The --track-assumes option makes smtbmc keep track of which assumptions
were used by the solver when reaching an unsat case and to output that
set of assumptions. This is particularly useful to debug PREUNSAT
failures.
The --minimize-assumes option can be used in addition to --track-assumes
which will cause smtbmc to spend additional solving effort to produce a
minimal set of assumptions that are sufficient to cause the unsat
result.
Note that this functionality is only used by diagnostics emitted by
the C++ testbench; diagnostics emitted by the RTL in `eval()` do not
need to be recorded since they will be emitted again during replay.
This commit is part of a PR that requires corresponding changes in SBY.
To prevent CI failures, detect whether those changes already landed and
skip the SBY using tests until then.
Previously `unroll_stmt` would recurse over the smtlib expressions as
well as recursively follow not-yet-emitted definitions the current
expression depends on. While the depth of smtlib expressions generated
by yosys seems to be reasonably bounded, the dependency chain of
not-yet-emitted definitions can grow linearly with the size of the
design and linearly in the BMC depth.
This makes `unroll_stmt` use a `list` as stack, using python generators
and `recursion_helper` function to keep the overall code structure of
the previous recursive implementation.
Rename formal cells in addition to witness signals. This is required to
reliably track individual property states for the non-smtbmc flows.
Also removes a misplced `break` which resulted in only partial witness
renaming.
This commit adds a `debug_scopes` container, which can collect metadata
about scopes in a design. Currently the only scope is that of a module.
A module scope can be represented either by a module and cell pair, or
a `$scopeinfo` cell in a flattened netlist. The metadata produced by
the C++ API is identical between these two cases, so flattening remains
transparent to a netlist with CXXRTL.
The existing `debug_items` method is deprecated. This isn't strictly
necessary, but the user experience is better if the path is provided
as e.g. `"top "` (as some VCD viewers make it awkward to select topmost
anonymous scope), and the upgrade flow encourages that, which should
reduce frustration later.
While the new `debug_items` method could still be broken in the future
as the C++ API permits, this seems unlikely since the debug information
can now capture all common netlist aspects and includes several
extension points (via `debug_item`, `debug_scope` types).
Also, naming of scope paths was normalized to `path` or `top_path`,
as applicable.
Processes can contain `MemWriteAction` entries which are invisible to
most passes operating on memories but which will be lowered to write
ports later on by `proc_memwr`. For that reason we can get corrupted
RTLIL if we sequence the memory passes before `proc`. Address that by
making the affected memory passes ignore modules with processes.
N. Engelhardt
Jannis Harder
Martin Povišer
Miodrag Milanovic
github-actions[bot]
Krystine Sherwin
Catherine
Jason Thorpe
Roland Coeurjoly