Re: Good advice but
BS. I spent eight years in asm because that was the only language that could handle the problem I was addressing. Going back up to C was astoundingly painful from a performance standpoint. MP computations without the carry bit? Here--let's just throw away half of our register size & reduce speed by a factor of four. Check for integer overflow? Let's see... Nope, that won't work. Naw, that won't either. Good thing I spent a lot of time working with registers--I would hate to think what would happen if someone without such experience tried this!
For absolutely critical performance, you want access to the parts of the instruction set that C denies you.