Add a new Dfg pass 'pushDownSel'. This will try to move selects through
a tree of concatenations in order to eliminate temporary nodes holding
intermediate concatenation results. This can get rid of a lot of
variables when packed arrays are assigned in parts (e.g. bit-wise).
Use uint32_t max value instead of zero as sentinel value for a trace
code being unassigned. Prep for follow on patch.
Note the actual trace file will still start codes from one, the codes
in the model are just an offset from the base code.
We use special C++ types for ports, e.g. SystemC types in --sc mode, and native C arrays for unpacked arrays in --cc mode. These types are not substitutable for internal types, e.g. VlUnpacked, however all the runtime primitives expect internal types.
I think the intention was to use these special IO types only for top level ports, but the current implementation also uses them for the ports of all non-inlined modules. This means the output C++ will not compile if such a port is passed to a runtime primitive (e.g. array 'sort' as in the new test) or DPI import.
Changed to use the special IO types only on the top level ports.
Note these are likely still broken if attempting to invoke on a top level port (we might be saved by wrapTop, but later optimizations might eliminate the intermediary)
Re-inline ConstPool entries in V3Subst that have been expanded into
word-wise accessed by V3Expand. This enables downstream constant folding
on the word-wise expressions.
As V3Subst now understands ConstPool entries, we can also omit expanding
straight assignments with a ConstPool entry on the RHS. This allows the
C++ compiler to see the memcpy directly.
V3Expand wide SHIFTL and SHIFTR if the shift amount is know and is a
multiple of VL_EDATA_SIZE. This case results in each word requiring a
simple copy from the original, or store of a constant zero, which
subsequent V3Subst can then eliminate.
A temporary introduced by V3Premit could not be eliminated in V3Subst if
it was involved in an expression that did a write back to a
non-temporary. To enables removing these, we need to track all variables
in V3Subst, not just the ones we would consider for elimination. Note
the new implementation is marginally faster than the old one even though
it does more work. It can eliminate ~5% more of wide temporaries on some
designs. Algorithm is largely the same.
Wilson Snyder
Geza Lore
github action
Leela Pakanati
Igor Zaworski
Pawel Kojma
Veripool API Bot
Geza Lore
Oleh Maksymenko
Christian Hecken
Krzysztof Bieganski
Rodrigo Batista de Moraes