A compressed assignment statement should give exactly the same
result as the equivalent uncompressed statement. This means
that the type (signed/unsigned) of the LHS affects the type of
the RHS expression (unlike in normal assignments). We need to
take care that bit/part selects and concatenations are correctly
identified as unsigned values, even in the cases where they
reduce to a single whole signal.
In generate blocks such as for loops, there may be many generated
scopes that have the same generated name. But in these cases, there
is an index number in the hname that can be used. So do so.
The reported problem was caused by a null statement in a case statement,
which caused the check for an infinite loop to fail. Further testing
exposed more problems with null statements in loop statements - these
caused crashes earlier in elaboration.
Implicit ports may be unnamed, either because the port expression
is not a simple/escaped identifier, or because there is no port
expression. To handle these cases, error messages should report
the port position as well as the port name.
The compiler was correctly detecting and reporting errors in loop
expressions and statements, but then crashing when it tried to build
the sensitivity list. Fix this by not adding a loop statement to the
netlist unless all its components have been successfully elaborated.
When unsized literals are used in case item expressions, it is likely
that the calculated expression width will be larger than necessary to
unambiguously select the correct case item (particularly when using
"strict" expression elaboration). This patch adds an optimisation
step that prunes the expressions to the minimum necessary width.
This goes all the way down to the vvp level, where we create support
for arrays of objects, generate the new code in the -tvvp code
generator, and elaborate the arrays in the first place.
The parser always passes a single NULL argument for system tasks. For a
method call which will add a signal to call the method on we need to
ignore this NULL argument.
This required keeping for-loops as actual things through the
netlist form so that the synthesizer can get at and understand
the parts of the for-loop. This may improve vvp code generation
in the future, but for now continue to present to the vvp code
generation the block-while form.
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.
It is better to leave the handling of PChainConstructor calls to
the elaboration, instead of stripping them out early. This allows
for handling the arguments of the chain constructor in the correct
scope.
Static properties are like variables in a named scope.
Detect these variables during elaboration so that the
code generator just sees them as variables.
This implementation works by detecting assignments
to constant properties in elaboration. Allow initializer
assignments to assign to the constant, error all other
assignments, and otherwise treat the constant like any
other property.
For constant word indices, issue a warning if the index is out of
range or an undefined value. In any case, the RHS value should be
discarded, and the actual assignment should be skipped.
If a logical pull device is converted into a CA then it is an assignment
with strength, so just emit the appropriate constant to get the correct
functionality (e.g. 1'b1 for a pull up and 1'b0 for a pull down).
Also add missing file/line information.
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.
The compiler was treating case and case item expressions as
self-determined. They should be context-sensitive, just like
the operands of a comparison operation.
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).
SystemVerilog allows a function to be called without an assignment for
the return value. This patch adds a warning that Icarus does not currently
support this and provides a place to add this functionality later.
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.
These two typedefs exactly matched earlier ones in the same scope and
gcc was complaining that they were shadowing the previous definitions.
Since the definitions matched exactly just deleting the second
typedef was acceptable.
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.
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.
When a conditional statement is unnamed, it doesn't create a scope
and we get into "direct" generate scheme elaboration. This direct
elaboration needs to handle case generate schemes.
Tasks call arguments may be dropped in favor of default values.
Allow for that in the syntax. This requires a little handling
of the non-SystemVerilog case during elaboration.
An @* with no sensitivities should be treated as something that will
never trigger vs something that will run continuously. This patch makes
this change and adds a warning when an @* has no sensitivities since
this is almost certainly a coding bug.
To avoid a variables not initialized in the construct this patch modifies
the PSpecPath class to take the polarity and full_flag as arguments to
the constructor.
In a specify block a full connection is defined to only support a single
source and destination path. This patch adds an error message when this
is found, except we skip the error if all the paths are a single bit
wide. This exemption was added to match the functionality found in
NC-Verilog and presumably Verilog-XL.
A message was also added in place of an assert if the source signals was
not found in the current scope.
This patch uses the full_flag to verify that the input and output have the
same width for a parallel connection. Icarus always uses a full connection
so this is just a portability issue with other simulators.
The pform dump code was also modified to correctly display the polarity
and full/parallel connection type.
If a wait statement has a constant argument then the mode must be defined
before test_width() is called since the current mode is used in the
PENumber test_width routine.
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.
Icarus uses 'i' in the net expressions for a cast to integer. Replacing
it with 'v' would free the character 'i' that can be used for increment
operators. This changes cast operators to become 'v', '2', and 'r'.
Signed-off-by: Prasad Joshi <prasad@canopusconsultancy.com>
Suggested-by: Cary R. <cygcary@yahoo.com>
Remove an unused variable (desired_vector_width) in elaborate.cc.
Reduce the scope of spin to make it obvious it is only used locally
in elaborate.cc. Initialize sel_type_ in the NetAssign_ constructor
(net_assign.cc). The code doesn't currently require this since
sel_type_ is only used when the base is not zero and it is always
defined when base is not zero, but giving this a default value in
the constructor hedges against accidentally using an undefined
value if someone checks the select type when the base is zero.
The compiler was handling bi-directional pass switches using the default
case for primitive gates, where the first port is treated as an output
and the remaining ports are treated as inputs. This patch adds a special
case for pass switches, so that the first two ports are treated as
bi-directional.
The -gno-specify flag should only control the delay and timing checks.
It should not also remove the specparams since they can be used outside
of a specify block.
The IEEE standard states that the port expressions used for arrays
of primitive gates must be the exact width required, but is silent
about the requirements for single instances. The consensus among
other simulators is that for input ports of single instances, the
expression is silently truncated to a single bit.
This patch also fixes a compiler crash if an error is found when
elaborating a primitive gate port expression.
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.
For now Icarus doesn't support a UDP instantiation with a range.
Instead of generating a warning about the port count being wrong
this patch adds code to calculate the range and print a message
if a range greater than one is found.
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.
Martin Whitaker
Christian Taedcke
Stephen Williams
Martin Whitaker
Larry Doolittle
Maciej Suminski
Cary R
Arun Persaud
Andrew Stevens
Jared Casper
Prasad Joshi