Right?.. There’s a reason I decided to spend the couple of hours it took to get libfirm to compile. Then again, it’s a shell benchmark, most of it is bound to be syscalls and (nonfancy) parsing, so the space for an optimizing compiler to make a difference is bound to be fairly limited. All the compilers in the test are within 2× of the best one, and CompCert isn’t exactly a speed demon either. I’d love to dig into this, but there are so many layers of stuff I don’t really know where to start.

I tested with tcc, cparser and my own slimcc, the benchmark showed multiple process with htop, so there are some dynamic cpu scaling randomness going on. I saw larger run-to-run differences with the same binary, than with comparing cherry-picked best-run of each, so probably not the best benchmark.