitInvokeArguments(cc, x.arguments(), pointerSlots);
+        List<CiValue> argList = visitInvokeArguments(cc, x, pointerSlots);
 
         if (C1XOptions.InvokeSnippetAfterArguments) {
             destinationAddress = emitXir(snippet, x, info.copy(), null, x.target(), false, pointerSlots);
@@ -1434,11 +1434,12 @@
         return new LIRDebugInfo(state, x.exceptionHandlers());
     }
 
-    List<CiValue> visitInvokeArguments(CiCallingConvention cc, Value[] args, List<CiValue> pointerSlots) {
+    List<CiValue> visitInvokeArguments(CiCallingConvention cc, Invoke x, List<CiValue> pointerSlots) {
         // for each argument, load it into the correct location
-        List<CiValue> argList = new ArrayList<CiValue>(args.length);
+        List<CiValue> argList = new ArrayList<CiValue>(x.argumentCount());
         int j = 0;
-        for (Value arg : args) {
+        for (int i = 0; i < x.argumentCount(); i++) {
+            Value arg = x.argument(i);
             if (arg != null) {
                 CiValue operand = cc.locations[j++];
                 if (operand.isRegister()) {
@@ -1456,7 +1457,7 @@
                     }
 
                     if (arg.kind == CiKind.Object && pointerSlots != null) {
-                        // This slot must be marked explicitedly in the pointer map.
+                        // This slot must be marked explicitly in the pointer map.
                         pointerSlots.add(slot);
                     }
                 }
@@ -1600,7 +1601,7 @@
 
     private CiValue emitInvokeKnown(RiMethod method, FrameState stateBefore, Value... args) {
         boolean isStatic = Modifier.isStatic(method.accessFlags());
-        Invoke invoke = new Invoke(isStatic ? Bytecodes.INVOKESTATIC : Bytecodes.INVOKESPECIAL, method.signature().returnKind(), args, method, null, stateBefore);
+        Invoke invoke = new Invoke(isStatic ? Bytecodes.INVOKESTATIC : Bytecodes.INVOKESPECIAL, method.signature().returnKind(), args, method, null, stateBefore, null);
         visitInvoke(invoke);
         return invoke.operand();
     }

--- a/graal/GraalCompiler/src/com/sun/c1x/graph/GraphBuilder.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/graph/GraphBuilder.java	Thu May 05 16:07:00 2011 +0200
@@ -901,7 +901,7 @@
 
     private void appendInvoke(int opcode, RiMethod target, Value[] args, int cpi, RiConstantPool constantPool) {
         CiKind resultType = returnKind(target);
-        Value result = append(new Invoke(opcode, resultType.stackKind(), args, target, target.signature().returnType(compilation.method.holder()), null));
+        Value result = append(new Invoke(opcode, resultType.stackKind(), args, target, target.signature().returnType(compilation.method.holder()), null, graph));
         pushReturn(resultType, result);
     }
 
@@ -1021,7 +1021,7 @@
                 lockAddress = new MonitorAddress(lockNumber);
                 append(lockAddress);
             }
-            append(new MonitorExit(rootMethodSynchronizedObject, lockAddress, lockNumber, stateBefore));
+            append(new MonitorExit(rootMethodSynchronizedObject, lockAddress, lockNumber, stateBefore, graph));
             curState.unlock();
         }
         append(new Return(x, !noSafepoints()));
@@ -1041,7 +1041,7 @@
             lockAddress = new MonitorAddress(lockNumber);
             append(lockAddress);
         }
-        MonitorEnter monitorEnter = new MonitorEnter(x, lockAddress, lockNumber, null);
+        MonitorEnter monitorEnter = new MonitorEnter(x, lockAddress, lockNumber, null, graph);
         appendWithoutOptimization(monitorEnter, bci);
         curState.lock(ir, x, lockNumber + 1);
         monitorEnter.setStateAfter(curState.immutableCopy(bci));
@@ -1058,7 +1058,7 @@
             lockAddress = new MonitorAddress(lockNumber);
             append(lockAddress);
         }
-        appendWithoutOptimization(new MonitorExit(x, lockAddress, lockNumber, null), bci);
+        appendWithoutOptimization(new MonitorExit(x, lockAddress, lockNumber, null, graph), bci);
         curState.unlock();
         killMemoryMap(); // prevent any optimizations across synchronization
     }

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/AccessMonitor.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/AccessMonitor.java	Thu May 05 16:07:00 2011 +0200
@@ -22,32 +22,58 @@
  */
 package com.sun.c1x.ir;
 
+import com.oracle.graal.graph.*;
 import com.sun.c1x.value.*;
 import com.sun.cri.ci.*;
 
 /**
  * The {@code AccessMonitor} instruction is the base class of both monitor acquisition and release.
- *
- * @author Ben L. Titzer
  */
 public abstract class AccessMonitor extends StateSplit {
 
-    /**
-     * The object locked or unlocked by this instruction.
-     */
-    private Value object;
+    private static final int INPUT_COUNT = 2;
+    private static final int INPUT_OBJECT = 0;
+    private static final int INPUT_LOCK_ADDRESS = 1;
+
+    private static final int SUCCESSOR_COUNT = 0;
+
+    @Override
+    protected int inputCount() {
+        return super.inputCount() + INPUT_COUNT;
+    }
+
+    @Override
+    protected int successorCount() {
+        return super.successorCount() + SUCCESSOR_COUNT;
+    }
 
     /**
-     * The address of the on-stack lock object or {@code null} if the runtime does not place locks on the stack.
+     * The instruction producing the object locked or unlocked by this instruction.
      */
-    private Value lockAddress;
+     public Value object() {
+        return (Value) inputs().get(super.inputCount() + INPUT_OBJECT);
+    }
+
+    public Value setObject(Value n) {
+        return (Value) inputs().set(super.inputCount() + INPUT_OBJECT, n);
+    }
+
+    /**
+     * The instruction producing the address of the lock object.
+     */
+    public Value lockAddress() {
+        return (Value) inputs().get(super.inputCount() + INPUT_LOCK_ADDRESS);
+    }
+
+    public Value setLockAddress(Value n) {
+        return (Value) inputs().set(super.inputCount() + INPUT_LOCK_ADDRESS, n);
+    }
 
     /**
      * The lock number of this monitor access.
      */
     public final int lockNumber;
 
-
     /**
      * Creates a new AccessMonitor instruction.
      *
@@ -55,33 +81,14 @@
      * @param lockAddress the address of the on-stack lock object or {@code null} if the runtime does not place locks on the stack
      * @param stateBefore the state before executing the monitor operation
      * @param lockNumber the number of the lock being acquired
-     */
-    public AccessMonitor(Value object, Value lockAddress, FrameState stateBefore, int lockNumber) {
-        super(CiKind.Illegal, stateBefore);
-        this.object = object;
-        this.lockAddress = lockAddress;
-        this.lockNumber = lockNumber;
-    }
-
-    /**
-     * Gets the instruction producing the object locked or unlocked by this instruction.
+     * @param inputCount
+     * @param successorCount
+     * @param graph
      */
-    public Value object() {
-        return object;
-    }
-
-    /**
-     * Gets the instruction producing the address of the lock object.
-     */
-    public Value lockAddress() {
-        return lockAddress;
-    }
-
-    @Override
-    public void inputValuesDo(ValueClosure closure) {
-        object = closure.apply(object);
-        if (lockAddress != null) {
-            lockAddress = closure.apply(lockAddress);
-        }
+    public AccessMonitor(Value object, Value lockAddress, FrameState stateBefore, int lockNumber, int inputCount, int successorCount, Graph graph) {
+        super(CiKind.Illegal, stateBefore, inputCount + INPUT_COUNT, successorCount + SUCCESSOR_COUNT, graph);
+        this.lockNumber = lockNumber;
+        setObject(object);
+        setLockAddress(lockAddress);
     }
 }

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/Invoke.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/Invoke.java	Thu May 05 16:07:00 2011 +0200
@@ -22,6 +22,7 @@
  */
 package com.sun.c1x.ir;
 
+import com.oracle.graal.graph.*;
 import com.sun.c1x.debug.*;
 import com.sun.c1x.util.*;
 import com.sun.c1x.value.*;
@@ -34,8 +35,38 @@
  */
 public final class Invoke extends StateSplit {
 
+    private final int argumentCount;
+
+    private static final int SUCCESSOR_COUNT = 0;
+
+    @Override
+    protected int inputCount() {
+        return super.inputCount() + argumentCount;
+    }
+
+    @Override
+    protected int successorCount() {
+        return super.successorCount() + SUCCESSOR_COUNT;
+    }
+
+    /**
+     * The list of instructions that produce input for this instruction.
+     */
+    public Value argument(int index) {
+        assert index >= 0 && index < argumentCount;
+        return (Value) inputs().get(super.inputCount() + index);
+    }
+
+    public Value setArgument(int index, Value n) {
+        assert index >= 0 && index < argumentCount;
+        return (Value) inputs().set(super.inputCount() + index, n);
+    }
+
+    public int argumentCount() {
+        return argumentCount;
+    }
+
     public final int opcode;
-    public final Value[] arguments;
     public final RiMethod target;
     public final RiType returnType;
 
@@ -49,12 +80,16 @@
      * @param target the target method being called
      * @param stateBefore the state before executing the invocation
      */
-    public Invoke(int opcode, CiKind result, Value[] args, RiMethod target, RiType returnType, FrameState stateBefore) {
-        super(result, stateBefore);
+    public Invoke(int opcode, CiKind result, Value[] args, RiMethod target, RiType returnType, FrameState stateBefore, Graph graph) {
+        super(result, stateBefore, args.length, SUCCESSOR_COUNT, graph);
         this.opcode = opcode;
-        this.arguments = args;
         this.target = target;
         this.returnType = returnType;
+
+        this.argumentCount = args.length;
+        for (int i = 0; i < args.length; i++) {
+            setArgument(i, args[i]);
+        }
     }
 
     /**
@@ -85,7 +120,7 @@
      */
     public Value receiver() {
         assert !isStatic();
-        return arguments[0];
+        return argument(0);
     }
 
     /**
@@ -97,14 +132,6 @@
     }
 
     /**
-     * Gets the list of instructions that produce input for this instruction.
-     * @return the list of instructions that produce input
-     */
-    public Value[] arguments() {
-        return arguments;
-    }
-
-    /**
      * Checks whether this invocation has a receiver object.
      * @return {@code true} if this invocation has a receiver object; {@code false} otherwise, if this is a
      *         static call
@@ -114,17 +141,6 @@
     }
 
     @Override
-    public void inputValuesDo(ValueClosure closure) {
-        for (int i = 0; i < arguments.length; i++) {
-            Value arg = arguments[i];
-            if (arg != null) {
-                arguments[i] = closure.apply(arg);
-                assert arguments[i] != null;
-            }
-        }
-    }
-
-    @Override
     public void accept(ValueVisitor v) {
         v.visitInvoke(this);
     }
@@ -144,12 +160,11 @@
 
         RiMethod target = target();
         out.print(target.name()).print('(');
-        Value[] arguments = arguments();
-        for (int i = argStart; i < arguments.length; i++) {
+        for (int i = argStart; i < argumentCount; i++) {
             if (i > argStart) {
                 out.print(", ");
             }
-            out.print(arguments[i]);
+            out.print(argument(i));
         }
         out.print(CiUtil.format(") [method: %H.%n(%p):%r]", target, false));
     }

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/MonitorEnter.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/MonitorEnter.java	Thu May 05 16:07:00 2011 +0200
@@ -22,16 +22,18 @@
  */
 package com.sun.c1x.ir;
 
+import com.oracle.graal.graph.*;
 import com.sun.c1x.debug.*;
 import com.sun.c1x.value.*;
 
 /**
  * The {@code MonitorEnter} instruction represents the acquisition of a monitor.
- *
- * @author Ben L. Titzer
  */
 public final class MonitorEnter extends AccessMonitor {
 
+    private static final int INPUT_COUNT = 0;
+    private static final int SUCCESSOR_COUNT = 0;
+
     private FrameState stateAfter;
 
     /**
@@ -41,9 +43,10 @@
      * @param lockAddress the address of the on-stack lock object or {@code null} if the runtime does not place locks on the stack
      * @param lockNumber the number of the lock
      * @param stateBefore the state before
+     * @param graph
      */
-    public MonitorEnter(Value object, Value lockAddress, int lockNumber, FrameState stateBefore) {
-        super(object, lockAddress, stateBefore, lockNumber);
+    public MonitorEnter(Value object, Value lockAddress, int lockNumber, FrameState stateBefore, Graph graph) {
+        super(object, lockAddress, stateBefore, lockNumber, INPUT_COUNT, SUCCESSOR_COUNT, graph);
     }
 
     @Override

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/MonitorExit.java	Thu May 05 15:49:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/MonitorExit.java	Thu May 05 16:07:00 2011 +0200
@@ -22,16 +22,18 @@
  */
 package com.sun.c1x.ir;
 
+import com.oracle.graal.graph.*;
 import com.sun.c1x.debug.*;
 import com.sun.c1x.value.*;
 
 /**
  * The {@code MonitorExit} instruction represents a monitor release.
- *
- * @author Ben L. Titzer
  */
 public final class MonitorExit extends AccessMonitor {
 
+    private static final int INPUT_COUNT = 0;
+    private static final int SUCCESSOR_COUNT = 0;
+
     /**
      * Creates a new MonitorExit instruction.
      *
@@ -39,9 +41,10 @@
      * @param lockAddress the address of the on-stack lock object or {@code null} if the runtime does not place locks on the stack
      * @param lockNumber the number of the lock
      * @param stateBefore the state before executing this instruction
+     * @param graph
      */
-    public MonitorExit(Value object, Value lockAddress, int lockNumber, FrameState stateBefore) {
-        super(object, lockAddress, stateBefore, lockNumber);
+    public MonitorExit(Value object, Value lockAddress, int lockNumber, FrameState stateBefore, Graph graph) {
+        super(object, lockAddress, stateBefore, lockNumber, INPUT_COUNT, SUCCESSOR_COUNT, graph);
     }
 
     @Override