Re: avr-gcc making really bad inlining decisions.

Another interesting data point or two:
1) This goes back to at least 4.7
2) It's not avr-specific (as you might begin to suspect, given
previous discussion.)
I can get the same sort of bad behavior out of gcc for x86:

BillW-MacOSX-2<10405> /sw/lib/gcc4.7/bin/g++-fsf-4.7 -c -Os -w foo.cpp
-fno-inline-small-functions
BillW-MacOSX-2<10406> size foo.o
__TEXT  __DATA  __OBJC  others  dec     hex
8725    209     0       0       8934    22e6
BillW-MacOSX-2<10407> /sw/lib/gcc4.7/bin/g++-fsf-4.7 -c -Os -w foo.cpp
BillW-MacOSX-2<10408> size foo.o
__TEXT  __DATA  __OBJC  others  dec     hex
29936   209     0       0       30145   75c1

(now, to build up the courage to bug the generic gcc people...)