- 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
Use SIMD intrinsics to render VCD traces.
I have measured 10-40% single threaded performance increase with VCD
tracing on SweRV EH1 and lowRISC Ibex using SSE2 intrinsics to render
the trace. Also helps a tiny bit with FST, but now almost all of the FST
overhead is in the FST library.
I have reworked the tracing routines to use more precisely sized
arguments. The nice thing about this is that the performance without the
intrinsics is pretty much the same as it was before, as we do at most 2x
as much work as necessary, but in exchange there are no data dependent
branches at all.
Convert trace buffer to 32-bit entries, rather than a union containing a
pointer type. Also tweaked trace entry layouts for a bit more
performance. This gains another 10% on SweRV EH1 CoreMark.
- Change templated trace routines to branch table.
Removed templating from trace chgBus and fullBus and replaced them with
a branch table like the other there is a very small (< 1%) penalty for
this on SwerRV EH1 CoreMark, but this is less than the variability of
disk IO so it's worth it to keep the code simpler and smaller.
- Prefetch VCD suffix buffer at the top of emit*
- Increase ILP in VCD emit* routines
- Use a 64-bit unaligned store to emit the VCD suffix (on x86 only)
The performance difference with these is very small, but the changes
hopefully make this code more performance-portable across various
micro-architectures.
VerilatedVcdC::openNext() failed to flush the tracing thread before
opening the next output file, which caused t_trace_cat.pl to fail
with --vltmt on occasion.
We used to include a .cpp file on the link line for the shared library,
which was ignored, but generated a .d file for the .so which contained
the header files required by the .cpp file. This then caused a rebuild
where we included the .d in verilated.mk to included in the .h headers
among the prerequisites of the .so, yielding a clang error about treating
.h files as c++-header rather than c-header... Long story short, we don't
do that anymore. This used t cause t_a4_examples to fail on occasion.
Note there is no need for a separate compilation rule for the
<--protect-lib>.cpp, as it will jsut pick up the standard OPT_FAST rule.
- Packaged SystemC lives in /usr so needed to update regex in test
driver
- Clang 10 complains about mixed named and positional initializers in
struct definitions.
Wilson Snyder
Tim Snyder
Geza Lore
John Demme
Peter Horvath
Qingyao Sun