move useless_dimshuffle_in_reshape into its own opt

theano/tensor/opt.py

@@ -559,7 +559,7 @@ def is_dimshuffle_useless(new_order, input):
     return is_useless
 
 
-@gof.local_optimizer([DimShuffle, Reshape])
+@gof.local_optimizer([DimShuffle])
 def local_dimshuffle_lift(node):
     """
     "Lifts" DimShuffle through Elemwise operations and merges
@@ -573,33 +573,8 @@ def local_dimshuffle_lift(node):
     After this transform, clusters of Elemwise operations are
     void of DimShuffle operations.
 
-    Also removes useless DimShuffle operation inside Reshape:
-
-      reshape(vector.dimshuffle('x', 0), shp) => reshape(vector, shp)
-      reshape(matrix.dimshuffle('x', 0, 'x', 1), shp) => reshape(matrix, shp)
-      reshape(row.dimshuffle(1, 'x'), shp) => reshape(row, shp)
-      reshape(col.dimshuffle(0), shp) => reshape(col, shp)
-
     """
     op = node.op
-    if (isinstance(op, Reshape) and
-            node.inputs[0].owner is not None and
-            isinstance(node.inputs[0].owner.op, DimShuffle)):
-        new_order = node.inputs[0].owner.op.new_order
-        input = node.inputs[0].owner.inputs[0]
-        broadcastables = node.inputs[0].broadcastable
-        new_order_of_nonbroadcastables = []
-        for i, bd in zip(new_order, broadcastables):
-            if not bd:
-                new_order_of_nonbroadcastables.append(i)
-        no_change_in_order = all(
-            new_order_of_nonbroadcastables[i] <= new_order_of_nonbroadcastables[i + 1]
-            for i in xrange(len(new_order_of_nonbroadcastables) - 1))
-        if no_change_in_order:
-            shape = node.inputs[1]
-            ret = op.__class__(node.outputs[0].ndim)(input, shape)
-            copy_stack_trace(node.outputs[0], ret)
-            return [ret]
     if not isinstance(op, DimShuffle):
         return False
 
@@ -633,6 +608,42 @@ def local_dimshuffle_lift(node):
         return [ret]
 
 
+@register_canonicalize
+@gof.local_optimizer([Reshape])
+def local_useless_dimshuffle_in_reshape(node):
+    """
+    Removes useless DimShuffle operation inside Reshape:
+
+      reshape(vector.dimshuffle('x', 0), shp) => reshape(vector, shp)
+      reshape(matrix.dimshuffle('x', 0, 'x', 1), shp) => reshape(matrix, shp)
+      reshape(row.dimshuffle(1, 'x'), shp) => reshape(row, shp)
+      reshape(col.dimshuffle(0), shp) => reshape(col, shp)
+
+    """
+    op = node.op
+    if not isinstance(op, Reshape):
+        return False
+    if not (node.inputs[0].owner is not None and
+            isinstance(node.inputs[0].owner.op, DimShuffle)):
+        return False
+
+    new_order = node.inputs[0].owner.op.new_order
+    input = node.inputs[0].owner.inputs[0]
+    broadcastables = node.inputs[0].broadcastable
+    new_order_of_nonbroadcast = []
+    for i, bd in zip(new_order, broadcastables):
+        if not bd:
+            new_order_of_nonbroadcast.append(i)
+    no_change_in_order = all(
+        new_order_of_nonbroadcast[i] <= new_order_of_nonbroadcast[i + 1]
+        for i in xrange(len(new_order_of_nonbroadcast) - 1))
+    if no_change_in_order:
+        shape = node.inputs[1]
+        ret = op.__class__(node.outputs[0].ndim)(input, shape)
+        copy_stack_trace(node.outputs[0], ret)
+        return [ret]
+
+
 @register_canonicalize
 @gof.local_optimizer([T.DimShuffle])
 def local_lift_transpose_through_dot(node):

theano/tensor/tests/test_opt.py

@@ -12,7 +12,7 @@ import unittest
 import numpy
 from six.moves import xrange
 from nose.plugins.skip import SkipTest
-from nose.tools import assert_raises
+from nose.tools import assert_raises, assert_true
 from numpy.testing import dec
 from numpy.testing.noseclasses import KnownFailureTest
 
@@ -32,6 +32,7 @@ import theano.tensor.opt as opt
 from theano.tensor.opt import (
         local_add_specialize,
         local_dimshuffle_lift,
+        local_useless_dimshuffle_in_reshape,
         local_useless_alloc,
         local_greedy_distributor,
         local_useless_reshape,
@@ -223,7 +224,8 @@ class test_dimshuffle_lift(unittest.TestCase):
         # Check stacktrace was copied over correctly after opt was applied
         self.assertTrue(hasattr(g.outputs[0].tag, 'trace'))
 
-    def test_useless_dimshuffle_in_presence_of_reshape(self):
+
+def test_useless_dimshuffle_in_reshape():
     vector = TensorType(broadcastable=(False,), dtype='float64')('vector')
     mat = TensorType(broadcastable=(False, False), dtype='float64')('mat')
     row = TensorType(broadcastable=(True, False), dtype='float64')('row')
@@ -238,17 +240,18 @@ class test_dimshuffle_lift(unittest.TestCase):
                       [reshape_dimshuffle_vector, reshape_dimshuffle_mat,
                        reshape_dimshuffle_row, reshape_dimshuffle_col])
 
-        self.assertTrue(str(g) == "[Reshape{1}(DimShuffle{x,0}(vector), Shape(vector)), "
+    assert_true(str(g) == "[Reshape{1}(DimShuffle{x,0}(vector), Shape(vector)), "
                           "Reshape{2}(DimShuffle{x,0,x,1}(mat), Shape(mat)), "
                           "Reshape{2}(DimShuffle{1,x}(row), Shape(row)), "
                           "Reshape{2}(DimShuffle{0}(col), Shape(col))]")
-        dimshuffle_lift.optimize(g)
-        self.assertTrue(str(g) == "[Reshape{1}(vector, Shape(vector)), "
+    useless_dimshuffle_in_reshape = out2in(local_useless_dimshuffle_in_reshape)
+    useless_dimshuffle_in_reshape.optimize(g)
+    assert_true(str(g) == "[Reshape{1}(vector, Shape(vector)), "
                           "Reshape{2}(mat, Shape(mat)), "
                           "Reshape{2}(row, Shape(row)), "
                           "Reshape{2}(col, Shape(col))]")
     # Check stacktrace was copied over correctly after opt was applied
-        self.assertTrue(hasattr(g.outputs[0].tag, 'trace'))
+    assert_true(hasattr(g.outputs[0].tag, 'trace'))
 
 
 def test_add_canonizer_problem0():