It looks like GCC arm has not yet supported adc sbb for arm while clang does. https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html clang: https://godbolt.org/z/8q9djE7fr gcc with aarch64 target: https://godbolt.org/z/Wxcf6r7sP gcc x86_64 correctly supports it while gcc arm does not: https://godbolt.org/z/caYMTxMba Can you fix it? Ty
