No matter how hard I tried, I hit a wall on size optimizations. And it's a really dramatic situation.
For instance, a simple integer BASIC interpreter I wrote took 61kb of space at one point! That's almost the entirety
of generic data memory available! So I decided that at the cost of a bit of speed, it was more than justified to
reduce code size. I applied extreme outlining policies, creating a small C library called libtec30 whose
only purpose is replacing costly duplicate instructions with a function call to a function in that library. All of this
is statically baked into the final executable. Savings were real: BASIC got in the 50kb range, PalMon (of which you can
find clips in the previous post) dropped by ~800 bytes in size.
It's not that you CAN'T make C fit in a smaller footprint: you CAN, and I did. Before touching any compiler internals, I manually replaced every "int" inside PalMon to a "signed char" type, and that had a pretty good size reduction by itself: simply shrinking types to fit. Sadly I can't really make this automatic in the compiler, as it'd need to track overflow and I'd just be making Ada Spark with C syntax.
At least I managed to turn TEC30 in a nice "Plug and play" experience: after all, it's meant as a ready to use solution. I took inspiration from-ahem shamelessly copied ahem-how professional IP cores are packaged. TEC30's RTL are now online! The C compiler is still being tweaked, as hopeless as I am, but the assembler is out already. I still lack proper documentation but I am writing right now. Too bad LibreOffice Writer actively tries to destroy my diagrams. This being said, TEC30 is so small you can just read the verilog directly at this point. But even more probable, nobody will care if I don't have proper documentation already because nobody even knows this is a thing.
Am I done now? Of course not! I have a lot to finish. Current TEC30 publication includes a UART module, and X7/G variants. I must at least implement a wishbone wrapper and some form of interrupt controller. Until those are ready I can't stop working on this. I also will have to confront myself with the vibe coding witch hunters I'm terrified of, which is why there's a very insecure disclaimer about AI usage in my README. I should probably make it sound more confident because it makes me sound more guilty than what I actually am, funnily enough.