share - perform sat-based resource sharing

yosys> help share
share [options] [selection]
This pass merges shareable resources into a single resource. A SAT solver
is used to determine if two resources are share-able.
Per default the selection of cells that is considered for sharing is
narrowed using a list of cell types. With this option all selected
cells are considered for resource sharing.

IMPORTANT NOTE: If the -all option is used then no cells with internal
state must be selected!
Per default some heuristics are used to reduce the number of cells
considered for resource sharing to only large resources. This options
turns this heuristics off, resulting in much more cells being considered
for resource sharing.
Only consider the simple part of the control logic in SAT solving, resulting
in much easier SAT problems at the cost of maybe missing some opportunities
for resource sharing.
-limit N
Only perform the first N merges, then stop. This is useful for debugging.