tf.config.get_soft_device_placement

Return status of soft device placement flag.

tf.config.get_soft_device_placement()

If enabled, ops can be placed on different devices than the device explicitly assigned by the user. This potentially has a large performance cost due to an increase in data communication between devices.

Some cases where soft_device_placement would modify device assignment are:

1. no GPU/TPU implementation for the OP
2. no GPU devices are known or registered
3. need to co-locate with reftype input(s) which are from CPU
4. an OP can not be compiled by XLA. Common for TPU which always requires the XLA compiler.

For TPUs, if this option is true, a feature called automatic outside compilation is enabled. Automatic outside compilation will move uncompilable ops within a TPU program to instead run on the host. This can be used when encountering compilation failures due to unsupported ops.