added n_calls option to CLazyLinker to accelerate repeated calls

theano/gof/lazylinker_c.c

@@ -675,15 +675,22 @@ PyObject *
 CLazyLinker_call(PyObject *_self, PyObject *args, PyObject *kwds)
 {
   CLazyLinker * self = (CLazyLinker*)_self;
-  static char *kwlist[] = {(char*)"time_thunks", NULL};
-  if (! PyArg_ParseTupleAndKeywords(args, kwds, "|i", kwlist,
-                                    &self->do_timing))
+  static char *kwlist[] = {
+    (char*)"time_thunks",
+    (char *)"n_calls",
+    NULL};
+  int n_calls=1;
+  if (! PyArg_ParseTupleAndKeywords(args, kwds, "|ii", kwlist,
+                                    &self->do_timing,
+                                    &n_calls))
     return NULL;
   int err = 0;
   self->position_of_error = -1;
   PyObject * one = PyInt_FromLong(1);
   PyObject * zero = PyInt_FromLong(0);
   //clear storage of pre_call_clear elements
+  for (int call_i = 0; call_i < n_calls && (!err); ++call_i)
+    {
       Py_ssize_t n_pre_call_clear = PyList_Size(self->pre_call_clear);
       assert(PyList_Check(self->pre_call_clear));
       for (int i = 0; i < n_pre_call_clear; ++i)
@@ -712,6 +719,7 @@ CLazyLinker_call(PyObject *_self, PyObject *args, PyObject *kwds)
         {
           err = lazy_rec_eval(self, self->output_vars[i], one, zero);
         }
+    }
   Py_DECREF(one);
   Py_DECREF(zero);
   if (err) return NULL;