Hi,
On 1/16/20 12:01 AM, Nicolas Pomarède wrote:
Le 15/01/2020 à 22:49, Eero Tamminen a écrit :
I'd like to clarify in the Hatari manual what
the impact of cycle-exact option is for 68000.
I see that Hatari's cycle-exact option enables
both CPU and memory cycle-exact options from
the WinUAE CPU core.
WinUAE CPU core uses different functions for
instruction and exception handling when cycle-
exact is enabled, but what's the actual impact
of those for the speed of the emulated code?
that's sthg I'm planning to measure one day. The impact on exception
should not be noticable (they don't happen that often compared to
"normal" instructions).
>
Note that I have a devel tree not committed yet with even more CE
behaviour, including very accurate bus error emulation (that
Toni/WinUAE improved extensively in the latest weeks/months).
I'm interested more in actual details of how
the cycle-ccurate mode differs on 68000 from
non-cycle-accurate one, rather than measurements
from some specific tests.
This might have an impact too, maybe not that much in the end, but I'm
planning to measure it too.
Btw. On EmuTOS devel there was comment that VDI
vr_recfl() tester managed 30 loops in cycle-
accurate mode, and 39 nine otherwise, so
perf impact 68000 cycle-accuracy option can
apparently be quite noticeable.
This was for code that spent most of it's time
in loops of few instructions (not doing any exceptions).