加载fp16时同时设置auto_cast和fp16属性

fastNLP/core/drivers/torch_driver/torch_driver.py

@@ -259,6 +259,8 @@ class TorchDriver(Driver):
             grad_scaler_state_dict = states.pop('grad_scaler_state_dict')
             if not isinstance(self.grad_scaler, DummyGradScaler):
                 self.grad_scaler.load_state_dict(grad_scaler_state_dict)
+                self.auto_cast = torch.cuda.amp.autocast
+                self.fp16 = True
                 logger.debug("Load grad_scaler state dict...")
         elif not isinstance(self.grad_scaler, DummyGradScaler):
             logger.warning(f"Checkpoint {folder} is not trained with fp16=True, while resume to a fp16=True training, "