Commit Graph

3 Commits

Author SHA1 Message Date
Jannis Harder 95db5a9d38 formalff: New -setundef option
Find FFs with undefined initialization values for which changing the
initialization does not change the observable behavior and initialize
them. For -ff2anyinit, this reduces the number of generated $anyinit
cells that drive wires with private names.
2022-08-16 13:37:30 +02:00
Jannis Harder a5e1d3b997 formalff: Set new replaced_by_gclk attribute on removed dff's clks
This attribute can be used by formal backends to indicate which clocks
were mapped to the global clock. Update the btor and smt2 backend which
already handle clock inputs to understand this attribute.
2022-08-16 13:37:30 +02:00
Jannis Harder c0063288d6 Add the $anyinit cell and the formalff pass
These can be used to protect undefined flip-flop initialization values
from optimizations that are not sound for formal verification and can
help mapping all solver-provided values in witness traces for flows that
use different backends simultaneously.
2022-08-16 13:37:30 +02:00