adidng an autotuner test file for ppsp

autotune/apps/ppsp_delta_stepping.gt

@@ -0,0 +1,34 @@
+element Vertex end
+element Edge end
+const edges : edgeset{Edge}(Vertex,Vertex, int) = load (argv[1]);
+const vertices : vertexset{Vertex} = edges.getVertices();
+const dist : vector{Vertex}(int) = 2147483647; %should be INT_MAX
+const pq: priority_queue{Vertex}(int);
+
+func updateEdge(src : Vertex, dst : Vertex, weight : int)
+    var new_dist : int = dist[src] + weight;
+    pq.updatePriorityMin(dst, dist[dst], new_dist);
+end
+
+func reset(v: Vertex)
+    dist[v] = 2147483647;
+end
+
+func main()
+    for trail in 0:10
+        startTimer();
+        vertices.apply(reset);
+        var start_vertex : int = 10;
+        var end_vertex : int = 10000;
+        dist[start_vertex] = 0;
+        pq = new priority_queue{Vertex}(int)(false, false, dist, 1, 2, false, start_vertex);
+        while (pq.finishedNode(end_vertex) == false)
+            var frontier : vertexset{Vertex} = pq.dequeue_ready_set(); % dequeue lowest priority nodes
+            #s1# edges.from(frontier).applyUpdatePriority(updateEdge);
+            delete frontier;
+        end
+        var elapsed_time : float = stopTimer();
+        print "elapsed time: ";
+        print elapsed_time;
+    end
+end