+addGlobalScalar :: Var -> VM ()
+addGlobalScalar var
+ = updGEnv $ \env -> pprTrace "addGLobalScalar" (ppr var) env{global_scalars = extendVarSet (global_scalars env) var}
+
+deleteGlobalScalar :: Var -> VM ()
+deleteGlobalScalar var
+ = updGEnv $ \env -> pprTrace "deleteGLobalScalar" (ppr var) env{global_scalars = delVarSet (global_scalars env) var}
+
+