Avoid repeated hash computation, reduce irept::dt size

tautschnig · tautschnig · commit ca5192a3df5f · 2019-03-24T16:56:59.000Z
On SV-COMP benchmarks, hashing accounts for &gt;22% of CPU time (with
profiling enabled).
diff --git a/src/util/irep.h b/src/util/irep.h
@@ -17,8 +17,8 @@ Author: Daniel Kroening, kroening@kroening.com
 #include "irep_ids.h"
 
 #define SHARING
-// #define HASH_CODE
-// #define NAMED_SUB_IS_FORWARD_LIST
+#define HASH_CODE
+#define NAMED_SUB_IS_FORWARD_LIST
 
 #ifdef NAMED_SUB_IS_FORWARD_LIST
 #include <forward_list>
