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.
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.
This is a pretty trivial fix for the code generation of compressed
assign to a memory word. We generated incorect code for the stash
of the calculated word index, causing the assign of the result to
not work properly.
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.
If a wired and/or net has more than four connections all the other
resolution branches must also be wired and/or. All other nets can
just be tri since tri0/tri1 only needs the final resolution to be
an active pull up/down.
Since synthesis is not currently supported we do not support/generate
sync/async set or clear control inputs. This is further complicated by
the fact that the VVP DFF primitive is not fully implemented.
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.
This patch adds error messages that forcing a word to/from a variable
array is not currently supported. This is because variable arrays no
longer are fully populated and don't have an access functor for each
word. Forcing a word from/to a net array does work as expected since
each word in a net array is created.
Technically forcing a variable array word is not supported in 1364-2005.
Reading from an array word, which is supported, will be fixed in
development once the expression rework is finished.
The error message printed when forcing a bit/part select l-value was
also improved.
This patch fixes a few more bugs in the enumeration code.
It add support for saving the file and line information to make
diagnostic messages better.
It updates some of the compiler warning messages to use the file
and line information.
It passes if the enumeration type is signed all the way to the
code generators.
It fixes the parser to correctly have the range after the signed
designation for the vector types.
It adds a warning that vvp does not currently support a negative
two state enumeration value.
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 support for increment/decrement operators as an
expression. The operations on real and vector slices have been
disabled for now.
These operators can be used as in independent statements. However, the
corresponding support is not added in parser.
Changes since V2:
- Additional error checking in elaboration to deny operation on vector
slices and real (suggested by Martin)
Changes since V1:
- Use 'i' and 'I' for increment (suggested by Cary)
- Evaluate sub-expression once (suggested by Cary and Stev)
- Add necessary checks during elaboration to ensure that the
expression is valid (suggested Stev)
- Proper width handling with vectors (suggested by Martin)
Signed-off-by: Prasad Joshi <prasad@canopusconsultancy.com>
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>
The vvp target code generator may not elide a BUFZ if the output of
the BUFZ is connected to a net that is the subject of a procedural
force statement.
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 ensures that the result of a shift is an undefined value
if the right operand is an undefined value. It also improves the
code generated for right shifts where the right operand is constant
and optimises away shifts where the right operand is a constant 0.
It also fixes a few places where the expression type (signed/unsigned)
was not being set correctly.
A valarray of an enum does not initialize to 0 so explicitly specify the
value to fill the array with. This was causing the compiler to incorrectly
report that fixed width elements in a concatenation had no size.
The following was done to remove compiler warning when using the native
compiler on OpenSolaris.
Remove the anonymous unions in tgt-vlog95/stmt.c and tgt-vvp/vvp_process.c.
Use UINT_MAX for the maximum unsigned unsigned instead of -1 in
tgt-vvp/draw_net_input.c.
Even though lex defines yywrap() to have no arguments when %option
noyywrp is used it generates a define that takes an argument that is not
used. The compiler warned about this so remove the option and add a
dummy yywrap function.
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.
Currently the vvp target emits multiple single bit %mov instructions
to perform sign extension. This patch adds a new %pad instruction
that allows sign extension to be performed with just one instruction.
This patch fixes a few compilation warnings introduced by the
enumeration code. It also updates the ivl.def file so that the
proper routines get exported under windows.
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.
At the moment we only support one real driver. This patch adds a
combined error routine for a uwire or a real net with multiple
drivers. We display the top level net in the hierarchy. It also
reworks the nexus data_type calculation.
In ivl_alloc.h we redefine malloc(), realloc() and calloc() to have
standard error checking. We don't want to do this for anything that
comes from the standard headers. This specifically doesn't work if
a C++ header files does std::malloc, etc.
Also change to -W instead of -Wextra since that is more portable. I
plan to add a check from -Wextra and use it when available since it
is more descriptive.
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 support for running cppcheck from the Makefile. It also
standardizes the order of some of the targets. It renames vpip_format.c
to vpip_format.cc and fixes the size of the array tables to make room
for the trailing NULL. Found when using a C++ compiler.
IVL_VT_BOOL variables at the code generator should generate
.var/2x records so that the run time can do 2-value optimizations
and otherwise support atom2 values.
Fix all the Icarus files that can be so that we do not have any
signed/unsigned compare warnings. It also removes const as a
return qualifier for two routines in discipline.h.
To prevent a force from back propagating we need to keep a BUFZ
that represents a continuous assignment between two nets. This
only effects continuous assignments of the form assign out = in.
In general these are fairly rare so keeping them has minimal
impact on the simulation speed.
This patch adds a check in the vvp back end that a uwire has
at most one driver. Previously this was just converted (with
a warning message) to a wire just after elaboration.
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.
These checks are not needed since we have already verified that
we have a 64 bit immediate value. This is likely old code that
should have been removed when the original functionality was
changed.
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.
This patch modifies the real ternary operator code to support
unlimited tail recursion without overflowing the thread
registers. Head recursion is still limited by the available
registers.
It fixes the thread word checks to use a new define that has
the correct number of thread words (16). It adds a message
instead of just an assert if the thread words are exhausted.
And it also changes some of the error messages to use vvp.tgt
in the message to be consistent with the other messages.
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.
The functions (malloc, free, etc.) that used to be provided in
malloc.h are now provided in cstdlib for C++ files and stdlib.h for
C files. Since we require a C99 compliant compiler it makes sense
that malloc.h is no longer needed.
This patch also modifies all the C++ files to use the <c...>
version of the standard C header files (e.g. <cstdlib> vs
<stdlib.h>). Some of the files used the C++ version and others did
not. There are still a few other header changes that could be done,
but this takes care of much of it.
gcc on OpenBSD reported shadow warnings for variables, arguments named
log, time and exp. This patch renanes those variables to logic, timerec
and expr.
This patch updates all the Makefile.in files and configure.in
as follows:
Do not use the -Wall warning flag when using the SunPro compiler.
The SunPro compiler uses -xMD instead of -MD.
There are still more fixes needed before Icarus will compile
on OpenSolaris.
The comparison and reduction operators only have a single output bit
that can be delayed.
The comparison of real values always produces a logical value so the
delay type is not dependent on the arguments type.
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.
To match the behaviour of other simulators, delayed bit-based signals
should have the value 'x' and delayed real valued signals should have
the value 0.0 until the true initial value has propagated. This patch
provides this behaviour.
When building a modpath the source for the modpath must have the
same scope as the modpath. This is required to make the back
annotation work correctly (have the correct names).
This patch enhances elaboration to drop/ignore zero replication
count constants. Not doing this was causing problems later in
the compiler. We still pass non-constant expressions since
both user and system functions must be run for their possible
side effects. Constants can never have a side effect so just
dropping them is acceptable.
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).
This patch mimics what was done for normal assignments to get the
width correct for nonblocking assignments when converting a real
r-value to a l-value vector.
When selecting bits from unsized literals, we do not put a limit
on the size of the literal, so there is no top above which we
stop getting literal bits.
When handling the $signed/$unsigned system functions, the compiler
was applying the new signed/unsigned property to the NetExpr object
representing the input argument. This caused the input argument to
be evaluated incorrectly. This patch fixes this by applying the new
property to the NetExpr object created to pad the result to the
required size.
In testing this fix, it was also discovered that the width of the
input argument expression was not being calculated correctly. This
patch also fixes this issue.
The padding for a signal select was using the signal to determine
if the padding should be singed or not. In reality this should be
unsigned padding unless the select was enclosed in a $signed().
In combination with the patch to make all operations on thread words
operate on 64-bit values, this patch ensures casts between real values
and large vector values work correctly.
Stephen Williams
Martin Whitaker
Cary R
Prasad Joshi
Jared Casper
Martin Whitaker
Larry Doolittle