AVR-Chat

> This is one of the reasons I don't trust architecture specific keywords
> (interrupt keywords in particular).
>
> And also a good illustration of where mixing asm with C can be of great
> benefit (reducing the latency substantially and decreasing size to boot)

This is hilarious to me in several layers.

The most obvious one is the one I pointed out, NOTHING needs be pushed.
Then we have the fact that ISRs aren't supposed to be able to count on
R1 being zeroed, but the code DOES that.

Can't a modern compiler figure out that all this was unnecessary?