fix a bug in CrossEntropyNode where m_leftDivRight is used without

allocation.
ivannp · Oct 3, 2016 · b019f33 · b019f33
1 parent 1b38d9f
commit b019f33
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/Source/ComputationNetworkLib/TrainingNodes.h b/Source/ComputationNetworkLib/TrainingNodes.h
@@ -258,6 +258,8 @@ class CrossEntropyNode : public ComputationNodeNonLooping /*ComputationNode*/<El
         }
         else
         {
+            // Resize m_lefDivRight as it has not been done before.
+            m_leftDivRight->Resize(InputRef(1).Value());
             BackpropToRight(*m_leftDivRight, InputRef(0).ValueFor(fr), InputRef(1).ValueFor(fr), InputRef(1).GradientFor(fr), Gradient());
         }
     }
@@ -285,8 +287,8 @@ class CrossEntropyNode : public ComputationNodeNonLooping /*ComputationNode*/<El
 
     virtual void UpdateFunctionMBSize() override
     {
+        // Delay resize of m_leftDivRight to backprop, as it is not allocated for forwardprop.
         m_logOfRight->Resize(InputRef(1).Value());
-        m_leftDivRight->Resize(InputRef(1).Value());
     }
 
     // -sum(left_i * log(right_i))
@@ -315,7 +317,10 @@ class CrossEntropyNode : public ComputationNodeNonLooping /*ComputationNode*/<El
         {
             auto node = dynamic_pointer_cast<CrossEntropyNode<ElemType>>(nodeP);
             node->m_logOfRight->SetValue(*m_logOfRight);
-            node->m_leftDivRight->SetValue(*m_leftDivRight);
+            if (m_leftDivRight != nullptr)
+            {
+                node->m_leftDivRight->SetValue(*m_leftDivRight);
+            }
         }
     }