avoid creating std::string every time log_move_abort is called

Author: soheilshahrouz

vpr/src/draw/manual_moves.cpp

@@ -212,7 +212,7 @@ void manual_move_cost_summary_dialog() {
     gtk_window_set_transient_for((GtkWindow*)dialog, (GtkWindow*)draw_state->manual_moves_state.manual_move_window);
 
     //Create elements for the dialog and printing costs to the user.
-    GtkWidget* title_label = gtk_label_new(NULL);
+    GtkWidget* title_label = gtk_label_new(nullptr);
     gtk_label_set_markup((GtkLabel*)title_label, "<b>Move Costs and Outcomes</b>");
     std::string delta_cost = "Delta Cost: " + std::to_string(draw_state->manual_moves_state.manual_move_info.delta_cost) + "   ";
     GtkWidget* delta_cost_label = gtk_label_new(delta_cost.c_str());

vpr/src/place/move_utils.cpp

@@ -16,10 +16,15 @@
 bool f_placer_breakpoint_reached = false;
 
 //Records counts of reasons for aborted moves
-static std::map<std::string, size_t> f_move_abort_reasons;
+static std::map<std::string, size_t, std::less<>> f_move_abort_reasons;
 
-void log_move_abort(const std::string& reason) {
-    ++f_move_abort_reasons[reason];
+void log_move_abort(std::string_view reason) {
+    auto it = f_move_abort_reasons.find(reason);
+    if (it != f_move_abort_reasons.end()) {
+        it->second++;
+    } else {
+        f_move_abort_reasons.emplace(reason, 1);
+    }
 }
 
 void report_aborted_moves() {

vpr/src/place/move_utils.h

@@ -86,7 +86,7 @@ struct t_range_limiters {
 };
 
 //Records a reasons for an aborted move
-void log_move_abort(const std::string& reason);
+void log_move_abort(std::string_view reason);
 
 //Prints a breif report about aborted move reasons and counts
 void report_aborted_moves();