Add theano.gpuarray.use similar to theano.sandbox.cuda.use() to manually enable it.

theano/gpuarray/__init__.py

@@ -110,15 +110,36 @@ def init_dev(dev, name=None):
 # This maps things like 'cuda0' to the context object on that device.
 init_dev.devmap = {}
 
+
+def use(device,
+        force=False,
+        default_to_move_computation_to_gpu=True,
+        move_shared_float32_to_gpu=True):
+    if device:
+        init_dev(device)
+    elif forece:
+        raise Exception("No device provided")
+    if default_to_move_computation_to_gpu:
+        optdb.add_tags('gpuarray_opt', 'fast_run', 'fast_compile')
+        optdb.add_tags('gpua_scanOp_make_inplace', 'fast_run')
+    if move_shared_float32_to_gpu:
+        import theano.compile
+        theano.compile.shared_constructor(gpuarray_shared_constructor)
+
+    from .basic_ops import (GpuAlloc, GpuAllocEmpty, GpuContiguous, GpuEye,
+                            GpuFromHost, GpuJoin, GpuReshape, GpuSplit,
+                            HostFromGpu)
+    from .basic_ops import host_from_gpu, GpuFromHost
+    from .elemwise import GpuElemwise
+    from .subtensor import (GpuSubtensor, GpuIncSubtensor,
+                            GpuAdvancedIncSubtensor1)
+
+
 if pygpu:
     try:
         if (config.device.startswith('cuda') or
             config.device.startswith('opencl')):
-            init_dev(config.device)
-            import theano.compile
-            theano.compile.shared_constructor(gpuarray_shared_constructor)
-            optdb.add_tags('gpuarray_opt', 'fast_run', 'fast_compile')
-            optdb.add_tags('gpua_scanOp_make_inplace', 'fast_run')
+            use(config.device)
         elif (config.init_gpu_device.startswith('cuda') or
               config.init_gpu_device.startswith('opencl')):
             if config.device != 'cpu':
@@ -130,18 +151,8 @@ if pygpu:
         if config.contexts != '':
             for n, d in (c.split('->') for c in config.contexts.split(';')):
                 init_dev(d.strip(), n.strip())
-            import theano.compile
-            theano.compile.shared_constructor(gpuarray_shared_constructor)
-            optdb.add_tags('gpuarray_opt', 'fast_run', 'fast_compile')
-            optdb.add_tags('gpua_scanOp_make_inplace', 'fast_run')
-
-        from .basic_ops import (GpuAlloc, GpuAllocEmpty, GpuContiguous, GpuEye,
-                                GpuFromHost, GpuJoin, GpuReshape, GpuSplit,
-                                HostFromGpu)
-        from .basic_ops import host_from_gpu, GpuFromHost
-        from .elemwise import GpuElemwise
-        from .subtensor import (GpuSubtensor, GpuIncSubtensor,
-                                GpuAdvancedIncSubtensor1)
+            # To have shared var default on the GPU and opt to move to the GPU.
+            use("")
 
     except Exception:
         error("Could not initialize pygpu, support disabled", exc_info=True)