Use existing irep_idts instead of strings

Author: tautschnig

src/cpp/cpp_typecheck_resolve.cpp

@@ -839,11 +839,11 @@ exprt cpp_typecheck_resolvet::do_builtin(
                             << ": " << original_scope->prefix
                             << messaget::eom;
   }
-  else if(base_name=="size_t")
+  else if(base_name == ID_size_t)
   {
     dest=type_exprt(size_type());
   }
-  else if(base_name=="ssize_t")
+  else if(base_name == ID_ssize_t)
   {
     dest=type_exprt(signed_size_type());
   }

src/goto-programs/remove_asm.cpp

@@ -195,7 +195,7 @@ void remove_asmt::process_instruction(
       {
         gcc_asm_function_call("__asm_"+id2string(command), code, tmp_dest);
       }
-      else if(command=="sync") // Power
+      else if(command == ID_sync) // Power
       {
         goto_programt::targett t=tmp_dest.add_instruction(OTHER);
         t->source_location=code.source_location();
@@ -210,7 +210,7 @@ void remove_asmt::process_instruction(
         t->code.set(ID_RRcumul, true);
         t->code.set(ID_WRcumul, true);
       }
-      else if(command=="lwsync") // Power
+      else if(command == ID_lwsync) // Power
       {
         goto_programt::targett t=tmp_dest.add_instruction(OTHER);
         t->source_location=code.source_location();
@@ -223,7 +223,7 @@ void remove_asmt::process_instruction(
         t->code.set(ID_RWcumul, true);
         t->code.set(ID_RRcumul, true);
       }
-      else if(command=="isync") // Power
+      else if(command == ID_isync) // Power
       {
         goto_programt::targett t=tmp_dest.add_instruction(OTHER);
         t->source_location=code.source_location();

src/goto-symex/slice_by_trace.cpp

@@ -244,7 +244,7 @@ void symex_slice_by_tracet::compute_ts_back(
        !i->io_args.empty() &&
        i->io_args.front().id()=="trace_event")
     {
-      irep_idt event=i->io_args.front().get("event");
+      irep_idt event = i->io_args.front().get(ID_event);
 
       if(!alphabet.empty())
       {

src/solvers/smt2/smt2_parser.cpp

@@ -774,7 +774,7 @@ exprt smt2_parsert::function_application()
         }
         else if(id=="rotate_left" ||
                 id=="rotate_right" ||
-                id=="repeat" ||
+                id == ID_repeat ||
                 id=="sign_extend" ||
                 id=="zero_extend")
         {
@@ -826,7 +826,7 @@ exprt smt2_parsert::function_application()
 
             return typecast_exprt(op[0], unsigned_type);
           }
-          else if(id=="repeat")
+          else if(id == ID_repeat)
           {
             return nil_exprt();
           }