vivado/vitis support sample broadcasting merge ops

[calad0i]

Description

Allow add/subtract/mul/avg/... between tensors of shape (a, b, c) and (1, c) or (c,) or (1, b, c) (must match the last dimensions) in vivado/vitis backends. Illegal operations still fail silently like what they do now.

Type of change

• New feature (non-breaking change which adds functionality)

Tests

Checklist

• all

[JanFSchulte]

Looks like there are issues with the streaming implementation of merge, all the test failures are caused by compiler errors like

firmware/nnet_utils/nnet_merge_stream.h:15:35: error: ‘n_elem’ is not a member of ‘config3’
   15 |     for (int i = 0; i < CONFIG_T::n_elem / input1_T::size; i++) {

[calad0i]

Streaming supported is not added, so it is still broken as what it was.

[JanFSchulte]

But your change introduces compilation errors because it removes n_elem from the config and replaces it with n_elem1 and n_elem2. So the streaming application needs to get a dedicated configuration if you don't want to implement this feature for it.

Or if it is indeed broken, streaming needs to be excluded from the affected tests.