opt_merge - consolidate identical cells#

yosys> help opt_merge#
opt_merge [options] [selection]

This pass identifies cells with identical type and input signals. Such cells
are then merged to one cell.

-nomux

Do not merge MUX cells.

-share_all

Operate on all cell types, not just built-in types.

-keepdc

Do not merge flipflops with don't-care bits in their initial value.