The IEEE standard does not specify the behaviour of a tranif primitive
when its control input is an 'x' or 'z'. vvp currently treats these as
if the tran was turned off, but it would be better to propagate the
uncertainty to the tran bi-directional ports. For compatibility with
other simulators, we adopt the behaviour specified for MOS primitives.
The standard specifies that the size of a vecval should be calculated as
(size - 1)/32 + 1. When size is a PLI_INT32 this is needed to prevent an
overflow, but when the size is unsigned this can be simplified to
(size + 31)/32 since the size must fit into an integer, but we have an
extra significant bit in an unsigned so no overflow can happen.
This patch changes the code to use the correct version of the equation
depending on the context.
The previous patch does this in vvp/vpi_priv.cc
When vpi_put_value() is asked to delay the assignment any pointer data
needs to be duplicated so that the caller can clean up the locally
allocated memory without causing memory access problems.
Also update word calculation to match the next patch.
If a tranif gate has a delay, the vvp code generator needs to generate
a unique label for the island port used for the tranif enable, to
prevent a name collision if the undelayed signal is also connected
to the island.
Also add an assertion in vvp to catch bugs like this.
The clang compiler does not like using struct to reference a class object.
This patch removes all the struct keywords for __vpiNamedEvent objects
since they are now a class and can be called without a struct/class
qualifier.
This patch also removes all the extra class qualifiers from the rest of
the source code.
When looking for a value change on a part select of an array word,
the callback handle has to save the current value and test it with
the new value to see if there is an actual change. If not, then
suppress the callback.
The clang compiler does not like mixing class and struct references. This
patch updates all the struct __vpiHandle, etc. to use class since that is
how they are now defined.
All the methods that this structure supported are now pulled
into the __vpiHandle class as virtual methods. This includes
the vpi_free_object_ method, which required some extra trickery.
Instead of C-like data structures where the __vpiHandle base is a
leading member, make the __vpiHandle a derived class. Give the base
class a virtual destructor so that dynamic_cast works reliably, and
now pretty much all of the junk for testing if an object really is
of the derived class goes away. Also, problems with casting up to
a vpiHandle become trivial non-issues.
Full vector assigns are able to short circuit the propagation of
the value if it finds that there are no value changes. This patch
supports that behavior in writes to parts as well. Put this change
to use in logic devices as well.
Not all the lex/yacc (flex/bison) targets were using a consistent syntax.
This patch fixes that and explicitly serializes the *.c/*.cc and *.h build.
Not doing this was causing problem when using make -j. The issue appears to
be that if two targets are specified for a rule (e.g. file.cc file.h: file.y)
make does not realize they are both built by the same call so the rule is
executed twice. Once for the .cc target and once for the .h target. This is
not a problem for a serial build. To work around this only use the .c/.cc
file in the main target and then make the .h file depend on the .c/.cc file
as a sub-target.
Now we have a code generator that can handle compressed assignments
as they have been re-imagined in elaboration. There are some cases
that are not yet supported, we'll patch them up in due course.
Both UDPs and system functions use the wide input functor. This patch
modified the code generator to create a local net declaration for the
output net if we have either a delay or modpath connecting the output
to the true output. This is needed so that the wide input can be
cleaned up correctly.
Local real nets were also added to the local net pool when testing with
valgrind. This allows them to be cleaned up at the end.
For a delay we do not know exactly what type we will be propagating
until the initialization event has happened. Because of this we
allocate both a vec4 and a vec8 value. Once the initialization event
has happened we can free the unneeded element(s).
When scaling a time value we would often use the power operator to
create constants 10**-N that were then multiplied with the original
value. The problem with this is that there is some errors in the
representation of the fractional number. It is better to create a
integer value 10**N and then divide the original value by this
exact constant. You still have the calculation error, but the scale
value is now an exactly real value.
The name is not currently used, but when it is it makes sense for it to
be in the base class. Also the name cannot be deleted after compiling
since it may be used later.
The VPI object data model diagrams show a one to many relationship
between the "mod path" and "path term" objects. This means that the
correct way to obtain handles to "path term" objects is to use the
vpi_iterate and vpi_scan functions.
Support for the old method of obtaining handles to "path term" objects
using the vpi_handle function is retained for backwards compatibility.
The standard defines how to calculate the name for an access function
or iterator if one is not given. It is supposed to be vpi followed by
the words in the name with each word capitalized. For the one to many
(iterator) interface from the enumeration typespec to the individual
constants this is vpiEnumConst not vpiMember.
We don't currently have the information needed to correctly provide the
base typespec, but in the next() and prev() methods I need to know if
the enumeration is two or four state. This patch sets the base typespec
for four state enumerations to vpiReg and to vpiBitVar for two state
enumerations. This provide enough information to get next() and prev()
working correctly.
This patch adds vpiEnumTypespec to the list so that vpi_get_str(vpiType, ...)
returns an appropriate string when an enum type is passed.
It also adds the initial hook to allow iteration (global) over the UDP
definitions. This along with table traversal will be needed to free the
memory allocated when the UDP definition is created. Ultimately this
will all the UDP test to be valgrind clean.
Update the line number for a couple cppcheck suppressions and add one for
the pool variable in the vvp directory.
Also move a check for null to the correct place.
Gordon McGregor
Martin Whitaker
Cary R
Larry Doolittle
Stephen Williams