!1992 fix lstm weight initializer

Merge pull request !1992 from baihuawei/cpulstm

mindspore/ccsrc/kernel/cpu/mkldnn/lstm_cpu_kernel.cc

@@ -27,6 +27,7 @@ void LstmCPUKernel::InitKernel(const CNodePtr &kernel_node) {
   using dim = dnnl::memory::dims;
   std::vector<size_t> src_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 0);
   std::vector<size_t> src_h_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 1);
+  std::vector<size_t> src_c_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 2);
   bidirectional_ = AnfAlgo::GetNodeAttr<bool>(kernel_node, "bidirectional");
   input_size_ = AnfAlgo::GetNodeAttr<int>(kernel_node, "input_size");
   hidden_size_ = AnfAlgo::GetNodeAttr<int>(kernel_node, "hidden_size");
@@ -41,6 +42,12 @@ void LstmCPUKernel::InitKernel(const CNodePtr &kernel_node) {
   if (num_directions_ * num_layers_ != SizeToInt(src_h_shape[0])) {
     MS_LOG(EXCEPTION) << "error iteration shape!";
   }
+  if (num_layers_ <= 0) {
+    MS_LOG(EXCEPTION) << "layers must be greater than zero!";
+  }
+  if (src_shape.size() != 3 || src_h_shape.size() != 3 || src_c_shape.size() != 3) {
+    MS_LOG(EXCEPTION) << "conv2d only support 3-D input!";
+  }
   const int gate_size = 4 * hidden_size_;
   for (int i = 0; i < num_layers_; ++i) {
     weight_size_ += gate_size * (i == 0 ? input_size_ : hidden_size_ * num_directions_);

mindspore/ccsrc/kernel/cpu/mkldnn/lstm_grad_cpu_kernel.cc

@@ -31,6 +31,7 @@ void LSTMGradCPUKernel::InitKernel(const CNodePtr &kernel_node) {
   auto eng = MKLKernelEngine::Get().engine();
   std::vector<size_t> src_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 0);
   std::vector<size_t> src_h_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 1);
+  std::vector<size_t> src_c_shape = AnfAlgo::GetInputDeviceShape(kernel_node, 2);
   bidirectional_ = AnfAlgo::GetNodeAttr<bool>(kernel_node, "bidirectional");
   input_size_ = AnfAlgo::GetNodeAttr<int>(kernel_node, "input_size");
   hidden_size_ = AnfAlgo::GetNodeAttr<int>(kernel_node, "hidden_size");
@@ -45,6 +46,12 @@ void LSTMGradCPUKernel::InitKernel(const CNodePtr &kernel_node) {
   if (num_directions_ * num_layers_ != SizeToInt(src_h_shape[0])) {
     MS_LOG(EXCEPTION) << "error iteration shape!";
   }
+  if (num_layers_ <= 0) {
+    MS_LOG(EXCEPTION) << "layers must be greater than zero!";
+  }
+  if (src_shape.size() != 3 || src_h_shape.size() != 3 || src_c_shape.size() != 3) {
+    MS_LOG(EXCEPTION) << "conv2d only support 3-D input!";
+  }
   const int gate_size = 4 * hidden_size_;
   for (int i = 0; i < num_layers_; ++i) {
     weight_size_ += gate_size * (i == 0 ? input_size_ : hidden_size_ * num_directions_);

mindspore/nn/layer/lstm.py

@@ -13,8 +13,8 @@
 # limitations under the License.
 # ============================================================================
 """lstm"""
+import math
 import numpy as np
-
 import mindspore.nn as nn
 from mindspore import context
 from mindspore._checkparam import Validator as validator
@@ -148,7 +148,9 @@ class LSTM(Cell):
                 if self.has_bias:
                     increment_size += 2 * gate_size
                 weight_size += increment_size * num_directions
-            self.weight = Parameter(initializer(0.0, [weight_size, 1, 1]), name='weight')
+            stdv = 1 / math.sqrt(hidden_size)
+            w_np = np.random.uniform(-stdv, stdv, (weight_size, 1, 1)).astype(np.float32)
+            self.weight = Parameter(initializer(Tensor(w_np), [weight_size, 1, 1]), name='weight')
         else:
             input_size_list = []
             input_size_list.append(self.input_size)
@@ -157,14 +159,13 @@ class LSTM(Cell):
             weights = []
             layers = []
             bias_size = 0 if not self.has_bias else num_directions * self.hidden_size * 4
+            stdv = 1 / math.sqrt(hidden_size)
             for i in range(num_layers):
                 weight_size = (input_size_list[i] + self.hidden_size) * num_directions * self.hidden_size * 4
-                w_np = np.ones([weight_size, 1, 1]).astype(np.float32) * 0.01
                 if has_bias:
-                    bias_np = np.zeros([bias_size, 1, 1]).astype(np.float32)
-                    w_np = np.concatenate([w_np, bias_np], axis=0)
+                    weight_size = weight_size + bias_size
+                w_np = np.random.uniform(-stdv, stdv, (weight_size, 1, 1)).astype(np.float32)
                 weights.append(Parameter(initializer(Tensor(w_np), w_np.shape), name='weight' + str(i)))
-
                 layers.append(nn.LSTMCell(input_size=input_size_list[i],
                                           hidden_size=self.hidden_size,
                                           has_bias=self.has_bias,