The previous commit introduced code that optimizes the activation
patterns to be able to generate smaller activation logic. The resulting
supercell was then enqueued as shareable using those optimized
activation patterns. The condition represented by the optimized patterns
is an over-approximation of the actual activiation condition. This means
using it as activiation for the supercell loses precision and pessimises
sharing of the supercell with further cells, breaking the sat/share
test.
This commit fixes that by using the optimized activiation patterns only
for the generation of activation logic and using the original patterns
for enqueuing the supercell.
In case the two sets of activation patterns are mutually exclusive
without considering the logic feeding into the activation signals, an
activation condition can only be relevant if present in both sets with
opposite polarity.
This detects pattern-only mutual exclusion by running an additional SAT
query before importing the input cone logic. If that is already UNSAT,
we remove all non-relevant condition and re-simplify the remaining
patterns.
In cases of pattern-only mutual exclusion, this will often produce much
smaller selection logic and avoid the more costly SAT query that
includes the input cones.
If all the (non-select) inputs of a `$_MUX{4,8,16}_` are undefined, replace it, just like we do for `$mux` and `$_MUX_`.
Add `tests/opt/opt_expr_mux_undef.ys` to verify this.
This doesn't do any const folding on the wide muxes, or shrinking to less wide muxes. It only handles the case where all inputs are 'x and the mux can be completely removed.
- Techlib pmgens are now in relevant techlibs/*.
- `peepopt` pmgens are now in passes/opt.
- `test_pmgen` is still in passes/pmgen.
- Update `Makefile.inc` and `.gitignore` file(s) to match new `*_pm.h` location,
as well as the `#include`s.
- Change default `%_pm.h` make target to `techlibs/%_pm.h` and move it to the
top level Makefile.
- Update pmgen target to use `$(notdir $*)` (where `$*` is the part of the file
name that matched the '%' in the target) instead of `$(subst _pm.h,,$(notdir
$@))`.
The B port is for single-bit summands. These can just as well be
represented as an additional summand on the A port (which supports
summands of arbitrary width). An upcoming `$macc_v2` cell won't be
special-casing single-bit summands in any way.
In preparation, make the following changes:
* remove the `bit_ports` field from the `Macc` helper (instead add any
single-bit summands to `ports` next to other summands)
* leave `B` empty on cells emitted from `Macc::to_cell`
Each call to `handle_clkpol_celltype_swap` has a conversion of the
cell's type ID to an allocated string. This can sum up to a
non-negligible time being spent in the clkpol code even for a design
which doesn't have any flip-flop gates.
Avoid building a cell-to-inbit map when sorting the cells, add a warning
if we are unable to sort, and move the code treating non-combinational
cells ahead of the rest (this means we don't need to pass
non-combinational cells to the TopoSort object at all).
