[Bug target/23322] New: performance regression, possibly related to caching

[danalis at cis dot udel dot edu]

We ran the bench++ suite, mentioned as well in
http://gcc.gnu.org/ml/gcc/2005-08/msg00197.html ,
using -O2 and we noticed one more interesting case.

Namely, S000005m runs slower (x4) when compiled with
g++-4.0.1 than when compiled with either g++-2.95.3,
or g++-4.1.0-20050723.
This regression does not occur when -O3 is used.
Apparently, it is related to the existance of a
*dead* cerr, as changing the cerr to printf makes
the regression go away, and the assembly shorter.

Is this a caching effect?

-- 
           Summary: performance regression, possibly related to caching
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danalis at cis dot udel dot edu
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: i686-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23322