yosys/tests/ice40/mul.ys

read_verilog mul.v
hierarchy -top top
equiv_opt -assert -map +/ice40/cells_sim.v synth_ice40 -dsp # equivalency check
design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
cd top # Constrain all select calls below inside the top module
select -assert-count 1 t:SB_MAC16
select -assert-none t:SB_MAC16 %% t:* %D