[MPlayer-dev-eng] [PATCH] CFLAGS cleanups

[Dominik 'Rathann' Mierzejewski]

On Friday, 13 January 2006 at 23:51, Dominik 'Rathann' Mierzejewski wrote:
> On Friday, 13 January 2006 at 23:41, Guillaume POIRIER wrote:
> > Hi,
> > 
> > On 1/13/06, Dominik 'Rathann' Mierzejewski <dominik at rangers.eu.org> wrote:
> > > This patch cleans up OPTFLAGS in Gui, removes hardcoded -Wall from
> > > libaf's and libmenu's Makefiles and -g from main Makefile.
> > > Now we can add -Wall to default CFLAGS and be sure it's used
> > > consistently.
> > 
> > Good idea! There's actually some more flags that are now stupid to put
> > by default, like fomit-frame-pointer (useless with AMD64 AKAIK).
> > 
> > I'll add this to my todo list.
> 
> I think somebody should run some benchmarks with different CFLAGS on
> various platforms and come up with the combination that produces the
> fastest binaries. ;)
> 
> But that's a lot of work:
> -O2 vs -O3

Ok, I did test the above on my Athlon:

for i in `seq 1 5`; do mplayer -benchmark -frames 1000 -fs -nosound \
file.mp4 | grep BENCHMARK >> mplayer-<arch>-<opt>-benchmark.log ; done

The results (average from 5 runs) are as follows:
$ benchavg.pl < mplayer-i386-O2-benchmark.log
5 results processed
average  VC is: 20.315s
average  VO is: 4.472s
average SYS is: 0.293s
average tot is: 25.079s
$ benchavg.pl < mplayer-i386-O3-benchmark.log
5 results processed
average  VC is: 19.692s
average  VO is: 4.382s
average SYS is: 0.280s
average tot is: 24.353s
$ benchavg.pl < mplayer-athlon-O2-benchmark.log
5 results processed
average  VC is: 19.650s
average  VO is: 4.493s
average SYS is: 0.284s
average tot is: 24.426s
$ benchavg.pl < mplayer-athlon-O3-benchmark.log
5 results processed
average  VC is: 19.451s
average  VO is: 4.387s
average SYS is: 0.278s
average tot is: 24.115s

i386 binary was compiled with runtime detection and -march=i386
-mtune=pentium4 (the default OPTFLAGS in Fedora). Yes, I know it's
a stupid default. -O3 is 3% faster in this case.
athlon binary was compiled with -march=athlon. -O3 is 1.3% faster.

Next up: more CFLAGS tests and new liba52 tests (any idea how to test it,
Diego?).

Good night and good luck,
R.

-- 
MPlayer RPMs maintainer: http://rpm.greysector.net/mplayer/
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 We stand between the darkness ... and the light."
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