# From https://github.com/cliffordwolf/icestorm/blob/be0bca0/icefuzz/timings_up5k.txt
# NB: Inputs/Outputs must be ordered alphabetically
# Inputs: CI I0 I1
# Outputs: CO
SB_CARRY 1 1 3 1
278 675 609
# Inputs: I0 I1 I2 I3
# Outputs: O
SB_LUT4 2 0 4 1
1285 1231 1205 874