RE: [PATCH v5 41/48] target/nios2: Introduce shadow register sets

[Amir Gonnen]

(Continue discussion from Re: [PATCH v4 24/33] target/nios2: Introduce shadow 
register sets)

> > How does "cpu_crs_R" work?
> > ... Otherwise, each gpr access would be indirect. I'm probably missing 
> > something here.

> They are indirect, but with some optimization.

Why not always access directly?  
With an EIC each interrupt handler is associated with a specific shadow 
register set, so we can expect that (on a sane use case) each block always 
executes on the same register set.  
If we update cpu_get_tb_cpu_state to translate differently based on STATUS.CRS 
we would still end up with a single translation for each block.  
This way the translator could emit direct registers access for shadow 
registers, and we won't need to rely on optimizations to lower indirect access.

Thanks,
Amir