[SPARC] how to add a ScheduleHazardRecognizer

Hi list,

Following the discussion "[SPARC]: leon2 and leon3: not respecting
delayed-write to Y-register" I'm trying to add a
ScheduleHazardRecognizer to the Sparc-backend.

However, I'm unable to register my HazardRecognizer to the Scheduler.

To understand better how LLVM is architectured I overrode all of the
CreateTarget*HazardRecognizer()-methods in SparcInstrInfo. These get
never called.

The SparcSubtarget is enabling/requesting the (default?)
MachineScheduler.

Seeing that it is not straightforward to have these integrated I'm
afraid that more complicated things have to be changed in the
Sparc-backend to make this work.

What do I need to do to have a HazardRecognizer called by the Scheduler?

Thanks for any help,