Verilator should now correctly re-evaluate any logic that depends on
state set in a DPI exported function, including if the DPI export is
called outside eval, or if the DPI export is called from a DPI import.
Whenever the design contains a DPI exported function that sets a
non-local variable, we create a global __Vdpi_export_trigger flag, that
is set in the body of the DPI export, and make all variables set in any
DPI exported functions dependent on this flag (this ensures correct
ordering and change detection on state set in DPI exports when needed).
The DPI export trigger flag is cleared at the end of eval, which ensured
calls to DPI exports outside of eval are detected. Additionally the
ordering is modifies to assume that any call to a 'context' DPI import
might call DPI exports by adding an edge to the ordering graph from the
logic vertex containing the call to the DPI import to the DPI export
trigger variable vertex (note the standard does not allow calls to DPI
exports from DPI imports that were not imported with 'context', so we
do not enforce ordering on those).
All parameters that are required in the output are now emitted as
'static constexpr, except for string or array of strings parameters,
which are still emitted as 'static const' (required as std::string is
not a literal type, so cannot be constexpr). This simplifies handling
of parameters and supports 'real' parameters.
This patch partitions AstCFuncs under an AstNodeModule based on which
header files they require for their implementation, and emits them
into separate files based on the distinct dependency sets. This helps
with incremental recompilation of the output C++.
The -G option now correctly parses simple integer literals as signed
numbers, which is in line with the standard and is significant when
overriding parameters without a type specifier.
Fixes#3060
V3Simulate reuses allocated AstConst nodes for efficiency, however this
used to be implemented in a way that required a deep copy of a
std::unorderd_map<_, std::deque<_>>, which was quite inefficient when it
grew large. The free list is now managed without any copying. This takes
the V3Table pass from taking 12s to 0.2s on SweRV EH1.
We incorrectly treated two different struct types the same when passed
as an actual parameter to a `parameter type` parameter in an instance,
if the actual parameter expression both hash to the same value and the
structs have the same struct name. This is now corrected.
Fixes#3055.
This patch implements #3032. Verilator creates a module representing the
SystemVerilog $root scope (V3LinkLevel::wrapTop). Until now, this was
called the "TOP" module, which also acted as the user instantiated model
class. Syms used to hold a pointer to this root module, but hold
instances of any submodule. This patch renames this root scope module
from "TOP" to "$root", and introduces a separate model class which is
now an interface class. As the root module is no longer the user
interface class, it can now be made an instance of Syms, just like any
other submodule. This allows absolute references into the root module to
avoid an additional pointer indirection resulting in a potential speedup
(about 1.5% on OpenTitan). The model class now also contains all non
design specific generated code (e.g.: eval loops, trace config, etc),
which additionally simplifies Verilator internals.
Please see the updated documentation for the model interface changes.
Teach V3Localize how to localize variables that are used in multiple
functions, if in all functions where they are used, they are always
written in whole before being consumed. This allows a lot more variables
to be localized (+20k variables on OpenTitan - when building without
--trace), and can cause significant performance improvement (OpenTitan
simulates 8.5% - build single threaded and withuot --trace).
What previously used to be per module static constants created in
V3Table and V3Prelim are now merged globally within the whole model and
emitted as part of a separate constant pool. Members of the constant
pool are global variables which are declared lazily when used (similar to
loose methods).
This patch introduces the concept of 'loose' methods, which semantically
are methods, but are declared as global functions, and are passed an
explicit 'self' pointer. This enables these methods to be declared
outside the class, only when they are needed, therefore removing the
header dependency. The bulk of the emitted model implementation now uses
loose methods.
