Remove the undocumented and unused tag.context_name.

theano/sandbox/gpuarray/opt.py

@@ -172,25 +172,24 @@ class InputToGpuOptimizer(Optimizer):
                     for cl in input.clients)):
                 continue
 
-            target = getattr(input.tag, 'target', None)
-            if target == 'cpu':
-                continue
+            if input.type.dtype.startswith('float'):
+                default = None
+            else:
+                default = 'cpu'
 
-            if (not input.type.dtype.startswith('float') and
-                    not hasattr(input.tag, 'target')):
+            target = getattr(input.tag, 'target', default)
+            if target == 'cpu':
                 continue
 
-            ctx_name = getattr(input.tag, 'context_name', target)
             try:
-                new_input = host_from_gpu(GpuFromHost(ctx_name)(input))
+                new_input = host_from_gpu(GpuFromHost(target)(input))
                 fgraph.replace_validate(input, new_input,
                                         "InputToGpuOptimizer")
             except TypeError:
                 # This could fail if the inputs are not TensorTypes
                 pass
             except ContextNotDefined:
-                if (hasattr(input.tag, 'context_name') or
-                    hasattr(input.tag, 'target')):
+                if hasattr(input.tag, 'target'):
                     raise
                 # If there is no context tag and no default context
                 # then it stays on the CPU