[rswail]

Because C was originally for PDP/DEC equipment and the instruction set had standard register access modes including both pre and post increment.

So the (for example) strcmp "while (s++ == d++);" made sense as efficient code, because the pointer access and the post increment effectively compiled down to almost a single instruction.

https://en.wikipedia.org/wiki/PDP-11_architecture#General_re...

[im3w1l]

x86 has cmps for doing comparison with postincrement / postdecrement.

[rswail]

Sure, but the point was that C was designed to implement Unix and Unix was implemented on DEC machines and DEC machines had a particular architecture around registers that included the pre/post increment, which lead to the C *p++ style to iterate.

[im3w1l]

I wanted to point out that such instructions are in use to this day rather than being than being something from a long gone era.

[azinman2]

Do compilers use that if you break it apart to something more legible? If you don’t, does the intel cpu end up doing the right thing anyway?

[umanwizard]

Yes, modern compilers should treat them the same.