Re: [Qemu-devel] Re: dyngen-exec.h cleanup

[Laurent Desnogues <laurent.desnogues@gmail.com>]

On Sun, Mar 8, 2009 at 4:36 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> Laurent Desnogues wrote:
>> On Sun, Mar 8, 2009 at 3:41 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
>>> Also, some discussion on this list suggested that it's more efficient to
>>> look into converting the remaining AREGS to TCG and finally do the
>>> ultimative "rm dyngen-exec.h". Don't you want to spend some time on this
>>> already?
>>
>> This requires modifying ARM translator which is the last one to use
>> AREGn with n>0. And don't all targets use AREG0 as a pointer to the
>> CPU state?
>
> Yes, but wasn't it you who suggested that all those users should be
> converted over to the tcg_global_reg API?

Yes, and I did the work for ARM.  However when considering the
removal of AREG0, and after looking at generated code, I came
to the perhaps premature conclusion that removing it would not
bring me any speedup (at least for a not so register starved
target as x86_64).

> There is surely some work to do, and that probably across all archs. But
> the sooner we should start. dyngen-exec.h is a constant source of pain
> when you try to introduce new headers or refactor existing ones.

Well dyngen-exec.h is long gone in my sources even though
AREG0 is still used.  I would have to backtrack my changes to
see how I arrived to that, but for sure the first thing to do is to
remove cpu_T from ARM target.


Laurent