yosys/tests/opt/opt_expr_constconn.ys

read_verilog opt_expr_constconn.v
select -assert-count 1 t:$add
select -assert-count 1 t:$add %ci w:C %i
equiv_opt -assert opt_expr
design -load postopt
select -assert-count 1 t:$add
select -assert-count 0 t:$add %ci w:C %i