The Verilog-A abs(), min() and max() functions can be converted if the
expressions do not have side effects. Also note the new, null and class
property operators from SystemVerilog are not supported.
This patch updates the code to translate the SystemVerilog assignments with
an opcode to the appropriate vlog95. This includes ++ and -- when used in
a statement context. The ++ and -- operators are not currently translated
in an expression context. This translation only occurs in two places:
A simple assignment statement (foo += 2;) and the increment of a for
statement. I still need to check if there are other places where these
operators are allowed.
SystemVerilog supports using assignments with opcodes (e.g. +=). This
patch checks for these in a few common places and prints a warning
that they are not currently supported. Eventually the simple cases
will be converted.
We can not convert SystemVerilog strings or dynamic arrays to valid vlog95.
This patch adds an error message that they are not supported. There are still
issues with converting some of the dynamic array constructs (the compiler
crashes), but the message is printed before the crash.
This patch adds support for SystemVerilog packed arrays and adds sorry
messages for generate blocks as well as the new SV final and
fork/join_any/join_none statements.
Rework the nexus emitting code to correctly translate most I/O ports.
Fix a few other expression issues uncovered when port translation was
done correctly. Ignore and warn that the SV ++/-- operators and enum
types are not translatable. More updates of the nexus debug code.
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>
isprint() is defined to take an int and if it is defined as a macro then
you can get a warning that a char is being used as an array index. This
patch fixes this warning in tgt-vlog95/msic.c
This patch adds the ability to print a constant string in a
structural context. It also fixes the argument order for
structural function calls and makes a few improvements in
nexus identification.
This patch adds code to make sure a double (Verilog real) constant
is printed correctly. It also adds code to trim any leading escaped
NULLs from an expression string.
This patch uses the new function (ivl_logic_is_cassign) to determine
if a logical was really the base of a continuous assignment. This
allows creating code that more closely matches the original.
This patch adds support for correctly handling most unconnected ports.
Most important is top level ports that are the root of the conversion.
This patch also adds support for emitting more signed constructs when
they are requested. $signed() and $unsigned() are still not supported
or recognized as an error when not emitting signed constructs.
This patch adds a flag -pallowsigned=1 to the vlog95 converter that
tells it to allow signed signals. There is currently no code to check
for and warn/emit the $signed() and $unsigned() system functions. I
need to determine if >>> emitting should also be controlled by the
allow signed flag.
This patch adds support for emitting escaped identifiers and adds
code to correctly emit most module port expressions/definitions.
There are some minor code optimizations/cleanup included as well.
The logic_lpm.c file uses the nexus private data pointer as an
unsigned counter. This patch makes the value unsigned long to
avoid a compilation warning on 64 bit systems.
This patch adds support for emitting fixed CA selects (zero based
variable bit and array selects also work), emitting a for statement
as a single statement and fixes for numerous little bugs. It also
adds the start of emitting module port information.
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.
The 1364-1995 version of Verilog does not support non zero based
parameters. This patch removes the comment requesting the parameter
MSB/LSB information to denormalize the expression and replaces it
with one stating that we need to keep the compiler normalization.
This patch adds the rest of the functionality needed to correctly
emit both L-value and R-value procedural variable indexed part
selects as a concatenation of variable bit selects.
This patch adds partial support of procedural variable indexed part
selects (both R and L-value). The restriction is that this currently
only works on a zero based little endian vector. I need to know if
the select is an up or down select to correctly denormalize the base
expression for the general case.
This patch adds copyright information for the Icarus generated UDPs
(lesser GPL version 2.1). It also prints a note to let the user know
that this copyrighted code is being included in the output file. They
can then remove the primitives if needed. These are likely only
needed when the output is from synthesis. At the moment we only have
a positive edge D-FF. In the future a negative edge FF and D latches
will also be needed.
Add a preliminary gate name and range (zero based) for logic primitives.
Also assert that a logic gate in a continuous assignment has the correct
number of inputs/outputs.
This patch adds code to emit variable real procedural delays by
removing the scaling that is added by the compiler. It also
recognizes that all variable continuous assignment delays are
scaled at run time.
This patch reworks the delay emitting code to handle delay expressions
better. It also encloses the emitted unary operators in parenthesis to
make sequenced unary operators work properly.
It was incorrect to extend emit_expr_signal() to handle a local signal
(a continuous assignment). The only way this should ever happen is
when evaluating a variable delay expression. It is better to do this
checking in the delayx evaluation where we know if we are processing
a delay for a statement or a continuous assignment. This keeps the
emit_expr_signal() routine cleaner and we only allow a CA delay for
a continuous assignment.
This patch fixes the following bugs in the vlog95 converter:
When emitting a signal as an expression, if the signal is local then
emit the expression that is driving the local signal.
The casts need to emit the expression.
When emitting pull devices they have different default strength rules
(pull is the default).
For compatibility pull devices should only have a single output net.
Extend the code that searches for the <var> = <delay> <value> pattern
to also check for an <event>. The previous event code only looks for
the repeat event pattern.
This patch adds a flag that emits file and line information for
most lines. This can help the user understand where the various
lines came from in the original code. They are printed as
comments so the generated code still runs correctly.
When emitting a logical device as part of a continuous assignment
we need to use the actual inputs (not the output). We also do not
need to emit anything if the nexus is NULL. Also skip logical gates
that have a local output since they are part of a continuous
assignment and the inputs to a logical gate can be an expression
so emit them as a continuous assignment.
This patch adds the following to the vlog95 converter.
Add support for emitting and calling UDPs.
Generate a UDP for a synthesized DFF.
Add the ability do emit a constant assigned to a net.
This patch adds code that when it find a select of a constant it looks
for a parameter in the enclosing scope and the module scope that has
the same line, file and value information. If it find one that is
used to rebuild the expression. A more exhaustive search is need to
make this 100% clean.
It also uses the named scope when emitting statement inside a named
begin or fork instead of the enclosing scope.
This patch moves the logic and lpm code to a new file. It refactors
the strength emitting routine and adds support for emitting the
standard tran style of gates.
This patch adds the ability to translate the code produced by the
compiler for a wait statement back into a wait statement. It also
reworks the strength emitting code to only emit a single strength
for the pull gates and fixes a bug in the strength emitting code.
A NOOP at the end of an existing statement can be represented as ";\n"
(a simple line termination). In general a NOOP represents an empty
begin/end pair.
This patch add the following functionality to the vlog95 generator.
Add support for most CAs. Selects still don't work correctly.
Emitting a named event as an expression.
Enhance the ability to find a signal in a nexus.
Add code to emit a nexus driven by a constant.
Rework the delay/strength code for logic gates/CAs
Refactor some of the number code.
Refactor the variable emitting code to support named blocks.
Translate the compiler code back to <var> = <event> <value>
This patch adds support for emitting an array as an expression. This is
used as a system task/function argument.
It partially reworks the real display code to print an appropriate
expression for NaN, inf and -inf. To get other real numbers to always
display correctly we need to build a custom printing routine that adjusts
what is displayed based on the actual bits in the double.
Add the ability to print a real variable delay. They are not scaled by
the compiler.
Since a delayx delay may be variable we must always enclose this type of
delay with parenthesis.
Fix the L-value concatenation to be in the correct order.
Handle the special case that an if with a single if as the true statement
does not loose any associated else clause to the enclosed if. Basically
add a begin/end pair as needed to make things work out correctly.
This patch adds the ability for the user to change the spacing increment
from the command line using the -pspacing=<num> flag. The is restricted to
be a value between and including 1 and 16.
This patch adds preliminary support for finding the correct name for
a nexus at a given scope level. It also does the following.
Report that real modulus is not supported.
Fix a bug in the generation of concat expressions.
Add missing generation of unary ! operator.
Add ability to generate > integer delays.
Refactor some of the support code.
Make some of the error messages more descriptive.
Ignore the ALLOC and FREE statements (only used with automatic tasks).
If the left power operator expression is a numeric constant that has a
value 2^n n>0 then we can use a left shift to calculate the result. This
patch adds code to do this. All other power expressions are flagged as a
compilation error.
This patch adds significantly more functionality to the vlog95 back end.
The following are the major additions:
Display unsigned numbers without undefined bits in hex.
Add support for both L-Value and R-value bit and part selects.
Added support for out of scope references.
Added support for emitting logic gates (range not finished, name is invalid).
Added support for emitting initial/always blocks.
Add support for event inter statement delays.
Convert a blocking inter statement delay assign back to the original form.
Added support for rescaling variable delays.
Added support for the disable statement.
Added support for an event trigger statement (event name is missing).
Added support for calling a user task (calling arguments are missing).
Added support for an event based delay statement (@) (event name is missing)
Not all of these are working as expected since there is not currently a
routine to find a nexus name as a function of scope (needed for event names,
logic gate ports, etc.). Since the Icarus compiler generates structural code
the arguments to modules, module instantiations and calling user tasks are
also still missing.
This patch adds support for using a scope in an expression and calling
a user function. It also fixes an issue in the module name mangling
and calling a system task/function with multiple arguments.
This patch adds support for the various case statements and adds
preliminary support for instantiating modules. The module instantiation,
just like the module definition, is still missing ports. Adding this
will require modification to the compiler to get the port order correct.
Because of defparams and passed parameters any module that has a
parameter must be generated uniquely for each instance since they may not
all be the same. Modules without parameters are only generated once.
This patch adds the ability to print a delay expression (it is rescaled
to the module timescale) and adds support the following statement types:
nonblocking assignment with a delay (event control is still missing)
condition (if/else)
forever
repeat
while (Icarus translated for loops to while loops)
fork
procedural continuous assign
deassign
force
release
This patch adds support to the vlog95 convert for the ternary operator,
the concat/repeat operator and calling a system function. It also adds
the `celldefine information when appropriate.
This patch adds more support to the Verilog 1995 converter. There is
still a lot that is missing and there is still some implemented
functionality that is not 100%.
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.
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.
This is the initial commit in an effort to build a 1364-1995
back end for Icarus Verilog. It is expected that this back end
will allow the user to write 1364-2005 RTL and then using this
back end (converter) generate functionally equivalent 1364-1995
compatible code. This can be used to support older tools in a
work flow. The primary focus will be simulation equivalence,
though I expect to verify logical equivalence as well.
Cary R
Arun Persaud
Prasad Joshi
Larry Doolittle