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().
- The case expression and case item expressions are extended to the
maximum width among them, and are only interpreted as signed if all of
them are signed
- Add overall width and sign detection for AST_CASE
- Add sign argument to genWidthRTLIL helper
- Coverage for both const and non-const case statements
* xilinx: add SCC test for DSP48E1
* xilinx: Gate DSP48E1 being a whitebox behind ALLOW_WHITEBOX_DSP48E1
Have a test that checks it works through ABC9 when enabled
* abc9 to break SCCs using $__ABC9_SCC_BREAKER module
* Add test
* abc9_ops: remove refs to (* abc9_keep *) on wires
* abc9_ops: do not bypass cells in an SCC
* Add myself to CODEOWNERS for abc9*
* Fix compile
* abc9_ops: run -prep_hier before scc
* Fix tests
* Remove bug reference pending fix
* abc9: fix for -prep_hier -dff
* xaiger: restore PI handling
* abc9_ops: -prep_xaiger sigmap
* abc9_ops: -mark_scc -> -break_scc
* abc9: eliminate hard-coded abc9.box from tests
Also tidy up
* Address review
Calling log_signal is problematic for several reasons:
- with recent changes, empty string is serialized as { }, which violates
the "no spaces in IdString" rule
- the type (plain / real / signed / string) is dropped, wrongly conflating
functionally different values and potentially introducing a subtle
elaboration bug
Instead, use a custom simple serialization scheme.
This breaks the ability to use a global typename as a standard
identifier in a subsequent input file. This is otherwise backwards
compatible, including for sources which previously included conflicting
typedefs in each input file.
From IEEE1364-2005, section 7.3 buf and not gates:
> These two logic gates shall have one input and one or more outputs.
> The last terminal in the terminal list shall connect to the input of the
> logic gate, and the other terminals shall connect to the outputs of
> the logic gate.
yosys does not follow this and instead interprets the first argument as
the output, the second as the input and ignores the rest.