68060 integer instruction emulation in 2.7.0

[jotd]

Hi,

I'm using WinUAE 2.7.0 and I think that the checkbox "unimplemented CPU emu" is inverted for 68060 at least:

- when I check it, each MOVEP triggers an illegal instruction. Of course JIT forces it so no JIT for me...
- when I uncheck it (and remove JIT), MOVEP are emulated.

Another strange fact: whdload does not patch those instructions whereas it should
I think it detects a non-68060 CPU because winuae has a problem, and does not patch the calls. Something is broken here.

oh BTW: winuae with MMU and all really rocks!!!! I'm back after 3 years of not checking winuae and it is really something. so thanks a million Toni.

Regards

[thomas]

Originally Posted by jotd

I'm using WinUAE 2.7.0 and I think that the checkbox "unimplemented CPU emu" is inverted for 68060 at least:

- when I check it, each MOVEP triggers an illegal instruction. Of course JIT forces it so no JIT for me...
- when I uncheck it (and remove JIT), MOVEP are emulated.

That's exactly how it should be. "Unimplemented CPU emu" emulates correct behaviour of unimplemented instructions. If you uncheck it, non-existent instructions do not trigger an exception.

[Toni Wilen]

It works as designed. It prevents users from ticking it because it looks interesting. (and break their system, they also most likely don't have correct CPU libraries installed and then complaining emulation being broken..)

How does it detect 68060?

[jotd]

ok, but you should check the tooltip. it's confusing.
then why is it not possible to enable it in jit mode? the checkbox is checked and disabled

about whdload i don t know, i ve asked Bert

once again, only constructive comments, winuae is still great stuff!

bye

[Dr.Venom]

Originally Posted by Toni Wilen

It works as designed. It prevents users from ticking it because it looks interesting. (and break their system, they also most likely don't have correct CPU libraries installed and then complaining emulation being broken..)

Possibly you could add a more descriptive tooltip? Personally when it comes to tooltips in general (for any program) I prefer them to not only contain the "technical" aspect, but also to indicate what the use is of the option, to me as a user. Such that I can make a better judgement whether I should tick or untick it, even when I don't know the exact technicality of it.

As a suggestion it could be something along the lines of "Emulate 68060 unimplemented integer instruction. Check this option for more accurate 68060 emulation. Note that it causes issues when you don't have correct CPU libraries installed." It's still short, but more descriptive in a non-technical sense.


Edit to add: since you'd probably want it shorter it could also be something like "Emulate 68060 unimplemented integer instruction. More accurate, but will cause issues when you don't have correct (68040/060) CPU libraries installed."

[Toni Wilen]

No. If you don't know what it means, you either should forget about it or research it yourself instead of blindly changing the option.

No "normal" user need to ever select 68060 emulation, there is no 68060-only user space programs. (No, there really isn't any, some may say so but only because REAL 68040 or older is too slow)

"I know i have correct libraries, I have 68060.library in libs:". No, it isn't that simple, he/she may still have 68040.library that crashes with 68060 or no dummy 68040.library and old enough setpatch which ignores 68060.library. Or the library may be hardware specific one and not "generic" or. or. and so on.

You really have to know what are you doing if you use 68060. It is same with real 68060 hardware, search and you find out that there are lots of questions about 68060 crashing or working slowly or FPU not working and so on..

[jotd]

Hi Toni,

I want to make sure my whdload slave is running on a 68060. That's why I use this setting (and also my original amiga uses that).

I talked with Bert and I think he figured this out:

maybe winuae is wrong because it has to fault with an 'unimplemented
integer instruction' instead of 'illegal instruction' when encountering a "MOVEP".

Regards

[Toni Wilen]

MOVEP generates unimplemented integer instruction exception and 68060.library exception handler also emulates it correctly.

[Mad-Matt]

Are the 'Recommended' CPU Libraries still the generic MMULib ones? Also, is there any recommended WinUAE specific settings for the mmulib config file such as the mmu cache config when using CybergraphX for rtg cards.

[Toni Wilen]

Originally Posted by Mad-Matt

Are the 'Recommended' CPU Libraries still the generic MMULib ones? Also, is there any recommended WinUAE specific settings for the mmulib config file such as the mmu cache config when using CybergraphX for rtg cards.

Nothing is recommended but anything that does not require or assume any extra hardware should work. Cache settings make no difference. Caches are only emulated if 68020 or 030 and cycle-exact mode.

But as I said in previous post: do you really need 68060 or MMU? Answer seems to be: no.

[Mad-Matt]

Its more for the feeling that the emulation acts and behaves exactly like a real Amiga. It matters not that an emulated 020 can outrun a real 060 Amiga

[jotd]

okay, still a mystery
i ll switch to 68040, lets drop the 060 setting

[Toni Wilen]

whdload seems to set exception handler to all "unexpected" exceptions and it checks if exception format and vector offset word is 00F4 (4*61) and if it is, it emulates unimplemented instruction.

-> include example slave that uses movep and I'll check if there is some other wrong bit somewhere..

[jotd]

Hi Toni

Made a quick empty slave.

on 040 config it stops on "ILLEGAL"
on 060 config it stops on "MOVEP"

thx & regards

movep_test.zip

[Toni Wilen]

Originally Posted by jotd

Hi Toni

Made a quick empty slave.

on 040 config it stops on "ILLEGAL"
on 060 config it stops on "MOVEP"

It works 100% correctly, problem is your test case. It does not crash on MOVEP.

MOVEP is emulated (by whdload exception handler), it crashes with ILLEGAL because next instruction after MOVEP is 4AFC!