Modern bloat comes from the software footprint, not so much about performance gains anymore. Compare the UI of MenuetOS with the latest GTK and the 100 shared libraries involved.
It's not so much that C would be slow but that with C and high-level languages it's very easy to do lots of the wrong kind of work.
C is so close to assembly that these seems quite unnecessary. Although I do agree with one of the developer's points that Assembly has a kind of beauty about it.
It's even more impressive because it's a one-man effort, IMO.
Replace the word "Assembly" with "C" in the above sentence, and it remains true.
Good on them for doing it Assembly. I don't have the patience for Assembly or C, so I appreciate those who do.
This was how DEC VMS was ported from VAX to Alpha and later to Itanium, as a substantial part of that operating system is written in VAX Macro32 assembler.
Similarly, if you attempt to port this (admittedly neat) system to ARM using such approach there'd be a lot of bumps. Beginning with all those clever SSE2 hacks not being able to expand automatically, through deficiency of caching and optimization assumptions made for original architecture in new circumstances, to conceptual mismatch of certain parts. E.g. what if you want to handle a case when system has to boot up in ARM Thumb mode? You just can't abstract that away with assembly.
The porting to C also cemented C's winning of the systems programming race, and fully liberated systems programmers from the underlying machine. C made the machine-word obselete by standardizing on a few types with relative widths.
If that wasn't the case, something like BLISS would have caught on, and BLISS didn't look the same on different platforms; its data types mapped 1:1 to underlying machine words and you had to deal with explicit alignment, allocation, and linkage. Explicit addressing modes and explicit heap and stack allocation modes. IOW, a royal pain in the butt, even though bliss was expression-based and well thought out (read all about Olin Shivers' praises for Bliss, though personally I don't see why: http://www.paulgraham.com/thist.html)
C is good.
http://www.cconcepts.co.uk/products/publish.htm
Lol. Looking at those dialogs brings it back. I probably laid most of those suckers out.
One of the great things about writing the core in C and then either optimizing for the compiler or writing the inner loop in the target ISA is that one can adapt with the CPU architecture. Anyone who has done development for true high performance architectures knows that you need to optimize for memory architecture as much as CPU architecture. When the new Xeons come out with double the L2 and a larger cache line and X cores in NUMA layout, writing everything in the Pentium 3 ISA is going to look pretty stupid.