I've done some experiments with inlining this morning. First I blindly
removed all of the inline keywords from all JSBSim headers, then
compiled with -O2 -fno-default-inline. For the c172 in a 300 sim second
run of steady-level flight following a trim, this required right at 3
seconds.
The same
Tony Peden writes:
Also, I was able to better quantify the performance change due to
incorporating the properties code. Prior to this, I had done speed
comparisons with the profiling code compiled in, but now I'm not so sure
that's fair. So:
pre-props: 1.3 seconds average
The other possibility is that the new multi-FDM stubs are slowing
things down, but that seems unlikely.
There's very little there that's being used - and nothing being used unless
it's defined in the config file as a multi-body sim.
Jon
___
On Sat, 2002-03-23 at 06:26, David Megginson wrote:
Tony Peden writes:
Also, I was able to better quantify the performance change due to
incorporating the properties code. Prior to this, I had done speed
comparisons with the profiling code compiled in, but now I'm not so sure
Tony Peden writes:
What property-related methods show up
near the top in the profiling?
SGPropertyNode::getDoubleValue()
This makes perfect sense, because it's called in place of
FGState::GetParameter which used to be the big hitter.
I had been thinking about eliminating tying
On Sat, 2002-03-23 at 07:02, David Megginson wrote:
Tony Peden writes:
What property-related methods show up
near the top in the profiling?
SGPropertyNode::getDoubleValue()
This makes perfect sense, because it's called in place of
FGState::GetParameter which used to be
Tony Peden writes:
This seems very attractive, but it also seems to break the OO. My
personal feeling is that it would be better to chase JSBSim design
improvements and live with the cost of tieing to object methods.
Sounds fair -- that's the kind of approach I've learned to appreciate
Tony Peden wrote:
I've done some experiments with inlining this morning. First I
blindly removed all of the inline keywords from all JSBSim headers,
then compiled with -O2 -fno-default-inline. For the c172 in a 300 sim
second run of steady-level flight following a trim, this required
How about compile time? I've been meaning to bug you about this. :)
The new version of FGState.cpp, as checked in a few days ago, takes
five (!) minutes to build on my machine. Yikes. The whole of JSBSim
is running well over 15 minutes of compile time now. Turning off
optimization, or
Jon S. Berndt wrote:
Andy Ross wrote:
Is it possible that the JSBSim from CVS builds without
optimization and that therefore the core developers aren't aware
how slow things are for those building from the FlightGear tree?
This is really hard to believe. On my machine (which is a
Try the version in FlightGear, not the standalone one. I think my
theory about you guys having optimization disabled is sounding more
correct. The one that gets built out of FlightGear's CVS uses the
standard -O2 flag, and is dog slow.
OK, I ran a test using the -O2 setting just to see
* Norman Vine -- Friday 22 March 2002 13:58:
Melchior FRANZ writes:
[...] because the plib developers don't seem to be keen to fix it.
Hey that's completely unfair !
OK, it =was= completely unfair, indeed. Well, Steve was actually not
keen to fix it (waste of time), but Sebastian pushed it
On Sat, 2002-03-23 at 12:17, Jon Berndt wrote:
Try the version in FlightGear, not the standalone one. I think my
theory about you guys having optimization disabled is sounding more
correct. The one that gets built out of FlightGear's CVS uses the
standard -O2 flag, and is dog slow.
Tony Peden wrote:
Jon S. Berndt wrote:
With optimization turned on as described above I got a build time (total
rebuild) of 3 minutes 30 seconds. So, in my case it didn't quite double.
Thanks for the heads-up.
Tony, what do you see on your machine?
[tony@raptor
Tony -
Did you come up with any recommendations on what we should do
with inlining
given your test results?
Not really, I was just after trying to find out how much inlining is
worth to us.
It did look like we might benefit from un-inlining some of the tied
methods, though I have
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