  We propose two tiers of modifications to FPGA logic cell architecture to
deliver a variety of performance and utilization benefits with only minor area
overheads. In the irst tier, we augment existing commercial logic cell
datapaths with a 6-input XOR gate in order to improve the expressiveness of
each element, while maintaining backward compatibility. This new architecture
is vendor-agnostic, and we refer to it as LUXOR. We also consider a secondary
tier of vendor-speciic modifications to both Xilinx and Intel FPGAs, which we
refer to as X-LUXOR+ and I-LUXOR+ respectively. We demonstrate that compressor
tree synthesis using generalized parallel counters (GPCs) is further improved
with the proposed modifications. Using both the Intel adaptive logic module and
the Xilinx slice at the 65nm technology node for a comparative study, it is
shown that the silicon area overhead is less than 0.5% for LUXOR and 5-6% for
LUXOR+, while the delay increments are 1-6% and 3-9% respectively. We
demonstrate that LUXOR can deliver an average reduction of 13-19% in logic
utilization on micro-benchmarks from a variety of domains.BNN benchmarks
benefit the most with an average reduction of 37-47% in logic utilization,
which is due to the highly-efficient mapping of the XnorPopcount operation on
our proposed LUXOR+ logic cells.
