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by flohofwoe 1658 days ago
C++ or even C isn't exactly "fine" on any 8-bit system though. It's nice for a little demo, it can even be tolerable for some real-world projects when mixed with large amounts of inline assembly, but those 8-bit ISAs have been designed mainly for manual assembly coding, not high level compiled languages like C.
2 comments
mananaysiempre 1658 days ago
Honestly unless you’re on something like an ATtiny with < 1K of RAM or doing cycle-counted stuff a properly adapted high-level language is fine. I mean, Forth (doesn’t have to but usually) uses an interpreted virtual machine and people have used and liked it on 6502s since those were the new hotness.

As far as I’ve seen, two things make C and C++ specifically problematic on 8-bitters: automatic promotion to int for all expressions, with int required to be at least 16 bits (a language problem); and subpar codegen on accumulator architectures and other things that are not like desktops (a compiler problem).

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flohofwoe 1657 days ago
Forth is much better for creating tiny executables than C on 8-bit ISAs though, performance takes a hit because of all the calls/jmps, but it's still surprisingly good. C compilers on the other hand often create "obviously" dumb and inefficient code, at least in my experience (6502 may be better than Z80 in that regard though).
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uuidgen 1658 days ago
C translates directly to ASM in many cases. It just makes managing offsets and other stuff easier.

C++ adds type-safety on top of that for no cost. It's great when your compiler tells you that there is no operator =|(PORTD, PINA). Did you mean |=(PORTD,PIND) or =|(PORTA,PINA).

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flohofwoe 1657 days ago
> C translates directly to ASM in many cases.

But usually much worse ASM than what a human would write on such CPUs, because the C compiler is still restricted by artificial high-level concepts like calling conventions, and it needs to wrestle with instruction sets that are not very compiler-friendly and tiny non-orthogonal register sets. C++ just adds a whole level of code obfuscation on top, so it's harder to tweak what code the compiler actually generates.

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mananaysiempre 1658 days ago
If you really want that in C, you can either use functions and wrap everything in (incompatible but internally identical) structs, or use Sparse and annotate those integer types to be incompatible. Not that you must prefer that to C++ (even if I do), just to note that you can make do with C if you want to.
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