[Bug target/56439] global and local register variables don't work in a useful way -- AVR

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56439



--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-02-25 
03:53:25 UTC ---

(In reply to comment #2)

> Any specific sections you can point me to? I'd be interested to hear a

> justification for this behavior.



Simple answer, an interrupt can happen any time after the access/assignment of

the global register variable so it needs to be set to the value and treated as

a volatile variable.