[lmm]

> Their compiler fails to compile (well, at least link) some C programs altogether, and in other cases it produces code that is 150,000x slower than a real C compiler with optimisations turned off

I would bet that those things are also true of at least one expensive commercial C compiler.

[vajrabum]

I'd love to hear of any currently available commerical C compiler which has that level of issues. I would bet you'll be hard pressed to find one. C compilation is a quite thoroughly solved problem. In any case please provide an example.