Fix time_once and guess_once CuDNN options

theano/sandbox/cuda/dnn_fwd.c

@@ -141,6 +141,7 @@ APPLY_SPECIFIC(conv_fwd)(CudaNdarray *input, CudaNdarray *kerns,
         // Store the shapes of the inputs and kernels as well as the chosen
         // algorithm for future use.
         APPLY_SPECIFIC(previous_algo) = chosen_algo;
+        APPLY_SPECIFIC(previous_algo_set) = true;
         for (int i = 0; i < nb_dim; i++)
         {
             APPLY_SPECIFIC(previous_input_shape)[i] =

theano/sandbox/cuda/dnn_gi.c

@@ -138,6 +138,7 @@ APPLY_SPECIFIC(conv_gi)(CudaNdarray *kerns, CudaNdarray *output,
         // Store the shapes of the kernels and output as well as the chosen
         // algorithm for future use.
         APPLY_SPECIFIC(previous_bwd_d_algo) = chosen_algo;
+        APPLY_SPECIFIC(previous_algo_set) = true;
         for (int i = 0; i < nb_dim; i++)
         {
             APPLY_SPECIFIC(previous_kerns_shape)[i] =

theano/sandbox/cuda/dnn_gw.c

@@ -138,6 +138,7 @@ APPLY_SPECIFIC(conv_gw)(CudaNdarray *input, CudaNdarray *output,
         // Store the shapes of the inputs and kernels as well as the chosen
         // algorithm for future use.
         APPLY_SPECIFIC(previous_bwd_f_algo) = chosen_algo;
+        APPLY_SPECIFIC(previous_algo_set) = true;
         for (int i = 0; i < nb_dim; i++)
         {
             APPLY_SPECIFIC(previous_input_shape)[i] =