--- a/graal/GraalCompiler/src/com/sun/c1x/graph/GraphBuilder.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/graph/GraphBuilder.java	Thu May 05 13:47:14 2011 +0200
@@ -182,7 +182,7 @@
         // 3. setup internal state for appending instructions
         curBlock = startBlock;
         lastInstr = startBlock;
-        lastInstr.setNext(null, -1);
+        lastInstr.appendNext(null, -1);
         curState = initialState;
 
         if (isSynchronized(rootMethod.accessFlags())) {
@@ -1165,7 +1165,7 @@
         if (lastInstr instanceof Base) {
             assert false : "may only happen when inlining intrinsics";
         } else {
-            lastInstr = lastInstr.setNext(x, bci);
+            lastInstr = lastInstr.appendNext(x, bci);
         }
         if (++stats.nodeCount >= C1XOptions.MaximumInstructionCount) {
             // bailout if we've exceeded the maximum inlining size
@@ -1289,7 +1289,7 @@
                 curBlock = b;
                 curState = b.stateBefore().copy();
                 lastInstr = b;
-                b.setNext(null, -1);
+                b.appendNext(null, -1);
 
                 iterateBytecodesForBlock(b.bci(), false);
             }
@@ -1321,7 +1321,7 @@
             if (nextBlock != null && nextBlock != block) {
                 // we fell through to the next block, add a goto and break
                 end = new Goto(nextBlock, null, false);
-                lastInstr = lastInstr.setNext(end, prevBCI);
+                lastInstr = lastInstr.appendNext(end, prevBCI);
                 break;
             }
             // read the opcode

--- a/graal/GraalCompiler/src/com/sun/c1x/graph/IR.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/graph/IR.java	Thu May 05 13:47:14 2011 +0200
@@ -179,7 +179,7 @@
 
         // This goto is not a safepoint.
         Goto e = new Goto(target, null, false);
-        newSucc.setNext(e, bci);
+        newSucc.appendNext(e, bci);
         newSucc.setEnd(e);
         // setup states
         FrameState s = source.end().stateAfter();

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/BlockBegin.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/BlockBegin.java	Thu May 05 13:47:14 2011 +0200
@@ -842,7 +842,7 @@
 
     /**
      * Formats a given instruction as a value in a {@linkplain FrameState frame state}. If the instruction is a phi defined at a given
-     * block, its {@linkplain Phi#inputCount() inputs} are appended to the returned string.
+     * block, its {@linkplain Phi#phiInputCount() inputs} are appended to the returned string.
      *
      * @param index the index of the value in the frame state
      * @param value the frame state value
@@ -858,7 +858,7 @@
             // print phi operands
             if (phi.block() == this) {
                 sb.append(" [");
-                for (int j = 0; j < phi.inputCount(); j++) {
+                for (int j = 0; j < phi.phiInputCount(); j++) {
                     sb.append(' ');
                     Value operand = phi.inputAt(j);
                     if (operand != null) {

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/Instruction.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/Instruction.java	Thu May 05 13:47:14 2011 +0200
@@ -24,6 +24,7 @@
 
 import java.util.*;
 
+import com.oracle.graal.graph.*;
 import com.sun.c1x.*;
 import com.sun.c1x.value.*;
 import com.sun.cri.ci.*;
@@ -42,6 +43,34 @@
  */
 public abstract class Instruction extends Value {
 
+    public static final int INPUT_COUNT = 0;
+
+    public static final int SUCCESSOR_COUNT = 1;
+    public static final int SUCCESSOR_NEXT = 0;
+
+    @Override
+    protected int inputCount() {
+        return super.inputCount() + INPUT_COUNT;
+    }
+
+    @Override
+    protected int successorCount() {
+        return super.successorCount() + SUCCESSOR_COUNT;
+    }
+
+    /**
+     * Links to next instruction in a basic block, to {@code null} if this instruction is the end of a basic block or to
+     * itself if not in a block.
+     */
+    public Instruction next() {
+        return (Instruction) successors().get(super.successorCount() + SUCCESSOR_NEXT);
+    }
+
+    public Node setNext(Instruction next) {
+        return successors().set(super.successorCount() + SUCCESSOR_NEXT, next);
+    }
+
+
     public static final int SYNCHRONIZATION_ENTRY_BCI = -1;
 
     /**
@@ -51,11 +80,6 @@
     private int bci;
 
     /**
-     * Links to next instruction in a basic block or to {@code} itself if not in a block.
-     */
-    private Instruction next = this;
-
-    /**
      * List of associated exception handlers.
      */
     private List<ExceptionHandler> exceptionHandlers = ExceptionHandler.ZERO_HANDLERS;
@@ -63,10 +87,16 @@
     /**
      * Constructs a new instruction with the specified value type.
      * @param kind the value type for this instruction
+     * @param inputCount
+     * @param successorCount
      */
+    public Instruction(CiKind kind, int inputCount, int successorCount, Graph graph) {
+        super(kind, inputCount + INPUT_COUNT, successorCount + SUCCESSOR_COUNT, graph);
+        C1XMetrics.HIRInstructions++;
+    }
+
     public Instruction(CiKind kind) {
-        super(kind);
-        C1XMetrics.HIRInstructions++;
+        this(kind, 0, 0, null);
     }
 
     /**
@@ -91,20 +121,9 @@
      * @return {@code true} if this instruction has been added to the basic block containing it
      */
     public final boolean isAppended() {
-        return next != this;
+        return next() != this;
     }
 
-    /**
-     * Gets the next instruction after this one in the basic block, or {@code null}
-     * if this instruction is the end of a basic block.
-     * @return the next instruction after this one in the basic block
-     */
-    public final Instruction next() {
-        if (next == this) {
-            return null;
-        }
-        return next;
-    }
 
     /**
      * Sets the next instruction for this instruction. Note that it is illegal to
@@ -113,13 +132,13 @@
      * @param bci the bytecode index of the next instruction
      * @return the new next instruction
      */
-    public final Instruction setNext(Instruction next, int bci) {
-        this.next = next;
+    public final Instruction appendNext(Instruction next, int bci) {
+        setNext(next);
         if (next != null) {
             assert !(this instanceof BlockEnd);
             next.setBCI(bci);
-            if (next.next == next) {
-                next.next = null;
+            if (next.next() == next) {
+                next.setNext(null);
             }
         }
         return next;
@@ -134,7 +153,7 @@
     public final Instruction resetNext(Instruction next) {
         if (next != null) {
             assert !(this instanceof BlockEnd);
-            this.next = next;
+            setNext(next);
         }
         return next;
     }
@@ -164,7 +183,7 @@
         // TODO(tw): Make this more efficient.
         Instruction cur = this;
         while (!(cur instanceof BlockEnd)) {
-            cur = cur.next;
+            cur = cur.next();
         }
         return ((BlockEnd) cur).begin;
     }

--- a/graal/GraalCompiler/src/com/sun/c1x/ir/Phi.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/Phi.java	Thu May 05 13:47:14 2011 +0200
@@ -125,8 +125,7 @@
      * Get the number of inputs to this phi (i.e. the number of predecessors to the join block).
      * @return the number of inputs in this phi
      */
-    @Override
-    public int inputCount() {
+    public int phiInputCount() {
         if (block.isExceptionEntry()) {
             return block.exceptionHandlerStates().size();
         } else {

--- a/graal/GraalCompiler/src/com/sun/c1x/opt/PhiSimplifier.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/opt/PhiSimplifier.java	Thu May 05 13:47:14 2011 +0200
@@ -78,7 +78,7 @@
             // attempt to simplify the phi by recursively simplifying its operands
             phi.setFlag(Value.Flag.PhiVisited);
             Value phiSubst = null;
-            int max = phi.inputCount();
+            int max = phi.phiInputCount();
             boolean cannotSimplify = false;
             for (int i = 0; i < max; i++) {
                 Value oldInstr = phi.inputAt(i);

--- a/graal/GraalCompiler/src/com/sun/c1x/value/FrameState.java	Thu May 05 13:27:48 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/value/FrameState.java	Thu May 05 13:47:14 2011 +0200
@@ -363,7 +363,7 @@
                 if (x instanceof Phi) {
                     Phi phi = (Phi) x;
                     if (phi.block() == block) {
-                        for (int j = 0; j < phi.inputCount(); j++) {
+                        for (int j = 0; j < phi.phiInputCount(); j++) {
                             if (phi.inputIn(other) == null) {
                                 throw new CiBailout("phi " + phi + " has null operand at new predecessor");
                             }