* Fixes a non-deterministic polarity error for $eqx/$nex cells
* Fixes a deterministic polarity error for $_NOR_ and $_ORNOT_ cells
* Generates hdlnames when xprop is run after flatten
ABC's read_lib command has a dont_use
cell list that is configurable by the user.
This PR exposes that option to Yosys.
See
5405d4787a/src/map/scl/scl.c (L285)
for documentation on this option.
Signed-off-by: Ethan Mahintorabi <ethanmoon@google.com>
Group the reconnections, so that instead of producing
connect $auto$wreduce.cc:455:run$24 [0] 1'0
connect $auto$wreduce.cc:455:run$23 [31] 1'0
connect $auto$wreduce.cc:455:run$23 [30] 1'0
... (40 more lines)
we produce
connect $auto$wreduce.cc:461:run$23 [31:11] 21'000000000000000000000
connect $auto$wreduce.cc:461:run$24 [31:10] 22'0000000000000000000000
.
If the `$ge` cell we are replacing has wide output port, the upper bits
on the port should be driven to zero. That's not what a `$not` cell with
a single-bit input does. Instead opt for a `$logic_not` cell, which does
zero-pad its output.
Fixes#3867.
C does not guarantee that stdout/stderr can be reassigned.
Most platforms do make them assignable, however musl and WASI that
is based on musl do not. WASI does not have `dup2()`; instead it has
its own non-portable version of it that can only assign to previously
allocated fds.
Update the stream redirection code so that it does the right thing
on WASI and other platforms.
This is mostly important for YoWASP builds, since those do not have
a way to build with external ABC (I prototyped it but for some reason
ABC always segfaults when built as an independent Wasm binary...)
Distinguish between the A, B input ports of `$_ANDNOT_`, `$_ORNOT_`
gates when considering those for sharing. Unlike the input ports of the
other supported single-bit gates, those are not interchangeable.
Fixes#3848.
An `std::vector<T>::reverse_iterator` stores the
`std::vector<T>::iterator` which points to the (forwards-ordered)
*following* item. Thus while `vec.rbegin()` dereferences to the final
item of `vec`, the iterator it wraps (`vec.rbegin().base()`) is equal to
`vec.end()`.
In the remove case here, we advance `it` (backwards), erasing the item
we just advanced past by grabbing its (pre-increment) base
forward-iterator and subtracting 1.
The iterator maths here is obviously all OK, but the forward-iterator
that `it` wraps post-increment actually points to the item we just
removed. That iterator was invalidated by the `erase()` call.
That this works anyway is (AFAICT) some combination of luck and/or
promises that aren't part of the C++ spec, but MSVC's debug iterator
support picks this up.
`erase()` returns the new iterator that follows the item just erased,
which happens to be the exact one we want our reverse-iterator to wrap
for the next loop; we get a fresh iterator to the same base, now without
the preceding item.
This makes clk2fflogic add an attr to $ff cells that carry the state of
the emulated async FF. The $ff output doesn't have any async updates
that happened in the current cycle, but the $ff input does, so the $ff
input corresponds to the async FF's output in the original design.
Hence this patch also makes the following changes to passes besides
clk2fflogic (but only for FFs with the clk2fflogic attr set):
* opt_clean treats the input as a register name (instead of the
output)
* rename -witness ensures that the input has a public name
* the formal backends (smt2, btor, aiger) will use the input's
name for the initial state of the FF in witness files
* when sim reads a yw witness that assigns an initial value to the
input signal, the state update is redirected to the output
This ensures that yosys witness files for clk2fflogic designs have
useful and stable public signal names. It also makes it possible to
simulate a clk2fflogic witness on the original design (with some
limitations when the original design is already using $ff cells).
It might seem like setting the output of a clk2fflogic FF to update the
input's initial value might not work in general, but it works fine for
these reasons:
* Witnesses for FFs are only present in the initial cycle, so we do
not care about any later cycles.
* The logic that clk2fflogic generates loops the output of the
genreated FF back to the input, with muxes in between to apply any
edge or level sensitive updates. So when there are no active updates
in the current gclk cycle, there is a combinational path from the
output back to the input.
* The logic clk2fflogic generates makes sure that an edge sensitive
update cannot be active in the first cycle (i.e. the past initial
value is assumed to be whatever it needs to be to avoid an edge).
* When a level sensitive update is active in the first gclk cycle, it
is actively driving the output for the whole gclk cycle, so ignoring
any witness initialization is the correct behavior.
When assigning values to input ports of nested modules in cosimulation,
sim needs to find the actual driver of the signal to perform the
assignment. The existing code didn't handle unconnected inputs in that
scenario.
Allow Liberty canonical identifier including double quotes in if-body and pass-through for Synopsys-style unquoted identifiers issue#3498
Co-authored-by: Aki <201479+lethalbit@users.noreply.github.com>
Writeback of simulation state into initial state was only working for `run()` and `run_cosim_fst()`.
This change moves the writeback into the `write_output_files()` function so that all simulation modes work with the writeback option.
This was renaming cells while iterating over them which would always
cause an assertion failure. Apparently having to rename cells to make
all witness signals public is rarely required, so this slipped through.
In two places, we are joining label pieces by a '|' separator. We go
about it by putting the separator behind each entry, then removing the
trailing separator in a final fixup pass on the built string. For easier
reading, replace those occurrences by a new factored-out
'join_label_pieces' function.
Signed-off-by: Martin Povišer <povik@cutebit.org>
When the 'show' pass generates portboxes to detail the connection of
cell ports to wires, it has special handling of signal chunk
repetitions, but those repetitions are not accounted for in the
displayed bit range in case of cell outputs. Fix that, and so bring it
into consistence with the behavior on cell inputs.
So, taking for example the following Verilog snippet,
module DRIVER (Q);
output [7:0] Q;
assign Q = 8'b10101010;
endmodule
module main;
wire w;
DRIVER driver(.Q({8{w}}));
endmodule
make the show pass display '7:0 - 8x 0:0' in the driver-to-w portbox
instead of '7:7 - 8x 0:0' which it displayed formerly.
Signed-off-by: Martin Povišer <povik@cutebit.org>
This matches the behavior of smtbmc.
This also updates the sim internal memory API to allow masked writes
where State::Sa bits (internal don't care - not a valid value for a
signal) leave the memory content unchanged.
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.
The new bitwise case equality (`$bweqx`) and bitwise mux (`$bwmux`)
cells enable compact encoding and decoding of 3-valued logic signals
using multiple 2-valued signals.
The previous approach only initialized past_d and past_ad while for FST
cosim we also need to initialize the other past values like past_clk,
etc. Also to properly initialize them, we need to run a combinational
update step in case any of the wires feeding into the FF are private or
otherwise not part of the FST.
Otherwise the final values will not show up in gtkwave waveforms
when looking at the generated traces.
Signed-off-by: Claire Xenia Wolf <claire@clairexen.net>
* Change simlib's $mux cell to use the ternary operator as $_MUX_
already does
* Stop opt_expr -keepdc from changing S=x to S=0
* Change const eval of $mux and $pmux to match the updated simlib
(fixes sim)
* The sat behavior of $mux already matches the updated simlib
The verilog frontend uses $mux for the ternary operators and this
changes all interpreations of the $mux cell (that I found) to match the
verilog simulation behavior for the ternary operator. For 'if' and
'case' expressions the frontend may also use $mux but uses $eqx if the
verilog simulation behavior is requested with the '-ifx' option.
For $pmux there is a remaining mismatch between the sat behavior and the
simlib behavior. Resolving this requires more discussion, as the $pmux
cell does not directly correspond to a specific verilog construct.
andyfox-rushc
Martin Povišer
Jannis Harder
Miodrag Milanovic
Ethan Mahintorabi
Charlotte
whitequark
N. Engelhardt
Claire Xen
Charlotte
Eddie Hung
gatecat
Muthiah Annamalai (முத்து அண்ணாமலை)
Muthu Annamalai
Krystine Sherwin
Muthu Annamalai
Aki Van Ness
Benjamin Barzen
Lofty
Peter Gadfort