[QNN][TFLite] Parsing QNN Add op. Adding MobilenetV2.

Author: anijain2305

python/tvm/relay/frontend/tflite.py

@@ -224,6 +224,18 @@ def has_same_qnn_params(self, lhs_tensor, rhs_tensor):
         return lhs_tensor.qnn_params['scale'] == rhs_tensor.qnn_params['scale'] and \
                 lhs_tensor.qnn_params['zero_point'] == rhs_tensor.qnn_params['zero_point']
 
+    def is_quantized(self, op):
+        """Check if an input tensor is quantized."""
+        try:
+            from tflite.Operator import Operator
+        except ImportError:
+            raise ImportError("The tflite package must be installed")
+
+        assert isinstance(op, Operator)
+        input_tensors = self.get_input_tensors(op)
+        first_tensor = input_tensors[0]
+        return first_tensor.qnn_params is not None
+
     def convert_conv2d(self, op):
         """Convert TFLite conv2d"""
         return self.convert_conv(op, "conv2d")
@@ -498,7 +510,25 @@ def _convert_elemwise(self, relay_op, op):
             rhs_type_str = self.get_tensor_type_str(rhs_tensor.tensor.Type())
             rhs_expr = self.exp_tab.new_const(self.get_tensor_value(rhs_tensor),
                                               dtype=rhs_type_str)
-        out = relay_op(lhs_expr, rhs_expr)
+
+        output_tensors = self.get_output_tensors(op)
+        assert len(output_tensors) == 1, "output tensors length should be 1"
+        output_tensor = output_tensors[0]
+
+        # If quantized, extracts qnn params and call QNN add operator.
+        if lhs_tensor.qnn_params:
+            assert rhs_tensor.qnn_params, "Both tensors should be quantized."
+            assert output_tensor.qnn_params, "Output tensor should be quantized."
+            out = relay_op(lhs=lhs_expr,
+                           rhs=rhs_expr,
+                           lhs_scale=lhs_tensor.qnn_params['scale'],
+                           lhs_zero_point=lhs_tensor.qnn_params['zero_point'],
+                           rhs_scale=rhs_tensor.qnn_params['scale'],
+                           rhs_zero_point=rhs_tensor.qnn_params['zero_point'],
+                           output_scale=output_tensor.qnn_params['scale'],
+                           output_zero_point=output_tensor.qnn_params['zero_point'])
+        else:
+            out = relay_op(lhs_expr, rhs_expr)
 
         # Options (fused_activation_function)
         options = None
@@ -517,36 +547,70 @@ def _convert_elemwise(self, relay_op, op):
             fused_activation_fn = options.FusedActivationFunction()
             # if we have activation fn
             if fused_activation_fn != ActivationFunctionType.NONE:
+                if output_tensor.qnn_params:
+                    raise tvm.error.OpNotImplemented(
+                        'Elemwise operators with fused activation are not supported yet.')
                 out = self.convert_fused_activation_function(out, fused_activation_fn)
 
         return out
 
     def convert_add(self, op):
         """Convert TFLite ADD"""
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            return self._convert_elemwise(_qnn.op.add, op)
         return self._convert_elemwise(_op.add, op)
 
     def convert_sub(self, op):
         """Convert TFLite SUB"""
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized sub operator is not supported yet.')
         return self._convert_elemwise(_op.subtract, op)
 
     def convert_mul(self, op):
         """Convert TFLite MUL"""
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized mul operator is not supported yet.')
         return self._convert_elemwise(_op.multiply, op)
 
     def convert_div(self, op):
         """Convert TFLite DIV"""
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized div operator is not supported yet.')
         return self._convert_elemwise(_op.divide, op)
 
     def convert_pow(self, op):
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized pow operator is not supported yet.')
         return self._convert_elemwise(_op.power, op)
 
     def convert_maximum(self, op):
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized maximum operator is not supported yet.')
         return self._convert_elemwise(_op.maximum, op)
 
     def convert_minimum(self, op):
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized minimum operator is not supported yet.')
         return self._convert_elemwise(_op.minimum, op)
 
     def convert_greater(self, op):
+        # Check if the input tensor is quantized, call QNN op
+        if self.is_quantized(op):
+            raise tvm.error.OpNotImplemented(
+                'TFlite quantized greater operator is not supported yet.')
         return self._convert_elemwise(_op.greater, op)
 
     def convert_zeros_like(self, op):

tests/python/frontend/tflite/test_forward.py

@@ -1037,6 +1037,26 @@ def test_forward_qnn_mobilenet_v1_net():
     tvm_sorted_labels = tvm_predictions.argsort()[-3:][::-1]
     tvm.testing.assert_allclose(tvm_sorted_labels, tflite_sorted_labels)
 
+def test_forward_qnn_mobilenet_v2_net():
+    """Test the Quantized TFLite Mobilenet V2 model."""
+    # MobilenetV2
+    tflite_model_file = tf_testing.get_workload_official(
+        "https://storage.googleapis.com/download.tensorflow.org/models/tflite_11_05_08/mobilenet_v2_1.0_224_quant.tgz",
+        "mobilenet_v2_1.0_224_quant.tflite")
+    with open(tflite_model_file, "rb") as f:
+        tflite_model_buf = f.read()
+    # Checking the labels because the requantize implementation is different between TFLite and
+    # Relay. This cause final output numbers to mismatch. So, testing accuracy via labels.
+    np.random.seed(0)
+    data = np.random.random_integers(low=0, high=128, size=(1, 224, 224, 3)).astype('uint8')
+    tflite_output = run_tflite_graph(tflite_model_buf, data)
+    tflite_predictions = np.squeeze(tflite_output)
+    tflite_sorted_labels = tflite_predictions.argsort()[-3:][::-1]
+    tvm_output = run_tvm_graph(tflite_model_buf, data, 'input')
+    tvm_predictions = np.squeeze(tvm_output)
+    tvm_sorted_labels = tvm_predictions.argsort()[-3:][::-1]
+    tvm.testing.assert_allclose(tvm_sorted_labels, tflite_sorted_labels)
+
 #######################################################################
 # SSD Mobilenet
 # -------------
@@ -1111,6 +1131,6 @@ def test_forward_ssd_mobilenet_v1():
     test_forward_ssd_mobilenet_v1()
 
     # End to End quantized
-    # TODO - MobilenetV2 fails for now. Remove when fixed.
     test_forward_qnn_inception_v1_net()
     test_forward_qnn_mobilenet_v1_net()
+    test_forward_qnn_mobilenet_v2_net()