gpu Elemwise uses custom exception SupportCodeError

theano/sandbox/cuda/elemwise.py

@@ -28,6 +28,10 @@ def get_str_list_logical_scalar(node, value_str='ii_i%i_value', data_str='ii_i%i
         else: l+=[data_str%ipos]
     return l
 
+class SupportCodeError(Exception):
+    """It is currently not possible to auto-generate a GPU implementation for
+    an elementwise Op with support code."""
+
 class NaiveAlgo(object):
     verbose = 0 # 1, 2 or 3 for more verbose output.
     cache_version = ()
@@ -39,9 +43,7 @@ class NaiveAlgo(object):
         :param sync: if True, will wait after the kernel launch and check for error call.
         """
         if scalar_op.c_support_code_apply(node=None, nodename="nodename"):
-            raise ValueError(('It is currently not possible to auto-generate'
-                    ' a GPU implementation for an elementwise Op with support'
-                    ' code'), scalar_op)
+            raise SupportCodeError(scalar_op)
         self.scalar_op = scalar_op
         self.sync = sync
         self.inplace_pattern = inplace_pattern

theano/sandbox/cuda/opt.py

@@ -22,6 +22,7 @@ from theano.sandbox.cuda.nnet import (
         GpuCrossentropySoftmaxArgmax1HotWithBias,
         GpuCrossentropySoftmax1HotWithBiasDx,
         GpuSoftmax, GpuSoftmaxWithBias)
+from theano.sandbox.cuda.elemwise import SupportCodeError
 from theano.compile import optdb
 from theano.tensor.blas import _is_real_vector, _is_real_matrix
 
@@ -146,7 +147,7 @@ def local_gpu_elemwise_0(node):
                 # gpu_inplace_elemwise_optimizer will do it later
                 try:
                     new_op = GpuElemwise(node.op.scalar_op)
-                except ValueError:
+                except SupportCodeError:
                     # This happens when scalar_op requires support code
                     return False
 
@@ -194,7 +195,7 @@ def local_gpu_elemwise_1(node):
             # gpu_inplace_elemwise_optimizer will do it later
             try:
                 new_op = GpuElemwise(elemwise_node.op.scalar_op)
-            except ValueError:
+            except SupportCodeError:
                 # This happens when scalar_op requires support code
                 return False
             if all([i.dtype=='float32' for i in elemwise_node.inputs]):