Inlining used to set some VarRefs to point to new Var nodes, without
updating the dtype of the VarRef to the dtype of the new Var.
AstNode::sameTree does identity comparison on the dtype, so some trees
that were semantically the same did not compare as such with sameTree
because of the dtype. This in turn results in some missed opportunities
for combining equivalent SenTree sensitivities when the clock came from
outside.
The main goal of this patch is to enable splitting the full and
incremental tracing functions into multiple functions, which can then be
run in parallel at a later stage. It also simplifies further
experimentation as all of the interesting trace code construction now
happens in V3Trace. No functional change is intended by this patch, but
there are some implementation changes in the generated code.
Highlights:
- Pass symbol table directly to trace callbacks for simplicity.
- A new traceRegister function is generated which adds each trace
function as an individual callback, which means we can have multiple
callbacks for each trace function type.
- A new traceCleanup function is generated which clears the activity
flags, as the trace callbacks might be implemented as multiple functions.
- Re-worked sub-function handling so there is no separate sub-function
for each trace activity class. Sub-functions are generate when required
by splitting.
- traceFull/traceChg are now created in V3Trace rather than V3TraceDecl,
this requires carrying the trace value tree in TraceDecl until it
reaches V3Trace where the TraceInc nodes are created (previously a
TraceInc was also created in V3TraceDecl which carries the value).
Includes `timescale, $printtimescale, $timeformat.
VL_TIME_MULTIPLIER, VL_TIME_PRECISION, VL_TIME_UNIT have been removed
and the time precision must now match the SystemC time precision.
To get closer behavior to older versions, use e.g. --timescale-override
"1ps/1ps".
Replace the virtual type() method on AstNode with a non-virtual, inlined
accessor to a const member variable m_type. This means that in order to be
able to use this for type testing, it needs to be initialized based on the
final type of the node. This is achieved by passing the relevant AstType
value back through the constructor call chain. Most of the boilerplate
involved is auto generated by first feeding V3AstNodes.h through astgen to
get V3AstNodes__gen.h, which is then included in V3Ast.h. No client code
needs to be aware and there is no functional change intended.
Eliminating the virtual function call to fetch the node type identifier
results in measured compilation speed improvement of 5-10% as it
eliminates up to 20% of all mispredicted branches from the execution.
dynamic_cast can have large run-time cost, so here we implement type
tests for AstNode instances by checking the unique type() property, which
in turn is a constant generated by astgen. For leaf types in the AstNode
type hierarchy, this is a simple equality check. To handle intermediate
types, we generate the type ids of leaf types in a pre-order traversal of
the type hierarchy. This yields contiguous ranges of ids for sub-type
trees, which means we can check membership of a non-leaf type via 2
comparisons against a low and high id. This single patch makes Verilator
itself 6-13% faster (depending on which optimizations are enabled) on a
large design of over 250k lines of Verilog.
* Add more directives to configuration files
Allow to set the same directives in configuration files that can also
be set by comment attributes (such as /* verilator public */ etc).
* Add support for lint messsage waivers
Add configuration file switch '-match' for lint_off. It takes a string
with wildcards allowed and warnings will be matched against it (if
rule and file also match). If it matches, the warning is waived.
Fixes#1649 and #1514Closes#2072
Wilson Snyder
Yutetsu TAKATSUKASA
Geza Lore
Yossi Nivin
Stefan Wallentowitz
Todd Strader