- Simplify synthetic localparams for normal calls to update their width
- This step was inadvertently removed alongside `added_mod_children`
- Support redeclaration of constant function arguments
- `eval_const_function` never correctly handled this, but the issue
was not exposed in the existing tests until the recent change to
always attempt constant function evaluation when all-const args
are used
- Check asserts in const_arg_loop and const_func tests
- Add coverage for width mismatch error cases
This adds a mechanism for marking certain portions of elaboration as
occurring within unevaluated ternary branches. To enable elaboration of
the overall ternary, this also adds width detection for these
unelaborated function calls.
This fixes binding signed memory reads, signed unary expressions, and
signed complex SigSpecs to ports. This also sets `is_signed` for wires
generated from signed params when -pwires is used. Though not necessary
for any of the current usages, `is_signed` is now appropriately set when
the `extendWidth` helper is used.
This change set contains a number of bug fixes and improvements related to
scoping and resolution in generate and procedural blocks. While many of the
frontend changes are interdependent, it may be possible bring the techmap
changes in under a separate PR.
Declarations within unnamed generate blocks previously encountered issues
because the data declarations were left un-prefixed, breaking proper scoping.
The LRM outlines behavior for generating names for unnamed generate blocks. The
original goal was to add this implicit labelling, but doing so exposed a number
of issues downstream. Additional testing highlighted other closely related scope
resolution issues, which have been fixed. This change also adds support for
block item declarations within unnamed blocks in SystemVerilog mode.
1. Unlabled generate blocks are now implicitly named according to the LRM in
`label_genblks`, which is invoked at the beginning of module elaboration
2. The Verilog parser no longer wraps explicitly named generate blocks in a
synthetic unnamed generate block to avoid creating extra hierarchy levels
where they should not exist
3. The techmap phase now allows special control identifiers to be used outside
of the topmost scope, which is necessary because such wires and cells often
appear in unlabeled generate blocks, which now prefix the declarations within
4. Some techlibs required modifications because they relied on the previous
invalid scope resolution behavior
5. `expand_genblock` has been simplified, now only expanding the outermost
scope, completely deferring the inspection and elaboration of nested scopes;
names are now resolved by looking in the innermost scope and stepping outward
6. Loop variables now always become localparams during unrolling, allowing them
to be resolved and shadowed like any other identifier
7. Identifiers in synthetic function call scopes are now prefixed and resolved
in largely the same manner as other blocks
before: `$func$\func_01$tests/simple/scopes.blk.v:60$5$\blk\x`
after: `\func_01$func$tests/simple/scopes.v:60$5.blk.x`
8. Support identifiers referencing a local generate scope nested more
than 1 level deep, i.e. `B.C.x` while within generate scope `A`, or using a
prefix of a current or parent scope, i.e. `B.C.D.x` while in `A.B`, `A.B.C`,
or `A.B.C.D`
9. Variables can now be declared within unnamed blocks in SystemVerilog mode
Addresses the following issues: 656, 2423, 2493
The changes in #2476 ensured that function inputs like `input x;`
retained their single-bit size when instantiated with a constant
argument and turned into a localparam. That change did not handle the
possibility for an input to be redeclared later on with an explicit
width, such as `integer x;`.
- Signed cell outputs are sign extended when bound to larger wires
- Signed connections are sign extended when bound to larger cell inputs
- Sign extension is performed in hierarchy and flatten phases
- genrtlil indirects signed constants through signed wires
- Other phases producing RTLIL may need to be updated to preserve
signedness information
- Resolves#1418
- Resolves#2265
Before this fix, equiv_induct only assumed that one of the following is
true:
- defined value of A is equal to defined value of B
- A is undefined
This lets through valuations where A is defined, B is undefined, and
the defined (meaningless) value of B happens to match the defined value
of A. Instead, tighten this up to OR of the following:
- defined value of A is equal to defined value of B, and B is not
undefined
- A is undefined
This patch should support things like
`define foo(a, b = 3, c) a+b+c
`foo(1, ,2)
which will evaluate to 1+3+2. It also spots mistakes like
`foo(1)
(the 3rd argument doesn't have a default value, so a call site is
required to set it).
Most of the patch is a simple parser for the format in preproc.cc, but
I've also taken the opportunity to wrap up the "name -> definition"
map in a type, rather than use multiple std::map's.
Since this type needs to be visible to code that touches defines, I've
pulled it (and the frontend_verilog_preproc declaration) out into a
new file at frontends/verilog/preproc.h and included that where
necessary.
Finally, the patch adds a few tests in tests/various to check that we
are parsing everything correctly.
Claire Xenia Wolf
Lofty
Kamil Rakoczy
Eddie Hung
gatecat
Michael Singer
whitequark
Zachary Snow
Claire Xen
Xiretza
Marcelina Kościelnicka
diego
Alberto Gonzalez
Claire Wolf
David Shah
Rupert Swarbrick
Miodrag Milanović
Marcus Comstedt