https://github.com/apache/arrow/pull/7341#issuecomment-638241193
How should arithmetic kernels handle integer overflow? The approach currently taken in the linked PR is to promote such that overflow will not occur, for example `(int8, int8)->int16` and `(uint16, uint16)->uint32`. I'm not sure that's desirable. For one thing this leads to inconsistent handling of 64 bit integer types, which are currently allowed to overflow since we cannot promote further (NB: that means this kernel includes undefined behavior for int64). There are a few other approaches we could take (ordered by personal preference): - define explicit overflow behavior for signed integer operands (for example if we declared that add(i8(a), i8(b)) will always be equivalent to i8(i16(a) + i16(b)) then we could instantiate only unsigned addition kernels) - raise an error on signed overflow - provide ArithmeticOptions::overflow_behavior and allow users to choose between these - require users to pass arguments which will not overflow
