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.
Disable MULTIDRIVENPROC for static variables used as loop induction
variables. Same way as we disable similar warning in Dfg. While bad
style and bad for performance, it's common legacy code style.
The loops modelling the SystemVerilog scheduling regions are no longer
generated. They now live in 'VerilatedEvalLoop' in the runtime library.
The generated model holds one as a member, passing itself to it, and
exposes each evaluation entry point to it as a pure virtual method on
VerilatedModel. The model's 'eval' and 'eval_step' remain the top level
entry points, and are backward compatible.
V3Sched no longer emits '_eval' or '_eval_settle', etc.. Instead every
evaluation entry point called from the runtime is enumerated by 'VEval',
Scheduling creates all entry points, for all scheduling regions, even if
they are empty, and the runtime eval loop calls everything
unconditionally. If regions are empty, this is simply a call to an empty
function. This will hurt performance on very small models, but should
not be noticeable on anything meaningful, so it is likely best to keep
to reduce complexity.
A scheduling entry points evaluate a single iteration and returns
whether it did any work, they are effectively the previous
`_eval_phase_*` functions.
Nazar Zibilyuk
Wilson Snyder
Hongseok Choi
Saqib Khan
Geza Lore
Francesco Urbani
Deanyone Su
Marco Bartoli
Bartłomiej Chmiel
Noam Gallmann
David Harris
Tynan McAuley
Shriyans Sahoo
Kaleb Barrett
Nick Brereton
Jesús Alberto López Soto
Edmund Lam
Mike Murunov
CatalpaEel
Kristof Marien
Drew Risinger
Martijn Wobbes
Marco Frank
Drew Risinger
Paul Rigge
Jakub Wasilewski
Eddie Rydell
Aisha
Artur Bieniek