llvm-mos VS cc65

> Suppose you have 100 functions that each need 100 bytes of scratch space. Statically allocating everything like you describe means you need 10KB of memory reserved. But suppose there is one main function, and the rest are helper functions, and the main function calls each helper function one at time and the helper functions don't call anything. With the static approach, you still need 10KB. With the stack-based approach, you only need 200 bytes (the stack space for the main function, and the stack space for the helper function it is currently calling).

This is not necessarily the case: if you statically analyze the call graph, you may be able to prove that two functions will never be live at the same time, and thus reuse memory regions for their local variables: https://github.com/llvm-mos/llvm-mos/blob/main/llvm/lib/Targ...

Of course, recursion, function pointers, and dynamic linking will defeat (or at least complicate) this scheme.

Too late: https://github.com/llvm-mos/llvm-mos

I don’t think it’s in the official repo, but yes:

https://github.com/llvm-mos/llvm-mos

You could look at LLVM-MOS, the port of LLVM to the 6502. It might give you some ideas around the problems to solve https://llvm-mos.org/wiki/Welcome https://github.com/llvm-mos/llvm-mos

The MEGA 65 doesn't appear to have shipped yet. The best data I could find is the MEGA 65 is based on a "GS4510". The "GS4510" is compatible with a "4502", which in turn is compatible with the 65CE02. The 65CE02 uses a different manufacturing process but the same ISA as the 6502, which is supported by rust-mos and lvm-mos](https://github.com/llvm-mos/llvm-mos).

It really is a cool project. https://github.com/cc65/cc65

It provides some template configuration files describing different memory layouts. And provides common libraries for input/output.

There's also a LLVM fork for MOS: https://github.com/llvm-mos/llvm-mos

They've got some interesting hacks with ZeroPage memory and register allocation: https://llvm-mos.org/wiki/Code_generation_overview

Interesting if you geek out on that kind of research.

Using llvm-mos, rust-mos, a lot of time compiling compilers and support from Mariusz (the rust-mos author), I was finally able to program like it was 1982...

SNES: 65C816 derivative, may eventually be supported by https://github.com/llvm-mos/llvm-mos

Doing it with the mouse IRQ has an advantage when one requires a mouse, though: it works the same way on the whole line of Apple II computers, starting with the II+.

Without the mouse IRQ, if one wants to support the whole line of Apple II computers, one has to vapor lock on the II+, remember that the IIgs's $C019 high bit means the inverse than the IIe, and the //c requires more trickery around it. (cf https://github.com/cc65/cc65/blob/master/libsrc/apple2/waitv...)

True. The code generated by https://cc65.github.io/ is pretty decent but there are a few places where hand-rolled assembler will perform much better when you need it. Although I've made things for 6502-based systems in C with this handy compiler (thanks cc65 contributors!).

Is there something intrinsic to how C handles addressing that makes segmented architectures more painful than they ought to be? Or maybe is there a language where segmented addressing is easier?

I hadn't really thought about it in a while. :)

cc65

There's tools like cc65 that let you write C code for the NES.

You can use any text editor for coding and the tutorial uses cc65 for compiling assembly to machine code.

You can use cc65 https://cc65.github.io/ but because you are compiling it in a limit hardware the cc65 has its rules and recommendations to follow in order to get the most optimal binaries, and more specifically I read this when I made the "Pong" game for NES as a practice long time ago https://nesdoug.com/ , I hope it helps, happy coding!

What assembler/tools did you use anyways? Personally I'd recommend ca65 from the cc65 C compiler utility. It's very powerful, open source, and kept updated (unlike a lot of ancient 6502 tools, like WDC's)

It really is a cool project. https://github.com/cc65/cc65

It provides some template configuration files describing different memory layouts. And provides common libraries for input/output.

There's also a LLVM fork for MOS: https://github.com/llvm-mos/llvm-mos

They've got some interesting hacks with ZeroPage memory and register allocation: https://llvm-mos.org/wiki/Code_generation_overview

Interesting if you geek out on that kind of research.