Normally it's better to focus on high-level time-complexity improving optimizations but there's still a whole lot of things where you really need assembly micro

Normally it's better to focus on high-level time-complexity improving optimizations but there's still a whole lot of things where you really need assembly micro-optimizations, since they usually offer a 10x or 100x speedup. It's just that those things usually only concern core libraries. Stuff like crc32. But the rest of the time we're just writing code that glues all the assembly optimized subroutines together.