[cm3]

> Realistically the vast majority of C and C++ codebases today will never touch anything more than x86 and ARM, and I wouldn't be surprised if most never even get past x86, so I don't buy the portability argument.

Just recently a Gentoo developer ported GHC to m68k and found some portability issues who fixed in the process, which benefit all architectures. This is also why OpenBSD devs are still on gcc3.

RISC and POWER are just two very modern ISAs to mention and not something you can ignore easily. We need more ISAs like in the past, not just two. It's very dangerous to limit ourselves to just ARM/x86 and diversity is a plus for writing more correct code and having more options. lowRISC is a nice fit for many things as is POWER, while of course ARM and x86 are here to stay. I'd count Nvidia's and AMD's GPUs as the other major architectures, but we don't usually deal directly at that level with GPUs. You choose the right chip for the job, just as phones select different SoCs for different use cases.

[clevernickname]

The idea that compiling your code for 68000 or MIPS can reveal bugs in your code does not change the fact that x86 and ARM are pretty much the only relevant CPU architectures that all but the most entrenched of government contractors could ship a product on today or in the foreseeable future that would have any use for SIMD. If you actually have a need to do extensive SIMD optimizations (say, it could shave 5ms off your frame time in a game, or save you $XXXXXX/year in your data center), PowerPC does not enter your mind at any moment.

You see it as weeding out bugs and future proofing your code in case x86 or ARM disappears tomorrow, I see it as a load of completely wasted work and optimization opportunities.

Also lowRISC learned nearly nothing from the past 20 years of CPU architecture advancement. It is not modern, it is a naive copy of a very outdated design.