tree-ssa performance

[Gerald Pfeifer]

On Tue, 10 Jun 2003 law@redhat.com wrote:
> Our handling of EH is far from optimal from a compile-time performance
> standpoint due to how we handle cleanups.  I've got a patch here which
> addresses that problem, but it's queued behind a couple other things
> I have to nail down.

To give you some motivation to push it to the head of the queue...

> Changing the #if 0 around "skip-cleanups = 0" in tree-cfg.c to an #if 1
> should give folks an idea of whether or not my pending patch will help
> (though don't try to use such a compiler for real work :-)  Gerald, if
> you could try that, it would be helpful.

...here you are some results of today's tree-ssa branch without and with
this change for the testcase from PR8361. :-)

  -O0
       37.25
       35.39
  -O1
       98.32
       95.25
  -O2
      160.24
      119.83
  -O3
      162.72
      126.49

(Timings may be a bit inaccurate, but the trend is quite clear, especially
for -O2 and -O3!)

Gerald

PS: I strongly recommend http://gcc.gnu.org/PR8361 for regular use in
assessing your improvements.