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).
- Allow arbitrary number of open array dimensions, not just 3. Note
right now this only works with the array querying functions specified
in IEEE 1800-2017 H.12.2
- Issue error when passing dynamic array or queue as DPI open array
(currently unsupported)
- Also tweaked AstVar::vlArgTypeRecurse, which should now error or fail
for unsupported types.
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".
This looks like a bits/bytes bug. The affected m_codeInc member
determines how many 32-bit words to allocate in a buffer used to store
previous values of the signal, but this was off by a factor of 8, so
we used to use too much memory.
SweRV VCD tracing speed +6.5% (excluding IO, clang 6.0), due mainly to
reduced D cache misses.
Wilson Snyder
Maciej Sobkowski
Maarten De Braekeleer
Geza Lore
Stephen Henry
Yossi Nivin