Comment 11 for bug 1112499

(In reply to comment #8)
> I'm not going to be able to look at it anytime soon, but just some general
> thoughts:

I think that I'm ready to explain the bug.

> 1. Disabling caller-saves probably isn't appropriate. Just looking at
> codesize isn't the way to evaluate caller-saves either as caller-saves is
> tasked with improving performance, possibly at the expense of codesize.

I'm agree. I don't want to disable caller-saves.

>
> 2. The first thing someone needs to do is provide information as to why that
> insn needs reloads. I don't know enough about the AVR to hazard as guess why
> that insn needs reloads.
>
> 3. Find out where insn 172 comes from. There are restrictions on the insns
> created by caller-save. So if caller-save creates a bogus insn, then that
> needs to be investigated.

Generally, caller-save generate right insn.

1. AVR port have a specific dependency between frame_pointer_neede and
gat_frame_size()