Looking for advice to implement a loop in Sleigh

[esaulenka]

I'm trying to improve RH850 support, in particular PUSHSP / POPSP.

These opcodes used to put (get) multiple registers in the stack in a time.

Specification says:

GR[cur] here is a general register, r0..r31.

But as I know, getting the register address in Sleigh not the best approach, sometimes Ghidra produses weird decompilation in this case.

Any ideas, how to handle it? Make a context register 'SPcopy' and load/save regsters in relation to it (it will require 32 subtables both for pop and push) ? Or there is some easier way?

Full specification: RH850G4MH User’s Manual: Software pages 135, 140

[GhidorahRex]

I think if you have a context value that can track the current register and compare it to the end of the list, you should be able to build it up.

See buildVldmSdList in ARMneon.sinc. It uses a recursive sub-constructor and a 32-element subtable that is used for both push/pop (SReg) that should do exactly what you need here.

[esaulenka]

vldmia looks exactly the same as I'm looking for.
slaspec in this place is not simple enough, but i'll try to dig there.

Thanks!

[esaulenka]

Looks like it works:
esaulenka/ghidra_v850@948ee89

thanks one more time!