Deprecate LightningModule.use_amp

CHANGELOG.md

@@ -503,6 +503,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Deprecated `LightningDataModule.on_save/load_checkpoint` in favor of `state_dict/load_state_dict` ([#11893](https://github.com/PyTorchLightning/pytorch-lightning/pull/11893))
 
 
+- Deprecated `LightingModule.use_amp` ([#12315](https://github.com/PyTorchLightning/pytorch-lightning/pull/12315))
+
 ### Removed
 
 - Removed deprecated parameter `method` in `pytorch_lightning.utilities.model_helpers.is_overridden` ([#10507](https://github.com/PyTorchLightning/pytorch-lightning/pull/10507))

docs/source/common/lightning_module.rst

@@ -1037,11 +1037,6 @@ Pointer to the trainer
         max_steps = self.trainer.max_steps
         any_flag = self.trainer.any_flag
 
-use_amp
-~~~~~~~
-
-``True`` if using Automatic Mixed Precision (AMP)
-
 prepare_data_per_node
 ~~~~~~~~~~~~~~~~~~~~~
 

docs/source/starter/core_guide.rst

@@ -944,15 +944,15 @@ default implementation
 
 .. testcode::
 
-    def backward(self, use_amp, loss, optimizer):
+    def backward(self, loss, optimizer):
         loss.backward()
 
 With your own
 
 .. testcode::
 
     class LitMNIST(LightningModule):
-        def backward(self, use_amp, loss, optimizer, optimizer_idx):
+        def backward(self, loss, optimizer, optimizer_idx):
             # do a custom way of backward
             loss.backward(retain_graph=True)
 

pytorch_lightning/core/lightning.py

@@ -96,8 +96,7 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
         # pointer to the trainer object
         self.trainer = None
 
-        # true if using amp
-        self.use_amp: bool = False
+        self._use_amp: bool = False
 
         # the precision used
         self.precision: int = 32
@@ -1966,6 +1965,23 @@ def model_size(self) -> float:
             )
         return get_model_size_mb(self)
 
+    @property
+    def use_amp(self) -> bool:
+        """Returns true if using AMP.
+
+        .. deprecated:: v1.6     This property was deprecated in v1.6 and will be removed in v1.8.
+        """
+        rank_zero_deprecation(
+            "`LightningModule.use_amp` was deprecated in v1.6 and will be removed in v1.8."
+            " Please use `Trainer.amp_backend`.",
+            stacklevel=5,
+        )
+        return self._use_amp
+
+    @use_amp.setter
+    def use_amp(self, use_amp: bool) -> None:
+        self._use_amp = use_amp
+
     def add_to_queue(self, queue: pl.strategies.launchers.spawn._FakeQueue) -> None:
         """Appends the :attr:`trainer.callback_metrics` dictionary to the given queue. To avoid issues with memory
         sharing, we cast the data to numpy.

pytorch_lightning/trainer/connectors/data_connector.py

@@ -164,6 +164,7 @@ def _copy_trainer_model_properties(self, model):
 
         for m in [model, ref_model]:
             m.trainer = proxy(self.trainer)
+            # Remove next line in v1.8
             m.use_amp = self.trainer.amp_backend is not None
             m.precision = self.trainer.precision
 

tests/deprecated_api/test_remove_1-8.py

@@ -817,3 +817,9 @@ def on_load_checkpoint(self, checkpoint):
         " v1.6 and will be removed in v1.8. Use `load_state_dict` instead."
     ):
         _check_datamodule_checkpoint_hooks(trainer)
+
+
+def test_v1_8_0_lightning_module_use_amp():
+    model = BoringModel()
+    with pytest.deprecated_call(match="`LightningModule.use_amp` was deprecated in v1.6"):
+        _ = model.use_amp