--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/GraalCompiler/src/com/sun/c1x/ir/Merge.java	Fri May 27 11:29:28 2011 +0200
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2009, 2011, 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.sun.c1x.ir;
+
+import com.oracle.graal.graph.*;
+import com.sun.c1x.debug.*;
+import com.sun.c1x.util.*;
+import com.sun.c1x.value.*;
+import com.sun.cri.ci.*;
+
+/**
+ * Denotes the beginning of a basic block, and holds information
+ * about the basic block, including the successor and
+ * predecessor blocks, exception handlers, liveness information, etc.
+ */
+public final class Merge extends StateSplit {
+
+    private static final int INPUT_COUNT = 0;
+
+    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;
+    }
+
+    @Override
+    public boolean needsStateAfter() {
+        return false;
+    }
+
+    public final boolean isLoopHeader;
+
+    /**
+     * Index of bytecode that generated this node when appended in a basic block.
+     * Negative values indicate special cases.
+     */
+    private int bci;
+
+    /**
+     * Constructs a new Merge at the specified bytecode index.
+     * @param bci the bytecode index of the start
+     * @param blockID the ID of the block
+     * @param graph
+     */
+    public Merge(int bci, boolean isLoopHeader, Graph graph) {
+        super(CiKind.Illegal, INPUT_COUNT, SUCCESSOR_COUNT, graph);
+        this.bci = bci;
+        this.isLoopHeader = isLoopHeader;
+    }
+
+    /**
+     * Gets the bytecode index of this instruction.
+     * @return the bytecode index of this instruction
+     */
+    public int bci() {
+        return bci;
+    }
+
+    @Override
+    public void accept(ValueVisitor v) {
+        v.visitMerge(this);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append("merge #");
+        builder.append(id());
+        builder.append(" [");
+
+        builder.append("]");
+        //if (end() != null) {
+            builder.append(" -> ");
+            boolean hasSucc = false;
+            for (Node s : this.successors()) {
+                if (hasSucc) {
+                    builder.append(", ");
+                }
+                builder.append("#");
+                builder.append(s.id());
+                hasSucc = true;
+            }
+        //}
+        return builder.toString();
+    }
+
+    public void printWithoutPhis(LogStream out) {
+        // print block id
+        out.print("B").print(id()).print(" ");
+
+        // print flags
+        StringBuilder sb = new StringBuilder(8);
+        if (sb.length() != 0) {
+            out.print('(').print(sb.toString()).print(')');
+        }
+
+        // print block bci range
+        out.print('[').print(-1).print(", ").print(-1).print(']');
+
+        // print block successors
+        //if (end != null && end.blockSuccessors().size() > 0) {
+            out.print(" .");
+            for (Node successor : this.successors()) {
+                if (successor instanceof Value) {
+                    out.print((Value) successor);
+                } else {
+                    out.print(successor.toString());
+                }
+            }
+        //}
+
+        // print predecessors
+        if (!blockPredecessors().isEmpty()) {
+            out.print(" pred:");
+            for (Instruction pred : blockPredecessors()) {
+                out.print(pred.block());
+            }
+        }
+    }
+
+    @Override
+    public void print(LogStream out) {
+
+        printWithoutPhis(out);
+
+        // print phi functions
+        boolean hasPhisInLocals = false;
+        boolean hasPhisOnStack = false;
+
+        //if (end() != null && end().stateAfter() != null) {
+            FrameState state = stateBefore();
+
+            int i = 0;
+            while (!hasPhisOnStack && i < state.stackSize()) {
+                Value value = state.stackAt(i);
+                hasPhisOnStack = isPhiAtBlock(value);
+                if (value != null && !value.isIllegal()) {
+                    i += value.kind.sizeInSlots();
+                } else {
+                    i++;
+                }
+            }
+
+            for (i = 0; !hasPhisInLocals && i < state.localsSize();) {
+                Value value = state.localAt(i);
+                hasPhisInLocals = isPhiAtBlock(value);
+                // also ignore illegal HiWords
+                if (value != null && !value.isIllegal()) {
+                    i += value.kind.sizeInSlots();
+                } else {
+                    i++;
+                }
+            }
+        //}
+
+        // print values in locals
+        if (hasPhisInLocals) {
+            out.println();
+            out.println("Locals:");
+
+            int j = 0;
+            while (j < state.localsSize()) {
+                Value value = state.localAt(j);
+                if (value != null) {
+                    out.println(stateString(j, value));
+                    // also ignore illegal HiWords
+                    j += value.isIllegal() ? 1 : value.kind.sizeInSlots();
+                } else {
+                    j++;
+                }
+            }
+            out.println();
+        }
+
+        // print values on stack
+        if (hasPhisOnStack) {
+            out.println();
+            out.println("Stack:");
+            int j = 0;
+            while (j < stateBefore().stackSize()) {
+                Value value = stateBefore().stackAt(j);
+                if (value != null) {
+                    out.println(stateString(j, value));
+                    j += value.kind.sizeInSlots();
+                } else {
+                    j++;
+                }
+            }
+        }
+
+    }
+
+    /**
+     * Determines if a given instruction is a phi whose {@linkplain Phi#block() join block} is a given block.
+     *
+     * @param value the instruction to test
+     * @param block the block that may be the join block of {@code value} if {@code value} is a phi
+     * @return {@code true} if {@code value} is a phi and its join block is {@code block}
+     */
+    private boolean isPhiAtBlock(Value value) {
+        return value instanceof Phi && ((Phi) value).block() == this;
+    }
+
+
+    /**
+     * 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#valueCount() inputs} are appended to the returned string.
+     *
+     * @param index the index of the value in the frame state
+     * @param value the frame state value
+     * @param block if {@code value} is a phi, then its inputs are formatted if {@code block} is its
+     *            {@linkplain Phi#block() join point}
+     * @return the instruction representation as a string
+     */
+    public String stateString(int index, Value value) {
+        StringBuilder sb = new StringBuilder(30);
+        sb.append(String.format("%2d  %s", index, Util.valueString(value)));
+        if (value instanceof Phi) {
+            Phi phi = (Phi) value;
+            // print phi operands
+            if (phi.block() == this) {
+                sb.append(" [");
+                for (int j = 0; j < phi.valueCount(); j++) {
+                    sb.append(' ');
+                    Value operand = phi.valueAt(j);
+                    if (operand != null) {
+                        sb.append(Util.valueString(operand));
+                    } else {
+                        sb.append("NULL");
+                    }
+                }
+                sb.append("] ");
+            }
+        }
+        if (value != null && value.hasSubst()) {
+            sb.append("alias ").append(Util.valueString(value.subst()));
+        }
+        return sb.toString();
+    }
+
+    @Override
+    public String shortName() {
+        return "Merge #" + id();
+    }
+}