[jchw]

Well, and Android and iOS and many microcontrollers (well, often a shitty GCC fork in that case but still) and way more platforms (OpenBSD, Minix, HP-UX, Solaris, VxWorks, bare metal) and architectures (Alpha, ARM, AVR, x86, m68k, microblaze, MIPS, PDP-11, Risc-V, SPARC, VMS) than that, not including third party ports in SDKs.

Yeah, I get that with embedded, it's a crapshoot. However it's probably not ridiculous to say that GCC ports to microcontrollers is not terribly uncommon, either.

GCC and Clang certainly are a lot more useful than for just that tiny range you listed. The reality is they probably cover more platforms than any other individual compiler.

[pjmlp]

When I was involved in mainframe or commercial UNIX projects we always used the OS vendor SDK, hence why I left them out of my list.