I forgot to modify the LPM generating code with the
last patch. This *should* now always ensure a signal
is readable before code is generated to read from it.
This patch corrects several bugs with the generation of
VHDL `buffer' ports. The code generator should now
generate a buffer only if the port needs to be read inside
the architecture, otherwise it will stay `out'.
This also correct a bug where an output port is connected
directly to the output of an instantiated component. Generating
`buffer's would work here, but a more idiomatic VHDL approach is
to declare an intermediate signal which both outputs are connected
to. This is implemented in the patch (fixes the regression of
readout.v in the testsuite).
Noticed this as part of the test case for pr2516774b. Under some
circumstances the input arguments would be cast to the wrong type.
This patch ensures that all the arguments have the correct type.
This patch changes the output of VHDL unsigned bit strings
which are 4, 8, 16, 32, or 64 bits to use VHDL hex string
constants.
So the following:
"00000001"
Becomes
X"01"
Which is much easier to read
This is a fix for pr2527366 where draw_nexus would sometimes
generate code to drive an input from in an input (where they
should have been left unconnected)
The patch for pr2516774 exposed a bug which caused
always3.1.8A to fail. This patch corrects that.
The test to decide when to use a sensitivity list
rather than an explicit wait statement wasn't tight enough.
This patch is a fix for pr2516774.
The idea is to generate a local variable inside
a function whenever an argument is assigned to. The
variable has an initial value of the argument value
and is used in its place for the remainder of the
function. This patch also handles the case where the
argument is assigned to inside a while loop.
Previously the VHDL code generator managed memory for
the AST objects by requiring that each AST element be
responsible for deleting its children. The disadvantages
of this are that it's quite easy to accidentally leak
memory by forgetting to delete a child, and no AST pointers
may be shared by multiple parents (or we'd end up with
double-deletes) -- this results in unnecessary copies of
objects being made.
There's no real need for fine-grained memory management of
AST objects since once they're allocated they tend to
persist until the code generator is about to terminate, when
they should all be freed.
This patch provides a custom new/delete operator for
vhdl_element which logs the vhdl_element objects allocated
in a std::vector (after calling the default operator new).
Once the code generator is finished a single free_all_objects
call deletes all the AST objects in one go. The custom delete
operator is required so that we can still explicitly deallocate
vhdl_element objects before the code generator completes.
There are also some allocation statistics printed at the end
when -pdebug=1 is specified.
This patch generates VHDL sensitivity lists for sequential
as well as combinatorial processes which do not contain
a wait statement. Otherwise it falls back on the original
wait-on/until behaviour.
This should make the generated VHDL more acceptable to
synthesisers.
This patch generates a sensitivity list for combinatorial
VHDL processes if they don't contain a wait statement, and
a wait-on statement if they do contain another wait statement.
This should help synthesisers correctly identifier
level-sensitive latches.
In particular this improves the code generated for flip-flops
so the output can be synthesised with certain tools (e.g. Synopsis).
See the comments above draw_synthesisable_wait for more details.
Rather then spread VERSION= defines throughout all the makefiles, put
the base version in version_base.in. Use that to generate a version.h
that includes the base version as well as the detailed version.
This reverts commit 31d67fcd3e.
The concensus has been that this causes too many build problems in
the general case and what is needed instead is a way to turn on the
extra warnings for developers only.
The code base is almost shadow-free now, so this won't add much noise to the compiles.
Problems I know about:
lxt{,2}_write.c: patch sent upstream
cflexor.c: exposes gray area of name space boundary
Finish cleaning up shadowed variables, flagged by turning on -Wshadow.
No intended change in functionality. Patch looks right, and is tested
to compile and run on my machine. No regressions in the test suite.
This is the end of the simple, coordination-free patches.
The remaining shadows are special cases that will need extra attention.
Previously only the X/Z state of the label expression was
considered to be a don't care. This patch adds that
functionality to the conditional expression as well.
This patch cleans up the Makefile.in files.
We only need to delete config.log in the lower directories.
We reference the *.in files at $(srcdir)/
We need to make distclean for the tgt-(fpga,pal,verilog) directories.
This is to cleanup the Makefile.
Add some missing "rm -r f dep"
This patch adds support for concatenation/repetition, signals and
part and bit select of signals for casez/x expression labels.
These along with the original constants can be mixed in almost any
order. Only constant selects are currently supported.
Specifying -pdepth=N only outputs entities that correspond
to Verilog modules found at depth < N in the hierarchy.
Setting -pdepth=0 (the default) outputs all entities.
This is for feature request 2391457
Collapse all the configure checks to a single configure script in
the root of the source tree. This makes the configure process run
a lot faster, expecially on Windows systems that are slower in general.
This patch optimises away straight line sequences like:
wait for 0 ns;
wait for X ns;
to:
wait for X ns;
This tidies up the output a bit.
It also has the effect of removing all code from initial
processes where the assignments have been extracted as
VHDL signal intialisers. (c.f. pr2391337)
This prints out an error message rather than crashing out with
an assertion failure when a function assigns to a non-local
variable, which cannot be done in VHDL.
This changes the assignment statement generator so that
each VHDL declaration "knows" which type of assignment
statement can/should be used on (i.e. signals must be
assigned with <=). This will help us catch cases when
we try to use, for example, := with signals. This occurs
in pr2362211 where we try to assign to a signal within
a function (where only := can be used).
If a module's input was connected to a nexus that contained
a constant driver. That constant would be incorrectly generated
as an assignment to the input *inside* the child module (instead
of an assignment inside the instantiating module).
With this small patch, building succeeds with Debian's current gcc-snapshot,
gcc (Debian 20081130-1) 4.4.0 20081130 (experimental) [trunk revision 142292]
That gcc also warns about the remaining #idents in
vvp/concat.cc
vvp/dff.h
The resulting build shows some regressions in the test suite, that
I am still investigating. The patch does not break building, or show
test suite regressions, with gcc-4.3.
Signals of width 1 are declared in VHDL as std_logic, as this
is the usual way to represent them. Unfortunately, we cannot
distinguish between
reg [0:0] a;
and
reg a;
This patch avoids trying to slice a std_logic so a[0] is equivalent to a.
This patch removes the CVS ident information from the Makefile.in
files it also puts in the current version 0.9.devel for the default
VERSION definition. This is normally passed down, but a local make
will use the value from the local Makefile. This will eventually be
replaced with a file based version to give us just one place to
reliably modify the version.
This patch updates the GNU address in the -V output, adds the
VERSION_TAG info to the tgt-vvp back end and adds the whole -V
hook to the tgt-vhdl back end.
Fix for pr2224949
The compiler generates a concatenation LPM to zero-pad ports when the
signal widths don't match up. However, when the VHDL generator generated
the input signals to this LPM it incorrectly sized them to be the width
of the result.
The VHDL converter erroneously treated a casez and casex exactly
the same. In reality a casez compares a 'x' value (it is not a
don't care). It also adds support for a full don't care case by
just returning True for the condition.
This configure option causes the installed commands to have
a suffix string that makes them distinct from other versions
that also have a suffix string. This allows for multiple
installed versions of Icarus Verilog.
Also, move installed C/C++ header files into a subdirectory of
their own under the target include directory, to make clearer
the purpose and source of those files.
VHDL can't select bits from arbitrary expression so sometimes
translating IVL_EX_SELECT would fail. This is easily fixed by
replacing the select with a shift in this instance (and the
resizing)
make_safe_name now makes sure a VHDL signal is never given a
name that conflicts with any reserved words. If it does, we
just prepend VL_.
(This code was already present, but the full list of reserved
words wasn't.)
Continue cleaning up shadowed variables, flagged by turning on -Wshadow.
No intended change in functionality. This patch set covers the tgt-vhdl
directory, and was tested by Nick.
A casex statement cannot be directly translated to a VHDL case
statement as VHDL does not treat the don't-care bit as special.
The solution here is to generate an if statement from the casex
which compares only the non-don't-care bit positions.
Emitting a VHDL expression like Resize("01", 32) is ambiguous
between interpreting "01" as a Signed or an Unsigned. There's
no point actually outputting this as we can sign-extend the
constant value in the code generator, which is what this
patch does.
The exponentiation operator in VHDL is not defined for numeric_std
types. We can get around this by converting the operands to integers,
performing the operation, then converting the result back to the
original type. This will work OK in simulation but certainly will not
synthesise unless the operands are constant.
However, even this does not work quite correctly. The Integer type in
VHDL is signed and usually only 32 bits, therefore any result larger
than this will overflow and raise an exception. I can't see a way
around this at the moment.
Target selection is done by the DLL target code generator, so there
is no value having a layer of target selection ahead of it. Remove
all that redundant code and simplify the target config files to reflect
this.
Generate scopes were previously ignored, and this would cause a segfault
later on. This patch gives an error whenever it encounters a generate
scope. This should be removed once generate statements are implemented.
Previously only signedness was only corrected for the
result. This patch ensures the VHDL operands have the
same signedness as their Verilog counterparts.
This fixes a few of the signedX tests.
This splits up the monolithic and confusing vhdl_expr::cast function into
several smaller to_XXX functions which each generate code to cast an
expression to type XXX. This makes it much easier to understand and maintain.
Mostly this ensures that a recursive call to a function
is made with the correct types (this may involve generating
code to cast expressions to the correct type).
This is caused by using a hierarchical reference (which can't
be translated to VHDL). The result of get_decl is NULL since
the signal has been declared in a different VHDL architecture.
Adding the assert is cleaner than having it segfault, for the
moment, until a nicer error message can be added.
Previously this was handled by creating an internal
signal that was connected to the output and could also
be read inside the entity. The correct solution is to
make the output `buffer' rather than `out'. However, this
does not work in the case when an output is connected to
an output of a child entity, and that values is read
in the parent. In this case *both* the outputs of the child
and the parent need to be made `buffer'.
Combinatorial UDPs will be implemented with a `with ... select'
statemetnt. However the input to this must be "locally static".
This patch joins the inputs into a vector which can be used as
the select expression.
...with the correct behavior. It would be possible to
just translate it as a regular VHDL case statement (as
it was before this patch). But the behavior is not
correct as VHDL only does the equivalent of case-equality
in case statements and this can be confusing when debugging
the output. An alternative might be to emit a warning rather
than an error.
If the final statement in a process is a non-blocking
assignment then there is no point adding a `wait for 0ns'
after it since it will be immediately followed by another
wait. This case is suprisingly common, so this patch helps
generate much cleaner output without breaking the cases
where the 0ns wait is actually required (e.g. to implement
non-blocking assignment properly).
This patch adds a forward declaration for every user funciton.
This fixes VHDL compile problems if a function calls another
before it has been declared.
Multiple lvals are implemented by first assigning the complete
RHS to a temporary, and then assigning each lval in turn as
bit-selects of the temporary
Previously the code generator expanded ternary assignments to
and `if' statement. This patch replaces that with a single assignment
and a call to a Ternary_* support function. This will make it
much easier to support multiple lvals later.
Nick Gasson
Stephen Williams
Larry Doolittle
Cary R