[Freeciv-Dev] Re: [PATCH] Corecleanup_07Part2 has been put in incoming

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Mon, Sep 03, 2001 at 01:07:33AM +0200, Raimar Falke wrote:
> On Sun, Sep 02, 2001 at 11:43:32PM +0200, Gaute B Strokkenes wrote:
> > On Sun, 2 Sep 2001, hawk@xxxxxxxxxxxxxxxxxxxxxxx wrote:
> > > On Sun, Sep 02, 2001 at 07:58:15PM +0200, Gaute B Strokkenes wrote:
> > >> On Sun, 02 Sep 2001, gs234@xxxxxxxxx wrote:
> > >> 
> > >> Allow me to elaborate.  The above would be perfectly fine if we
> > >> inlined both mapstep() and normalize_map_pos().  As long as we
> > >> don't, the perfomance loss associated with tacking two function
> > >> calls on to half of the leaf functions in Freeciv is IMNSHO not
> > >> justifiable on the gounds that you can reduce the number of places
> > >> with topological knowledge in map.[ch] from ten to five.
> > > 
> > > In the long term I think we should/will have inline methods. I see
> > > no reason to not make the critical methods inline.
> > 
> > The concern that was raised the last time this came up was that inline
> > is not, strictly speaking, ISO C89 and also that current versions of
> > GCC expand inline functions at a fairly late stage in the compilation
> > process, so that optimization opportunities may be missed.
> > 
> > My own intuition is that just about all half-reasonable C compilers
> > support inline functions, and that we can live with real function
> > calls on the platforms that do not.  Also, GCC 3.0 and later has a
> > better inliner, and the penalty is not likely to be high.
> > 
> > I suggest that someone with the spare cycles tries to run a test game,
> > once with Jason's patch + inline normalize_map_pos() and once with no
> > changes at all.
> 
> work.clean == cvs
> work.adjust == map_adjust_[xy] as inline method
> work.get_city == map_get_city as inline method
> work.normalize == normalize_map_pos as inline method
> 
> $ size work.*/server/civserver
>    text    data     bss     dec     hex filename
>  562607   14736  607200 1184543  12131f work.adjust/server/civserver
>  563935   14736  607200 1185871  12184f work.clean/server/civserver
>  573407   14736  607200 1195343  123d4f work.get_city/server/civserver
>  569295   14736  607200 1191231  122d3f work.normalize/server/civserver
>  564031   14768  607200 1185999  1218cf work.sno/server/civserver
> 
> Normal compile flags plus "-Winline" was used.
> 
> Timing results were obtained by:
> -------------
> #!/bin/sh
> 
> cat >profile.rc <<EOF
> set randseed 42       # repeat a particular game (random) sequence
> set seed 42           # repeat a particular map generation sequence
> set timeout -1          # run a server only autogame
> set aifill 7            # fill to 7 players
> set endyear 500
> hard                    # make the AI do complex things
> create Caesar           # first player (with known name) created and
>                         # toggled to AI mode
> start
> EOF
> 
> for i in a b c d e f g
> do
>     time ./ser -r profile.rc >out.run_$i
> done 2>&1 |
> grep user >user_times
> -------------
> 
> Results:
> 
> work.clean == cvs
> user  1m15.020s
> user  1m15.380s
> user  1m15.330s
> user  1m15.430s
> user  1m16.800s
> user  1m17.000s
> user  1m16.660s

average: 75.95s

> work.adjust == map_adjust_[xy] as inline method
> user  1m15.100s
> user  1m14.900s
> user  1m15.230s
> user  1m15.700s
> user  1m15.370s
> user  1m15.500s
> user  1m15.480s

average: 75.33s == -0.8%

Inline methods are equal to macros.

> work.get_city == map_get_city as inline method
> user  1m15.680s
> user  1m15.900s
> user  1m15.980s
> user  1m16.070s
> user  1m16.110s
> user  1m16.160s
> user  1m16.170s

average: 76.01s == +0.08%

map_get_city doesn't benefit from inline method.

> work.normalize == normalize_map_pos as inline method
> user  1m14.560s
> user  1m14.750s
> user  1m14.410s
> user  1m14.350s
> user  1m14.590s
> user  1m15.040s
> user  1m16.060s

average: 74.82s == -1.5%

normalize_map_pos benefits very small from inline method.

        Raimar

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