Fitter is off by one or two ALUTs?

Thanks for the response Rysc. You're trying to help me get a design working, and I feel bad because this is really a low priority issue. But let me shed some extra light on the situation anyhow.

I'm actually starting with an empty design (well, okay, it has a single input that goes nowhere -- I thought it would get trimmed, but it doesn't):

module mask_ffffffffffffffff (a); 
input a; 
endmodule

I push that through the entire flow, and come up with a design that uses 0 ALUTs and 0 LABs. I then invoke the TCL ::quartus::chip_editor::add_new_cell on every valid LCCOMB in the device, so the placement happens explicitly as part of the instantiation. Finally, my LUT values are all FFFF (or all 0000 in a different design), so the ALUTs have no inputs or outputs, and neither are there any control signals involved. In other words, there's essentially zero routing in the device.

All of that is what leads me to conclude that the fitter either feels it needs to hang on to an ALUT or two, or that there may be an instance of 0-based offset versus 1-based offset and/or < versus <= somewhere in the code. Regardless, as I said, this is not a high priority issue, and Rysc's contributions to this forum are too valuable to waste on this.