CPU Design at Segger

That was an interesting read. How do the resulting CPUs compare against their equivalents from other vendors? I know that most FPGA vendors also supply their own soft-core 8- and 32-bit CPUs.

One of the things I always think about this projects like this is "what does the maintenance look like"? Writing a custom CPU is one thing. But maintaining a custom compiler for it is a whole other ball of wax. I'd take the hit on code-density if it meant that I could use an off-the-shelf GCC.

Custom compilers (or even custom backends) are a hotspot for expensive-to-discover bugs. It's also a non-trivial maintenance burden.