This patch changes the method used to signal that a constant expression
is being elaborated from flags stored in global variables to flags
passed down the call chain. It also generates more informative error
messages when variable references are found in a constant expression.
This patch changes the module elaboration slightly to allow passing
the appropriate information for unconnected and top level ports. This
allows the vlog95 generator to get the basic structure correct.
There was a single message when the expression width was larger
than the port width. This patch makes it a bit more clear by
saying that the expression was pruned.
Currently the compiler coerces input ports to inout ports whenever
there is an internal driver connected to the internal port net.
This generates an error if the port is externally connected to
something other than a structural net. This patch modifies the
compiler to ensure port coercion only occurs in valid cases.
This patch adds support for tracing procedural statement execution in vvp.
This is accomplished by adding a new opcode that is inserted before the
code that represents a procedural statement. These opcodes also trigger
a message whenever time advances. By default these opcodes are not added.
To add them, pass the -pfileline=1 flag to the compiler. In the future we
may add support for turning the debug output on and off once the opcodes
have been added with a system task or from the interactive prompt.
This patch removes the code that was deleting the signals in an L-value
concat if the concatenation failed to elaborate. This is incorrect since
the signal could be used in another context that is processed later. The
error message when an output/inout port fails to elaborate was also
improved to give the expression that is connected to the port.
This patch fixes a bunch of objects to have the correct file/line
information. It also adds support for getting file/line information
for events (named events have a definition line).
This patch adds/fixes the following:
Adds file/line information to a UDP definition.
Prints an error message if a UDP is passed signals wider than 1 bit.
A UDP should supports a range, but the compiler currently does not.
Add scope information for constants.
Fix the Icarus extension UDP table entry element 'h' to use h.
The ivl_udp_init() value is a char not unsigned.
Add FILE_NAME() for a bunch more of the ivl interface objects.
The compiler currently performs parameter expression elaboration before
performing parameter overrides. This means that the information needed
to correctly determine the expression type and width may not be available
at the time elaboration is performed. This patch reworks the code to
delay elaboration until after all overrides have been performed. It
also provides a new -g option that controls how the width of parameter
expressions is calculated when the parameter itself is unsized.
This patch covers more than it should. It removes many of the -Wextra
warnings in the main ivl directory. It also makes some minor code
improvements, adds support for constant logicals in eval_tree (&&/||),
adds support for correctly sign extending === and !==, it starts to
standardize the eval_tree debug messages and fixes a strength bug
in the target interface (found with -Wextra). The rest of the warnings
and eval_tree() rework will need to come as a second patch.
This patch changes all the iterator code to use a prefix ++ instead
of postfix since it is more efficient (no need for a temporary). It
is likely that the compiler could optimize this away, but lets make
it efficient from the start.
I'm adding more uses of the make_range_from_width function, so
it seems like time to get rid of its use of the svector template.
This thread led to a lot of other uses of svector that had to
also be removed.
BOOL values have a specific cast from LOGIC, this node takes care
of it. Also arrange for the elaboration to insert them in the right
planes and for the code generator to generate them.
This patch adds the ability to call a system function as a task for
the SystemVerilog generation (-g2009). The return value is really
calculated, but it is ignored.
This patch adds support for a UDP with variable delays. In the process the
intrinsic support for delays was removed from the UDP functor and replaced
with a call to the .delay functor. Both a normal gate and a UDP now use the
same code to generate the delay.
This patch adds checks that the delay count is correct for the
various gates and adds support for a missing variable decay
time. For this case the decay time is the minimum of the rise
and fall times. This is denoted by setting the decay variable
to 0 in the vvp file. vvp notes this and sets an ignore decay
time property in the base delay. This turns off the ability
to set the decay time and the minimum delay calculation will
also update the decay time.
This patch pushes delays for tranif gates to the code generator.
We still need to add checks for the number of delays, etc. For
now an error message is printed when a tranif gate is given a
non-zero delay.
Elaborate conditional assignments with BUFZ devices that do *NOT*
preserve strengths. Add a BUFT (transparent) device that can be
used in those cases where I really need a transparent buffer.
A real delay must be scaled and rounded using the local precision
before it is finally scaled to the simulation time units. This
patch fixes the compiler to do this correctly or generate the
correct code for run time calculated delays. Delays in a CA
already worked correctly. The run time was also fixed to scale
modpath (SDF back annotation) delays correctly.
Some new shadow issues have crept in. This patch fixes these new
issues and adds -Wshadow to the normal warning flags to keep any
new occurrences from happening.
The repeat expression is evaluated in a self determined context
(expression width == -1). It needs to call probe_expr_width() to
figure out the width needed by the expression before calling
elab_and_eval() to elaborate the expression.
This patch adds support for converting bit based ports to real signals.
You can only do this for single instances. Arrayed instance would
create multiple instances driving the same real signal.
Any real port can be connected to a bit based signal. The only limitation
is that the signal width must be an integer multiple of the instance
count since all the real conversions must have the same width.
Also add an error message for an arrayed instance with real to real
output connections. Again multiple drivers.
This patch also adds errors for inout real and bit based inout ports
driving a real signal. There is no logical way to deal with the full
capabilities of inout and real ports/signals. So for now they are not
allowed.
This patch cleans up some style issues: no need to check that a value
is defined before freeing or deleting it, use C++ style casts, make
sure to NULL terminate strncpy(), empty() is faster than size() for
size == 0 or size >= 0 checks, re-scope some variables, etc.
A named event does not have an edge so taking a posedge or negedge
is illegal. This patch adds an error message for this. Before the
edge was being ignored for named events, but this is incompatible
with other tools.
Creation of implicit nets requires knowledge of whether an identifier
has been declared before it is used. Currently implicit nets are
created during elaboration, but by this stage the order of declaration
and use is not known. This patch moves the creation of implicit nets
into the parser stage.
The Cygwin compiler is a bit picky. This patch adds some casts
to remove compilation warnings. In the past I have had warnings
off because of problems with the STL, but for this directory we
mas as well remove the warnings we can. It also does not
recognize that an assert(0) or assert(false) ends a routine so
it complains about no return at end of function or variables
not being defined.
Currently the compiler only applies defparam statements that are
found in the initial root module hierarchy. This patch ensures that
defparam statements within scopes created by generate constructs or
instance arrays are also applied.
This patch is based on one from "bruce <bruce1914@gmail.com>".
I've applied all but the elaboration code, which I rewrote to
properly work with the elaboration work queue. I also constrained
the implementation so that the parameter name must have exactly
two components: the root scope name and the parameter name. This
is necessary to keep the defparm processing sane. The comments
from bruce's original patch are as follows:
--
This patch would provide function to define parameter from command
line. This serves the same functionality as 'defparam' in Verilog
source code, but provide much more ease for using. Parameter
definition can be write in command file, with following syntax:
+parameter+<scope>.<parameter>=<val>
*Do not apply any space between them*
The scope name should be full hierachical name with root name at
the begining. The following example would override test.T1 with
new value 2'b01:
+parameter+test.T1=2'b01
'test' here is the root module name. The parameter value here
should be constant. Parameter definition can also be write in
the command line:
iverilog -Ptest.T1=2'b01
This serves the same functionality with the previous example.
If we define the same parameter in command file and command line,
the one in command line would over-write all others.
This patch cleans up some unneeded code. Releases some allocated
memory before the compiler quits and fixes a couple minor memory
leaks in the compiler and vvp code generator.
Icarus has recognized this directive, but it did not do anything
with the information. This patch adds the functionality for most
common cases. It adds this by changing the input net type from
wire/tri to tri1 or tri0 depending on the pull. The issue is that
if the input net is not a wire or tri this is not safe and should
really be done as an external pull gate connected to the input.
We will need to handle this is it ever comes up. For now a sorry
message is printed.
This patch add code to print a warning message if it finds both a
default and `timescale based delays. The -Wall or more specifically
the -Wtimescale flag can be used to find the module with the missing
`timescale directive.
When a PGAssign is driven by (r-value) a bit, part or indexed
select and the strength is not the default (supply). Then
we need to create a driver (BUFZ) to convey the strength
information.
This patch adds messages in various places to warn that constant
user functions are not supported. It uses a global variable to
indicate when we are in a constant context. This is a bit of a
kludge, but works well without needing to change a bunch of code.
It is interesting to note that ports are elaborated late enough
that if we had the constant function evaluation code they would
evaluate correctly. This also applies to the function return
range, the concatenation repeat, specparams and initial values.
Signal definitions are early enough that elaboration is what is
failing because the function body is not available (has not been
elaborated). The same thing applies to both parameters and
localparms.
elaborate.cc:2456: warning: suggest parentheses around comparison in operand of &
vpi/vcd_priv.c:210: warning: operation on 'idx' may be undefined
Probable behavior change. Passes testsuite.
Functions that appear in continuous assignment expressions and that
have hidden dependencies or side effects need to be re-evaluated
whenever any input to the expression changes. This patch adds support
in the compiler and vvp runtime to enable this. This is currently
activated for any system function call that has no arguments. The
user may also force it to be used for any user function by passing
the option -gstrict-ca-eval to the compiler driver.
This patch also removes the -dautomatic option which was used for
gaining confidence in the code that supports automatic tasks and
functions. It is believed that the testsuite provides reasonable
fault coverage, and further tests can be added if bugs are found.
Probe the widths of the case statement expressions. The expressions
are self-determined in that context, but the probe is needed to
setup the expression types.
Verilog generate schemes support a special case where conditional
generate schemes that contain only a nested conditional generate
scheme do not create a new scope. Instead, it relies on the nested
generate scheme to generate the scope.
unary expressions that have problems should not assert in the
test_width method. Instead, let the error propagate back and be
handled during expression elaboration. This found a few places
where expression widths/types weren't probed before elaboration.
When padding a signal or when creating a local signal the file and
line information should be related to where the new object was
created not the signal value it is being created from.
This patch modifies the NetE* pad_to_width() routines to take a
LineInfo object to set the location to the correct value.
It fixes some set_line() calls to use the correct location.
It fixes ports to not set the file/line information if it is
already defined. Doing this was causing the definition of
signals to become the instantiation instead of the real
module declaration.
A simple typo in the rhs of an expression would crash the compiler.
Example:
module crash3;
reg clk;
integer cnt1=0;
always @(posedge clk) begin
cnt1 <= (cnt==81) ? 0 : (cnt1+1);
end
endmodule
This patch adds a number of compile and run-time checks for illegal
uses of variables declared in automatic tasks and functions. It
also adds a check for event expressions in automatic tasks that use
features not yet supported in VVP.
The goal is to completely remove the svector class because the standard
vector class works perfectly well. This removes the uses in the Module.h
header file.
This patch splits any VVP net functor that needs to access both
statically and automatically allocated state into two sub-classes,
one for handling operations on statically allocated state, the
other for handling operations on automatically allocated state.
This undoes the increase in run-time memory use introduced when
automatic task/function support was first introduced.
This patch also fixes various issues with event handling in automatic
scopes. Event expressions in automatic scopes may now reference either
statically or automatically allocated variables or arrays, or part
selects or word selects thereof. More complex expressions (e.g.
containing arithmetic or logical operators, function calls, etc.) are
not currently supported.
This patch introduces some error checking for language constructs
that may not reference automatically allocated variables. Further
error checking will follow in a subsequent patch.
Put together the infrastructure for elaborating analog statements,
including create the NetAnalogTop objects that hold analog statements
and are in turn held by the design.
While doing this, clean up the various unique initial/always enumerations
to use the ivl_process_type_t type.
This fixes the sign calculation for port padding. It also reports if
the padding will be signed or not in the warning message. The inout
calculation may not be correct. It requires both the signal and the
port to be signed, but inout is not currently padded anyway.
Continue cleaning up shadowed variables, flagged by turning on -Wshadow.
No intended change in functionality. Patch looks right, and is tested
to compile and run on my machine. No regressions in test suite.
Later passes need the intermediate results for width and size so that
some special cases, were self-determined arguments occur, can be
processed properly during elaboration. This can be especially tricky
and interesting for ternary expressions.
This patch removes all the checks for constant expressions performed
during the parsing phase, as these checks are (mostly) repeated during
elaboration. It adds the missing check in the elaboration phase (the
RHS of a register initialisation), and improves the error reporting
and error recovery in other checks.
This patch fixes pr2132552, which was caused by a fault in the parser
constant expression checking.
In assignments, the expression width may be defined by the width of
operands, and not that of the l-value. Choose whichever is creater and
set (or pad) the expression to that width.
This patch pads inputs and output ports correctly when the port
and the port expression have different widths. It does not fix
inout ports.
It also sets the file and line number information in the unsigned
pad_to_width() routine.
There are cases where the r-value doesn't pad itself to the width
that is requested by the call to elaborate_expr. This impacts the
elaboration of PGAssign. Pad/sign extend as appropreate.
Widths of real values are always 1. When paired with vectorable types
in expressions, the vectorable type is processed as losslessly self-
determined. ("unsized" in the test_width methods.)
the PGAssign elaborate method used the test_width to get the width
of the r-value expression. This should be completely sufficient to
get the width of the expression, so always use a defined width to
elaborate the expression.
It takes a carefully crafted source file to cause elabortion to make
an arrayed multiple-output gate that is not vectorized into a single
wide gate. But that special case does need to be handled.
Logic gates usually have one output and several inputs, but a few
have multiple outputs and one input. Since the NetNode objects have
only a single output, handle the case by creating multiple NetNode
objects, one for each output.
The r-value expression takes on at least the width of the l-value. If
there is a sized width greater then the l-value width, take that on
instead. But if the r-value is unsized, there are unsized sub-expressions
that cause the expression as a whole to be unlimited width, so elaborate
and evalulate the r-value as lossless.
This patch pushes the non-blocking event control information to
the code generator. It adds the %evctl statements that are used
to put the event control information into the special thread
event control registers. The signed version (%evctl/s) required
the implementation of %ix/getv/s to load a signed value into
an index register. It then adds %assign/wr/e event control based
non-blocking assignment for real values. It also fixes the other
non-blocking real assignments to use Transport instead of inertial
delays.
This patch adds blocking repeat event controls and also makes the
base repeat statement sign aware. If the argument to repeat is
negative (it must be a signed variable) then this is treated just
like an argument of 0 (there is no looping). Doing this allows us
to model the repeat event control as follows.
lhs = repeat(count) @(event) rhs;
is translated to:
begin
temp = rhs;
repeat (count) @(event);
lhs = temp;
end
This patch also pushes the non-blocking event control
information to the elaboration phase where it will report they
are not currently supported.
This patch moves the always zero or possibly zero delay checks
to a point after the circuit is full elaborated. Before it
could try to check tasks that had not already been evaluated
resulting in a crash.
Martin Whitaker
Cary R
Jared Casper
Larry Doolittle
Stephen Williams
Martin Whitaker