checkpoint

[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 7bba6a6..645fa8f 100644 (file)
--- a/src/edu/berkeley/sbp/GSS.java
+++ b/src/edu/berkeley/sbp/GSS.java
@@ -92,8 +92,7 @@ class GSS {
                 if (token==null) break;
                 int count = 0;
                 Parser.Table.Reduction r = null;
-                for(Parser.Table.Reduction red : token==null ? state.getEofReductions() : state.getReductions(token)) { r = red; count++; }
-                if (count==0) return;     // BEWARE! this optimization is suspected to cause really nasty heisenbugs
+                if (!state.hasReductions(token)) return;
                 //if (count > 1) break;
                 //if (r.numPop == 0) break;
                 //r.reduce(pending, parent, null, Phase.this, null);
@@ -116,8 +115,12 @@ class GSS {
             int num = hv.size();
             for(int i=0; i<num; i++) {
                 Node n = reducing_list[i];
-                reducing_list[i] = null;
                 n.queueEmptyReductions();
+                // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
+            }
+            for(int i=0; i<num; i++) {
+                Node n = reducing_list[i];
+                reducing_list[i] = null;
                 n.queueReductions();
             }
         }
@@ -182,72 +185,44 @@ class GSS {
             private Forest.Ref holder = null;
             private boolean allqueued = false;
 
-            private HashMap<Parser.Table.Reduction,Forest> cache = null;
-
-            /** the set of nodes to which there is an edge starting at this node */
-            //public final FastSet<Node> parents = new FastSet<Node>();  /* ALLOC */
-
             /** what state this node is in */
             public final Parser.Table.State state;
 
             /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
             public Phase phase() { return Phase.this; }
 
-            public  HashMap<Parser.Table.Reduction,Forest> cache() {
-                return cache==null ? (cache = new HashMap<Parser.Table.Reduction,Forest>()) : cache;
-            }
             public  Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
             public  Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
             public  FastSet<Node> parents() { return this; }
 
-            /** FIXME */
             public void queueReductions() {
                 if (allqueued) return;
                 allqueued = true;
                 int where = parents().size();
-                for(int i=0; i<where; i++) queueReductions(get(i));
+                for(Parser.Table.Reduction r : state.getReductions(token))
+                    if (r.numPop >= 1)
+                        r.reduce(this);
             }
 
-            /** FIXME */
             public void queueReductions(Node n2) {
                 if (!allqueued) { queueReductions(); return; }
-                Node n = this;
-                for(Parser.Table.Reduction r : token==null ? n.state.getEofReductions() : n.state.getReductions(token)) {
-                    
-                    // UGLY HACK
-                    // The problem here is that a "reduction of length 1"
-                    // performed twice with different values of n2 needs
-                    // to only create a *single* new result, but must add
-                    // multiple parents to the node holding that result.
-                    // The current reducer doesn't differentiate between
-                    // the next node of an n-pop reduction and the
-                    // ultimate parent of the last pop, so we need to
-                    // cache instances here as a way of avoiding
-                    // recreating them.
-                    if (r.numPop <= 0) continue;
-                    if (r.numPop == 1) {
-                        Forest ret = n.cache().get(r);
-                        if (ret != null) r.reduce(this, n2, ret);
-                        else n.cache().put(r, r.reduce(this, n2, null));
-                    } else {
-                        r.reduce(this, n2, null);
-                    }
-                }
+                for(Parser.Table.Reduction r : state.getReductions(token))
+                    if (r.numPop > 0)
+                        r.reduce(this, n2);
             }
 
 
-            /** FIXME */
             public void queueEmptyReductions() {
                 if (reducing)
                     for(Parser.Table.Reduction r : token==null ? state.getEofReductions() : state.getReductions(token))
                         if (r.numPop==0)
-                            r.reduce(this, null, r.zero());
+                            r.reduce(this);
             }
 
             private Node(Node parent, Forest pending, Parser.Table.State state, Phase start) {
                 this.state = state;
                 if (pending != null) this.holder().merge(pending);
-                if (parent != null) parents().add(parent, true);
+                if (parent != null) parents().add(parent);
                 if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
                 Phase.this.hash.put(code(state, start), this);
                 Phase.this.numNodes++;