vpr: Fix compilation warnings

Author: kmurray

vpr/src/pack/cluster.cpp

@@ -1792,8 +1792,10 @@ static void update_cluster_stats(t_pack_molecule *molecule,
 	}
 
     // if this molecule came from the transitive fanout candidates remove it
-    cb->pb_stats->transitive_fanout_candidates.erase(molecule);
-    cb->pb_stats->explore_transitive_fanout = true;
+    if (cb) {
+        cb->pb_stats->transitive_fanout_candidates.erase(molecule);
+        cb->pb_stats->explore_transitive_fanout = true;
+    }
 }
 
 static void start_new_cluster(

vpr/src/route/rr_graph_reader.cpp

@@ -771,7 +771,7 @@ void process_rr_node_indices(const DeviceGrid& grid) {
             for (int iy = node.ylow(); iy <= node.yhigh(); iy++) {
                 for (int ix = node.xlow(); ix <= node.xhigh(); ix++) {
                     count = node.ptc_num();
-                    if(count >= indices[CHANX][iy][ix][0].size()) {
+                    if(count >= int(indices[CHANX][iy][ix][0].size())) {
                         VPR_THROW(VPR_ERROR_ROUTE,
                             "Ptc index %d for CHANX (%d, %d) is out of bounds, size = %zu",
                             count, ix, iy, indices[CHANX][iy][ix][0].size());
@@ -783,7 +783,7 @@ void process_rr_node_indices(const DeviceGrid& grid) {
             for (int ix = node.xlow(); ix <= node.xhigh(); ix++) {
                 for (int iy = node.ylow(); iy <= node.yhigh(); iy++) {
                     count = node.ptc_num();
-                    if(count >= indices[CHANY][ix][iy][0].size()) {
+                    if(count >= int(indices[CHANY][ix][iy][0].size())) {
                         VPR_THROW(VPR_ERROR_ROUTE,
                             "Ptc index %d for CHANY (%d, %d) is out of bounds, size = %zu",
                             count, ix, iy, indices[CHANY][ix][iy][0].size());