A comment below reminded me of these: https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins..., which are close, but have an insane API as they replace your arithmetic operations with ugliness.

I think they can be fixed with sensible macros, though:

    #define ADDITION_WOULD_OVERFLOW(a, b) \
      ({ typeof((a) + (b)) __r; __builtin_add_overflow((a), (b), &__r); })

Hopefully the compiler would optimise:

    if (ADDITION_WOULD_OVERFLOW(a, b))
    {
       return 0;
    }
    return a + b;

to only do the addition once.