[Darknet] softmax temperature in frontend (#1429)

nnvm/python/nnvm/frontend/darknet.py

@@ -260,6 +260,9 @@ def _darknet_reshape(inputs, attrs):
 
 def _darknet_softmax_output(inputs, attrs):
     """Process the softmax operation."""
+    temperature = attrs.get('temperature', 1)
+    if temperature != 1:
+        inputs[0] = inputs[0] / float(temperature)
     op_name, new_attrs = 'softmax', {}
     if _darknet_parse_bool_str(attrs, 'multi_output'):
         new_attrs['axis'] = 1
@@ -529,6 +532,8 @@ def _get_darknet_attrs(net, layer_num):
     elif LAYERTYPE.SOFTMAX == layer.type:
         attr.update({'axis' : 1})
         attr.update({'use_flatten' : True})
+        if layer.temperature:
+            attr.update({'temperature' : str(layer.temperature)})
 
     elif LAYERTYPE.SHORTCUT == layer.type:
         add_layer = net.layers[layer.index]

nnvm/tests/python/frontend/darknet/test_forward.py

@@ -267,6 +267,28 @@ def test_forward_elu():
     test_forward(net)
     LIB.free_network(net)
 
+def test_forward_softmax():
+    '''test softmax layer'''
+    net = LIB.make_network(1)
+    layer_1 = LIB.make_softmax_layer(1, 75, 1)
+    layer_1.temperature=1
+    net.layers[0] = layer_1
+    net.w = net.h = 5
+    LIB.resize_network(net, net.w, net.h)
+    test_forward(net)
+    LIB.free_network(net)
+
+def test_forward_softmax_temperature():
+    '''test softmax layer'''
+    net = LIB.make_network(1)
+    layer_1 = LIB.make_softmax_layer(1, 75, 1)
+    layer_1.temperature=0.8
+    net.layers[0] = layer_1
+    net.w = net.h = 5
+    LIB.resize_network(net, net.w, net.h)
+    test_forward(net)
+    LIB.free_network(net)
+
 if __name__ == '__main__':
     test_forward_resnet50()
     test_forward_alexnet()
@@ -279,6 +301,8 @@ if __name__ == '__main__':
     test_forward_shortcut()
     test_forward_dense()
     test_forward_dense_batchnorm()
+    test_forward_softmax()
+    test_forward_softmax_temperature()
     test_forward_reorg()
     test_forward_region()
     test_forward_elu()