Add back GPUAccelerator and deprecate it

src/pytorch_lightning/accelerators/__init__.py

@@ -13,6 +13,7 @@
 from pytorch_lightning.accelerators.accelerator import Accelerator  # noqa: F401
 from pytorch_lightning.accelerators.cpu import CPUAccelerator  # noqa: F401
 from pytorch_lightning.accelerators.cuda import CUDAAccelerator  # noqa: F401
+from pytorch_lightning.accelerators.gpu import GPUAccelerator  # noqa: F401
 from pytorch_lightning.accelerators.hpu import HPUAccelerator  # noqa: F401
 from pytorch_lightning.accelerators.ipu import IPUAccelerator  # noqa: F401
 from pytorch_lightning.accelerators.mps import MPSAccelerator  # noqa: F401

src/pytorch_lightning/accelerators/gpu.py

@@ -0,0 +1,31 @@
+# Copyright The PyTorch Lightning team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from pytorch_lightning.accelerators.cuda import CUDAAccelerator
+from pytorch_lightning.utilities.rank_zero import rank_zero_deprecation
+
+
+class GPUAccelerator(CUDAAccelerator):
+    """Accelerator for NVIDIA GPU devices.
+
+    .. deprecated:: 1.9
+
+        Please use the ``CUDAAccelerator`` instead.
+    """
+
+    def __init__(self) -> None:
+        rank_zero_deprecation(
+            "The `GPUAccelerator` has been renamed to `CUDAAccelerator` and will be removed in v1.9."
+            " Please use the `CUDAAccelerator` instead!"
+        )
+        super().__init__()

tests/tests_pytorch/deprecated_api/test_remove_1-9.py

@@ -18,6 +18,7 @@
 
 import pytorch_lightning.loggers.base as logger_base
 from pytorch_lightning import Trainer
+from pytorch_lightning.accelerators.gpu import GPUAccelerator
 from pytorch_lightning.core.module import LightningModule
 from pytorch_lightning.demos.boring_classes import BoringModel
 from pytorch_lightning.profiler.advanced import AdvancedProfiler
@@ -195,3 +196,13 @@ def test_pytorch_profiler_schedule_wrapper_deprecation_warning():
 def test_pytorch_profiler_register_record_function_deprecation_warning():
     with pytest.deprecated_call(match="RegisterRecordFunction` is deprecated in v1.7 and will be removed in in v1.9."):
         _ = RegisterRecordFunction(None)
+
+
+def test_gpu_accelerator_deprecation_warning():
+    with pytest.deprecated_call(
+        match=(
+            "The `GPUAccelerator` has been renamed to `CUDAAccelerator` and will be removed in v1.9."
+            + " Please use the `CUDAAccelerator` instead!"
+        )
+    ):
+        GPUAccelerator()