http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46779
--- Comment #4 from Michael Schulze <mschulze at ivs dot cs.ovgu.de> 2010-12-03 14:16:30 UTC --- > I don't know anything about AVR, so I can't say that (I just noticed the r1 > issue). Ok due to the compiler abi for the avr, r0,r1 are fixed registers that are never allocated by gcc for local data, but often used for fixed purposes. r0 is a temporary register that may be globbered by any C-code. r1 is assumed to be always zero in any C-code. This is the reason, why it is cleared at the end of the inline assembler.
