remove the import of pycuda in the new back-end.

theano/sandbox/gpuarray/elemwise.py

@@ -175,9 +175,34 @@ class GpuElemwise(HideC, Elemwise):
         # implementation
         k = self.generate_kernel(node, nodename)
         nd = node.inputs[0].type.ndim
-        import pycuda._cluda
+        CLUDA_PREAMBLE = """
+#define local_barrier() __syncthreads();
+
+#define WITHIN_KERNEL __device__
+#define KERNEL extern "C" __global__
+#define GLOBAL_MEM /* empty */
+#define LOCAL_MEM __shared__
+#define LOCAL_MEM_ARG /* empty */
+#define REQD_WG_SIZE(X,Y,Z) __launch_bounds__(X*Y*Z, 1)
+
+#define LID_0 threadIdx.x
+#define LID_1 threadIdx.y
+#define LID_2 threadIdx.z
+
+#define GID_0 blockIdx.x
+#define GID_1 blockIdx.y
+#define GID_2 blockIdx.z
+
+#define LDIM_0 blockDim.x
+#define LDIM_1 blockDim.y
+#define LDIM_2 blockDim.z
+
+#define GDIM_0 gridDim.x
+#define GDIM_1 gridDim.y
+#define GDIM_2 gridDim.z
+"""
         res = ["CUdeviceptr (*cuda_get_ptr)(gpudata *g);",
-               pycuda._cluda.CLUDA_PREAMBLE]
+               CLUDA_PREAMBLE]
         for i in range(0, nd + 1):
             res.append(k.render_basic(i, name="elem_" + str(i)) + ';')
         res.append(k.contig_src + ';')