The newest versions of GCC 4 have improved the 68k code generation and fixed bugs. It's as good as most of the old 68k compilers now.
its my impression, but im not an expert;) like you.
it doesn't schedule instructions for the 68060, it uses bitfield instructions way to much for the 68060 (shift+mask is usually faster in registers) and the FPU support is worse than earlier versions of GCC but probably not used much by AROS.
aros is not compiled with 68060 target, im not sure what target it actually is but i guess widest common denominator, either 020 or even 000. however the fpu effectivity is wort to check, thanks for reminder.
Piotr tried compiling ffmpeg without bitfields and it didn't make much difference so I would expect some of these large complex programs are cache/memory bound on the 68060. We saw the same with NovaCoder's AmiQuake 2 where some of the assembler optimizations I did didn't make much different. Optimizations can still help but not nearly as much.
toni calls it micro optimisations. probably this should really wait, but peter k's icon lib proves worthy to take care of it already where its due.
All my Amiga code is free with sources available. The AROS devs have my code and I expect some of it has been integrated in some form. If we can't revive the Amiga then it's not going to do anyone any good.
certainly, your code patches for mem copy are applied by aros setpatch depending on what cpu be detected. thats all how cpu bound optimisations are currently haldled on aros, as patches for the sensible functions, and i think its a good way. jason have introduced these inlines (?) you are probably mentioned in the sources.