When `setundef -undriven` connects an undriven wire to a replacement
value, the wire's \\init attribute (if present) is now removed. Previously,
the init attribute was left intact, causing downstream passes like
opt_merge to report "Conflicting init values" errors because the init
value contradicted the newly assigned constant.
For wires that are entirely undriven, the init attribute is removed
completely. For partially undriven wires (where only some bits are
undriven), only the corresponding init bits are cleared to x.
Wires driven by flip-flops or other cells are not affected, as they
are excluded from the undriven signal set before this code runs.
Previously, setundef would rewrite sigspecs in all cells, processes,
and connections regardless of the active selection. Only modules and
memories were correctly filtered by selection.
Fix by using module->selected_cells() for cells, adding a
module->selected() check for processes, and checking wire selection
on the lhs of each connection before rewriting.
Fixes#5624
This adds the xprop_decoder attribute to bwmuxes that drive the original
unencoded signals. Setundef is changed to ignore the x inputs of these
bwmuxes, so that they survive the prep script of SBY's formal flow. This
is required to make simulation (via sim) using the prep model show the
decoded x signals instead of 0/1 values made up by the solver.
A few passes included the same list of FF cell types. Make it a global
const instead.
The zinit pass also seems to include a list like that, but given that
it seems to be completely broken at the time (see #1568 discussion),
I'm going to pretend I didn't see that.
The initial list of hits was generated with the codespell command
below, and each hit was evaluated and fixed manually while taking
context into consideration.
DIRS="kernel/ frontends/ backends/ passes/ techlibs/"
DIRS="${DIRS} libs/ezsat/ libs/subcircuit"
codespell $DIRS -S *.o -L upto,iff,thru,synopsys,uint
More hits were found by looking through comments and strings manually.
o Not all derived methods were marked 'override', but it is a great
feature of C++11 that we should make use of.
o While at it: touched header files got a -*- c++ -*- for emacs to
provide support for that language.
o use YS_OVERRIDE for all override keywords (though we should probably
use the plain keyword going forward now that C++11 is established)
