If the l-value is an unresolved wire, then elaboration can allow
the assignment as long as it is to bits that are not otherwise
driven. Handle this in some simple cases.
When a module is instantiated multiple times, the enum
types contained within would cause trouble. This fixes
that by elaborating in proper scope context.
This patchs adds support for the $dimensions() and $unpacked_dimensions()
array functions. Since the argument is only used to get the type information
these functions can always be evaluated at compile time.
For the following functions if the dimension argument is constant or omitted
and the first argument is not dynamic (a string or dynamic array) they will
return the specified information.
$left(), $right(), $high(), $low(), $increment() and $size()
Dynamic information and a variable second argument will be implement in a
future patch.
This allows for syntax like a.b.c where a is a class with member
b, which is a class with member c, and so on. The handling is mostly
for the support of compound objects like classes.
This gets nested l-values to (but just short of) the ivl_target API.
Now the elaborator can process nested l-values, but I haven't figured
out how to present that at the ivl_target.h API.
Add support for case, forever, and repeat statements in constant
functions. Also fix a bug in the constant function implementation
of NetESelect when used for zero/sign extension.
This patch implements the evaluate_function method for the NetDisable
and NetSTask classes. It also makes the checks for a function being
constant work when the function contains nested scopes (named blocks).
This patch adds support for implicit casts to the elaborate_rval_expr()
function. This will handle the majority of cases where an implicit cast
can occur.
This patch implements the evaluate_function method for the NetEBBits,
NetEBDiv, NetEBLogic, NetEBMinMax, and NetEBPow classes. It also
factors out some common code into the NetEBinary class.
If a signal s driven by multiple non-overlapping NetPartSelect(PV)
objects, then combine them into a single NetConcat object. This
eliminates the need for resolvers in the target.
This provides the ivl_target.h interface for class definitions
and expressions, the vvp code generator support for class objects
and properties, and the vvp run time support. Trivial class objects
now seem to work.
Add properties to the classes, and elaborate expressions that
have class properties. Describe class object property references
all the way down to the stub target.
This involves working out the code to get the base type of a select
expression of a darray. Also added the runtime support for darrays
with real value elements.
Added: basic vpiPort VPI Objects for vpiModulkes
vpiDirection, vpiPortIndex, vpiName, vpiSize attributes
Since ports do not exist as net-like entities (nets either side
module instance boundaries are in effect connect directly in
the language front-ends internal representation) the port information
is effectively just meta-data passed through t-dll interface and
output as a additional annotation of module scopes in vvp.
Added: vpiLocalParam attribute for vpiParameter VPI objects
Added: support build for 32-bit target on 64-bit host (--with-m32
option to configure.in and minor tweaks to Makefiles and systemc-vpi).
Making the scope type NESTED_MODULE was just plain wrong, because
it didn't really encapsulate the meaning of program blocks OR
nested modules. So instead create nested_module() and program_block()
flags and use those to test scope constraints.
An important advantage of program blocks is its ability to nest
within a module. This winds up also allowing modules to nest, which
is legal but presumably less used feature.
A NetScope object currently has two lists of parameters, 'parameters'
and 'localparams'. However, user-declared localparams are stored in
the 'parameters' list, and 'localparams' is only used for adding
genvar values to the parameter list. There seems no good reason to
maintain separate lists, as the lists are merged before being passed
to the target DLL. This is most likely a hang-over from older code.
This patch extends the compiler to support all specparam declarations
allowed by the 1364-2005 standard. For compatibility with other
simulators, it allows specparam values to be used in any constant
expression, but outputs a warning message and disables run-time
annotation of a specparam if it is used in an expression that must
be evaluated at compile time.
Add a new IVL_PR_FINAL process type.
Add a flag to NetScope in_final_ which is set when elaborating the
statement of a final procedure.
Add checks during statement elaboration for invalid statements in a
final procedure, similar to checks for statements in functions.
Do a final check to make sure no final blocks have delays.
In the vvp runtime, use "$final" as the flag for the thread created by
the final procedure. During compilation, instead of adding such a
thread to the sched_list, add it to a new schedule_final_list that
mirrors the schedule_init_list, but is run at the end of simulation.
This patch adds code to the compiler so that a constant string
in a structural context can maintain the string property. This
is needed but not currently implemented in vvp (it's still
converted to a number). A pending patch for the vlog95 target
does use this new information.
This patch allows the compiler to perform early elaboration
of functions if they are encountered in expressions that are
elaborated before the function would normally be elaborated.
This makes the function available for constant evaluation.
Suitable error messages are generated if a function that is
used in a constant expression is not a valid constant function.
This patch adds code that allows the targets to determine if a logical
gate came from a continuous assignment. This helps some of the targets
generate code that more closely matches the input.
It also reworks/simplifies the synthesis of && and || since the
compiler has already converted the two operands to single bit form
and fixes a mismatched delete from a previous patch.
This patch adds some preliminary module port information to the ivl
interface. This may change as I investigate exactly what is needed.
It also fixes a few minor bugs (a missed local variable and spacing)
This patch modifies the compiler and the ivl interface to pass the
type of indexed part select that is being represented (up/down) in
a procedural L-value or R-value. This is needed by any back end that
wants to correctly denormalize the (zero based) base expression.
This patch adds support to the compiler/ivl interface for getting the
original UDP definition port names. ivl_udp_port() was added to get
this information.
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.
It was documented that ivl_scope_port(s)() could be used with tasks,
but the code did not support this. This patch adds that functionality
as documented. It also removes the documentation for ivl_lval_mem()
since that function no longer exists.
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 gets the enumeration type through to the ivl_target API so
that code generators can do something with it. Generate stub
output with tgt-stub, and generate the proper vvp run time to
make simple enumerations work from end to end.
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.
When enum names are used as r-values in expressions, use their
values. Treat the enum names similar to (but not exactly as)
localparams so that they fit into the rest of the elaboration
flow naturally.
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.
SystemVerilog allows variables to be either variables or unresolved
nets, depending on how they are used. If they are assigned by
procedural code, then they are variables. If they are assigned
by a continuous assignment, they are unresolved nets. Note that
they cannot be both, and when they are unresolved nets they can
only be assigned once.
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.
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.
This patch adds support for passing the delay selection to vvp.
It adds a new header :ivl_delay_selection "<value>"; that has
the values TYPICAL, MINIMUM or MAXIMUM depending on the -T
flag to iverilog. This information is needed by $sdf_annotate
to select that appropriate value for a triplet when
"TOOL_CONTROL" is specified (default).
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.
It turns out that although there was all kinds of code to manage
these members, there were no uses anywhere. It must have been a
legacy from a previous era. So remove the dead code so that it
doesn't confuse me again.
Remove some wasteful and excess scans of the Nexus of some links,
and remove dead code so we can see what we're doing. Also inline
some commonly used and trivial functions.
Once code generation starts, the Nexus structure no longer needs to
support fast insertion/connect operations. So have the code generator
lock down the Nexus structures and adjust the Link lists for optimal
access during readout.
When netlists get very large, the Nexus::connect() method tickles
the O(N) performance and elaboration gets very slow. Rework the
connect method to be O(C), for a drastic performance boost for
large designs.
This simplifies and reorganizes this function in order to improve
the performance of this function by a constant factor. I think we
really need to improve this by an entire order (and not just a
simple factor) but this helps.
It turns out that it is possible for an otherwise constant net
mux to be non-constant if there is a force that can drive the
net. This can be detected as an l-value reference to an otherwise
constant selector.
If a signed signal is driving a part select in a CA and the width
is less than 32 bits. the value will be zero extended and will
not work for negative values. This patch adds a warning that this
could happen. This will be fixed in development.
This patch is a major rewrite of the indexed part selects (+: and -:).
It made the following enhancements:
1. Make indexed part selects work correctly with both big and little
endian vectors.
2. Add a warning flag that warns about constant out of bounds/or 'bx
indexed selects.
3. Moved the -: parameter code to its own routine.
4. Added support for straddling before part selects in a CA.
5. Added more assert(! number_is_unknown) statements.
6. Add warning for &PV<> select with a signed index signal that is
less than the width of an int. This will be fixed later.
7. Add support for loading a 'bx/'bz constant into a numeric register.
8. Add a number of signed value fixes to the compiler/code generator.
9. Major fix of draw_select_expr() in the code generator.
This patch adds genvars to the elaboration process. It adds checks
that a genvar is defined for a generate loop and that a genvar does
not conflict with any other items in its name space.
This patch adds -g2001-noconfig command line flag. The compiler
already supported this with `begin_keywords. Document this in
the manual page and fix a few other issues.
Fix endgenerate to be a 2001 keyword and add a few missing
keywords at the appropriate standard level e.g.(unsigned).
Add uwire and deprecate wone. wone used to just convert without
a warning to a wire. uwire will display a warning that it is
being converted to a wire without a check. wone is converted to
a uwire with a warning and then prints the uwire message. The
uwire message will be replaced with a real check fairly soon.
This patch adds real functionality for `celldefine and pushes this
property to the run time which can access this with vpiCellInstance.
This is technically only available for a module, but all scopes
have the property and only modules should return true when the
'endmodule' is between a `celldefine and `endcelldefine directive.
In 1364-2005 it is an explicit error to take the select of a scalar
or real value. We added the checks for real a while ago. This patch
adds the functionality for scalar values. In the future we may want
to push the scalar property to the run time.
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.
The arithmetic operands are signed only if both operands are signed.
If the expression is unsigned, then the expression as a whole needs
to be processed as unsigned in order to get padding right.
When a pin array is virtual, dll_target::signal() doesn't need
to make a corresponding set of stub nexa.
This patch includes new detection of oversized arrays, configurable
with the ARRAY_SIZE_LIMIT flag. This limit only applies to devirtualized
arrays; virtual arrays are only limited by your architecture's
unsigned int type.
The concept and earlier versions of this patch have been successfully
stress-tested by multiple people. This one causes no testsuite
regressions on my machine.
Closes: pr2023076
Reduces resource usage when compiling large memories.
Normal usage patterns still create large nexus arrays
in t-dll.cc:dll_target::signal().
This patch is extensively tested; it shouldn't break anything.
The existing debug "optimizer" flag is (ab)used to control
message printing when large (>1000 element) arrays are
devirtualized or nexus-ized.
The new global variable disable_virtual_pins is available
to force allocation of Pin arrays when they are declared,
but no user interface is provided.
See extensive discussion on iverilog-devel, March 4-5 2009,
title "pr2023076: large memories".
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.
Previously Icarus normalized the results so array [7:0] would
be the same as array [0:7]. This works just fine for
simulation, but the VPI calls can select the left or right
value and this was incorrect for the [7:0] case since it was
being normalized to [0:7]. This patch swaps the two values in
the a.out file and from this creates the previous first/last
values and a new flag that can be used to get the correct
left and right values for the VPI interface.
Seemingly does nothing, just refactors to create two new methods:
bool NetPins::is_linked(void)
void NetNet::initialize_value_and_dir(verinum::V init_value, Link::DIR dir)
and rearranges netlist.h.
This patch causes no regression in the testsuite.
It smooths the way for any attempt to address pr2023076.
By not creating Nexus objects until necessary, we avoid creating a
lot of spurious objects. In fact, it is true that almost every
link that is created and connected to another link will create a
spurious Nexus object without this patch.
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.
This fixes up the elaboration of binary expressions found in
parameter expressions. Parameter expressions are special because
they elaborate early, before all the other parameters are necessarily
completed.
Stephen Williams
Larry Doolittle
Cary R
Martin Whitaker
Arun Persaud
Andrew Stevens
Martin Whitaker
Jared Casper