Fwd: [hatari-devel] ARM JIT

2014-08-06 11:24 GMT+02:00 Nicolas Pomarède <npomarede@xxxxxxxxxxxx>:

Le 06/08/2014 11:12, Adam Klobukowski a écrit :

Hi

Have you guys considered adapting Cyclone m68k emulator?
(http://notaz.gp2x.de/cyclone.php). It offers JIT on some popular ARM
architectures. It seems thatHataroid guy already tried it
(https://github.com/squalldc/hataroid/blob/master/Projects/jni/hatari/Android.mk).
This CPU emulator may make running Hatari on RasPi more fluent (and
other cheap ARM boards)

Hi,

no, unless it features a similar api to uae/winuae 68000 emulation, it would be too much work to maintain several cpu cores.

It seems, it does. On the other hand, Hatari already has a "glue" code for CPU cores, so this should not be a problem.

And we don't target a specific architecture such as arm, we try to have as much portable C code to compile on any architecture (and I'm not sure from its description that cyclone handles prefetch and sub cycle accuracy for all opcodes, which is required for proper emulation).

That is not true. There is already JIT core for x86, so hatari has platform dependent code.

Cyclone does not handle prefetch, as for cycle accuracy, it is as good as Muashi in Mame. It will not be perfect but Hatari already has an option "slower, but more accurate emulation".

Maintaining JIT version in assembly at a time where computers / phones / tablets are more and more powerful every 6 months also looks IMO like a waste of time ; Hatari has reached a point where remaining issues are not about speed but about accuracy in very low level functions (ram speed, prefetch, rare video timings, ...).

Of course, there will always be some devices where you wished emulation would run faster, but there's a point where perfect accuracy requires cpu power in a higher order of mgnitude, and JIT will only bring a small increased compared to the need

I want Cyclone core inside, so as a rule os OS projects, I'll do it. But I'll ned help with the build system, as I'm unfamiliar with those beasts. Anyone can help?

--
Semper Fidelis

Adam Klobukowski
adamklobukowski@xxxxxxxxx