message: Fix performance regression with convolution layers by lazily creating the convolution op attribute.
diff: @@ -176,6 +176,7 @@ class Conv(Layer):
  self.bias = None
  self.input_spec = InputSpec(ndim=self.rank + 2,
  axes={channel_axis: input_dim})
  + self._convolution_op = None
  self.built = True
  def call(self, inputs):
  @@ -185,7 +186,8 @@ class Conv(Layer):
  op_padding = self.padding
  if not isinstance(op_padding, (list, tuple)):
  op_padding = op_padding.upper()
  - conv_op = nn_ops.Convolution(
  + if self._convolution_op is None:
  + self._convolution_op = nn_ops.Convolution(
  inputs.shape,
  filter_shape=self.kernel.shape,
  dilation_rate=self.dilation_rate,
  @@ -193,7 +195,7 @@ class Conv(Layer):
  padding=op_padding,
  data_format=conv_utils.convert_data_format(self.data_format,
  self.rank + 2))
  - outputs = conv_op(inputs, self.kernel)
  + outputs = self._convolution_op(inputs, self.kernel)
  if self.use_bias:
  if self.data_format == 'channels_first':
  