unrolling forests without recursion

[sbp.git] / src / edu / berkeley / sbp / GSS.java

diff --git a/src/edu/berkeley/sbp/GSS.java b/src/edu/berkeley/sbp/GSS.java
index 3df0c21..7af8b07 100644 (file)
--- a/src/edu/berkeley/sbp/GSS.java
+++ b/src/edu/berkeley/sbp/GSS.java
@@ -8,9 +8,11 @@ import java.util.*;
 import java.lang.reflect.*;
 
 /** implements Tomita's Graph Structured Stack */
 import java.lang.reflect.*;
 
 /** implements Tomita's Graph Structured Stack */

-class GSS {
+public class GSS {

 
     public static int count = 0;
 
     public static int count = 0;

+    public static int shifts = 0;
+    public static int reductions = 0;

     
     public GSS() { }
 
     
     public GSS() { }
 

@@ -18,6 +20,7 @@ class GSS {
     public int resets = 0;
     public int waits = 0;
 
     public int resets = 0;
     public int waits = 0;
 

+    // FIXME: right now, these are the performance bottleneck

     HashMapBag<Sequence,Phase.Waiting> waiting         = new HashMapBag<Sequence,Phase.Waiting>();
     HashMapBag<Integer,Sequence>       performed       = new HashMapBag<Integer,Sequence>();
     HashMapBag<Integer,Sequence>       lastperformed   = new HashMapBag<Integer,Sequence>();
     HashMapBag<Sequence,Phase.Waiting> waiting         = new HashMapBag<Sequence,Phase.Waiting>();
     HashMapBag<Integer,Sequence>       performed       = new HashMapBag<Integer,Sequence>();
     HashMapBag<Integer,Sequence>       lastperformed   = new HashMapBag<Integer,Sequence>();

@@ -31,6 +34,7 @@ class GSS {
 
         public Iterator<Phase.Node> iterator() { return hash.iterator(); }
         public void invoke(State st, Forest result, Node n) {
 
         public Iterator<Phase.Node> iterator() { return hash.iterator(); }
         public void invoke(State st, Forest result, Node n) {

+            shifts++;

             good |= next.newNode(n, result, st, false);
         }
 
             good |= next.newNode(n, result, st, false);
         }
 

@@ -285,6 +289,7 @@ class GSS {
             public Iterable<Forest.Ref> results() { return resultMap; }
             public FastSet<Node> parents() { return set; }
             public boolean merge(Node parent, Forest result) {
             public Iterable<Forest.Ref> results() { return resultMap; }
             public FastSet<Node> parents() { return set; }
             public boolean merge(Node parent, Forest result) {

+                // FIXME: inefficient!

                 for(Forest.Ref f : results()) {
                     if (f.parents.contains(parent) /* UGLY: */ && f.parents.size()==1) {
                         f.merge(result);
                 for(Forest.Ref f : results()) {
                     if (f.parents.contains(parent) /* UGLY: */ && f.parents.size()==1) {
                         f.merge(result);

@@ -312,6 +317,7 @@ class GSS {
 
             public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
             public final void invoke(Position r, Node n, Node n2) {
 
             public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
             public final void invoke(Position r, Node n, Node n2) {

+                reductions++;

                 if (n==null || n2==null || r.pos==0) {
                     if (r.pos==0) {
                         if (n==null) n = this;
                 if (n==null || n2==null || r.pos==0) {
                     if (r.pos==0) {
                         if (n==null) n = this;

@@ -319,37 +325,31 @@ class GSS {
                     }
                     if (n==null) return;
                     Forest[] holder = new Forest[r.pos];
                     }
                     if (n==null) return;
                     Forest[] holder = new Forest[r.pos];

-                    if (r.pos==0) n.finish(r, r.zero(), n.phase(), holder);
-                    else          n.reduce(r, r.pos-1,  n.phase(), holder, null);
+                    if (r.pos==0) n.finish(r, r.zero(), n.phase());
+                    else          n.reduce(r, r.pos-1,  n.phase(), null);

                 } else {
                 } else {

-                    Forest[] holder = new Forest[r.pos];

                     if (r.pos<=0) throw new Error("called wrong form of reduce()");
                     int pos = r.pos-1;
                     if (r.pos<=0) throw new Error("called wrong form of reduce()");
                     int pos = r.pos-1;

-                    n.reduce(r, pos, n.phase(), holder, n2);
+                    n.reduce(r, pos, n.phase(), n2);

                 }
             }
 
                 }
             }
 

-            public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
-                holder = r.holder;
+            public void reduce(Position r, int pos, Phase target, Node only) {
+                Forest[] holder = r.holder;

                 Forest old = holder[pos];
 
                 for(Forest result : results())
                     for(Node child : ((Forest.Ref<?>)result).parents) {
                         if (only != null && child!=only) continue;
                         holder[pos] = result;
                 Forest old = holder[pos];
 
                 for(Forest result : results())
                     for(Node child : ((Forest.Ref<?>)result).parents) {
                         if (only != null && child!=only) continue;
                         holder[pos] = result;

-                        if (pos==0) {
-                            //System.arraycopy(holder, 0, r.holder, 0, holder.length);
-                            for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
-                            child.finish(r, r.rewrite(phase().getLocation()), target, holder);
-                        } else {
-                            child.reduce(r, pos-1, target, holder, null);
-                        }
+                        if (pos==0) child.finish(r, r.rewrite(phase().getLocation()), target);
+                        else        child.reduce(r, pos-1, target, null);

                     }
 
                 holder[pos] = old;
             }
 
                     }
 
                 holder[pos] = old;
             }
 

-            public void finish(Position r, Forest result, Phase<Tok> target, Forest[] holder) {
+            public void finish(Position r, Forest result, Phase<Tok> target) {

                 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
                 if (result==null) throw new Error();
                 if (state0!=null)
                 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
                 if (result==null) throw new Error();
                 if (state0!=null)