[de] 2004-12-27 - On windows, there are at least two supported and
well-working build systems for tcl: [Building Tcl/Tk with Mingw]
or use the MS VC++ compiler (6.0 is known to work well, this wiki has
reports, that even the free VC++ 7.0 toolkit will work
[http://mini.net/tcl/11431]) and the platform specific makefile.vc,
which is included into the source distribution.

I build tcl8.4.9 on a w2k system, using:

   * VC++ 6.0 and makefile.vc
   * VC++ 6.0, msys and configure
   * mingw 3.1 (based on gcc 3.2.3), msys and configure

and tested that tclsh84 binaries with tclbench (from cvs,
2004-12-27). The over-all runtimes for the tclbench run was:

  VC++ 6.0/makefile.vc:   10:34 min
  VC++ 6.0/mys/configure: 13:28 min
  mingw/msys/configure:   11:41 min

The notable difference between the VC++ 6.0 with makefile.vc build
tclsh84 and the VC++ 6.0 with msys/configure build tclsh84 was
surprising. The reason for this was obviously, that configure picked
other build/linker options, than makefile.vc. After I've hand-edited
the configure created Makefile to use the same optimization options,
than makefile.vc, both VC++ 6.0 builds run equal fast, according to tclbench,
as expected. That results triggered a bug report
[http://sourceforge.net/tracker/index.php?func=detail&aid=1091967&group_id=10894&atid=110894]
and that triggered an update of the core build system, if you use VC++ 6.0 w/ configure.

While the default optimization level for gcc on unix some times ago
was cranked up from the for ages used -O to -O2, under windows the
default for gcc based builds at 8.4.9 is still -O. Bumping that up to
-02 sucked a bit more speed out of the mingw build. On the same box as
above, the over-all time for the tclbench run was 11:01.