diff --git a/core/base/mergeTreeClustering/MergeTreeBarycenter.h b/core/base/mergeTreeClustering/MergeTreeBarycenter.h
index b946bf3ecf..f74f1f6a28 100644
--- a/core/base/mergeTreeClustering/MergeTreeBarycenter.h
+++ b/core/base/mergeTreeClustering/MergeTreeBarycenter.h
@@ -506,7 +506,7 @@ namespace ttk {
       std::tuple<dataType, dataType> birthDeath;
       // Normalized Wasserstein
       if(normalizedWasserstein_)
-        birthDeath = getNormalizedBirthDeathDouble<dataType>(tree1, nodeId1);
+        birthDeath = getNormalizedBirthDeath<dataType>(tree1, nodeId1);
       // Classical Wasserstein
       else
         birthDeath = tree1->getBirthDeath<dataType>(nodeId1);
@@ -526,10 +526,10 @@ namespace ttk {
         baryTree, nodeId, newScalarsVector, false);
       dataType mu_min = getMinMaxLocalFromVector<dataType>(
         baryTree, nodeId, newScalarsVector);
-      double newBirth = 0, newDeath = 0;
+      dataType newBirth = 0, newDeath = 0;
 
       // Compute projection
-      double tempBirth = 0, tempDeath = 0;
+      dataType tempBirth = 0, tempDeath = 0;
       double alphaSum = 0;
       for(unsigned int i = 0; i < trees.size(); ++i)
         if(nodes[i] != std::numeric_limits<ftm::idNode>::max())
@@ -539,18 +539,18 @@ namespace ttk {
         if(nodes[i] != std::numeric_limits<ftm::idNode>::max()) {
           auto iBirthDeath
             = getParametrizedBirthDeath<dataType>(trees[i], nodes[i]);
-          double tTempBirth = 0, tTempDeath = 0;
+          dataType tTempBirth = 0, tTempDeath = 0;
           tTempBirth += std::get<0>(iBirthDeath);
           tTempDeath += std::get<1>(iBirthDeath);
           tempBirth += tTempBirth * alphas[i] / alphaSum;
           tempDeath += tTempDeath * alphas[i] / alphaSum;
         }
       }
-      double const projec = (tempBirth + tempDeath) / 2;
+      dataType const projec = (tempBirth + tempDeath) / 2;
 
       // Compute newBirth and newDeath
       for(unsigned int i = 0; i < trees.size(); ++i) {
-        double iBirth = projec, iDeath = projec;
+        dataType iBirth = projec, iDeath = projec;
         // if node is matched in trees[i]
         if(nodes[i] != std::numeric_limits<ftm::idNode>::max()) {
           auto iBirthDeath
@@ -562,8 +562,12 @@ namespace ttk {
         newDeath += alphas[i] * iDeath;
       }
       if(normalizedWasserstein_) {
-        newBirth = newBirth * (mu_max - mu_min) + mu_min;
-        newDeath = newDeath * (mu_max - mu_min) + mu_min;
+        // Forbid compiler optimization to have same results on different
+        // computers
+        volatile dataType tempBirthT = newBirth * (mu_max - mu_min);
+        volatile dataType tempDeathT = newDeath * (mu_max - mu_min);
+        newBirth = tempBirthT + mu_min;
+        newDeath = tempDeathT + mu_min;
       }
 
       return std::make_tuple(newBirth, newDeath);
@@ -584,21 +588,23 @@ namespace ttk {
         = getMinMaxLocalFromVector<dataType>(baryTree, nodeB, newScalarsVector);
 
       auto birthDeath = getParametrizedBirthDeath<dataType>(tree, nodeId);
-      double newBirth = std::get<0>(birthDeath);
-      double newDeath = std::get<1>(birthDeath);
-      double const projec = (newBirth + newDeath) / 2;
+      dataType newBirth = std::get<0>(birthDeath);
+      dataType newDeath = std::get<1>(birthDeath);
+      dataType const projec = (newBirth + newDeath) / 2;
 
       newBirth = alpha * newBirth + (1 - alpha) * projec;
       newDeath = alpha * newDeath + (1 - alpha) * projec;
 
       if(normalizedWasserstein_) {
-        newBirth = newBirth * (mu_max - mu_min) + mu_min;
-        newDeath = newDeath * (mu_max - mu_min) + mu_min;
+        // Forbid compiler optimization to have same results on different
+        // computers
+        volatile dataType tempBirthT = newBirth * (mu_max - mu_min);
+        volatile dataType tempDeathT = newDeath * (mu_max - mu_min);
+        newBirth = tempBirthT + mu_min;
+        newDeath = tempDeathT + mu_min;
       }
 
-      dataType newBirthT = newBirth;
-      dataType newDeathT = newDeath;
-      return std::make_tuple(newBirthT, newDeathT);
+      return std::make_tuple(newBirth, newDeath);
     }
 
     template <class dataType>
diff --git a/core/base/mergeTreeClustering/MergeTreeDistance.h b/core/base/mergeTreeClustering/MergeTreeDistance.h
index 2b43efaff8..0ce6bb929f 100644
--- a/core/base/mergeTreeClustering/MergeTreeDistance.h
+++ b/core/base/mergeTreeClustering/MergeTreeDistance.h
@@ -582,7 +582,7 @@ namespace ttk {
       ftm::MergeTree<dataType> &mTree2Int = (saveTree_ ? mTree2Copy : mTree2);
       ftm::FTMTree_MT *tree1 = &(mTree1Int.tree);
       ftm::FTMTree_MT *tree2 = &(mTree2Int.tree);
-      if(not isCalled_) {
+      if(not isCalled_ and not isPersistenceDiagram_) {
         verifyMergeTreeStructure<dataType>(tree1);
         verifyMergeTreeStructure<dataType>(tree2);
       }
diff --git a/core/base/mergeTreeClustering/MergeTreeUtils.h b/core/base/mergeTreeClustering/MergeTreeUtils.h
index b1ae2d28bd..56d97b19e2 100644
--- a/core/base/mergeTreeClustering/MergeTreeUtils.h
+++ b/core/base/mergeTreeClustering/MergeTreeUtils.h
@@ -60,26 +60,6 @@ namespace ttk {
     return std::make_tuple(min, max);
   }
 
-  template <class dataType>
-  std::tuple<double, double>
-    getNormalizedBirthDeathDouble(ftm::FTMTree_MT *tree,
-                                  ftm::idNode nodeId,
-                                  dataType newMin = 0.0,
-                                  dataType newMax = 1.0) {
-    auto birthDeath = tree->getBirthDeath<dataType>(nodeId);
-    double birth = std::get<0>(birthDeath);
-    double death = std::get<1>(birthDeath);
-    dataType shiftMin = getMinMaxLocal<dataType>(tree, nodeId);
-    dataType shiftMax = getMinMaxLocal<dataType>(tree, nodeId, false);
-    if((shiftMax - shiftMin) == 0)
-      return std::make_tuple(0, 0);
-    birth = (newMax - newMin) * (birth - shiftMin)
-            / (shiftMax - shiftMin); // + newMin;
-    death = (newMax - newMin) * (death - shiftMin)
-            / (shiftMax - shiftMin); // + newMin;
-    return std::make_tuple(birth, death);
-  }
-
   template <class dataType>
   std::tuple<dataType, dataType> getNormalizedBirthDeath(ftm::FTMTree_MT *tree,
                                                          ftm::idNode nodeId,