Re: [PATCH 0/9] RFC: selftests based on RTL dumps

[Jeff Law <law at redhat dot com>]

On 09/13/2016 05:15 AM, Bernd Schmidt wrote:
> > Note that the loader now resets INSN_CODE to -1, regardless of the
> > actual code passed in, to force re-recognition, and to isolate the
> > dumps somewhat from changes to the .md files.  So although the above
> > says insn 641 and 642 (for some snapshot of the aarch64 md file), it
> > gets reset to -1.
>
> Best to find out a way to avoid including it in the strings then, to
> avoid confusion.
We should also twiddle how we represent registers in the dumps. 
Identifying hard regs by name (so we can map back to a hard reg if the 
hard regs change), identifying pseudos by number that isn't affected if 
the hard register set changes ie, p0, p1, p2, p3 where the number is 
REGNO (x) - FIRST_PSEUDO_REGISTER. identifying the virtual registers, etc.

The key being rather than put a ton of smarts/hacks in a reader, we 
should work to have the RTL writer give us something more useful.  That 
may mean simple changes to the output, or some conditional changes (like 
not emitting the INSN_CODE or its name).

jeff