Using SSE is specifically one of the cases where writing something in assembly can make sense (and in fact, the only case where I've written things in asm for p

Using SSE is specifically one of the cases where writing something in assembly can make sense (and in fact, the only case where I've written things in asm for purely performance reasons). Let's go back to the original statement: I'd assume any intense math operations that happen inside a loop would be much faster. That's what I was responding to. Just trasnlating the logic to asm won't make it fast. If you look at my earlier followup, I mentioned that if you could make assumptions about your code that the compiler can't know, then you're back in the land where asm optimizations can make sense. That seems to be what you're getting at with the rest of your points.