This patch makes OpenTitan verilation with --debug-check 22% faster, and
the same with --debug --no-dump-tree 91% faster. Functionality is the
same (including when VL_LEAK_CHECKS is defined), except V3Broken can now
always find duplicate references via child/next pointers if the target
node is not `maybePointedTo()` (previously this only happened when
compiled with VL_LEAK_CHECKS). The main change relates to storing the
v3Broken traversal state in the AstNode by stealing a byte from what
used to be unused flags. We retain an unordered_set only for marking
pointers as valid to be referenced via a non-child/non-next member
pointer.
Do not sort and hoist function local variables to the top of the
function definition. The stack layout of automatic variables is not
defined by C so the compilers can lay these out optimally. Simplifies
internals for follow on work. Effect on model performance is neutral to
very slight improvement, so we do not seem to be loosing anything.
V3Broken now checks that AstVar nodes referenced in an AstCFunc are
either external, or appear in the tree before the reference, and are in
scope.
Fix V3Begin to move lifted AstVars to beginning of FTask, rather than
end, which trips the above check.
debug() declared by VL_DEGUB_FUNC used to cache the result of the debug
level lookup (which depends on options) in a static. This meant that if
the debug() function was called before option parsing, the default debug
level of 0 would be used for the rest of the program, even if a --debug
option was given. Fixed by not caching the debug level until after
option parsing is complete.
The bool AstNode flags fit in a padding gap after m_type. This reduces
memory consumption by about 2% on OpenTitan. Initializing the unused
bits in the flags then avoids a read-modify-write in the constructor
(replacing it with a store constant). Overall verilation speed is about
1% faster.
The -G option now correctly parses simple integer literals as signed
numbers, which is in line with the standard and is significant when
overriding parameters without a type specifier.
Fixes#3060
Remove magic code fragments form EmitCTrace, so Emit need not be aware
that a function is tracing related or not (apart from the purpose of
file name generation). All necessary code is now generated via text
nodes in V3TraceDecl and V3Trace. No functional change intended.
For consistency with the rest of the generated code, generated methods
related to tracing now use snake_case instead of camelCase. No
functional change intended.
* Move MTaskState to ThreadSchedule
MTaskState does not concern itself with sandbagging, and thus solely contains information related to the finalized schedule, i.e., completion time, thread ID and next MTask on thread.
* Add .dot graph visualization of ThreadSchedule
Follow-up to #2779.
This commit adds the creation of .dot files - used by GraphViz - to visualize how mtasks are statically scheduled across the set of specified threads.
We visualize each thread as a row, with nodes of a row being the mtasks scheduled for the given thread. The width of the mtask nodes are proportional to their cost. MTask dependencies are shown using an edge between the source and sink mtasks.
V3Simulate reuses allocated AstConst nodes for efficiency, however this
used to be implemented in a way that required a deep copy of a
std::unorderd_map<_, std::deque<_>>, which was quite inefficient when it
grew large. The free list is now managed without any copying. This takes
the V3Table pass from taking 12s to 0.2s on SweRV EH1.
Tests used to silently pass when vcddiff aborted. Now fixed. Updated
large array trace reference files for FST, added same reference files
for VCD.
Developers need to update their local vcddiff.
We incorrectly treated two different struct types the same when passed
as an actual parameter to a `parameter type` parameter in an instance,
if the actual parameter expression both hash to the same value and the
structs have the same struct name. This is now corrected.
Fixes#3055.
This commit adds the '--simbenchmark' option to the regression test compile command.
The option is not intended as a fully-fledged benchmarking infrastructure, but rather a
utility for easily generating cycle- and execution time information when executing a verilated test.
As an example use case, the included test file shows how optimization level is varied across
three different builds+simulations, with the statistics for each run output to the same file in
the output directory.
Future work:
- 'sim_time' in the generated top-level main file should be a parameter.
- Given the above, the test execution script from verilog-sim-benchmark can be integrated
to generate better estimates of cycles/second through varying 'sim_time' over multiple executions.
This patch implements #3032. Verilator creates a module representing the
SystemVerilog $root scope (V3LinkLevel::wrapTop). Until now, this was
called the "TOP" module, which also acted as the user instantiated model
class. Syms used to hold a pointer to this root module, but hold
instances of any submodule. This patch renames this root scope module
from "TOP" to "$root", and introduces a separate model class which is
now an interface class. As the root module is no longer the user
interface class, it can now be made an instance of Syms, just like any
other submodule. This allows absolute references into the root module to
avoid an additional pointer indirection resulting in a potential speedup
(about 1.5% on OpenTitan). The model class now also contains all non
design specific generated code (e.g.: eval loops, trace config, etc),
which additionally simplifies Verilator internals.
Please see the updated documentation for the model interface changes.
This commit removes shadowing of the vlSymsp member of the emitted
modules, allowing models to compile when -Werror=shadow is set. This may
be useful when i.e., an external project which defines its own error
flags depends on the verilated model.
Factored out bits from V3EmitC.cpp that is required to emit a whole
(non-trace) AstCFunc. This is mostly what used to be the EmitCStmts
class plus relevant bits from EmitCImp. These now live in EmitCFunc,
which is reusable by anything that needs to emit a regular AstCFunc
(differences in tracing to be addressed later). EmitCImp now extends
EmitCFunc instead of EmitCStmts. No functional change intended.
Moved these 2 function into V3EmitCBase so we can reuse them later.
emitVarDecl required minor alteration to move building of m_ctorVarsVec
back into V3EmitC (which is now done in V3EmitC::emitSortedVarList).
No functional change intended.
These are necessary to link the executables. So far we have been saved
by one of the generated headers forward declaring these functions with
extern "C", but changing that header would break these tests.
* Add a test to reproduce #3023. Also applied verilog-mode formatting.
* use unique_ptr. No functional change is intended.
* Introduce restorer that reverts changes during iterate() if failed.
This used to be done in the constructor of the top module, but there is
no reason to do it there. Internals are cleaner with this in the Sym
constructor. No functional change intended.
