Start to replace IterPeeps

Author: dibyendumajumdar

seaofnodes/src/main/java/com/compilerprogramming/ezlang/compiler/IterPeeps2.java

@@ -0,0 +1,62 @@
+package com.compilerprogramming.ezlang.compiler;
+
+import com.compilerprogramming.ezlang.compiler.codegen.CodeGen;
+import com.compilerprogramming.ezlang.compiler.node.Node;
+import com.compilerprogramming.ezlang.compiler.node.StopNode;
+
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class IterPeeps2 {
+
+    static void dfs(Node root, Consumer<Node> consumer, BitSet visited) {
+        visited.set(root._nid);
+        /* For each successor node */
+        for (int i = 0; i < root.nOuts(); i++) {
+            Node S = root.out(i);
+            if (S == null)
+                continue;
+            if (!visited.get(S._nid))
+                dfs(S, consumer, visited);
+        }
+        consumer.accept(root);
+    }
+
+    public static List<Node> rpo(Node root) {
+        List<Node> nodes = new ArrayList<>();
+        // note add below prepends
+        dfs(root, (n)->nodes.add(0,n), new BitSet());
+        return nodes;
+    }
+
+    public void iterate(CodeGen code) {
+        final Node startNode = code._start;    // We need the start node to get to the full graph
+        int iter = 1;
+        int count = 0;  // Count of nodes we peepholed
+        for (;;iter++) {
+            List<Node> rpos = rpo(startNode);
+            count += rpos.size();
+            boolean progress = false;
+            for (int i = 0; i < rpos.size(); i++) {
+                Node n = rpos.get(i);
+                if (n.isDead()) continue;
+                Node x = n.peepholeOpt();
+                if (x != null) {
+                    progress = true;
+                    if (x.isDead()) continue;
+                    // peepholeOpt can return brand-new nodes, needing an initial type set
+                    if( x._type==null ) x.setType(x.compute());
+                    if (x != n) n.subsume(x);
+                }
+                if( n.isUnused() && !(n instanceof StopNode) )
+                    n.kill();       // Just plain dead
+            }
+            if (!progress) break;
+        }
+        System.out.println("Completed in " + iter + " iterations; peepholed " + count + " nodes");
+//        if( show )
+//            System.out.println(new GraphVisualizer().generateDotOutput(stopNode,null,null));
+    }
+}

seaofnodes/src/main/java/com/compilerprogramming/ezlang/compiler/codegen/CodeGen.java

@@ -51,7 +51,8 @@ public CodeGen( String src, TypeInteger arg, long workListSeed ) {
         _stop = new StopNode(src);
         _src = src;
         _arg = arg;
-        _iter = new IterPeeps(workListSeed);
+        //_iter = new IterPeeps(workListSeed);
+        _iter = new IterPeeps2();
         _main = makeFun(TypeTuple.MAIN, Type.BOTTOM);
         P = new Compiler(this,arg);
     }
@@ -180,7 +181,7 @@ public CodeGen parse() {
 
     // ---------------------------
     // Iterator peepholes.
-    public final IterPeeps _iter;
+    public final IterPeeps2 _iter;
     // Stop tracking deps while assertin
     public boolean _midAssert;
     // Statistics on peepholes
@@ -206,8 +207,8 @@ public CodeGen opto() {
         // loop unroll, peel, RCE, etc
         return this;
     }
-    public <N extends Node> N add( N n ) { return _iter.add(n); }
-    public void addAll( Ary<Node> ary ) { _iter.addAll(ary); }
+    public <N extends Node> N add( N n ) { /* return _iter.add(n); */ return n; }
+    public void addAll( Ary<Node> ary ) { /* _iter.addAll(ary); */ }
 
 
     // ---------------------------