Merge pull request #2114 from verilog-to-routing/route_timing_offset

Addressing route_timing Offset

Author: vaughnbetz

vpr/src/route/route_timing.cpp

@@ -893,9 +893,14 @@ void alloc_timing_driven_route_structs(float** pin_criticality_ptr,
 
     int max_sinks = std::max(get_max_pins_per_net() - 1, 0);
 
-    *pin_criticality_ptr = new float[max_sinks] - 1; /* First sink is pin #1. */
-    *sink_order_ptr = new int[max_sinks] - 1;
-    *rt_node_of_sink_ptr = new t_rt_node*[max_sinks] - 1;
+    *pin_criticality_ptr = new float[max_sinks + 1]; /* First sink is pin #1.*/
+    *sink_order_ptr = new int[max_sinks + 1];
+    *rt_node_of_sink_ptr = new t_rt_node*[max_sinks + 1];
+
+    /* Element 0 should be an invalid value so we are likely to crash if we accidentally use it. */
+    (*pin_criticality_ptr)[0] = -1;
+    (*sink_order_ptr)[0] = -1;
+    (*rt_node_of_sink_ptr)[0] = nullptr;
 
     alloc_route_tree_timing_structs();
 }
@@ -908,11 +913,11 @@ void free_timing_driven_route_structs(float* pin_criticality, int* sink_order, t
     /* Frees all the structures needed only by the timing-driven router.        */
 
     // coverity[offset_free : Intentional]
-    delete[](pin_criticality + 1); /* Starts at index 1. */
+    delete[](pin_criticality);
     // coverity[offset_free : Intentional]
-    delete[](sink_order + 1);
+    delete[](sink_order);
     // coverity[offset_free : Intentional]
-    delete[](rt_node_of_sink + 1);
+    delete[](rt_node_of_sink);
 
     free_route_tree_timing_structs();
 }