Scope renames _scopes and _types as _idxs and _decls.

Drop isCFG and use instanceof instead

6 files changed, 54 insertions, 62 deletions

diff --git a/chapter15/src/main/java/com/seaofnodes/simple/GraphVisualizer.java b/chapter15/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
index 604770a4..f5fa1350 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
@@ -82,8 +82,8 @@ public class GraphVisualizer {
         for (Node n : all) {
             if (n instanceof ProjNode || n instanceof CProjNode || n instanceof ScopeNode || n==Parser.XCTRL)
                 continue; // Do not emit, rolled into MultiNode or Scope cluster already
-            if (_separateControlCluster && doCtrl && !n.isCFG()) continue;
-            if (_separateControlCluster && !doCtrl && n.isCFG()) continue;
+            if( _separateControlCluster &&  doCtrl && !(n instanceof CFGNode) ) continue;
+            if( _separateControlCluster && !doCtrl &&  (n instanceof CFGNode) ) continue;
             sb.append("\t\t").append(n.uniqueName()).append(" [ ");
             String lab = n.glabel();
             if (n instanceof MultiNode) {
@@ -93,6 +93,7 @@ public class GraphVisualizer {
                 sb.append("\t\t\t<TR><TD BGCOLOR=\"yellow\">").append(lab).append("</TD></TR>\n");
                 sb.append("\t\t\t<TR>");
                 boolean doProjTable = false;
+                n._outputs.sort((x,y) -> x instanceof ProjNode xp && y instanceof ProjNode yp ? (xp._idx - yp._idx) : (x._nid - y._nid));
                 for (Node use : n._outputs) {
                     if (use instanceof ProjNode proj) {
                         if (!doProjTable) {
@@ -124,7 +125,7 @@ public class GraphVisualizer {
             } else {
                 // control nodes have box shape
                 // other nodes are ellipses, i.e. default shape
-                if (n.isCFG()) sb.append("shape=box style=filled fillcolor=yellow ");
+                if( n instanceof CFGNode ) sb.append("shape=box style=filled fillcolor=yellow ");
                 else if (n instanceof PhiNode) sb.append("style=filled fillcolor=lightyellow ");
                 sb.append("label=\"").append(lab).append("\" ");
             }
@@ -154,14 +155,14 @@ public class GraphVisualizer {
     private void scope( StringBuilder sb, ScopeNode scope ) {
         sb.append("\tnode [shape=plaintext];\n");
         int level=1;
-        for( int idx = scope._scopes.size()-1; idx>=0; idx-- ) {
-            var syms = scope._scopes.get(idx);
+        for( int idx = scope._idxs.size()-1; idx>=0; idx-- ) {
+            var syms = scope._idxs.get(idx);
             String scopeName = makeScopeName(scope, level);
             sb.append("\tsubgraph cluster_").append(scopeName).append(" {\n"); // Magic "cluster_" in the subgraph name
             sb.append("\t\t").append(scopeName).append(" [label=<\n");
             sb.append("\t\t\t<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\">\n");
             // Add the scope level
-            int scopeLevel = scope._scopes.size()-level;
+            int scopeLevel = scope._idxs.size()-level;
             sb.append("\t\t\t<TR><TD BGCOLOR=\"cyan\">").append(scopeLevel).append("</TD>");
             for(String name: syms.keySet())
                 sb.append("<TD PORT=\"").append(makePortName(scopeName, name)).append("\">").append(name).append("</TD>");
@@ -212,7 +213,7 @@ public class GraphVisualizer {
                     if ( n instanceof NewNode )
                         sb.append(" color=green");
                     // control edges are colored red
-                    else if( def.isCFG() )
+                    else if( def instanceof CFGNode )
                         sb.append(" color=red");
                     else if( def.isMem() )
                         sb.append(" color=blue");
@@ -229,8 +230,8 @@ public class GraphVisualizer {
     private void scopeEdges( StringBuilder sb, ScopeNode scope ) {
         sb.append("\tedge [style=dashed color=cornflowerblue];\n");
         int level=1;
-        for( int i = scope._scopes.size()-1; i>=0; i-- ) {
-            var syms = scope._scopes.get(i);
+        for( int i = scope._idxs.size()-1; i>=0; i-- ) {
+            var syms = scope._idxs.get(i);
             String scopeName = makeScopeName(scope, level);
             for( String name : syms.keySet() ) {
                 int idx = syms.get(name);
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/CFGNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/CFGNode.java
index 07ba0fa4..9e9d6970 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/CFGNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/CFGNode.java
@@ -23,9 +23,6 @@ public abstract class CFGNode extends Node {
 
     public CFGNode(Node... nodes) { super(nodes); }
 
-    @Override public boolean isCFG() { return true; }
-    @Override public boolean isPinned() { return true; }
-
     public CFGNode cfg(int idx) { return (CFGNode)in(idx); }
 
     // Block head is Start, Region, CProj, but not e.g. If, Return, Stop
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
index 016b0b9b..845b9d08 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
@@ -36,8 +36,6 @@ public class ConstantNode extends Node {
     }
 
     @Override public boolean isMultiTail() { return true; }
-    // The special forever-zero is pinned, all others can sink
-    @Override public boolean isPinned() { return this==Parser.ZERO; }
 
     @Override
     public Type compute() { return _con; }
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter15/src/main/java/com/seaofnodes/simple/node/Node.java
index 382f78ae..c3a0f20f 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -135,7 +135,7 @@ public abstract class Node implements OutNode {
 
     public boolean isUnused() { return nOuts() == 0; }
 
-   public CFGNode cfg0() { return (CFGNode)in(0); }
+    public CFGNode cfg0() { return (CFGNode)in(0); }
 
     /**
      * Change a <em>def</em> into a Node.  Keeps the edges correct, by removing
@@ -533,16 +533,13 @@ public abstract class Node implements OutNode {
     // ------------------------------------------------------------------------
     //
 
-    /** Is this Node control-flow-graph related */
-    public boolean isCFG() { return false; }
-
     /** Is this Node Memory related */
     public boolean isMem() { return false; }
 
     /** Return block start from a isCFG() */
     public Node getBlockStart() { return null; }
 
-    /** Pinned in the schedule */
+    /** Pinned in the schedule; these are data nodes whose input#0 is not allowed to change */
     public boolean isPinned() { return false; }
 
     // Semantic change to the graph (so NOT a peephole), used by the Parser.
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index ebed8dd1..0b5abc6c 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -73,7 +73,8 @@ public class PhiNode extends Node {
         //   Phi(op(A,B),op(Q,R),op(X,Y)) becomes
         //     op(Phi(A,Q,X), Phi(B,R,Y)).
         Node op = in(1);
-        if( op.nIns()==3 && op.in(0)==null && !op.isCFG() && same_op() ) {
+        if( op.nIns()==3 && op.in(0)==null && same_op() ) {
+            assert !(op instanceof CFGNode);
             Node[] lhss = new Node[nIns()];
             Node[] rhss = new Node[nIns()];
             lhss[0] = rhss[0] = in(0); // Set Region
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/ScopeNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
index 843ce733..877ae4a4 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
@@ -1,10 +1,9 @@
 package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.Utils;
-import com.seaofnodes.simple.type.TypeMemPtr;
-
+import com.seaofnodes.simple.type.*;
 import java.util.*;
 
 /**
@@ -21,24 +20,22 @@ public class ScopeNode extends Node {
     public static final String ARG0 = "arg";
 
     /**
-     * Names for every input edge
+     * Map variable names to Scope input edge
      */
-    public final Stack<HashMap<String, Integer>> _scopes;
+    public final Stack<HashMap<String, Integer>> _idxs;
 
     /**
-     * Tracks declared types for every name
+     * Map variable names to declared Type
      */
-    public Stack<HashMap<String, Type>> _types;
-
+    final Stack<HashMap<String, Type>> _decls;
 
     // A new ScopeNode
     public ScopeNode() {
-        _scopes = new Stack<>();
-        _types  = new Stack<>();
+        _idxs = new Stack<>();
+        _decls= new Stack<>();
         _type = Type.BOTTOM;
     }
 
-
     @Override public String label() { return "Scope"; }
 
     @Override
@@ -58,6 +55,20 @@ public class ScopeNode extends Node {
         return sb.append("]");
     }
 
+    public Node ctrl() { return in(0); }
+
+    /**
+     * The ctrl of a ScopeNode is always bound to the currently active
+     * control node in the graph, via a special name '$ctrl' that is not
+     * a valid identifier in the language grammar and hence cannot be
+     * referenced in Simple code.
+     *
+     * @param n The node to be bound to '$ctrl'
+     *
+     * @return Node that was bound
+     */
+    public Node ctrl(Node n) { return setDef(0,n); }
+
     /**
      * Recover the names for all variable bindings.
      * The result is an array of names that is aligned with the
@@ -67,7 +78,7 @@ public class ScopeNode extends Node {
      */
     public String[] reverseNames() {
         String[] names = new String[nIns()];
-        for( HashMap<String,Integer> syms : _scopes )
+        for( HashMap<String,Integer> syms : _idxs )
             for( String name : syms.keySet() )
                 names[syms.get(name)] = name;
         return names;
@@ -77,33 +88,34 @@ public class ScopeNode extends Node {
 
     @Override public Node idealize() { return null; }
 
-    public void push() { _scopes.push(new HashMap<>());  _types.push(new HashMap<>()); }
-    public void pop() { popN(_scopes.pop().size()); _types.pop(); }
+    public void push() { _idxs.push(new HashMap<>());  _decls.push(new HashMap<>()); }
+    public void pop() { popN(_idxs.pop().size()); _decls.pop(); }
 
     /**
-     * Create a new name in the current scope
+     * Create a new variable name in the current scope
      */
     public Node define( String name, Type declaredType, Node n ) {
-        HashMap<String,Integer> syms = _scopes.lastElement();
-        _types.lastElement().put(name,declaredType);
+        HashMap<String,Integer> syms = _idxs.lastElement();
+        _decls.lastElement().put(name,declaredType);
         if( syms.put(name,nIns()) != null )
             return null;        // Double define
         return addDef(n);
     }
+
     /**
      * Lookup a name in all scopes starting from most deeply nested.
      *
      * @param name Name to be looked up
      * @see #update(String, Node, int)
      */
-    public Node lookup( String name ) { return update(name,null,_scopes.size()-1);  }
+    public Node lookup( String name ) { return update(name,null,_idxs.size()-1);  }
     /**
      * If the name is present in any scope, then redefine else null
      *
      * @param name Name being redefined
      * @param n    The node to bind to the name
      */
-    public Node update( String name, Node n ) { return update(name,n,_scopes.size()-1); }
+    public Node update( String name, Node n ) { return update(name,n,_idxs.size()-1); }
     /**
      * Both recursive lookup and update.
      * <p>
@@ -117,7 +129,7 @@ public class ScopeNode extends Node {
      */
     private Node update( String name, Node n, int nestingLevel ) {
         if( nestingLevel<0 ) return null;  // Missed in all scopes, not found
-        var syms = _scopes.get(nestingLevel); // Get the symbol table for nesting level
+        var syms = _idxs.get(nestingLevel); // Get the symbol table for nesting level
         var idx = syms.get(name);
         if( idx == null ) return update(name,n,nestingLevel-1); // Not found in this scope, recursively look in parent scope
         Node old = in(idx);
@@ -135,29 +147,15 @@ public class ScopeNode extends Node {
         return n==null ? old : setDef(idx,n); // Not lazy, so this is the answer
     }
 
-    // Return declared type
+    // Return declared type for a variable
     public Type lookupDeclaredType( String name ) {
-        for( int i=_types.size(); i>0; i-- ) {
-            Type t = _types.get(i-1).get(name);
+        for( int i=_decls.size(); i>0; i-- ) {
+            Type t = _decls.get(i-1).get(name);
             if( t != null ) return t;
         }
         return null;
     }
 
-    public Node ctrl() { return in(0); }
-
-    /**
-     * The ctrl of a ScopeNode is always bound to the currently active
-     * control node in the graph, via a special name '$ctrl' that is not
-     * a valid identifier in the language grammar and hence cannot be
-     * referenced in Simple code.
-     *
-     * @param n The node to be bound to '$ctrl'
-     *
-     * @return Node that was bound
-     */
-    public Node ctrl(Node n) { return setDef(0,n); }
-
     /**
      * Duplicate a ScopeNode; including all levels, up to Nodes.  So this is
      * neither shallow (would dup the Scope but not the internal HashMap
@@ -165,7 +163,7 @@ public class ScopeNode extends Node {
      * also the program Nodes).
      * <p>
      * If the {@code loop} flag is set, the edges are filled in as the original
-     * Scope, as a indication of Lazy Phis at loop heads.  The goal here is to
+     * Scope, as an indication of Lazy Phis at loop heads.  The goal here is to
      * not make Phis at loop heads for variables which are never touched in the
      * loop body.
      * <p>
@@ -178,10 +176,10 @@ public class ScopeNode extends Node {
         // 1) duplicate the name bindings of the ScopeNode across all stack levels
         // 2) Make the new ScopeNode a user of all the nodes bound
         // 3) Ensure that the order of defs is the same to allow easy merging
-        for( HashMap<String,Integer> syms : _scopes )
-            dup._scopes.push(new HashMap<>(syms));
-        for( HashMap<String,Type> ts : _types )
-            dup._types.push(ts); // Types don't change, just keep stacks aligned
+        for( HashMap<String,Integer> syms : _idxs )
+            dup._idxs.push(new HashMap<>(syms));
+        for( HashMap<String,Type> ts : _decls )
+            dup._decls.push(ts); // Types don't change, just keep stacks aligned
 
         dup.addDef(ctrl());     // Control input is just copied
         for( int i=1; i<nIns(); i++ )