Re:GCC vs. LLVM
Since LLVM is used for JITs and is modular enough that it might be able to break down into small enough units that it could run on a RAM expanded Amiga outright. (Assuming it has a custom pass manager that only loads in the currently executing pass and flushes out all others.) GCC is popular among Linux Distros, that's true, but even Mandriva uses Clang instead of GCC when possible.
Clang is not really mature enough yet to build Debian packages and especially the kernel on all architectures. So I wouldn't be too optimistic.
Modernizing the m68k backend in gcc is currently the easier task.
Since you've worked with both LLVM and GCC, can you tell me if such a hand-over-hand pass manager would be possible on a recent GCC?
JITs are currently not our focus. gcc is gaining JIT support, but for the time being, the most important goal is to be able to use a modern C/C++ compiler on m68k.
Also, how much more work is required to finish the LLVM backend?
The TODO list can be found here:
https://github.com/M680x0/M680x0-llvm/issuesLooking at the BountySource page it's got about $1300 in it for GCC already. If we only get one shot at it though, I'd prefer Clang over GCC for the reasons I described above.
I disagree. LLVM/Clang is still much further ahead, in particular it will be very hard to upstream m68k support. For gcc, on the other hand, the only task is to convert the backend to MODE_CC in order to keep it in future versions of gcc.
Adrian