Initial definition of nodes that will be relevant for chapter 1.

7 files changed, 171 insertions, 0 deletions

diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/chapter01/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
new file mode 100644
index 00000000..7f798301
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
@@ -0,0 +1,16 @@
+package com.seaofnodes.simple.node;
+
+public class ConstantNode extends Node {
+
+    long _value;
+
+    public ConstantNode(int nid, long value) {
+        super(nid, OP_CONSTANT);
+        _value = value;
+    }
+
+    public ConstantNode(NodeIDGenerator idGenerator, long value) {
+        super(idGenerator, OP_CONSTANT);
+        _value = value;
+    }
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/Control.java b/chapter01/src/main/java/com/seaofnodes/simple/node/Control.java
new file mode 100644
index 00000000..48cf2b7a
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/Control.java
@@ -0,0 +1,9 @@
+package com.seaofnodes.simple.node;
+
+
+/**
+ * Control interface is a marker interface to be implemented
+ * by Control nodes.
+ */
+public interface Control {
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter01/src/main/java/com/seaofnodes/simple/node/Node.java
new file mode 100644
index 00000000..0c6cdd3f
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+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -0,0 +1,94 @@
+package com.seaofnodes.simple.node;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * All Nodes in the Sea of Nodes IR inherit from the Node class.
+ * The Node class provides common functionality used by all subtypes.
+ * Subtypes of Node specialize by overriding methods.
+ */
+public class Node {
+
+    static final byte OP_START = 1;
+    static final byte OP_REGION = 2;
+    static final byte OP_RETURN = 3;
+    static final byte OP_CONSTANT = 4;
+
+    /**
+     * The opcode for this node
+     */
+    public final byte _opCode;
+
+    /**
+     * Each node has a unique ID within a compilation context
+     */
+    public final int _nid;
+
+    /**
+     * Inputs to the node.
+     *
+     * Generally fixed length, ordered, nulls allowed, no unused trailing space.
+     * The first input (offset 0) must be a Control node.
+     * @see Control
+     */
+    public final List<Node> _inputs;
+
+    protected Node(int nid, byte opCode, Node ...inputs)
+    {
+        _nid = nid;
+        _opCode = opCode;
+        _inputs = Arrays.asList(inputs);
+    }
+
+    protected Node(NodeIDGenerator idGenerator, byte opCode, Node ...inputs)
+    {
+        _nid = idGenerator.newNodeID();
+        _opCode = opCode;
+        _inputs = Arrays.asList(inputs);
+    }
+
+    /**
+     * Gets the ith input node
+     * @param i Offset of the input node
+     * @return Input node or null
+     */
+    public Node in(int i) { return _inputs != null ? _inputs.get(i) : null; }
+
+    public int numInputs() { return _inputs != null ? _inputs.size() : 0; }
+
+    /**
+     * Is this a control node, all control nodes are marked with
+     * the interface Control.
+     */
+    public boolean isControl() { return this instanceof Control; }
+
+    /**
+     * Hash is function of this nodes type, its _nid and
+     * inputs, or opcode + input_nids
+     */
+    @Override
+    public int hashCode() {
+        int sum = _opCode;
+        for (int i = 0; i < numInputs(); i++)
+            if (in(i) != null)
+                sum ^= in(i)._nid;
+        return sum;
+    }
+
+    /**
+     * Equals is opcode + input nids.
+     * Note that nodes are compared by reference.
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Node n)) return false;
+        if (_opCode != n._opCode) return false;
+        if (numInputs() != n.numInputs()) return false;
+        for (int i = 0; i < numInputs(); i++)
+            if (in(i) != n.in(i))
+                return false;
+        return true;
+    }
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/NodeIDGenerator.java b/chapter01/src/main/java/com/seaofnodes/simple/node/NodeIDGenerator.java
new file mode 100644
index 00000000..96a292df
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/NodeIDGenerator.java
@@ -0,0 +1,19 @@
+package com.seaofnodes.simple.node;
+
+/**
+ * Nodes are given unique dense ids.
+ */
+public class NodeIDGenerator {
+    /**
+     * Counter for node IDs, do not hand out NID 0
+     * (Presumably) because it is used for the control node?
+     */
+    private int nodeIDCounter = 1;
+
+    public int newNodeID() {
+        if (nodeIDCounter > 100000) {
+            throw new RuntimeException("infinite node create loop");
+        }
+        return nodeIDCounter++;
+    }
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/chapter01/src/main/java/com/seaofnodes/simple/node/RegionNode.java
new file mode 100644
index 00000000..b740deff
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/RegionNode.java
@@ -0,0 +1,11 @@
+package com.seaofnodes.simple.node;
+
+public class RegionNode extends Node implements Control {
+    public RegionNode(int nid, Node... inputs) {
+        super(nid, OP_REGION, inputs);
+    }
+
+    public RegionNode(NodeIDGenerator idGenerator, Node... inputs) {
+        super(idGenerator, OP_REGION, inputs);
+    }
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/chapter01/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
new file mode 100644
index 00000000..655fd11f
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
@@ -0,0 +1,11 @@
+package com.seaofnodes.simple.node;
+
+public class ReturnNode extends Node implements Control {
+    public ReturnNode(int nid, Node... inputs) {
+        super(nid, OP_RETURN, inputs);
+    }
+
+    public ReturnNode(NodeIDGenerator idGenerator, Node... inputs) {
+        super(idGenerator, OP_RETURN, inputs);
+    }
+}
diff --git a/chapter01/src/main/java/com/seaofnodes/simple/node/StartNode.java b/chapter01/src/main/java/com/seaofnodes/simple/node/StartNode.java
new file mode 100644
index 00000000..8117c4f6
--- /dev/null
+++ b/chapter01/src/main/java/com/seaofnodes/simple/node/StartNode.java
@@ -0,0 +1,11 @@
+package com.seaofnodes.simple.node;
+
+public class StartNode extends Node implements Control {
+    public StartNode(int nid, Node... inputs) {
+        super(nid, OP_START, inputs);
+    }
+
+    public StartNode(NodeIDGenerator idGenerator, Node... inputs) {
+        super(idGenerator, OP_START, inputs);
+    }
+}