Re: GCC8 v.s. amiga

Hi,

On 2020/06/27 19:02, Michael van Elst wrote:
> [email protected] (Rin Okuyama) writes:
...
>> Hmm, then it is problem peculiar to 68060, or GCC miscompile something
>> with tuning for 68060. I observed the problem both for -m68060 and
>> -m68020-60.
> 
>> Which compiler flag do you use? Do you use GENERIC? Then, it is
>> compiled with -m68020-60 by arch/m68k/Makefile.cmachflags...
> 
> 
> I use a mostly stripped down GENERIC, but no change to CPU flags.
> So yes, it is built with -m68020-60.
> 
> 
>> Or emulator accepts some kinds of instructions that do not work on
>> real hardwares?
> 
> I don't think so. But it doesn't emulate caches and the TLB works
> differently.

Thank you for your comments! I understand the situation.

> Saying that, after a few hours idling in multi-user, the system
> paniced with an uvm_fault followed by an illegal instruction
> trap. Neither looked real in DDB.
> 
> I'll have to retry this with a gcc7-built kernel, it could be
> some other m68k instability introduced in -current.

Hmm, for my A1200, a GCC7-buit kernel as of last week works without
problems at least for several days. So, it can be due to GCC8.

Thanks,
rin