text: void GPUMatrix<ElemType>::RNNForward(const GPUMatrix<ElemType> &inputX, const GPUMatrix<ElemType> &paramW, size_t xDim, size_t yDim, const vector<size_t>& numSequencesForFrame, const RnnAttributes& rnnAttributes, GPUMatrix<ElemType>& reserve, GPUMatrix<ElemType>& workspace)
  