@paulwalker-arm, I'm guessing this hits the reduction legalisation problems that @kmclaughlin is working on? This patch currently falls apart during splitting of the reduction nodes. If not, I'll continue to build it out.
Some other notes:
- It looks like NEON FADDA support is missing upstream too.
- We'll likely need to change how the OperationAction types are determined for the reduction-with-accumulator ISD nodes (see LegalizeDAG.cpp change). The types are currently based off the start_value type, not the vector op type. @sdesmalen