Merge, although mq should have helped preventing this...

theano/sandbox/cuda/opt.py

@@ -280,6 +280,15 @@ def local_gpu_shape(node):
             return [gpu_shape(gpu_x)]
     return False
 
+@register_opt()
+@local_optimizer([])
+def local_gpu_rebroadcast(node):
+    '''rebroadcast(host_from_gpu(x)) -> host_from_gpu(rebroadcast(x))'''
+    if isinstance(node.op, tensor.Rebroadcast):
+        x, = node.inputs
+        if (x.owner and x.owner.op == host_from_gpu):
+            gpu_x = x.owner.inputs[0]
+            return [host_from_gpu(node.op(gpu_x))]
 
 def cast(x, dtype):
     stype = theano.scalar.Scalar(dtype)

theano/tensor/basic.py

@@ -2574,6 +2574,11 @@ class Rebroadcast(Op):
     view_map = {0: [0]}
     def __init__(self, *axis):
         self.axis = dict(axis)
+    def __str__(self):
+        broadcast_pattern = ['?' for i in range(1+numpy.max(self.axis.keys()))]
+        for k,v in self.axis.iteritems():
+            broadcast_pattern[k] = str(int(v))
+        return '%s{%s}' % (self.__class__.__name__, ','.join(broadcast_pattern))
     def make_node(self, x):
         t = x.type.__class__(dtype = x.type.dtype,
                        broadcastable = [self.axis.get(i, b)