Removed local_fill_cut optimization. Fixed flake8 error.

doc/optimizations.txt

@@ -91,7 +91,7 @@ Optimization                                              FAST_RUN  FAST_COMPILE
         * ``f(fill(a,b), c) -> f(b, c)``
         * ``f(fill(a, b), fill(c, d), e) -> fill(a, fill(c, f(b, d, e)))``
 
-        See :func:`opt.local_fill_cut`, :func:`opt.local_fill_sink`
+        See :func:`opt.local_fill_sink`
 
     inc_subtensor serialization  
         Incrementing a small subregion of a large tensor can be done quickly

theano/tensor/opt.py

@@ -4500,75 +4500,6 @@ if 0:
 # Middleman cuts #
 ##################
 
-
-@gof.local_optimizer([T.Elemwise])
-def local_fill_cut(node):
-    """
-    f(fill(a,b), c) -> f(b, c)
-    If c.type == a.type.
-    """
-    # this optimization is basically for getting broadcasting to
-    # replace fill.  This is always possible when using a Compound
-    # Elemwise operation, but it is not always possible without one
-    # (consider filling a large matrix with a scalar, and then adding
-    # another scalar).  The only numbers that count are the two
-    # scalars, but we can't ignore the large matrix because it gives
-    # the shape of the result.
-
-    # Julian: I've fixed the if line below to check if it's an instance.
-    #         Is this correct?
-    #         Also, I doubt this optimization is being applied anywhere.
-    #         See my comment below.
-
-    # if node.op != T.Elemwise:
-    #    return False
-    if (not isinstance(node.op, T.Elemwise)):
-        return False
-
-    output = node.outputs[0]
-    try:
-        # reference is some input with the same type as the output but
-        # that is not produced by a fill
-        reference = [input
-                     for input in node.inputs
-                     if input.type == output.type and
-                     (not input.owner or input.owner.op != T.fill)][0]
-    except IndexError:
-        return False
-
-    new_inputs = []
-    new = False
-    for input in node.inputs:
-        # Julian: no matter what kind of function I create,
-        #         it seems that input.owner.op == T.fill is never true.
-        #         Somehow the fill ops are replaced by other ops (e.g. Elemwise{second,no_inplace}).
-        #         If that's true, I don't think we have any tests for this opt.
-        if input.owner and input.owner.op == T.fill:
-            model, filling = input.owner.inputs
-            if encompasses_broadcastable(reference.type.broadcastable,
-                                         filling.type.broadcastable):
-                new_inputs.append(filling)
-                new = True
-                continue
-        new_inputs.append(input)
-
-    if not new:
-        return False
-
-    rval = node.op(*new_inputs)
-    # Copy over stacktrace from previous elementwise op output.
-    # Since we are certain that an error in the cg can never come
-    # from the removed fill op, it must come from the elemntwise op.
-    copy_stack_trace(node.outputs, rval)
-
-    if isinstance(rval, gof.Variable):
-        return rval.owner.outputs
-    else:
-        return rval[0].owner.outputs
-
-register_canonicalize(local_fill_cut)
-
-
 register_canonicalize(gof.OpRemove(T.tensor_copy), name='remove_tensor_copy')
 
 ################
@@ -6136,7 +6067,7 @@ def local_add_specialize(node):
         return False
 register_specialize(local_add_specialize)
 
-mul_canonizer = in2out(gof.LocalOptGroup(local_mul_canonizer, local_fill_cut,
+mul_canonizer = in2out(gof.LocalOptGroup(local_mul_canonizer,
                                          local_fill_sink, apply_all_opts=True),
                        name='mul_canonizer_groups')
 
@@ -6342,7 +6273,7 @@ def add_calculate(num, denum, aslist=False, out_type=None):
 
 
 local_add_canonizer = Canonizer(T.add, T.sub, T.neg, add_calculate)
-add_canonizer = in2out(gof.LocalOptGroup(local_add_canonizer, local_fill_cut,
+add_canonizer = in2out(gof.LocalOptGroup(local_add_canonizer,
                                          local_fill_sink, apply_all_opts=True),
                        name='add_canonizer_group')
 

theano/tensor/tests/test_opt.py

@@ -3431,7 +3431,7 @@ def test_local_subtensor_of_alloc():
 
 
 def test_local_fill_useless():
-    # Test opt local_fill_cut
+    # Test opt local_fill_useless
     x = dvector()
     y = dvector()
     z = lvector()
@@ -3446,8 +3446,6 @@ def test_local_fill_useless():
     f = function([x], T.fill(x, x) * 2, mode=mode_opt)
     assert [node.op for node in f.maker.fgraph.toposort()] == [T.mul]
     f(x_)
-    # Julian: This doesn't work. See comments inside local_fill_cut.
-    # assert check_stack_trace(f, ops_to_check='all')
 
     # basic case
     f = function([x, y], T.second(y, x) * 2, mode=mode_opt)
@@ -5659,8 +5657,8 @@ class T_local_sum_prod(unittest.TestCase):
         Test that stack trace is copied over correctly.
         """
         m0 = theano.compile.get_default_mode()\
-         .excluding('inplace_elemwise_opt')\
-         .including('canonicalize', 'specialize')
+            .excluding('inplace_elemwise_opt')\
+            .including('canonicalize', 'specialize')
 
         vect = T.dvector()
         mat = T.dmatrix()