memory_share - consolidate memory ports
memory_share [-nosat] [-nowiden] [selection]
This pass merges share-able memory ports into single memory ports.
The following methods are used to consolidate the number of memory ports:
- When multiple write ports access the same address then this is converted
to a single write port with a more complex data and/or enable logic path.
- When multiple read or write ports access adjacent aligned addresses, they are
merged to a single wide read or write port. This transformation can be
disabled with the "-nowiden" option.
- When multiple write ports are never accessed at the same time (a SAT
solver is used to determine this), then the ports are merged into a single
write port. This transformation can be disabled with the "-nosat" option.
Note that in addition to the algorithms implemented in this pass, the $memrd
and $memwr cells are also subject to generic resource sharing passes (and other
optimizations) such as "share" and "opt_merge".