ICE at -O1 and -02. Target specific error message at -O0. But even that would be more helpful if it told what the actual limit was.
$ avr-rtems4.10-gcc -mmcu=avr25 -O2 j.c -c
../../../../../rtems/cpukit/telnetd/des.c: In function 'des_init':
../../../../../rtems/cpukit/telnetd/des.c:274: internal compiler error: in tree_low_cst, at tree.c:4976
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ avr-rtems4.10-gcc -mmcu=avr25 -O0 j.c -c
../../../../../rtems/cpukit/telnetd/des.c:87: error: size of variable 'des_f' is too large
Created attachment 17298 [details]
preprocessed test case
The attached preprocessed file compiles fine with avr-gcc-4.4.0,4.3.2,4.3.3 with --mmcu=avr25 for all optimization levels.
I think you attached the wrong preprocessed source.
OK. Either I screwed up or it is fixed.