16:31 <litghost> mkurc: One thing you might try is CARRY_INF, and have a techmap for both Vivado and VPR. Less than ideal, but it would make a point in the flow where both Vivado and VPR output is possible

16:33 <litghost> That is less than ideal, but VPR cannot currently handle having the carry chain be a generic port. The reason CARRY0/CARRY have dedicated fabric and carry chain outputs is because VPR cannot route on or off of the carry chain on its own. VPR could be modified to handle this, but in the short term that is not an important feature, relative to other things.

18:02 <mkurc> litghost: Yes, you are right. This seems to be the only option for now. So I'll make a sort of "intermediate" techmap for carry chains that could be mapped again either for Vivado or VPR. Thanks.