[jacobush]

Z80 is quite OK with its real stack and the 16 bit registers. Almost exactly the same as the "small" (64 k data, 64 k instruction, IIRC) memory model in Borland C for DOS, which I used quite a lot back in the day. Only occasionally did my programs get large enough that I had to increase the memory model.

[beagle3]

The 8086 you used with Borland C is far from orthogonal (orthgonaliry, together with a large register file is what makes a cpu compiler friendly) - but it is significantly more orthogonal than the Z80.

And even the 8086 wasn’t compiler friendly - in those days I would easily outdo the compiler by a few hundred percents in right loops. I no longer dabble in assembly, but from what I heard, ARMs and AMD64 have gone far enough (as did compilers) that people rarely beat compilers on them.

People still win on vectorized architectures (GPU, AVX) and I suspect that will stop only when the languages become more vector friendly.

[jacobush]

I'm not saying the Z80 is a wonder for compiler construction. But it's decent enough for a C compiler. It has a stack spanning the full address range (up to 64k), so all auto variables can be easily allocated on the stack. Arguments are typically also pushed on the stack in C. So the number of registers is not as important to a naive C compiler as is a decent stack. Oh, and the last, you on the Z80 also have easy absolute and relative addressing to all addresses, so you can easily implement global and static variables.

It feels very much like coding for a modern machine, just instead of having a memory limit of 2 gigabytes of RAM or whatever (for a 32 bit CPU) you have a limit of 64 kilobytes. And the integers are 16 bit instead of 32 bit, but again, this was normal in DOS too.

So that is why I made the comparison, C in CP/M or whatever on the Z80 didn't feel that much different from Turbo C on DOS.