Re: Memory requirement regressions

[Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>]

Steven Bosscher wrote:
> On Wednesday 07 July 2004 17:48, Richard Guenther wrote:
>
> > The automated POOMA/tramp3d tester at
> > http://www.tat.physik.uni-tuebingen.de/~rguenth/gcc/monitor-summary.html
> > now tracks the maximum used virtual memory of cc1plus of mainline, too.
> >  As a first "hint", today it revealed that mainline needs about 1GB of
> > ram compared to 3.4.1 which needs only 625MB.  This is on ia64 for the
> > tramp3d-v3.cpp testcase at -O2 -funroll-loops -ffast-math with the
> > leafify patch included.
>
>
> I get the attached timings and memory used on i686 (with memory use
> "measured" with 'top') on a machine with 3GB RAM, gcc configured with

The results do not disagree with mine.  You need to do a comparison run 
with 3.4.1, that may show a difference.  I tested on ia64 and that 
obviously seems to use a lot more memory (btw. on a 16GB machine).

For measuring memory usage I use strace and some script hackery where 
the results are in good agreement with manually watching top.  If you 
are interested, it's at
http://www.tat.physik.uni-tuebingen.de/~rguenth/gcc/maxmem.sh
(for ia32, exchange 'mmap' with 'mmap2').

> * --disable-{nls,libmudflap,checking} --enable-languages=c,c++
> * your leafify patch applied
> * command line:
>   ./libexec/gcc/i686-pc-linux-gnu/3.5.0/cc1plus \
>   -iprefix /abuild/stevenb/lib/gcc/i686-pc-linux-gnu/3.5.0/ -D_GNU_SOURCE \
>   tramp3d-v3.cpp -dumpbase tramp3d-v3.cpp -mtune=pentium3 \
>   -auxbase tramp3d-v3 -version -o /tmp/cccsWqOw.s $FLAGS
>
> Where $FLAGS is the flags indicated before the time report...
>
> I did not use -quiet, I wanted to see how much memory we collect.  Not
> a surprise that it doesn't collect often, and when it does, it collects
> lots, e.g. numbers like {GC 445994k -> 236931k} are not unusual.

Yes, that's my observation, too.

> We consume a lot more time in 'integration' than I expected...

Indeed - whatever exactly integration is.

> Gr.
> Steven