Re: [B2-devel] New UAE JIT Compiler

[Christian B. <cb...@st...>]

Hi!

On Sun, Sep 03, 2000 at 11:16:49PM +0200, Gwenole Beauchesne wrote:
> > 1. Ability to directly access the Mac address space
> 
> Implemented. And indeed, what a nice piece of improvement: near twice
> the speed!

Cool!

> 4. Reversed Address Space
> [...]
> Note however that I didn't checked all the patches for "correctness"
> yet, especially audio that makes strange sounds.

It may not be obvious, but part of the intention behind the Mac2Host_memcpy()
etc. functions in cpu_emulation.h was to allow for a reversed address space.
It's not used consequently in all modules, however.

> I was hinted that a real m68k does not handle unaligned access, does it ?

Starting with the 68020, all 680x0 can access any data at any alignment
(except for the 68060 which needs operating system support under certain
circumstances).

> Another problem with reversed address space arises with the use of
> direct addressing when patching the ROM since PatchROM() relies on a
> native m68k byte-order.

Yes, that's because the WriteMac*() functions may not yet be operational
at PatchROM() time.

Bye,
Christian

-- 
  / Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/