Compile programs even for single device

model.py

@@ -347,8 +347,11 @@ class StaticGraphAdapter(object):
                 startup_prog = self._startup_prog._prune(uninitialized)
                 self._executor.run(startup_prog)
 
-        if len(device_ids) < 2:
-            return prog
+        compiled_prog = fluid.CompiledProgram(prog)
+        if len(device_ids) > 1:
+            loss_name = None
+            if self.mode == 'train' and self._loss_endpoint is not None:
+                loss_name = self._loss_endpoint.name
 
             share_vars_from = None
             if self.mode == 'eval' and 'train' in self._compiled_progs:
@@ -359,13 +362,10 @@ class StaticGraphAdapter(object):
             if self.mode == 'train' and 'eval' in self._compiled_progs:
                 del self._compiled_progs['eval']
 
-        compiled_prog = fluid.CompiledProgram(prog)
-        loss_name = None
-        if self._loss_endpoint is not None:
-            loss_name = self._loss_endpoint.name
             compiled_prog = compiled_prog.with_data_parallel(
                 loss_name=loss_name, places=places,
                 share_vars_from=share_vars_from)
+
         self._compiled_progs[self.mode] = compiled_prog
         return compiled_prog