In the examples the article this shows this will not help, as the overflow is in indirect addressing, not add instructions. I'm not a microcode expert but I guess arithmetic instructions, even without a jo, are not as efficient as indirect addressing, so we can't switch to arithmetic instructions with jo.
Perhaps we could have a new addressing mode that is the same as normal indirect but falls through and sets o if some part of it overflows. Then you'd do mov, jo which could then be fused. But I don't really know what I'm talking about.
