!11381 Mod Dense to support ND*2D by using reshape

From: @wanyiming
Reviewed-by: @kingxian,@zh_qh
Signed-off-by: @kingxian

mindspore/nn/layer/basic.py

@@ -195,15 +195,6 @@ class Flatten(Cell):
     def construct(self, x):
         return F.reshape(x, (F.shape(x)[0], -1))
 
-
-@constexpr
-def get_broadcast_weight_bias_shape(x_shape, out_channel, in_channel):
-    """get broadcast_weight_bias shape"""
-    broad_weight_shape = x_shape[:-2] + (out_channel, in_channel)
-    broad_bias_shape = x_shape[:-1] + (out_channel,)
-    return broad_weight_shape, broad_bias_shape
-
-
 class Dense(Cell):
     r"""
     The dense connected layer.
@@ -249,7 +240,7 @@ class Dense(Cell):
         (2, 4)
     """
 
-    @cell_attr_register(attrs=['has_bias', 'activation', 'in_channels', 'out_channels'])
+    @cell_attr_register(attrs=['has_bias', 'activation'])
     def __init__(self,
                  in_channels,
                  out_channels,
@@ -261,8 +252,10 @@ class Dense(Cell):
         self.in_channels = Validator.check_positive_int(in_channels)
         self.out_channels = Validator.check_positive_int(out_channels)
         self.has_bias = Validator.check_bool(has_bias)
+        self.reshape = P.Reshape()
         self.shape_op = P.Shape()
 
+
         if isinstance(weight_init, Tensor):
             if weight_init.ndim != 2 or weight_init.shape[0] != out_channels or \
                     weight_init.shape[1] != in_channels:
@@ -276,10 +269,8 @@ class Dense(Cell):
                     raise ValueError("Bias init shape error.")
             self.bias = Parameter(initializer(bias_init, [out_channels]), name="bias")
             self.bias_add = P.BiasAdd()
-            self.tensor_add = P.TensorAdd()
 
         self.matmul = P.MatMul(transpose_b=True)
-        self.batch_matmul = P.BatchMatMul(transpose_b=True)
         self.activation = get_activation(activation) if isinstance(activation, str) else activation
         if activation is not None and not isinstance(self.activation, (Cell, Primitive)):
             raise TypeError("The activation must be str or Cell or Primitive,"" but got {}.".format(activation))
@@ -287,27 +278,16 @@ class Dense(Cell):
 
     def construct(self, x):
         x_shape = self.shape_op(x)
-        x_dim = len(x_shape)
-        if x_dim == 2:
-            matmul = self.matmul
-            bias_add = self.bias_add if self.has_bias else None
-            weight = self.weight
-            bias = self.bias
-        else:
-            broad_weight_shape, broad_bias_shape = get_broadcast_weight_bias_shape(x_shape, self.out_channels,
-                                                                                   self.in_channels)
-            weight_broadcast_to = P.BroadcastTo(broad_weight_shape)
-            bias_broadcast_to = P.BroadcastTo(broad_bias_shape)
-            matmul = self.batch_matmul
-            bias_add = self.tensor_add if self.has_bias else None
-            weight = weight_broadcast_to(self.weight)
-            bias = bias_broadcast_to(self.bias) if self.has_bias else self.bias
-
-        x = matmul(x, weight)
+        if len(x_shape) != 2:
+            x = self.reshape(x, (-1, x_shape[-1]))
+        x = self.matmul(x, self.weight)
         if self.has_bias:
-            x = bias_add(x, bias)
+            x = self.bias_add(x, self.bias)
         if self.activation_flag:
             x = self.activation(x)
+        if len(x_shape) != 2:
+            out_shape = x_shape[:-1] + (-1,)
+            x = self.reshape(x, out_shape)
         return x
 
     def extend_repr(self):