Creation of implicit nets requires knowledge of whether an identifier
has been declared before it is used. Currently implicit nets are
created during elaboration, but by this stage the order of declaration
and use is not known. This patch moves the creation of implicit nets
into the parser stage.
This patch is a major rewrite of the indexed part selects (+: and -:).
It made the following enhancements:
1. Make indexed part selects work correctly with both big and little
endian vectors.
2. Add a warning flag that warns about constant out of bounds/or 'bx
indexed selects.
3. Moved the -: parameter code to its own routine.
4. Added support for straddling before part selects in a CA.
5. Added more assert(! number_is_unknown) statements.
6. Add warning for &PV<> select with a signed index signal that is
less than the width of an int. This will be fixed later.
7. Add support for loading a 'bx/'bz constant into a numeric register.
8. Add a number of signed value fixes to the compiler/code generator.
9. Major fix of draw_select_expr() in the code generator.
Previously Icarus only supported a default net type of wire or none.
This patch adds the rest of the supported net types (all except
uwire and trireg) to the `default_nettype directive. It also fixes
make_implicit_net_() to use the default_nettype instead of always
using implicit (the same as wire).
In 1364-2005 it is an explicit error to take the select of a scalar
or real value. We added the checks for real a while ago. This patch
adds the functionality for scalar values. In the future we may want
to push the scalar property to the run time.
Part selects need to be fully defined. If not, then the resulting
expression is 'bx no matter what. The same for bit selects, when
the bit select expression is constant.
This patch splits any VVP net functor that needs to access both
statically and automatically allocated state into two sub-classes,
one for handling operations on statically allocated state, the
other for handling operations on automatically allocated state.
This undoes the increase in run-time memory use introduced when
automatic task/function support was first introduced.
This patch also fixes various issues with event handling in automatic
scopes. Event expressions in automatic scopes may now reference either
statically or automatically allocated variables or arrays, or part
selects or word selects thereof. More complex expressions (e.g.
containing arithmetic or logical operators, function calls, etc.) are
not currently supported.
This patch introduces some error checking for language constructs
that may not reference automatically allocated variables. Further
error checking will follow in a subsequent patch.
If a part select (either a constant or constant indexed part select)
of a L-value is fully outside the signal the part select will be
omitted after printing a warning. If a part select straddles the
upper portion of a signal a warning will be printed. The run time
will use only the appropriate part of the select. Straddling the
lower part of the signal is not currently supported and a message
is printed for this case.
Continue 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 test suite.
Nothing to do with tab width! Eliminates useless
trailing spaces and tabs, and nearly all <space><tab>
pairings. No change to derived files (e.g., .vvp),
non-master files (e.g., lxt2_write.c) or the new tgt-vhdl
directory.
Low priority, simple entropy reduction. Please apply
unless it deletes some steganographic content you want
to keep.
In preparation for using the synthesize method to replace the
elaborate_net method of PExpr, rework the interface to the
synthesize() method. This changes no fnctionality, but does set
up the infrastructure for the next step.
Contribution statements have an l-value and r-value. Parse those
expressions into pform so that elaboration has something to work with.
In this process, this patch also changes the PECallFunction class to
use the vector template instead of the svector template. The latter
doesn't add anything over the STL vector template, so this is a start
of working the svector out.
This handles the general case of a non-real operand to a real-valued
division. This can turn up if only 1 operand of a divide is real. In
this case the division as a whole is real and the other operand must
be cast to real.
This method creates an extra node, but it should be a very compact
node and this node does no evaluation tricks so in the run time should
be no more expensive then folding the cast into the .arith/div.r itself.
Rather then join islands while branches are initially created, save the
island creating for the end. This way, the process is actually recursive
and greedy, reliably collecting branches into islands without conflict.
Fold the bi-directional part select into the pass switch (tran) support
so that it can be really bi-directional. This involves adding a new
tranvp device that does part select in tran islands, and reworking the
tran island resolution to handle non-identical nodes. This will be needed
for resistive tran devices anyhow.
The Verilog LRM specifies that it is legal to give constant part
selects that are beyond the bounds of the identifier being selected.
But elaboration was flagging that as an error. This patch changes it
to a warning, and handles the cases by generating 'bx bits as needed.
IEEE1364 has specific names for the various generations of Verilog that
are supported. Icarus Verilog should stick to those names for selection
the language feature set.
In the process, the extensions that were tied to the 2x generations
are pulled out out and given their own enable flags. The makes all the
feature control more regular and understandable.
In continuous assign expressions, the abs() operator can't easily be
burried in generic unary handling, so add the IVL_LPM_ABS type and
generate it as needed.
1364-2001 does not allow a replication count of zero, but
1364-2005 allows them when the replication is enclosed in
a concatenation with other valid bits. This patch adds
code to perform these checks for procedural expressions.
Because of the NetNet object must have a width greater
than zero a replication used in a continuous assignment
can never have a count of zero.
This patch fixes the elaboration of parameters in a continuous
assignment to only pad the constants to their defined width.
Previously they were padded to the l-value width which resulted
in a vvp runtime error. This appears to be because the width
for padding is the defined width, but the constant is printed
using its internal width which previously could be larger than
its defined width.
These constants are local nets so I added that flag as well.
Parameters with vector descriptions that are not zero based and
are used in net contexts should generate the properly ranged
temporary signals. This causes subsequent part selects to work
out properly.
Binary bit based operators were not padding arguments if they had
different widths. The reduction operators and ! were not correctly
evaluating their arguments in a self-determined context.
This patch only applies to the ternary operator when used in a
continuous assignment. It adds short circuiting when the expression
is a constant true or false. It does not optimize the special case of
a constant 'bx expression with constant T/F expressions.
If implicit nets are declared during elaboration, then the success
of binding during elaboration will depend on the order of the code
in the source file.
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).
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.
This patch adds the power operator for signed bit based values
in a continuous assignment. It also fixes a few other power
expression width problems. The expression width is still not
calculated correctly, since the correct method can produce huge
possible bit widths. The result is currently limited to the width
of the native long. This is because lround() is used to convert
from a double to an integer. A check in the code generator protects
the runtime from this limitation.
Martin Whitaker
Stephen Williams
Cary R
Martin Whitaker
Larry Doolittle