A question about mov pattern

[Revital1 Eres]

Hello,

In the new target I'm working on there are branch regs and gprs.
The loads and store instructions are only to/from the gprs, so if a
branch reg needs to be spilled it first needs to be moved to a gpr and
then stored to memory.  I've implemented mov pattern in the machine
description file for the gprs and a mov pattern between gprs and branch
regs; however I'm am not sure if I need to add more to model the behavior
described above and if so how to do it.

Thanks,
Revital