Don't move complex to the GPU in the new back-end.

theano/gpuarray/basic_ops.py

@@ -574,6 +574,8 @@ class GpuFromHost(Op):
     def make_node(self, x):
         if not isinstance(x.type, tensor.TensorType):
             raise TypeError(x)
+        if "complex" in x.dtype:
+            raise TypeError("complex not supported in the new gpuarray back-end.", x)
         return Apply(self, [x], [GpuArrayType(broadcastable=x.broadcastable,
                                               context_name=self.context_name,
                                               dtype=x.dtype)()])

theano/gpuarray/opt.py

@@ -191,8 +191,9 @@ def op_lifter(OP, cuda_only=False):
 
                 # Check if we should replace
                 if (not replace or
-                    (cuda_only and
-                     get_context(context_name).kind != b'cuda')):
+                        (cuda_only and
+                         get_context(context_name).kind != b'cuda') or
+                        any(["complex" in i.dtype for i in node.inputs])):
                     return False
 
                 # tag the inputs with the context in case
@@ -298,7 +299,8 @@ class GraphToGPU(Optimizer):
         for i in fgraph.inputs:
             # Do not move *int* scalar to the GPU.
             if (isinstance(i.type, tensor.TensorType) and
-               (i.ndim > 0 or 'int' not in i.dtype)):
+                    (i.ndim > 0 or 'int' not in i.dtype) and
+                    "complex" not in i.dtype):
                 mapping[i] = i.transfer(getattr(i.tag, 'target', target))
             else:
                 mapping[i] = i
@@ -344,6 +346,9 @@ class GraphToGPU(Optimizer):
                          self.local_optimizers_map.get(type(c.op), []))):
                         move_to_GPU = True
             new_ops = None
+            if move_to_GPU and any(["complex" in i.dtype for i in node.inputs]):
+                move_to_GPU = False
+
             # Apply the lifter
             if move_to_GPU:
                 for lopt in (self.local_optimizers_map.get(node.op, []) +

theano/gpuarray/tests/test_opt.py

@@ -472,3 +472,12 @@ def test_local_assert_no_cpu_op():
         theano.function([], out, mode=mode_local_assert)
     finally:
         theano.config.assert_no_cpu_op = old
+
+
+def test_no_complex():
+    width_var = tensor.cscalar()
+    freq_var = tensor.fscalar()
+    signal_var = tensor.fscalar()
+    stft_out = tensor.exp(width_var * freq_var) * signal_var
+    theano.function([width_var, freq_var, signal_var], stft_out,
+                    mode=mode_with_gpu)