Unfortunately, no, MATLAB Coder / codegen can't run in parallel. It is a good idea and the development team is aware of it, but this task is not trivial.
If you have an example that takes a long time to generate code and your example does not contain proprietary algorithms, you cna help the development team by sharing your code. We can profile, lear what part of the code generation process is slow, and try to make codegen faster. If you can share your code, please contact MathWorks technical support and ask them to pass the exaple to the MATLAB Coder develoment team.
Thanks!
