add tpu bfloat

Co-authored-by: Adrian Wälchli <aedu.waelchli@gmail.com>

pytorch_lightning/plugins/precision/tpu_bfloat.py

@@ -0,0 +1,28 @@
+# 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.
+import os
+
+import torch
+
+from pytorch_lightning.plugins.precision.precision_plugin import PrecisionPlugin
+
+
+class TPUHalfPrecisionPlugin(PrecisionPlugin):
+    """Plugin that enables bfloats on TPUs"""
+
+    precision = 16
+
+    def connect(self, model: torch.nn.Module, optimizers, lr_schedulers):
+        os.environ["XLA_USE_BF16"] = str(1)
+        return super().connect(model=model, optimizers=optimizers, lr_schedulers=lr_schedulers)