gather_op modified

paddle/operators/gather_op.cc

@@ -51,8 +51,10 @@ Y = X[Index]
 class GatherGradOp : public framework::OperatorWithKernel {
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
-    ctx.Output<Tensor>("X" + framework::kGradVarSuffix)
-        ->Resize(ctx.Input<Tensor>("X")->dims());
+    auto X_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
+    auto X = ctx.Input<Tensor>("X");
+
+    X_grad->Resize(X->dims());
   }
 };