The constant pool is now an ordinary package, created with the netlist
and instantiated under $root like any other package, and most special
handling has been removed, including AstConstPool. Lookups go through
V3ConstPool, which has a singleton instance owned by V3Global. Static
methods on V3Common form the public interfce to add/find constant pool
entries.
With that, the constant pool is usable at any stage during compilation,
so enum and dimension tables created by V3Width, and enum value tables
created by V3Randomize now also live in the constant pool instead of
$unit, so identical tables are shared.
Associative array constants are handled separately from unpacked
tables, which used to be broken but unused.
Emitted constant pool variables use direct initialization, and
`constinit` with C++20 where the type allows it. This ensures we don't
change a run-time in a way that would result in unintended code size
increase.
-fno-merge-const-pool, which was introduced years ago but never prompted
a bug report is deprecated and has no effect.
This is also prep for future work.
AstScopeName is an AstNodeExpr, but V3Task stashed the DPI export scoping
marker into the enclosing AstCFunc's statement list (addStmtsp), placing an
expression in a statement position.
Give AstCFunc a dedicated 'scopeNamep' operand to hold the marker instead.
Part of #6280
Restrict VL_RESTORER to be usable only with trivially copyable types.
Introduce VL_RESTORER_COPY and VL_RESTORER_CLEAR, which are more
efficient versions usable for non trivially copyable types.
VL_RESTORER_COPY semantically behaves the same as VL_RESTORER, but only
does one copy at initialization, and on scope exit restores via a move.
VL_RESTORER_CLEAR swaps the variable with an new one constructed via
the no-args constructor (e.g. empty collection), which does not require
any copying at any point.
Static assertions enforce picking one of the new flavours when copying
might be expensive.
- Allow reordering pure statements with DPI import calls iff no public
variables (including those read via a DPI export) are involved. This
ensures the DPI import can't observe the reordering
- Allow reordering of pure statements with AstDisplay and AstStop. This
requires an assumption that AstDisplay and AstStop will not read or
write model state other than via a VarRef explicitly present int the
Ast.
Overall this allows eliminating a lot of conditionals around assertions,
which were previously not possible.