Recognize "decoder" case statements (where every case item only assigns
constants to a fixed set of left-hand sides) and replace them with a
single packed constant lookup table indexed by the case expression.
Small tables are materialized inline in the generated code, and are
always optimized. Larger ones are placed in the constant pool and only
optimized if deemed beneficial over branches.
While this slightly conflicts with V3Table, and is not worth that much
on it's own, there will be a follow up patch that converts more cases of
this form which will be much more valuable. This patch does the
necessary analysis and the simple table conversion when possible.
Split -fcase into -fcase-table (this new conversion) and -fcase-tree (the
existing bitwise branch-tree conversion); -fno-case is now an alias for
both.
Default branches, assignments preceding the case (used as default values),
casez wildcards, multiple and partial left-hand sides, and both blocking and
non-blocking assignments are handled. Cases that cannot be safely tabled (e.g.
non-exhaustive with no default, overlapping writes to one variable, or mixed
blocking/non-blocking assignments) fall back to the existing if/else lowering.
Consequently disabled re-inlining of constant pool variables in V3Const,
and rebuild the constant pool hash in V3Dead (previously we didn't
create constant pool entries early enough for this to matter)
Introduce new pass that converts impure expressions, or those with
function and method calls into simple assignment statements. Please see
the blurb at the top of the file why this is useful and how it works.
In particular currently it enables more Dfg optimization as functions
will be inlined without AstExprStmt.
Ideally we should enforce this lowering is applied to every procedural
statement (there are still a handful of exceptions). With that, long
term with this pass + #6820, there should be no need to ever use an
AstExprStmt past this new lowering pass, which should enable more easier
optimization down the line.
Also ideally this should be run earlier. Currently it's after V3Tristate
as that calls pinReconnectSimple so we don't have to touch Cell ports.
Currently disabled when code coverage is enabled due to #7119.
Rename AstSelLoopVars to AstForeachHeader, and make it a non-NodeExpr.
Tweak parser to always create an AstForeachHeader, so no need to fix it
up later.
Added cppcheck-suppressions.txt in the repo root. You can add new
patterns in there instead of having to parse the XML output.
Also configure to add the -D__GNUC__ preprocessor macro, which makes it
understand UASSERT (it understands the 'noreturn' function attribute).
Added some case by case specific suppressions and fixed up other code,
especially in V3Ast*h and V3Dfg*.h, including code generated by astgen
that had some no-ops that irks cppcheck.
One thing it does not seem to like is `const` class members with default
initializers in the class. It will assume that's always the value, even
if overridden in the constructor. We had few so removed them.
With that a lot of files in `src/` are now clean or only have a handful
of issues. Therefore, I have also deleted cppcheck_filtered, and made it
produce human readable output straight to the terminal.
Regarding cleaning up the reported nits, I kind of got bored after
V3[A-E] so pausing here. Apologies for the merge conflicts.
Tested with cppcheck 2.13.0
- Rename `--dump-treei` option to `--dumpi-tree`, which itself is now a
special case of `--dumpi-<tag>` where tag can be a magic word, or a
filename
- Control dumping via static `dump*()` functions, analogous to `debug()`
- Make dumping independent of the value of `debug()` (so dumping always
works even without the debug flag)
- Add separate `--dumpi-graph` for dumping V3Graphs, which is again a
special case of `--dumpi-<tag>`
- Alias `--dump-<tag>` to `--dumpi-<tag> 3` as before