Re: [avr-gcc-list] GCC 3.0 patches

[Marek Michalkiewicz]

> 2. I noticed that when I use "-mtiny-stack", the function prologue of
> main() still adds two instructions to manipulate SPH. This patch makes sure

This is intentional - you can use -mtiny-stack on devices with 16-bit stack
pointer as well (if the stack fits within one 256-byte page), so SPH has to
be initialized somewhere...

> The code now (happily!) uses "inc r10" to bump the counter, but you'll also
> notice that the interrupt routine pushes and pops r10 from the stack! So
> routines that use "tick" don't see it getting updated at 1Khz. The third
> portion of my patch has the interrupt prologue code check to see if a
> register is in the fixed register list, and if so, doesn't push or pop it.

Good catch, thanks.

Marek