Internally we convert SystemVerilog variables that have a continuous
assignment into unresolved wires. But from a user's perspective they
are still variables, so we should refer to them as such in error
messages. This new flag lets us distinguish between such variables
and nets that were declared as uwires.
SystemVerilog allows variables to be driven by continuous assignments,
including port connections. Internally we handle this by converting
the NetNet from a REG to an UNRESOLVED_WIRE. Here we handle the case
of an unpacked array variable connected to a module output port.
This fixes issue #1001.
This test uses 'wire real' but specified the '-gno-xtypes' option.
This is because it named a variable 'wreal' which is a keyword when
that option is enabled.
When using the Icarus extension for wire types, only logic (4-state)
wires may have multiple drivers (as documented in extensions.rst).
Other types of wire should be treated as unresolved wires.
When the Icarus extension is disabled, only 4-state wires are
allowed (IEEE 1800-2017 section 6.7.1).
Whilst the wording in the IEEE standards is ambiguous, discussions on
the standards committee mailing lists clarify that an unsized literal is
supposed to be the same size as an integer (as shown in IEEE 1364-2005
table 5-22). The token following the base format character is specified
to be an unsized number. So to maintain compatibility with the standards
and with other tools, if the unsigned number part of an unsized signed
based literal can be represented in less than integer_width bits and the
MSB is a '1', we need to add a leading zero to ensure it is zero-extended
when used in an expression.
This fixes issue #1082.
Arguably this should be done in the target code generator, as the code
generator can infer the value for undriven bits from the net type. But
in practice it is quite hard to do this in the vvp code generator. So
adapt the cprop functor that concatenates part selects to do this as
well.
This fixes issue #1047 and issue #1083.
When driving a 2-state net, any undriven bits in the concatenation
of part selects should be driven to '0', not 'z'. This saves having
to cast the result.
This removes the regress-msys2.list file, fixes the output from the
pr2509349a.v test to not be different on different systems, and
documents the $readmempath task.
This file contained some SystemVerilog tests that are not yet supported.
Move the tests to the regress-vvp.list format, and mark them as NI so
that we know what's going on.
A concat typically has multiple inputs. Whenever one of the input values
change the output value of the concat is updated and propagated to its
downstream consumers.
When multiple inputs change within the same cycle each input will cause a
update propagation. Depending of the overall structure of the design this
can cause a significant performance penalty.
E.g. the following synthetic structure has a exponential runtime increase
based on the value of N.
```
reg [N-1:0] x;
generate for (genvar i = 0; i < N - 1; i++)
assign x[i+1] = ^{x[i],x[i]};
endgenerate
```
To improve this defer the value propagation of the concat to the end of the
current cycle, this allows multiple input updates to be included in a
single output update.
For the example in report #1052 this reduced the runtime from 2 minutes to
essentially 0.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The concat functors use individual bit access to initialize and copy
values.
For initialization pass the initial bit value to the constructor and for
coping use set_vec() instead. Both can be a fair bit faster since data is
copied word by word rather than bit by bit.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The implementation for partial receive for concat only differs from the
regular receive in that it takes an additional offset.
The regular receive can easily be implemented by calling the partial
receive with an offset of 0. This allows to remove some duplicated code.
The overhead of this is negligible, but to help the compiler to optimize this
a bit better mark the `recv_vec()` and `recv_vec_pv()` functions as final.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The pr1002 test has a always block with the `dataout` in its sensitivity
list. It compares `dataout` to `expected_dataout`.
Both `dataout` and `expected_dataout` depend on `datain` and are updated in
the same cycle. This means there is no guarantee in which order they are
updated and the always block might get scheduled before `expected_dataout`
has been updated. This can lead to a test failure.
To avoid this slightly change the test to use a task to perform the
comparison and add an explicit delay before the task is executed so that
all updates have a chance to be fully resolved
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The first evaluation of an `assign` statement is scheduled at the same time as
`initial` statements.
There are some test cases that evaluate the result of an `assign` statement
in an `initial` statement. This is an inherent race condition and might
fail depending on the exact order of evaluation.
To fix this add an additional delay in the `initial` block. This will make
sure that all `assign` statements get fully resolved first.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
`IVCXX` which contains the C++ compiler that will be invoked when building
an vpi module might contain additional arguments that get passed to the
compiler. E.g. such as the C++ version (`-std=c++11`). For this to work
properly `IVCXX` needs to be put in quotes.
This fixes intermittent CI failures for the MacOS target.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
To escape the `.` in the regex it needs to be prefixed with a `\`. But
since the `\` is a escape character in python strings it needs to be
escaped as well.
Without this some versions of python print the following warning:
run_ivl.py:36: SyntaxWarning: invalid escape sequence '\.'
match= re.search(b'Icarus Verilog version ([0-9]+)\.([0-9]+)', text)
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Martin Whitaker
Cary R
Flavien Solt
Stephen Williams
Lars-Peter Clausen
gatk555