gpuarray opt to move shape to the GPU.

theano/sandbox/gpuarray/opt.py

@@ -290,6 +290,16 @@ def local_gpua_specifyShape(node):
     return tensor.specify_shape(*inp)
 
 
+@register_opt('fast_compile')
+@op_lifter([theano.compile.ops.Shape])
+def local_gpua_shape(node):
+    # op_lifter will call this opt too frequently as the output is
+    # always on the CPU.
+    if isinstance(node.inputs[0].type, GpuArrayType):
+        return
+    return [gpu_from_host(node.inputs[0]).shape]
+
+
 def gpu_print_wrapper(op, cnda):
     op.old_op.global_fn(op.old_op, numpy.asarray(cnda))
 

theano/sandbox/gpuarray/tests/test_opt.py

@@ -4,7 +4,8 @@ import theano
 from theano import tensor
 from theano.tests import unittest_tools as utt
 import theano.sandbox.gpuarray
-from theano.sandbox.gpuarray.type import GpuArrayType
+from theano.sandbox.gpuarray.type import (
+    GpuArrayType, gpuarray_shared_constructor)
 from theano.sandbox.gpuarray.basic_ops import (
     GpuAlloc, GpuReshape, gpu_alloc, gpu_from_host, host_from_gpu)
 from theano.sandbox.gpuarray.elemwise import (