[prbs23]

Most architectures do not provide an interrupt that is generated by an integer overflow. Since this would be a significant architectural change in the hardware, it can't be simply added in.

Additionally, if you are running inside an operating system, handling an interrupt usually incurs a trip through the kernel, which would add extra overhead every time an overflow did happen. Since there's a lot of software which depends on integers overflowing, this overhead on each overflow could significantly impact legacy software.

[CorrectHorseBat]

Using a new instruction none of that would be an issue. And as someone pointed out, on x86 it wouldn't even be a new instruction, INTO already exists. But apparently it didn't make it in x64 because nobody used it :/