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.
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.
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.
The intention was that all subclasses of AstNode which are
intermediate must be abstract as well and called AstNode*. This was
violated recently by 28b9db1903. This
patch restores that property by:
- Renaming AstFile to AstNodeFile
- Introducing AstNodeSimpleText as the common base of AstText and
AstTextBlock, rather than AstTextBlock deriving from AstText.
In the generated Makefile the linker output is piped through c++filt
which was very useful for older linkers. But unfortunately the status
code is lost during the piping. So when the make process is embedded
in a larger setup a failure will not manifest to the outside flow.
As modern linkers do the job of c++filt, this removes it from the
generated Makefile. It will also produce a proper status code then.
Signed-off-by: Wilson Snyder <wsnyder@wsnyder.org>
