Re: [avr-gcc-list] Using X and Z register in global variables

[Joerg Wunsch]

As User Tomdean wrote:

> This is warning about using Z and X, but, not Y.

Maybe you could really use Y as a global reg variable, but I'd rather
avoid that.  It severely restricts the compilers freedom of choice to
generate decent code for the remaining program.  If you're linking
against avr-libc, you're also *heavily* at risk that some library code
(not knowing about your choice of a global register variable) clobbers
it.

> But, I could not get gcc to use Z+.

I think nobody taught GCC to use it, except perhaps in a few
fixed-pattern situations.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)