I can't imagine this doing well in a design where I instantiate xilinx primitives and want to port the design to altera. Unfortunately, there are plenty of time

I can't imagine this doing well in a design where I instantiate xilinx primitives and want to port the design to altera. Unfortunately, there are plenty of times where instantiating vendor primitives is completely necessary. The tools suck and I'm glad people are trying to make them suck less... but nothing is going to change substantially until the community demands that the vendors do their part or force their hands.