https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77353 --- Comment #12 from Berni <bseifert at gmx dot at> --- Thanks, Georg-Johann, I can confirm that avr-g++ -S -Os -mmcu=atmega128 main.cpp performs a 16-bit comparison but avr-gcc -S -Os -mmcu=atmega128 main.c works as expected (8-bit comparison)