Re: [tcljava-dev] Performance results for new TJC compiler

[Mo D. <md...@un...>]

Hello

I decided to try to get some "real world" numbers related to the TJC compiler.
What I did was to test how long the TJC compiler took to compile itself
and then compared that with how long a TJC compiled version of itself
took to compile itself. Just to make things even more interesting, I compared
those times to the amount of time it took to execute the TJC compiler in
the C version of Tcl which has an embedded compiler and byte code engine.
Here are the results.


C Tcl (Tcl byte code compiler)

$ time tjc -nocompile tjc.tjc
real    5m30s     (330 s)


Interpreted in Jacl (no compilation)

$ time tjc -nocompile tjc.tjc
real    21m17s    (1277 s)


TJC compiled in Jacl:

$ time tjc -nocompile tjc.tjc
real    2m42s     (162 s)


These results show that compiling with TJC lead to code
that executed 7.8 times faster. That is quite an improvement.
The TJC compiled Jacl version of this code even executes
about twice as fast as the same code running in the C version
of Tcl.

cheers
Mo DeJong

P.S.
I added support to the Makefile for a 2 stage build rule that
will recompile the TJC source with TJC. Just build the
normal way and then run "make install". After that, run
"make tjc2 tjc2.replace tjc.install" to 2 stage the compiler
and install the compiled versions of tjc.jar and tjcsrc.jar.
The numbers above show that this 2 stage will take
about 20 minutes to run the first time, but the compiler
will then execute about 8 times faster.