Created by: wanghaoshuang

When i run infershape function of fc layer, i got mul op dims error:

paddle.v2.fluid.core.EnforceNotMet: enforce y_dims.size() > y_num_col_dims failed, 1 <= 1
The input tensor Y's rank of MulOp should be larger than y_num_col_dims. at [/home/work/Paddle/paddle/operators/mul_op.cc:47]

and with debug log:

I1123 12:59:49.114255 28049 mul_op.cc:36] mul operator x.shape=1, 10 y.shape=0 x_num_col_dims=1 y_num_col_dims=1

And i print the protobuf about mul op in my net as bellow:

blocks {
  idx: 0
  parent_idx: -1
  
  vars {
    name: "fc2.w_0"
    type: LOD_TENSOR
    lod_tensor {
      tensor {
        data_type: FP32
        dims: 10
        dims: 4
      }
    }
    persistable: true
  }
 
  vars {
    name: "fc1.w_0"
    type: LOD_TENSOR
    lod_tensor {
      tensor {
        data_type: FP32
        dims: 10
        dims: 10
      }
    }
    persistable: true
  }
 ...
  ops {
    inputs {
      parameter: "X"
      arguments: "obs"
    }
    inputs {
      parameter: "Y"
      arguments: "fc1.w_0"
    }
    outputs {
      parameter: "Out"
      arguments: "fc1.tmp_0"
    }
    type: "mul"
    attrs {
      name: "y_num_col_dims"
      type: INT
      i: 1
    }
    attrs {
      name: "x_num_col_dims"
      type: INT
      i: 1
    }
  }
  ops {
    inputs {
      parameter: "X"
      arguments: "fc1.tmp_0"
    }
   
  
  ops {
    inputs {
      parameter: "X"
      arguments: "fc1.tmp_2"
    }
    inputs {
      parameter: "Y"
      arguments: "fc2.w_0"
    }
    outputs {
      parameter: "Out"
      arguments: "fc2.tmp_0"
    }
    type: "mul"
    attrs {
      name: "y_num_col_dims"
      type: INT
      i: 1
    }
    attrs {
      name: "x_num_col_dims"
      type: INT
      i: 1
    }
  }
...
}