diff --git a/include/clad/Differentiator/ReverseModeVisitor.h b/include/clad/Differentiator/ReverseModeVisitor.h
index cf1820a56..ad1a54c77 100644
--- a/include/clad/Differentiator/ReverseModeVisitor.h
+++ b/include/clad/Differentiator/ReverseModeVisitor.h
@@ -54,7 +54,7 @@ namespace clad {
     /// Based on To-Be-Recorded analysis performed before differentiation,
     /// tells UsefulToStoreGlobal whether a variable with a given
     /// SourceLocation has to be stored before being changed or not.
-    std::map<clang::SourceLocation, bool> m_ToBeRecorded;
+    std::set<clang::SourceLocation> m_ToBeRecorded;
     /// A flag indicating if the Stmt we are currently visiting is inside loop.
     bool isInsideLoop = false;
     /// Output variable of vector-valued function
diff --git a/include/clad/Differentiator/TBRAnalyzer.h b/include/clad/Differentiator/TBRAnalyzer.h
index b2677e4e7..c3c223f43 100644
--- a/include/clad/Differentiator/TBRAnalyzer.h
+++ b/include/clad/Differentiator/TBRAnalyzer.h
@@ -223,7 +223,7 @@ class TBRAnalyzer : public clang::ConstStmtVisitor<TBRAnalyzer> {
   enum Mode { markingMode = 1, nonLinearMode = 2 };
   /// Tells if the variable at a given location is required to store. Basically,
   /// is the result of analysis.
-  std::map<clang::SourceLocation, bool> TBRLocs;
+  std::set<clang::SourceLocation> TBRLocs;
 
   /// Stores modes in a stack (used to retrieve the old mode after entering
   /// a new one).
@@ -297,7 +297,7 @@ class TBRAnalyzer : public clang::ConstStmtVisitor<TBRAnalyzer> {
   TBRAnalyzer& operator=(const TBRAnalyzer&&) = delete;
 
   /// Returns the result of the whole analysis
-  std::map<clang::SourceLocation, bool> getResult() { return TBRLocs; }
+  std::set<clang::SourceLocation> getResult() { return TBRLocs; }
 
   /// Visitors
   void Analyze(const clang::FunctionDecl* FD);
diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
index d8b9e36a1..690472456 100644
--- a/lib/Differentiator/ReverseModeVisitor.cpp
+++ b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -2769,16 +2769,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     // current system that should have been decided by the parent expression.
     // FIXME: Here will be the entry point of the advanced activity analysis.
     if (isa<DeclRefExpr>(B) || isa<ArraySubscriptExpr>(B)) {
-      // auto line =
-      // m_Context.getSourceManager().getPresumedLoc(B->getBeginLoc()).getLine();
-      // auto column =
-      // m_Context.getSourceManager().getPresumedLoc(B->getBeginLoc()).getColumn();
-      // llvm::errs() << line << "|" <<column << "?\n";
-      auto it = m_ToBeRecorded.find(B->getBeginLoc());
-      if (it == m_ToBeRecorded.end()) {
-        return true;
-      }
-      return it->second;
+      auto found = m_ToBeRecorded.find(B->getBeginLoc());
+      return found != m_ToBeRecorded.end();
     }
 
     // FIXME: Attach checkpointing.
diff --git a/lib/Differentiator/TBRAnalyzer.cpp b/lib/Differentiator/TBRAnalyzer.cpp
index 62f826781..b5f6af7e6 100644
--- a/lib/Differentiator/TBRAnalyzer.cpp
+++ b/lib/Differentiator/TBRAnalyzer.cpp
@@ -295,20 +295,16 @@ void TBRAnalyzer::addVar(const clang::VarDecl* VD) {
 
 void TBRAnalyzer::markLocation(const clang::Expr* E) {
   VarData* data = getExprVarData(E);
-  if (data) {
+  if (!data || findReq(data)) {
     /// FIXME: If any of the data's child nodes are required to store then data
     /// itself is stored. We might add an option to store separate fields.
-    bool& ToBeRec = TBRLocs[E->getBeginLoc()];
     /// FIXME: Sometimes one location might correspond to multiple stores.
     /// For example, in ``(x*=y)=u`` x's location will first be marked as
     /// required to be stored (when passing *= operator) but then marked as not
     /// required to be stored (when passing = operator). Current method of
     /// marking locations does not allow to differentiate between these two.
-    ToBeRec = ToBeRec || findReq(data);
-  } else
-    /// If the current branch is going to be deleted then there is not point in
-    /// storing anything in it.
-    TBRLocs[E->getBeginLoc()] = true;
+    TBRLocs.insert(E->getBeginLoc());
+  }
 }
 
 void TBRAnalyzer::setIsRequired(const clang::Expr* E, bool isReq) {
@@ -723,15 +719,11 @@ void TBRAnalyzer::VisitCallExpr(const clang::CallExpr* CE) {
     // FIXME: this supports only DeclRefExpr
     const auto innerExpr = utils::GetInnermostReturnExpr(arg);
     if (passByRef) {
-      /// Mark SourceLocation as required for ref-type arguments.
+      /// Mark SourceLocation as required to store for ref-type arguments.
       if (isa<DeclRefExpr>(B) || isa<MemberExpr>(B)) {
-        TBRLocs[arg->getBeginLoc()] = true;
+        TBRLocs.insert(arg->getBeginLoc());
         setIsRequired(arg, /*isReq=*/false);
       }
-    } else {
-      /// Mark SourceLocation as not required for non-ref-type arguments.
-      if (isa<DeclRefExpr>(B) || isa<MemberExpr>(B))
-        TBRLocs[arg->getBeginLoc()] = false;
     }
   }
   resetMode();
@@ -755,13 +747,9 @@ void TBRAnalyzer::VisitCXXConstructExpr(const clang::CXXConstructExpr* CE) {
     if (passByRef) {
       /// Mark SourceLocation as required for ref-type arguments.
       if (isa<DeclRefExpr>(B) || isa<MemberExpr>(B)) {
-        TBRLocs[arg->getBeginLoc()] = true;
+        TBRLocs.insert(arg->getBeginLoc());
         setIsRequired(arg, /*isReq=*/false);
       }
-    } else {
-      /// Mark SourceLocation as not required for non-ref-type arguments.
-      if (isa<DeclRefExpr>(B) || isa<MemberExpr>(B))
-        TBRLocs[arg->getBeginLoc()] = false;
     }
   }
   resetMode();