The dup_expr() function for NetESignal was not copying the word_
expression. This would cause an individual array access to turn
into an entire array access. The file and line information was
also not being set correctly.
An assert() in tgt-vvp/eval_expr.c was also replaced with an
exit() since the appropriate information was already being
printed.
This patch adds functionality to do a bit or part select release
when a constant value is forced to the net/register. It also adds an
error message when the user tries to force a signal to a bit/part
select. This is not currently handled by the run time, so is now
caught in the compiler (tgt-vvp). Where when this functionality is
needed, it will be easy to know what to do instead of trying to track
down some odd runtime functionality.
What this all means is that you can force a signal to an entire
signal or you can force a constant to any part of a signal (bit,
part or entire) and release any of the above. Technically the
release of a constant value does not have to match the force.
The runtime verifies that if you are releasing a signal driver
it is being done as a full release. I don't see an easy way to
check this in the compiler.
To fix the signal deficiencies we need to rework the force_link
code to allow multiple drivers and partial unlinking. Much of
this is in the runtime, but the %force/link operator may also
need to be changed like I did to the %release opcode.
The IVL_EX_NONE type was not displaying any message and default did not
use the new ivl_expr_{file,lineno} functions to get the source location.
This patch remedies these problems.
vpi_put_value can mimic force and release with vpiForceFlag and
vpiReleaseFlag flags to the vpi_put_value call. With this patch,
the infrastructure is added to allow the flags argument to be passed
to the dispatched put_value function, and for signals handle those
flags as force/release of a net.
This patch reworks much of the ternary code to short circuit when
possible and supports real values better. It adds a blend operator
for real values that returns 0.0 when the values differ and the value
when they match. This deviates slightly from the standard which
specifies that the value for reals is always 0.0 when the conditional
is 'bx. There are also a couple bug fixes.
These fixes have not been ported to continuous assignments yet.
Ternary operators used at compile time and in procedural assignments
should be complete (short circuit and support real values).
When a bit port of a module instance is connected to a vector
argument, the MSB module instance should be connected to the MSB
of the vector argument. This matters only in the rare case that
the %m is used. It also makes wave dumps come out right.
The updates to the do_include code destroyed the
handling of absolute paths; all of the code that
handles buffer-switching was erroneously placed
in just the relative-path branch. Thanks go to
Cary R. for pointing out the problem.
Now the common code has been extracted yet again,
and the notorious goto statement has been used
in favor redundancy.
The test vvp_reg.pl produces the same output as
before, so hopefully nothing new is broken.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
Normally processes are found in the lexical scope of a module, but
there are special cases where processes (other then task/function
definitions) are in other lexical scopes. The most likely case is
initilizations that are in the lexical scope where the assigned
variable is declared.
In the process, the behaviors list is kept in the base PScope class
instead of the Module or any other derived lexical scope class.
Case-generate alternatives create sub-scopes that need to be scanned
by the scope scanner in order to get function definitions etc. that
are defined lexically within generated scopes.
This patch converts a constant real index to an integer value when
defining an array. This can happen when using 2**8 which returns a
real value since the operands are signed.
draw_number_bool64() in tgt-vvp/eval_bool.c was using %ix/load to
load immediate values into registers greater than three. The problem
was that of_IX_LOAD() in vvp/vthread.cc was masking off the upper
bits. This was putting the results in the wrong register. This patch
removes the bit masking from of_IX_LOAD() and updates the %ix/load
documentation.
The file lexor.lex was beginning to suffer a catastrophic
increase in entropy due mainly to the mingling of spaces
and tabs--an age-old problem that often finds itself as
the subject of many a religious war.
The key rule: Make it consistent in as many editors as
possible; this was achieved by converting all hard tabs
into soft tabs (composed of spaces) of width 4.
I couldn't help but make modifications to the code as I
tabifified, but most of the changes are strictly style.
While maintainers generally treat large scale whitespace and
formatting changes with much caution, I believe that the code
is now much more maintainable; moreover, the test suite
produces the same results as before.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
Macro names cannot be compiler directive names.
Such trespasses are now recognized and reported:
(1) Offending `define lines are skipped.
(2) Offending macros meant to be expanded
are replaced with nothing.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
Move the storage of wires (signals) out of the Module class into
the PScope base class, and instead of putting the PWires all into
the Module object, distribute them into the various lexical scopes
(derived from PScope) so that the wire names do not need to carry
scope information.
This required some rewiring of elaboration of signals, and rewriting
of lexical scope handling.
The ordering of the logic was a little strange before.
Also, there were unnecessary operations, like the assert
and the include_dir[0]=0 business.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
Discussions online and "standards" documents are never
conclusive, but the code that was present suggests that
iverilog adopts the sane practice of resolving relative
paths against the directory of the file that is currently
being processed.
Unfortunately, when a relative path is made absolute, the
code forgot to update the necessary include_stack_t object.
This has now been fixed.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
When the lexical analyzer encounters and EOF, the
analyzer invokes yywrap() to determine what to do
next. The function determines one of two paths of
execution:
(1) If yywrap() returns 0, then the analyzer
assumes that yywrap() has setup a new input
source, and so scanning continues.
(2) If yywrap() returns non-zero, then the analyzer
assumes that yywrap() has not setup a new input
source, and so the analyzer proceeds to run the
matching EOF action (the default of which invokes
yyterminate()).
NOTE: The analyzer does not touch the start condition.
The old implementation was using yywrap() to destroy the current
input source and setup the next one. However, this causes problems
when the analyzer is in the middle of parsing some directive:
(1) Because yywrap() is called before any EOF action,
the include_stack_t structure is destroyed before
being used in the EOF action; the result is a segfault.
(2) Because yywrap() does not change the start condition,
any EOF action would occur completely out of context;
however, because of (1), this problem never cropped
up.
The new implementation simply:
(1) Employs "%option noyywrap", which effectively causes
the analyzer to act as though yywrap() produces a non-zero.
(2) Renames yywrap "load_next_input".
(3) Calls load_next_input() explicitly in exhaustive EOF actions,
so that control is more fine grained.
The added benefit is that the code that finishes parsing EOF terminated
directives now works properly; `include and `define directives previously
segfaulted in such situations.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
This variable was used in yywrap purportedly to obviate
hidden access to a file that should be closable.
After investigating the code flex produces, it would
seem that these fears are unfounded.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
The verilog preprocessing language is sufficiently simple
that the parser may be implemented by hand on top of the
lexical analyzer.
In fact, ivlpp was already implemented in this way; relevant
[bison] parser files specified no grammar, and the parser
entry-point (yyparse) was simply an indirect use of the lexical
analyzer (yylex).
Therefore, parse.y has been removed, invocations of yyparse()
have been replaced by yylex(), references to bison generated
files have been removed, and Makefile.in has been updated
accordingly.
Signed-off-by: Michael Witten <mfwitten@mit.edu>
This patch fixes two problems. The first is that thr_check_addr()
was being used inconsistently. It should be passed a real address,
but the resize of the vector should be at least one more than this
address. The extra and unneeded CPU_WORD_BITS was also removed
from the routine.
The second problem involved an invalid memory access in
vvp_vector4_t::set_vec() when the vector being copied was an integer
multiple of the machine word width. Under this condition there would
be no remaining bits that needed to be copied but the routine was always
trying to copying some remaining bits. This code is now only executed
when there is a remainder.
Neither of these appear to be causing runtime problems. The second one
was found with valgrind. The first were found while tracking down the
second problem.
All the pform objects that represent lexical scope now are derived
from the PScope class, and are kept in a lexical_scope table so that
the scope can be managed.
This patch adds support for delaying constants at time zero. It also
cleans up the code in elab_net.cc to use this capability instead of
building it with an extra BUFZ to carry the delay information.
Modules, functions and tasks are named scopes so derive them all
from the PScope base class. These items all take scoped items, so
the eventual plan is to move these items into PScope.
Stephen Williams
Cary R
Michael Witten
Larry Doolittle