[hatari-devel] Faster MMU emulation + various cpu updates

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Hi

I merged some recent changes from WinUAE 3.5.1 beta regarding MMU. Toni 
added some internal caching for the MMU translations, so the cpu core 
now has his own cache of the most recent instruction/data accesses made 
by the MMU, which can improve emulation speed by 20% (depending on how 
much MMU intensive the emulated program is)

For example :
 - booting WinUAE Amiga + NetBSD dropped from 43s to 31s in 68040 mode
 - booting Hatari in TT mode (until reaching GEM) drops from ~23-25 sec 
to ~17 sec (on an old athlon pc)

Of course, if your PC is already fast enough to run in TT mode in real 
time, you won't see any speedup, but this will lower your cpu load anyway.

It could be interesting to get results from people running freemint ; 
Unix like OS have a bigger use of the MMY and should see more benefit.
What's the gain to boot in freemint whne compared with Hatari 2.0 ?


Aside from that, a few updates were made to cpu/fpu code.

some problems might remain in FPU, quoting toni :

"does Atari have full FPU software emulators that support 68040 or
68060? I found some bugs in f-line handling when using 68040/060 without
FPU (LC or EC model) but testing these is annoying. (68040+ has special
stack frame that contains effective address of FPU instruction, even if
model is LC or EC)"

I recall I saw some math libraries needed to run povray under 68040/60 
extension board for falcon. Does anyone has more info on this ? (doug 
maybe, as he replied in a thread about this in atari-forum ?)

Nicolas