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.
Concatenations that are only used by Sel expressions that do not consume
some bits on the edges can be narrowed to not compute the unused bits.
E.g.: `{a[4:0], b[4:0]}[5:4]` -> `{a[0], b[4]}[1:0]`
This is a superset or the PUSH_SEL_THROUGH_CONCAT DFG pattern, which is
removed.
Minor performance improvement, especially for assertions heavy code.
Strings are often used as temporaries in unlikely branches. Do not
localize them to avoid an unnecessary initialization on function entry.
Wilson Snyder
Geza Lore
Geza Lore
github action
Leela Pakanati
Oleh Maksymenko
Christian Hecken
Krzysztof Bieganski
Rodrigo Batista de Moraes
Pawel Kojma
Yangyu Chen