Fix nullptr check

paddle/operators/pad_op.cc

@@ -96,9 +96,10 @@ class PadOpGrad : public framework::OperatorWithKernel {
                             "Input(Out@GRAD) should not be null");
     auto x_dims = ctx.Input<Tensor>("X")->dims();
     auto *x_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
-
+    if (x_grad != nullptr) {
       x_grad->Resize(x_dims);
     }
+  }
 };
 
 }  // namespace operators

paddle/operators/pad_op.h

@@ -87,12 +87,13 @@ void PadGradFunction(const framework::ExecutionContext& context) {
   }
   auto* d_out = context.Input<Tensor>(framework::GradVarName("Out"));
   auto* d_x = context.Output<Tensor>(framework::GradVarName("X"));
+  if (d_x != nullptr) {
     d_x->mutable_data<T>(context.GetPlace());
-
     auto d_x_tensor = EigenTensor<T, D>::From(*d_x);
     auto d_out_tensor = EigenTensor<T, D>::From(*d_out);
     auto place = context.GetEigenDevice<Place>();
     d_x_tensor.device(place) = d_out_tensor.pad(paddings, 0);
+  }
 }
 
 template <typename Place, typename T>