response to Mitch Bailey's github issue #82:
(1) When skipping comments, skip the contents of "(* ... *)"
delimiters as well as "/* ... */" delimiters.
(2) When checking for qflow's "\abcd\" names (final space
replaced with a backslash for SPICE compatibility of
names), make sure that the last "\" is followed by end-
of-string. Otherwise names like "\a\bcd " will fail to
parse correctly.
when they are shorted, because doing so is scrambling the pin
order of cells with respect to the instance calls to the cell.
Not sure if there is any code that relies on shorted pins being
adjacent, though.
fault that would happen if the verilog had illegal syntax of a
misspelled net name (although normally netgen is expected not to
have to check the verilog for syntax, and there are probably many
such cases of netgen failing to handle incorrect verilog and then
crashing as a result).
tracks the output printed to stdout when matching pins. One section
of this subroutine used the wrong pointers when writing to the Tcl
list (for eventual JSON output) which was the fundamental error.
Beyond that, the "debug" case (if used) would fail to run some of
the matching code, and the "no matching pin" case needed to be
handled for the Tcl list output. Now the terminal output, terminal
debug output, and Tcl list output should all be in agreement on the
pin lists.
connected only to ports and not to any devices, then they do not
show up in NodeClasses() and so pass through most of the checks
in MatchPins(). A separate correspondence check is needed to make
sure that the same shorted ports appear in both netlists.
This is done by treating the loop variable as a temporary parameter
that is valid only inside the loop, and changing the parameter
value on each loop iteration. The file stream position is used
to iterate the loop with calls to fseek() and ftell(), so that the
input tokenizer continues to work within loops.
string for the setup file to be the "trivial default" previously
used in case of the setup file not being found. Put a newline
around the setup file messages so that they stand out from the
rest of the initial output information.
passed an invalid setup file, the netgen "lvs" script uses a
trivial default setup and issues no error or warning. Replaced
this behavior with an error message and a hard stop.
to have unique class hashes. This has the problem that it prevents
comparing N-to-1 cells because declaring X->X1 as equivalent breaks
the original name equivalence of X->X. The new implementation adds
the switch "-unique" to preserve the original behavior. Otherwise,
the class hashes are made the same as the 2nd cell passed to the
command, and it is the responsibility of the person running LVS to
ensure that this is done in the correct direction.
network parallel/series networks. Instead, added a global option
with command "property tolerance strict|relaxed" to reinstate the
original (strict) behavior on demand, while relaxing it by default.
This allows certain series/parallel networks to match numerically
even though the schematic netlist may have combined individual
devices.
with Tcl, since Tk is launched independently through the console
script and nothing inside of netgen itself involves graphics.
This prevents netgenexec from linking to Tk and X11 libraries.
the parallel sorting routine. This fixes occasional property
errors with series-connected devices such as resistors. (2) Added
a method to associate properties with specific pins when pins are
permutable. This allows netgen to properly check a value like
source/drain area when the definition of source and drain has
changed due to permutation of the device. (3) Added a "property"
command extension "associate" to associate a property with a pin,
for use with the method described in (2).
LVS result. The property matching was failing to match (M=1) to
(M!=1) if M was not registered as a property name (which it often
isn't). This would allow devices with different numbers of
instances in parallel to be put in the same matching group,
which then could later identify as a mismatch if the instances
were checked in a different order.
netgen is supposed to be checking properties for symmetry sorting,
but not reporting anything. This causes mysterious property
mismatch errors that don't actually exist to show up in the
output.
is that when the "class ignore" command is used, then ports of a
parent cell need to be checked for being disconnected if they
connect only to ports of an ignored/deleted child cell.
then flattening instances of that cell can cause a port of the parent
cell connected to the disconnected port of the child cell to itself
become disconnected. If the parent port is not changed to show the
disconnected state, then pin mismatch can occur if the netlist being
matched didn't have the same flattened subcell. This condition is
now detected and handled correctly.
underlying issue (which needs to be investigated), but it does
prevent netgen from crashing when it encounters it (netgen will
generate an erro message instead).
to the JSON format file (since JSON does not allow single backslash
characters. Previously nets had been handled correctly, but not
pins. Resolves github issue tracker Issue #60 from Proppy.
significant overhaul of the MatchPins() code, and better handles
issues with pins disconnected from nets and removes cases in
which proxy pins are incorrectly generated.
request #59 ("Pin match"). Because the pull request has rather
sweeping modifications, I am doing this in two steps. The change
that most breaks with existing comparison methods is in the
PinMatch() routine in netcmp.c, where the method of generating
proxy pins has been removed. There are specific cases for which
the proxy pin method exists, although these were coping with
issues arising from extraction in magic which have been dealt
with to some extend. Possibly the proxy pin method is no longer
needed. So the PinMatch() changes will be done in a second
commit where it's easier to revert or modify the changes without
affecting the modifications from this commit.
command option "flatten prohibit" (or "flatten deny") to prevent
a subcell from being flattened at any time during the compare
process. Previously, the "-noflatten" option for the "lvs"
script had been used to prevent flattening during initial
pre-match, but if the circuit passed the prematch phase and
subcells were mismatched, they would be flattened regardless of
whether or not they were listed by the "-noflatten" option. This
also codifies a way to prevent subcells from being flattened in
the setup file rather than in the "lvs" command line. Also:
Found and fixed a bug that prevents the use of "-noflatten=" with
a cell name or list of cell names instead of a filename.
second one of them, which is a failure to change CurrentTail when
an extra (implicit) pin was added to the last component in the
current cell, resulting in the failure of Node() to add the new
no-connect node, which instead overwrites the pin just created.
were implicit in the first instances but made explicit in a later
one. If more than one such implicit pin was handled for the same
cell, then the pin count would become wrong and rather unpredictable
behavior results.
even when the opposing netlist has a black-box entry for the same
cell. The black-box entry can't be flattened, so this just
results in the cell mysteriously disappearing from one side.
to a single net (as can be done with assignments in verilog or with
zero-voltage sources or zero-value resistors in SPICE). Corrected
an error in the SPICE netlist reader that prevented the proper use
of zero-voltage sources as net splitters.
delimiter set when parsing pin names (the correct delimiter set
was used in one place but not in another). Extended the pin
matching to include the minor hack of ignoring the backslash
before backslash-escaped verilog names when there is otherwise
no exact match, since many tools convert verilog to SPICE by
removing the backslash and trailing space. This avoids pin
mismatches in a known set of use cases.
definitions are handled correctly. Also: Added code to evaluate
simple expressions for array bounds. Previously the parser could
handle a value followed by "+" or "-" and a constant. Now it can
handle all basic arithmetic.
Tim Edwards
Donn
D. Mitch Bailey