insbuf - insert buffer cells for connected wires

yosys> help insbuf

insbuf [options] [selection]

Insert buffer cells into the design for directly connected wires.

-buf <celltype> <in-portname> <out-portname>

Use the given cell type instead of $_BUF_. (Notice that the next
call to "clean" will remove all $_BUF_ in the design.)

-chain

Chain buffer cells