What previously used to be per module static constants created in
V3Table and V3Prelim are now merged globally within the whole model and
emitted as part of a separate constant pool. Members of the constant
pool are global variables which are declared lazily when used (similar to
loose methods).
Using the standard model Makefile, when in addition to an explicit
target, the target 'ccache-report' is also given, a summary of ccache
hits/misses during this invocation of 'make' will be prited at the end
of the build.
** Add simulation context (VerilatedContext) to allow multiple fully independent
models to be in the same process. Please see the updated examples.
** Add context->time() and context->timeInc() API calls, to set simulation time.
These now are recommended in place of the legacy sc_time_stamp().
This allows compiling the run-time library with optimization even when OPT_FAST is not used in order to imporove model build speed, possibly during debug cycles.
This adds the flag --generate-waivefile <filename>. This will generate
a verilator config file with the proper lint_off statemens to turn off
warnings emitted during this particular run.
This feature can be used to start with using Verilator as linter and
systematically capture all known lint warning for further
elimination. It hopefully helps people turning of -Wno-fatal or
-Wno-lint and gradually improve their code base.
Signed-off-by: Stefan Wallentowitz <stefan.wallentowitz@hm.edu>
--output-split is now on by default with value 20000.
--output-split-cfuncs and --output-split-ctrace now defaults to the
value of --output-split unless explicitly specified.
Instead of __ALLfast.cpp and __ALLslow.cpp, we now create only a single
__ALL.cpp and compile it with OPT_FAST, this speeds up small builds
where the C compiler does not dominate. A separate patch will follow
turning VM_PARALLEL_BUILDS on by default at a certain size.
Given this change to the build there is now no point in emitting both
fast and slow routines into the same .cpp file when --output-split is
not set as they will be just included in the same __ALL.cpp file. To
keep things simpler and the output easier to comprehend, V3EmitC has
also been changed to always emit the fast and slow files separately.
Also change verilated.mk to apply OPT_SLOW to all slow files, not just
ones called *__Slow.cpp. This change in particular ensures __Syms.cpp
is build as slow.
Part of #2360.
- Issue an error when --build is used together with --make
- When given --build, always use GNU Make to perform the build
- Update documentation (examples were good as they were)
- Remove the broken t_flag_build_cmake test
Fixes#2280
The --trace-threads option can now be used to perform tracing on a
thread separate from the main thread when using VCD tracing (with
--trace-threads 1). For FST tracing --trace-threads can be 1 or 2, and
--trace-fst --trace-threads 1 is the same a what --trace-fst-threads
used to be (which is now deprecated).
Performance numbers on SweRV EH1 CoreMark, clang 6.0.0, Intel i7-3770 @
3.40GHz, IO to ramdisk, with numactl set to schedule threads on different
physical cores. Relative speedup:
--trace -> --trace --trace-threads 1 +22%
--trace-fst -> --trace-fst --trace-threads 1 +38% (as --trace-fst-thread)
--trace-fst -> --trace-fst --trace-threads 2 +93%
Speed relative to --trace with no threaded tracing:
--trace 1.00 x
--trace --trace-threads 1 0.82 x
--trace-fst 1.79 x
--trace-fst --trace-threads 1 1.23 x
--trace-fst --trace-threads 2 0.87 x
This means FST tracing with 2 extra threads is now faster than single
threaded VCD tracing, and is on par with threaded VCD tracing. You do
pay for it in total compute though as --trace-fst --trace-threads 2 uses
about 240% CPU vs 150% for --trace-fst --trace-threads 1, and 155% for
--trace --trace threads 1. Still for interactive use it should be
helpful with large designs.
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".
* Improve tracing performance.
Various tactics used to improve performance of both VCD and FST tracing:
- Both: Change tracing functions to templates to take variable widths as
template parameters. For VCD, subsequently specialize these to the
values used by Verilator. This avoids redundant instructions and hard
to predict branches.
- Both: Check for value changes via direct pointer access into the
previous signal value buffer. This eliminates a lot of simple pointer
arithmetic instructions form the tracing code.
- Both: Verilator provides clean input, no need to mask out used bits.
- VCD: pre-compute identifier codes and use memory copy instead of
re-computing them every time a code is emitted. This saves a lot of
instructions and hard to predict branches. The added D-cache misses
are cheaper than the removed branches/instructions.
- VCD: re-write the routines emitting the changes to be more efficient.
- FST: Use previous signal value buffer the same way as the VCD tracing
code, and only call the FST API when a change is detected.
Performance as measured on SweRV EH1, with the pre-canned CoreMark
benchmark running from DCCM/ICCM, clang 6.0.0, Intel i7-3770 @ 3.40GHz,
and IO to ramdisk:
+--------------+---------------+----------------------+
| VCD | FST | FST separate thread |
| (--trace) | (--trace-fst) | (--trace-fst-thread) |
------------+-----------------------------------------------------+
Before | 30.2 s | 121.1 s | 69.8 s |
============+==============+===============+======================+
After | 24.7 s | 45.7 s | 32.4 s |
------------+--------------+---------------+----------------------+
Speedup | 22 % | 256 % | 215 % |
------------+--------------+---------------+----------------------+
Rel. to VCD | 1 x | 1.85 x | 1.31 x |
------------+--------------+---------------+----------------------+
In addition, FST trace size for the above reduced by 48%.
When using the __ALL*.cpp based single compile mode (i.e.: without
VM_PARALLEL_BUILDS), the fast path tracing code used to be included in
__Allsup.cpp, which was compiled with OPT_SLOW, severely harming tracing
performance. We now have __ALLfast.cpp and __ALLslow.cpp instead of
__ALLcls.cpp and __ALLsup.cpp, so we can compile the fast support code
with OPT_FAST as well.
* Add +verilator+noassert flag
This allows to disable the assert check per simulation argument.
* Add AssertOn check for assert
Insert the check AssertOn to allow disabling of asserts.
Asserts can be disabled by not using the `--assert` flag or by calling
`AssertOn(false)`, or passing the "+verilator+noassert" runtime flag.
Add tests for this behavior.
Bad tests check that the assert still causes a stop.
Non bad tests check that asserts are properly disabled and cause no stop
of the simulation.
Fixes#2162.
Signed-off-by: Tobias Wölfel <tobias.woelfel@mailbox.org>
* Correct file location
Signed-off-by: Tobias Wölfel <tobias.woelfel@mailbox.org>
* Add description for single test execution
Without this description it is not obvious how to run a single test from
the regression test suite.
Signed-off-by: Tobias Wölfel <tobias.woelfel@mailbox.org>
* Add detailed location to XML output
* Fixing build failures
* less cryptic regulary expressions
* correcting typo in test
* Adding file letter to the location attribute, and cleaning up the regular expression in the tests.
* Add remaining test expected output files for XML changes
* spacing fix, adding documentation on changes
* 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
