Fixed placement cost computation when there are zero-capacity channels in the graph.

Signed-off-by: Maciej Kurc <[email protected]>

Author: mkurc-ant

vpr/src/place/place.cpp

@@ -2348,6 +2348,11 @@ static void alloc_and_load_for_fast_cost_update(float place_cost_exp) {
 
     for (size_t high = 0; high < device_ctx.grid.height(); high++)
         for (size_t low = 0; low <= high; low++) {
+            if (chanx_place_cost_fac[high][low] == 0.0f) {
+                VTR_LOG_WARN("CHANX place cost fac is 0 at %d %d\n", high, low);
+                chanx_place_cost_fac[high][low] = 1.0f;
+            }
+
             chanx_place_cost_fac[high][low] = (high - low + 1.)
                                               / chanx_place_cost_fac[high][low];
             chanx_place_cost_fac[high][low] = pow((double)chanx_place_cost_fac[high][low], (double)place_cost_exp);
@@ -2370,6 +2375,11 @@ static void alloc_and_load_for_fast_cost_update(float place_cost_exp) {
 
     for (size_t high = 0; high < device_ctx.grid.width(); high++)
         for (size_t low = 0; low <= high; low++) {
+            if (chany_place_cost_fac[high][low] == 0.0f) {
+                VTR_LOG_WARN("CHANY place cost fac is 0 at %d %d\n", high, low);
+                chany_place_cost_fac[high][low] = 1.0f;
+            }
+
             chany_place_cost_fac[high][low] = (high - low + 1.)
                                               / chany_place_cost_fac[high][low];
             chany_place_cost_fac[high][low] = pow((double)chany_place_cost_fac[high][low], (double)place_cost_exp);