The only use for the clocker attribute and the AstVar::isUsedClock that
is actually necessary today for correctness is to mark top level inputs
of --lib-create blocks as being (or driving) a clock signal. Correctness
of --lib-create (and hence hierarchical blocks) actually used to depend
on having the right optimizations eliminate intermediate clocks (e.g.:
V3Gate), when the top level port was not used directly in a sensitivity
list, or marking top level signals manually via --clk or the clocker
attribute. However V3Sched::partition already needs to trace through the
logic to figure out what signals might drive a sensitivity list, so it
can very easily mark all top level inputs as such.
In this patch we remove the AstVar::attrClocker and AstVar::isUsedClock
attributes, and replace them with AstVar::isPrimaryClock, automatically
set by V3Sched::partition. This eliminates all need for manual
annotation so we are deprecating the --clk/--no-clk options and the
clocker/no_clocker attributes.
This also eliminates the opportunity for any further mis-optimization
similar to #6453.
Regarding the other uses of the removed AstVar attributes:
- As of 5.000, initial edges are triggered via a separate mechanism
applied in V3Sched, so the use in V3EmitCFunc.cpp is redundant
- Also as of 5.000, we can handle arbitrary sensitivity expressions, so
the restriction on eliminating clock signals in V3Gate is unnecessary
- Since the recent change when Dfg is applied after V3Scope, it does
perform the equivalent of GateClkDecomp, so we can delete that pass.
Instead of installing redirect scripts in to bindir, and real
executables in to pkgdatadir/bin, we now put the real executables into
bindir, and add redirect scripts into pkgdatadir/bin. (That is, we
redirect in the opposite direction as before).
This enables the same relocatable and testable installations as before
without putting architecture specific binaries into pkgdatadir, so
hopefully we now conform to the Linux Filesystem Hierarchy Standard.
This requires a small fixup in the installed `verilator` script to
hardcode the relative path between bindir and pkgdatadir.
Fixes#5140
Wilson Snyder
Artur Bieniek
Geza Lore
Aleksander Kiryk
Bartłomiej Chmiel
Ryszard Rozak
Bartłomiej Chmiel
Tobias Jensen
Mateusz Gancarz
Kamil Rakoczy
Todd Strader
Krzysztof Bieganski
Andrew Nolte
Mariusz Glebocki
Ryan Ziegler
404allen404
Paul Wright
Szymon Gizler