fix in Matrix-vector multiplication

src/storm/storage/SparseMatrix.cpp

@@ -1181,24 +1181,18 @@ namespace storm {
 
         template<typename ValueType>
         void SparseMatrix<ValueType>::multiplyWithVectorSequential(std::vector<ValueType> const& vector, std::vector<ValueType>& result) const {
+            if (&vector == &result) {
+                STORM_LOG_WARN("Matrix-vector-multiplication invoked but the target vector uses the same memory as the input vector. This requires to allocate auxiliary memory.");
+                std::vector<ValueType> tmpVector(this->getRowCount());
+                multiplyWithVectorSequential(vector, tmpVector);
+                result = std::move(tmpVector);
+            } else {
                 const_iterator it = this->begin();
                 const_iterator ite;
                 std::vector<index_type>::const_iterator rowIterator = rowIndications.begin();
                 typename std::vector<ValueType>::iterator resultIterator = result.begin();
                 typename std::vector<ValueType>::iterator resultIteratorEnd = result.end();
 
-            // If the vector to multiply with and the target vector are actually the same, we need an auxiliary variable
-            // to store the intermediate result.
-            if (&vector == &result) {
-                for (; resultIterator != resultIteratorEnd; ++rowIterator, ++resultIterator) {
-                    ValueType tmpValue = storm::utility::zero<ValueType>();
-                    
-                    for (ite = this->begin() + *(rowIterator + 1); it != ite; ++it) {
-                        tmpValue += it->getValue() * vector[it->getColumn()];
-                    }
-                    *resultIterator = tmpValue;
-                }
-            } else {
                 for (; resultIterator != resultIteratorEnd; ++rowIterator, ++resultIterator) {
                     *resultIterator = storm::utility::zero<ValueType>();
 
@@ -1212,6 +1206,12 @@ namespace storm {
 #ifdef STORM_HAVE_INTELTBB
         template<typename ValueType>
         void SparseMatrix<ValueType>::multiplyWithVectorParallel(std::vector<ValueType> const& vector, std::vector<ValueType>& result) const {
+            if (&vector == &result) {
+                STORM_LOG_WARN("Matrix-vector-multiplication invoked but the target vector uses the same memory as the input vector. This requires to allocate auxiliary memory.");
+                std::vector<ValueType> tmpVector(this->getRowCount());
+                multiplyWithVectorParallel(vector, tmpVector);
+                result = std::move(tmpVector);
+            } else {
                 tbb::parallel_for(tbb::blocked_range<index_type>(0, result.size(), 10),
                                   [&] (tbb::blocked_range<index_type> const& range) {
                                       index_type startRow = range.begin();
@@ -1232,6 +1232,7 @@ namespace storm {
                                       }
                                   });
             }
+        }
 #endif
         
         template<typename ValueType>