Issue #1185 (Implemented c_code for AdvancedSubtensor1): Do not cast if indices…

theano/tensor/basic.py

@@ -6549,7 +6549,8 @@ class AdvancedSubtensor1(Op):
         # TypeError: array cannot be safely cast to required type.
         # Since we will probably not have an array with more than 2**31 items
         # on a 32-bit arch, I suppose it is safe to cast i into intp.
-        i = theano._asarray(i, dtype=numpy.intp)
+        if i.dtype != numpy.intp:
+            i = theano._asarray(i, dtype=numpy.intp)
 
         out[0] = x.take(i, axis=0, out=o)
 
@@ -6594,11 +6595,17 @@ class AdvancedSubtensor1(Op):
         fail = sub['fail']
         return """
             PyObject *indices;
-            // This cast makes c_code mimic the logic in perform(), but
-            // also makes theano code less safe.
-            indices = PyArray_Cast(%(i_name)s, NPY_INTP);
-            if (indices == NULL) {
-                %(fail)s;
+            if (PyArray_TYPE(%(i_name)s) != NPY_INTP) {
+                // This cast makes c_code mimic the logic in perform(), but
+                // also makes theano code less safe.
+                indices = PyArray_Cast(%(i_name)s, NPY_INTP);
+                if (indices == NULL) {
+                    %(fail)s;
+                }
+            }
+            else {
+                 indices = (PyObject *)%(i_name)s;
+                 Py_INCREF(indices);
             }
             if (%(output_name)s != NULL) {
                 npy_intp nd, i, *shape;