RE: [patch] k8 and amdfam10 cost model tuning

["Sjodin, Jan" <Jan dot Sjodin at amd dot com>]

> 
> Please note that -ftree-vectorize -fvect-cost-model is now 
> implicit in 
> -O3 and -msse3 is implicit in "-march=k8-sse3" as well as 
> "-march=amdfam10". This can save you some typing...
> 

Yes, I already had this in the configuration file and I 
didn't want to modify it. ;-) Same thing below, but I wanted to keep
the flags identical with the bug report, although I added -static.

> BTW: Is it possible for you to confirm 30% performance regression in 
> rnflow polyhedron benchmark for -m32 -mfpmath=387 on k8 
> target as seen 
> in [1]. This problem seems specific to k8 target, everything works 
> normal on Core2Duo. This performance regression is covered by PR 
> target/31897 [2].
> 
> [1]: http://www.physik.fu-berlin.de/~tburnus/gcc-trunk/benchmark/
> [2]: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31897
> 
> Thanks,
> Uros.

I ran rnflow with an unmodified compiler:
(Rev: 130934 Last Changed Date: 2007-12-14) 
I could not duplicate the performance regression using the flags 
from pr31897. Below is a run on a 2.4 GHz Athlon 64 x2:

20 Dec 2007 11:28:05 standardgfortransingle - Compile rnflow
command=gfortran -static -m32 -march=opteron -ffast-math -funroll-loops
-ftree-l
oop-linear -ftree-vectorize -mfpmath=sse -msse3 -O3 -w rnflow.f90 -o
rnflow
 
20 Dec 2007 11:28:20 standardgfortransingle - Execute rnflow
rnflow Run #  10    37.26570    37.23942 - Error=  0.0253%

Geometric Mean Execution Time =      37.24 seconds

command=gfortran -static -m64 -march=opteron -ffast-math -funroll-loops
-ftree-l
oop-linear -ftree-vectorize -mfpmath=sse -msse3 -O3 -w rnflow.f90 -o
rnflow
 
20 Dec 2007 11:37:09 standardgfortransingle - Execute rnflow
rnflow Run #  10    35.94570    35.99346 - Error=  0.0253%

Geometric Mean Execution Time =      35.99 seconds

Is anyone else able to reproduce the problem?

Thanks,
Jan