When a plugin is being loaded from Python source, the binding will be
available under
import libyosys
That is unfortunately different from how a self-standing Python program
would import the Yosys interface, which is
from pyosys import libyosys
Until that is made consistent, at least fix the example to have it
working as is.
Modifies smt2 backend to recognize `$anyconst` etc. assigned to a wire with the `maximize` or `minimize` attribute and emit `; yosys-smt2-maximize` or `; yosys-smt2-minimize` directives as appropriate.
Modifies `backends/smt2/smtbmc.py` and `smtio.py` to recognize those directives and emit a `(maximize ...)` or `(minimize ...)` command at the end of `smt_forall_assert()`, as described in the paper "νZ - An Optimizing SMT Solver" by Nikolaj Bjørner et al.
Adds an example `examples/smtbmc/demo9.v` to show how it can be used.
A few new attributes are defined for use in cell libraries:
- iopad_external_pin: marks PAD cell's external-facing pin. Pad
insertion will be skipped for ports that are already connected
to such a pin.
- clkbuf_sink: marks an input pin as a clock pin, requesting clock
buffer insertion.
- clkbuf_driver: marks an output pin as a clock buffer output pin.
Clock buffer insertion will be skipped for nets that are already
driven by such a pin.
All three are module attributes that should be set to a comma-separeted
list of pin names.
Clock buffer insertion itself works as follows:
1. All cell ports, starting from bottom up, can be marked as clock sinks
(requesting clock buffer insertion) or as clock buffer outputs.
2. If a wire in a given module is driven by a cell port that is a clock
buffer output, it is in turn also considered a clock buffer output.
3. If an input port in a non-top module is connected to a clock sink in a
contained cell, it is also in turn considered a clock sink.
4. If a wire in a module is driven by a non-clock-buffer cell, and is
also connected to a clock sink port in a contained cell, a clock
buffer is inserted in this module.
5. For the top module, a clock buffer is also inserted on input ports
connected to clock sinks, optionally with a special kind of input
PAD (such as IBUFG for Xilinx).
6. Clock buffer insertion on a given wire is skipped if the clkbuf_inhibit
attribute is set on it.
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)
Martin Povišer
Alberto Gonzalez
whitequark
Eddie Hung
Pepijn de Vos
Marcin Kościelnicki
Marcin Kościelnicki
Benedikt Tutzer
Benedikt Tutzer
Clifford Wolf
Kali Prasad
japm48
Henner Zeller
dh73
Larry Doolittle