diff --git a/src/bdd/cudd/cuddGroup.c b/src/bdd/cudd/cuddGroup.c
index d916ed5a3..4d5308a3c 100644
--- a/src/bdd/cudd/cuddGroup.c
+++ b/src/bdd/cudd/cuddGroup.c
@@ -679,11 +679,11 @@ ddUniqueCompareGroup(
   int * ptrX,
   int * ptrY)
 {
-#if 0
+//#if 0
     if (entry[*ptrY] == entry[*ptrX]) {
         return((*ptrX) - (*ptrY));
     }
-#endif
+//#endif
     return(entry[*ptrY] - entry[*ptrX]);
 
 } /* end of ddUniqueCompareGroup */
@@ -2170,4 +2170,3 @@ ddIsVarHandled(
 
 
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/bdd/cudd/cuddLinear.c b/src/bdd/cudd/cuddLinear.c
index b38ea7294..6ac8ef833 100644
--- a/src/bdd/cudd/cuddLinear.c
+++ b/src/bdd/cudd/cuddLinear.c
@@ -873,11 +873,11 @@ ddLinearUniqueCompare(
   int * ptrX,
   int * ptrY)
 {
-#if 0
+//#if 0
     if (entry[*ptrY] == entry[*ptrX]) {
         return((*ptrX) - (*ptrY));
     }
-#endif
+//#endif
     return(entry[*ptrY] - entry[*ptrX]);
 
 } /* end of ddLinearUniqueCompare */
@@ -1370,4 +1370,3 @@ cuddXorLinear(
 
 
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/bdd/cudd/cuddReorder.c b/src/bdd/cudd/cuddReorder.c
index e5aa86716..aac99b5ff 100644
--- a/src/bdd/cudd/cuddReorder.c
+++ b/src/bdd/cudd/cuddReorder.c
@@ -1325,11 +1325,11 @@ ddUniqueCompare(
   int * ptrX,
   int * ptrY)
 {
-#if 0
+//#if 0
     if (entry[*ptrY] == entry[*ptrX]) {
         return((*ptrX) - (*ptrY));
     }
-#endif
+//#endif
     return(entry[*ptrY] - entry[*ptrX]);
 
 } /* end of ddUniqueCompare */
@@ -2140,4 +2140,3 @@ ddCheckPermuation(
 
 
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/bdd/cudd/cuddSymmetry.c b/src/bdd/cudd/cuddSymmetry.c
index 310286c4a..490428f06 100644
--- a/src/bdd/cudd/cuddSymmetry.c
+++ b/src/bdd/cudd/cuddSymmetry.c
@@ -609,11 +609,11 @@ ddSymmUniqueCompare(
   int * ptrX,
   int * ptrY)
 {
-#if 0
+//#if 0
     if (entry[*ptrY] == entry[*ptrX]) {
         return((*ptrX) - (*ptrY));
     }
-#endif
+//#endif
     return(entry[*ptrY] - entry[*ptrX]);
 
 } /* end of ddSymmUniqueCompare */
@@ -1703,4 +1703,3 @@ ddSymmSummary(
 
 
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/bdd/cudd/cuddZddGroup.c b/src/bdd/cudd/cuddZddGroup.c
index 67f9472f1..fc57132fa 100644
--- a/src/bdd/cudd/cuddZddGroup.c
+++ b/src/bdd/cudd/cuddZddGroup.c
@@ -610,11 +610,11 @@ zddUniqueCompareGroup(
   int * ptrX,
   int * ptrY)
 {
-#if 0
+//#if 0
     if (entry[*ptrY] == entry[*ptrX]) {
         return((*ptrX) - (*ptrY));
     }
-#endif
+//#endif
     return(entry[*ptrY] - entry[*ptrX]);
 
 } /* end of zddUniqueCompareGroup */
@@ -1341,4 +1341,3 @@ zddMergeGroups(
 
 
 ABC_NAMESPACE_IMPL_END
-
diff --git a/src/bdd/cudd/cuddZddReord.c b/src/bdd/cudd/cuddZddReord.c
index c195f5b56..6943cbc89 100644
--- a/src/bdd/cudd/cuddZddReord.c
+++ b/src/bdd/cudd/cuddZddReord.c
@@ -460,6 +460,11 @@ cuddZddUniqueCompare(
   int * ptr_x,
   int * ptr_y)
 {
+//#if 0
+    if (zdd_entry[*ptr_y] == zdd_entry[*ptr_x]) {
+        return((*ptr_x) - (*ptr_y));
+    }
+//#endif
     return(zdd_entry[*ptr_y] - zdd_entry[*ptr_x]);
 
 } /* end of cuddZddUniqueCompare */
@@ -1665,4 +1670,3 @@ zddFixTree(
 
 ABC_NAMESPACE_IMPL_END
 
-