[saagarjha]

> The unexplained and useless nop is also puzzling. Why is it there? What is it for? The same goes for the many other instructions which aren't actually contributing to the calculation, and initially made me think it was compiler output when I first glanced over the code. Writing a program that performs the given task is relatively straightforward even in Asm, but your solution is unnecessarily complex.

It is explained:

> Line 5 is a no-operation (or noop), which means that it is a filler instruction and doesn’t actually do anything but take up a CPU clock cycle. Older versions of GDB require this proceeding _start, and so I have left it in for these examples.

[userbinator]

So it is. It would've been much clearer to mention that at the beginning when it's first introduced, since it's not commented like the other instructions and I first thought it was a left-over placeholder.

That said, it must be a very old GDB since I've otherwise not ever seen a NOP as the very first instruction of any nontrivial program in all these years... maybe two NOPs in the early days for patching, but that's about it.

[willvk]

I agree the structure of some of my explanations could have been a bit better. The book I was using as a basis was from the mid-90s so it would be a version of GDB from 20 years ago that requires the NOP.