dfflibmap - technology mapping of flip-flops

yosys> help dfflibmap

dfflibmap [-prepare] [-map-only] [-info] -liberty <file> [selection]
Map internal flip-flop cells to the flip-flop cells in the technology
library specified in the given liberty file.

This pass may add inverters as needed. Therefore it is recommended to
first run this pass and then map the logic paths to the target technology.

When called with -prepare, this command will convert the internal FF cells
to the internal cell types that best match the cells found in the given
liberty file, but won't actually map them to the target cells.

When called with -map-only, this command will only map internal cell
types that are already of exactly the right type to match the target
cells, leaving remaining internal cells untouched.

When called with -info, this command will only print the target cell
list, along with their associated internal cell types, and the arguments
that would be passed to the dfflegalize pass.  The design will not be