keras/src/dtype_policies/dtype_policy.py/DTypePolicy/compute_dtype
class DTypePolicy:    def compute_dtype(self):
        """The compute dtype of this policy.

        This is the dtype layers will do their computations in. Typically layers
        output tensors with the compute dtype as well.

        Note that even if the compute dtype is float16 or bfloat16, hardware
        devices may not do individual adds, multiplies, and other fundamental
        operations in float16 or bfloat16, but instead may do some of them in
        float32 for numeric stability. The compute dtype is the dtype of the
        inputs and outputs of the ops that the layer executes.
        Internally, many ops will do certain internal calculations in
        float32 or some other device-internal intermediate format with higher
        precision than float16/bfloat16, to increase numeric stability.

        Returns:
            The compute dtype of this policy, as a string.
        """
        return self._compute_dtype