Bias is always searched in BlasNceSoftmaxAdapter

[mattiadg]

rasr/src/Lm/BlasNceSoftmaxAdapter.cc

Line 25 in 473d202

auto const& bias_tensor_info = output_map.get_info("bias");

As you can see in the highlighted code, the parameter "bias" is always searched in the config, but in my experience the bias doesn't exist for the output layer more often than yes. Also, when the parameter name is not found, the program just crashes with a criticalError.

As a side note, the error message doesn't show the parameter name causing the error.

[mattiadg]

As mentioned in #12, there is other code assuming the existence of this tensor. Should we create a zero bias tensor when it doesn't exist, or more cleanly check the existence of this tensor? In the second case, the retrieval of the bias tensor should be able to handle the error.
Also making another class for the case without a bias is an easy option to follow.