- Add support for assignments within expressions, e.g., `x[y++] = z;` or
`x = (y *= 2) - 1;`. The logic is handled entirely within the parser
by injecting statements into the current procedural block.
- Add support for pre-increment/decrement statements, which are
behaviorally equivalent to post-increment/decrement statements.
- Fix non-standard attribute position used for post-increment/decrement
statements.
We add a new flow graph node type, PRINT_SYNC, as they don't get handled
with regular CELL_EVALs. We could probably move this grouping out of
the dump method.
Removing some signed checks and logic where we've already guaranteed the
values to be positive. Indeed, in these cases, if a negative value got
through (per my realisation in the signed fuzz harness), it would cause
an infinite loop due to flooring division.
We need to invoke "read_verilog" manually, since the default action on
input files is to defer processing. Under such conditions, we never
simplify the AST, and initial $prints never execute.
If the `$ge` cell we are replacing has wide output port, the upper bits
on the port should be driven to zero. That's not what a `$not` cell with
a single-bit input does. Instead opt for a `$logic_not` cell, which does
zero-pad its output.
Fixes#3867.
Extend the aigmap.ys test with SAT-based comparison of the original
cells and their AIG implementations.
This tests both the usual cells and the single-bit Yosys gates.
Distinguish between the A, B input ports of `$_ANDNOT_`, `$_ORNOT_`
gates when considering those for sharing. Unlike the input ports of the
other supported single-bit gates, those are not interchangeable.
Fixes#3848.
genvar declaration cannot take an initial value when declared as a module_or_generate_item_declaration.
Correct this test so that it doesn't fail unexpectedly if Yosys aligns with the standard.
(* nowrshmsk *) on a struct / union variable now affects dynamic
bit slice assignments to members of the struct / union.
(* nowrshmsk *) can in some cases yield significant resource savings; the
combination of pipeline shifting and indexed writes is an example of this.
Constructs similar to the one below can benefit from (* nowrshmsk *), and
in addition it is no longer necessary to split out the shift assignments
on separate lines in order to avoid the error message "ERROR: incompatible
mix of lookahead and non-lookahead IDs in LHS expression."
always_ff @(posedge clk) begin
if (rotate) begin
{ v5, v4, v3, v2, v1, v0 } <= { v4, v3, v2, v1, v0, v5 };
if (res) begin
v0.bytes <= '0;
end else if (w) begin
v0.bytes[addr] <= data;
end
end
end
When the verilog frontend perfomed constant evaluation of unbased
unsized constants in a context-determined expression it did not properly
extend them by repeating the bit value. This only affected constant
evaluation and not constants that made it through unchanged to RTLIL.
The latter case was already covered by tests and working before.
This fixes the const-eval issue by checking the `is_unsized` flag in
bitsAsConst and extending the value accordingly.
The newly added test also tests the already working non-const-eval case
to highlight that both cases should behave the same.
The difference between void functions and tasks is that always_comb's
implicit sensitivity list behaves as if functions were inlined, but
ignores signals read only in tasks. This only matters for event based
simulation, and for synthesis we can treat a void function like a task.
This uses the same constant parsing for enum_values and for attributes
and extends it to handle signed values as those are used for enums that
implicitly use the int type.
Use `$finish(0)` to silently exit even when using recent iverlog
versions. Run `write_verilog -noexpr` before `write_verilog` as the
latter can modify the design.
This also enables checking the tests results, as xprop should be in a
state where the existing tests pass.
This brings the metadata for packed arrays in packed structs
in line with the metadata for unpacked arrays, and correctly
handles the case when both lsb and msb in an address range are
non-zero.
This is primarily intended to enable the standard-permitted use of
module-scoped identifiers to refer to tasks and non-constant functions.
As a side-effect, this also adds support for the non-standard use of
module-scoped identifiers referring to constant functions, a feature
that is supported in some other tools, including Iverilog.
The witness metadata was missing fine grained FFs completely and for
coarse grained FFs where the output connection has multiple chunks it
lacked the offset of the chunk within the SMT expression. This fixes
both, the later by adding an "smtoffset" field to the metadata.
This adds a native json based witness trace format. By having a common
format that includes everything we support, and providing a conversion
utility (yosys-witness) we no longer need to implement every format for
every tool that deals with witness traces, avoiding a quadratic
opportunity to introduce subtle bugs.
Included:
* smt2: New yosys-smt2-witness info lines containing full hierarchical
paths without lossy escaping.
* yosys-smtbmc --dump-yw trace.yw: Dump results in the new format.
* yosys-smtbmc --yw trace.yw: Read new format as constraints.
* yosys-witness: New tool to convert witness formats.
Currently this can only display traces in a human-readable-only
format and do a passthrough read/write of the new format.
* ywio.py: Small python lib for reading and writing the new format.
Used by yosys-smtbmc and yosys-witness to avoid duplication.
genrtlil.cc and simplify.cc had inconsistent and slightly broken
handling of signedness for array querying functions. These functions are
defined to return a signed result. Simplify always produced an unsigned
and genrtlil always a signed 32-bit result ignoring the context.
Includes tests for the the relvant edge cases for context dependent
conversions.
The previously generated logic assumed an unconstrained past value in
the initial state and did not handle 'x values. While the current formal
verification flow uses 2-valued logic, SVA value change expressions
require a past value of 'x during the initial state to behave in the
expected way (i.e. to consider both an initial 0 and an initial 1 as
$changed and an initial 1 as $rose and an initial 0 as $fell).
This patch now generates logic that at the same time
a) provides the expected behavior in a 2-valued logic setting, not
depending on any dont-care optimizations, and
b) properly handles 'x values in yosys simulation
For SVAs that have an explicit clock and are contained in a procedure
which conditionally executes the assertion, verific expresses this using
a mux with one input connected to constant 1 and the other output
connected to an SVA_AT. The existing code only handled the case where
the first input is connected to 1. This patch also handles the other
case.
The `-keepdc` option prevents merging flipflops with dont-care bits in
their initial value, as, in general, this is not a valid transform for
formal verification.
The keepdc option of `opt` is passed along to `opt_merge` now.
- Prevent unmatched expected error patterns from self-matching
- Prevent infinite recursion on unmatched expected warnings
- Always print the error message for unmatched error patterns
- Add test coverage for all unmatched message types
- Add test coverage for excess matched logs and warnings
Anlogic FPGAs all have two kinds of BRAMs, one is 9bit*1K when being
true dual port (or 18bit*512 when simple dual port), the other is
16bit*2K.
Supports mapping of these two kinds of BRAMs. 9Kbit BRAM in SDP mode and
32Kbit BRAM with 8bit width are not support yet.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
The preprocessor currently destroys double slash containing escaped
identifiers (for example \a//b ). This is due to next_token trying to
convert single line comments (//) into /* */ comments. This then leads
to an unintuitive error message like this:
ERROR: syntax error, unexpected '*'
This patch fixes the error by recognizing escaped identifiers and
returning them as single token. It also adds a testcase.
- Attempt to lookup a derived module if it potentially contains a port
connection with elaboration ambiguities
- Mark the cell if module has not yet been derived
- This can be extended to implement automatic hierarchical port
connections in a future change
- FfData now keeps track of the module and underlying cell, if any (so
calling emit on FfData created from a cell will replace the existing cell)
- FfData implementation is split off to its own .cc file for faster
compilation
- the "flip FF data sense by inserting inverters in front and after"
functionality that zinit uses is moved onto FfData class and beefed up
to have dffsr support, to support more use cases
This enables the usage of declarations of wand or wor with a base type
of logic, integer, or a typename. Note that declarations of nets with
2-state base types is still permitted, in violation of the spec.
- Root AST_PREFIX nodes are now subject to genblk expansion to allow
them to refer to a locally-visible generate block
- Part selects on AST_PREFIX member leafs can now refer to generate
block items (previously would not resolve and raise an error)
- Add source location information to AST_PREFIX nodes
This is accomplished by generating a unique name for the genvar,
renaming references to the genvar only in the loop's initialization,
guard, and incrementation, and finally adding a localparam inside the
loop body with the original name so that the genvar can be shadowed as
expected.
Previously, opt_clean would reconnect all ports (including FF Q ports)
to a "canonical" SigBit chosen by complex rules, but would leave the
init attribute on the old wire. This change applies the same
canonicalization rules to the init attributes, ensuring that init moves
to wherever the Q port moved.
Part of another jab at #2920.
- User-defined types must be data types. Using a net type (e.g. wire) is
a syntax error.
- User-defined types without a net type are always variables (i.e.
logic).
- Nets and variables can now be explicitly declared using user-defined
types:
typedef logic [1:0] W;
wire W w;
typedef logic [1:0] V;
var V v;
Fixes#2846
These parts keep rereading a Verilog module, then using chparam
to test it with various parameter combinations. Since the default
parameters are on the large side, this spends a lot of time
needlessly elaborating the default parametrization that will then
be discarded. Fix it with -deref and manual hierarchy call.
Shaves 30s off the test time on my machine.
If width of a case expression was large, explicit patterns could cause
the existing logic to take an extremely long time, or exhaust the
maximum size of the underlying set. For cases where all of the patterns
are fully defined and there are no constants in the case expression,
this change uses a simple set to track which patterns have been seen.
This adds one simple piece of functionality to opt_expr: when a cell
port is connected to a fully-constant signal (as determined by sigmap),
the port is reconnected directly to the constant value. This is just
enough optimization to fix the "non-constant $meminit input" problem
without requiring a full opt_clean or a separate pass.
This doesn't do anything useful yet: the patch just adds support for
the syntax to the lexer and parser and adds some tests to check the
syntax parses properly. This generates AST nodes, but doesn't yet
generate RTLIL.
Since our existing hierarchical_identifier parser doesn't allow bit
selects (so you can't do something like foo[1].bar[2].baz), I've also
not added support for a trailing bit select (the "constant_bit_select"
non-terminal in "bind_target_instance" in the spec). If we turn out to
need this in future, we'll want to augment hierarchical_identifier and
its other users too.
Note that you can't easily use the BNF from the spec:
bind_directive ::=
"bind" bind_target_scope [ : bind_target_instance_list]
bind_instantiation ;
| "bind" bind_target_instance bind_instantiation ;
even if you fix the lookahead problem, because code like this matches
both branches in the BNF:
bind a b b_i (.*);
The problem is that 'a' could either be a module name or a degenerate
hierarchical reference. This seems to be a genuine syntactic
ambiguity, which the spec resolves (p739) by saying that we have to
wait until resolution time (the hierarchy pass) and take whatever is
defined, treating 'a' as an instance name if it names both an instance
and a module.
To keep the parser simple, it currently accepts this invalid syntax:
bind a.b : c d e (.*);
This is invalid because we're in the first branch of the BNF above, so
the "a.b" term should match bind_target_scope: a module or interface
identifier, not an arbitrary hierarchical identifier.
This will fail in the hierarchy pass (when it's implemented in a
future patch).
- disallow [gen]blocks with an end label but not begin label
- check validity of module end label
- fix memory leak of package name and end label
- fix memory leak of module end label
The recent fix for case expression width detection causes the width of
the expressions to be queried before they are simplified. Because the
logic supporting module scope identifiers only existed in simplify,
looking them up would fail during width detection. This moves the logic
to a common helper used in both simplify() and detectSignWidthWorker().
Martin Povišer
Zachary Snow
andyfox-rushc
Miodrag Milanovic
Asherah Connor
Charlotte
Charlotte
whitequark
N. Engelhardt
Dag Lem
Jannis Harder
Eddie Hung
Lofty
CORRADI Quentin
Muthiah Annamalai (முத்து அண்ணாமலை)
Muthu Annamalai
Muthu Annamalai
Ralf Fuest
Benjamin Barzen
gatecat
KrystalDelusion
Lloyd Parkes
Claire Xenia Wolf
Archie
George Rennie
Jacob Lifshay
Marcelina Kościelnicka
Kamil Rakoczy
Icenowy Zheng
Thomas Sailer
Patrick Urban
Pepijn de Vos
Brett Witherspoon
Rupert Swarbrick