Migrate pruning assign to 2.X/1.X public APIs.

PiperOrigin-RevId: 286029751

Author: alanchiao

tensorflow_model_optimization/python/core/sparsity/keras/BUILD

@@ -132,7 +132,6 @@ py_library(
     deps = [
         ":pruning_utils",
         # tensorflow dep1,
-        # python:state_ops tensorflow dep2,
         # python:summary tensorflow dep2,
     ],
 )

tensorflow_model_optimization/python/core/sparsity/keras/pruning_impl.py

@@ -20,12 +20,11 @@
 
 import tensorflow as tf
 
-# b/(139939526): update assign ops to v2 API.
-from tensorflow.python.ops import state_ops
 from tensorflow.python.ops import summary_ops_v2
 from tensorflow.python.summary import summary as summary_ops_v1
 from tensorflow_model_optimization.python.core.sparsity.keras import pruning_utils
 
+
 class Pruning(object):
   """Implementation of magnitude-based weight pruning."""
 
@@ -54,6 +53,13 @@ def __init__(self, training_step_fn, pruning_vars, pruning_schedule,
 
     self._validate_block()
 
+  @staticmethod
+  def _assign(ref, value):
+    if tf.__version__[0] == '1':
+      return tf.assign(ref, value)
+    else:
+      return ref.assign(value)
+
   def _validate_block(self):
     if self._block_size != [1, 1]:
       for weight, _, _ in self._pruning_vars:
@@ -144,8 +150,15 @@ def _maybe_update_block_mask(self, weights):
          squeezed_weights.get_shape()[1]])
     return new_threshold, tf.reshape(sliced_mask, tf.shape(weights))
 
-  def _get_weight_assign_ops(self):
-    """Gather the assign ops for assigning weights<=weights*mask."""
+  def _weight_assign_objs(self):
+    """Gather the assign objs for assigning weights<=weights*mask.
+
+    The objs are ops for graph execution and tensors for eager
+    execution.
+
+    Returns:
+      group of objs for weight assignment.
+    """
 
     def update_fn(distribution, values_and_vars):
       # TODO(yunluli): Need this ReduceOp because the weight is created by the
@@ -158,34 +171,34 @@ def update_fn(distribution, values_and_vars):
       values_and_vars = zip(reduced_values, var_list)
 
       def update_var(variable, reduced_value):
-        return state_ops.assign(variable, reduced_value)
+        return self._assign(variable, reduced_value)
 
-      update_ops = []
+      update_objs = []
       for value, var in values_and_vars:
-        update_ops.append(
+        update_objs.append(
             distribution.extended.update(var, update_var, args=(value,)))
 
-      return tf.group(update_ops)
+      return tf.group(update_objs)
 
-    assign_ops = []
+    assign_objs = []
 
     if tf.distribute.get_replica_context():
       values_and_vars = []
       for weight, mask, _ in self._pruning_vars:
         masked_weight = tf.math.multiply(weight, mask)
         values_and_vars.append((masked_weight, weight))
       if values_and_vars:
-        assign_ops.append(tf.distribute.get_replica_context().merge_call(
+        assign_objs.append(tf.distribute.get_replica_context().merge_call(
             update_fn, args=(values_and_vars,)))
     else:
       for weight, mask, _ in self._pruning_vars:
         masked_weight = tf.math.multiply(weight, mask)
-        assign_ops.append(state_ops.assign(weight, masked_weight))
+        assign_objs.append(self._assign(weight, masked_weight))
 
-    return assign_ops
+    return assign_objs
 
   def weight_mask_op(self):
-    return tf.group(self._get_weight_assign_ops())
+    return tf.group(self._weight_assign_objs())
 
   def conditional_mask_update(self):
     """Returns an op to updates masks as per the pruning schedule."""
@@ -200,35 +213,39 @@ def mask_update():
       """Updates mask without distribution strategy."""
 
       def update():
-        assign_ops = []
+        assign_objs = []
 
         for weight, mask, threshold in self._pruning_vars:
           new_threshold, new_mask = self._maybe_update_block_mask(weight)
-          assign_ops.append(state_ops.assign(threshold, new_threshold))
-          assign_ops.append(state_ops.assign(mask, new_mask))
+          assign_objs.append(self._assign(threshold, new_threshold))
+          assign_objs.append(self._assign(mask, new_mask))
 
-        return tf.group(assign_ops)
+        return tf.group(assign_objs)
 
       return tf.cond(maybe_update_masks(), update, no_update)
 
     def mask_update_distributed(distribution):
       """Updates mask with distribution strategy."""
 
       def update(var, value):
-        return state_ops.assign(var, value)
+        return self._assign(var, value)
 
       def update_distributed():
-        """Gather distributed update ops."""
-        assign_ops = []
+        """Gather distributed update objs.
+
+        The objs are ops for graph execution and tensors for eager
+        execution.
+        """
+        assign_objs = []
 
         for weight, mask, threshold in self._pruning_vars:
           new_threshold, new_mask = self._maybe_update_block_mask(weight)
-          assign_ops.append(
+          assign_objs.append(
               distribution.extended.update(mask, update, (new_mask,)))
-          assign_ops.append(
+          assign_objs.append(
               distribution.extended.update(threshold, update, (new_threshold,)))
 
-        return tf.group(assign_ops)
+        return tf.group(assign_objs)
 
       return tf.cond(maybe_update_masks(), update_distributed, no_update)
 

tensorflow_model_optimization/python/core/sparsity/keras/pruning_impl_test.py

@@ -59,7 +59,7 @@ def setUp(self):
   # setUp() lies outside of the "eager scope" that wraps the test cases
   # themselves, resulting in initializing graph tensors instead of eager
   # tensors when testing eager execution.
-  def initialize_training_step_fn_and_all_variables(self):
+  def initialize(self):
     self.global_step = tf.Variable(
         tf.zeros([], dtype=dtypes.int32),
         dtype=dtypes.int32,
@@ -81,7 +81,7 @@ def testUpdateSingleMask(self):
         dtype=weight_dtype)
     threshold = tf.Variable(
         tf.zeros([], dtype=weight_dtype), name="threshold", dtype=weight_dtype)
-    self.initialize_training_step_fn_and_all_variables()
+    self.initialize()
 
     p = pruning_impl.Pruning(
         pruning_vars=[(weight, mask, threshold)],
@@ -102,7 +102,7 @@ def testUpdateSingleMask(self):
     self.assertAllEqual(np.count_nonzero(mask_after_pruning), 50)
 
   def testConstructsMaskAndThresholdCorrectly(self):
-    self.initialize_training_step_fn_and_all_variables()
+    self.initialize()
     p = pruning_impl.Pruning(
         lambda: 0, None,
         # Sparsity math often returns values with small tolerances.
@@ -125,7 +125,7 @@ def _blockMasking(self, block_size, block_pooling_type, weight,
         dtype=weight.dtype)
     threshold = tf.Variable(
         tf.zeros([], dtype=weight.dtype), name="threshold", dtype=weight.dtype)
-    self.initialize_training_step_fn_and_all_variables()
+    self.initialize()
 
     # Set up pruning
     p = pruning_impl.Pruning(
@@ -163,7 +163,7 @@ def testBlockMaskingMax(self):
     self._blockMasking(block_size, block_pooling_type, weight, expected_mask)
 
   def testBlockMaskingWithHigherDimensionsRaisesError(self):
-    self.initialize_training_step_fn_and_all_variables()
+    self.initialize()
     block_size = (2, 2)
     block_pooling_type = "AVG"
     # Weights as in testBlockMasking, but with one extra dimension.
@@ -186,7 +186,7 @@ def testConditionalMaskUpdate(self):
         dtype=weight_dtype)
     threshold = tf.Variable(
         tf.zeros([], dtype=weight_dtype), name="threshold", dtype=weight_dtype)
-    self.initialize_training_step_fn_and_all_variables()
+    self.initialize()
 
     def linear_sparsity(step):
       sparsity_val = tf.convert_to_tensor(

tensorflow_model_optimization/python/core/sparsity/keras/pruning_wrapper.py

@@ -236,6 +236,8 @@ def no_op():
     # Always execute the op that performs weights = weights * mask
     # Relies on UpdatePruningStep callback to ensure the weights
     # are sparse after the final backpropagation.
+    #
+    # self.add_update does nothing during eager execution.
     self.add_update(self.pruning_obj.weight_mask_op())
 
     return self.layer.call(inputs)