The Fastest C++ Code is Inline Assembly

Lower than this you should not get

In the fast-paced world of C++ developers, where efficiency is paramount, optimizing code to squeeze out every last drop of performance has always been a fascinating challenge. This journey often takes developers down to the very roots of computing, where C++ meets assembly language, and every CPU cycle counts.

Circa three decades ago, during the wild 90s, programmers frequently had to manually craft every byte of executable code, often diving into the murky waters of assembly language (and even lower) to achieve the desired performance. These early pioneers of optimization developed techniques that, while rudimentary by today’s standards, laid the groundwork for understanding the power and limitations of both C++ and assembly.

This exploration delves into the specifics of optimizing a seemingly simple task, lighting up a pixel on the screen, by comparing handcrafted and optimized assembly routines...