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.
This reverts commit 08be796cb8, reversing
changes made to 38dbb44fa0.
This fixes#2728. PR #641 did not actually "fix" #639.
The actual issue in #639 is not equiv_make, but assumptions in equiv_simple
that are not true for the test case provided in #639.
This is a complete rewrite of the FF replacing code.
The previous implementation tried to implement the negative hold time by
wrapping async control signals individually with pulse stretching. This
did not correctly model the interaction between different simultaneously
changing inputs (e.g. a falling ALOAD together with a changing AD would
load the changed AD instead of the value AD had when ALOAD was high; a
falling CLR could mask a raising SET for one cycle; etc.).
The new approach first has the logic for all updates using only sampled
values followed by the logic for all updates using only current values.
That way, e.g., a falling ALOAD will load the sampled AD value but a
still active ALOAD will load the current AD value.
The new code also has deterministic behavior for the initial state: no
operation is active when that operation would depend on a specific
previous signal value. This also means clk2fflogic will no longer
generate any additional uninitialized FFs.
I also documented the negative hold time behavior in the help message,
copying the relevant part from async2sync's help messages.
In 2fcc1ee72e, the following is apparantly added in order to mark any
number of undefined LUT inputs:
lut_a.append(RTLIL::Const(State::Sx, minlut - input_nodes.size()));
However this can only be done if the number of input nodes is less
than minlut.
This fixes#3317
Aki Van Ness
Jannis Harder
Benjamin Barzen
N. Engelhardt
Miodrag Milanović
Lofty
gatecat
Claire Xenia Wolf
Martin Povišer
Peter Gadfort
KrystalDelusion
Kamyar Mohajerani
Dag Lem