[Bug regression/26290] New: [4.1 Regression]: some loop optimizations no longer run at -O2

["t dot artem at mailcity dot com" <gcc-bugzilla@gcc.gnu.org>]

In this simple testcase (file will be attached)

1) GCC 4.1 with -O2 produces code which runs two time slower than with -O3 thus
some optimizations are missing at -O2 because GCC 4.0.2 -O2 works OK and
produces results on par with -O3.

2) GCC 4.1 produces slightly slower code with -O3 than GCC 4.0.2 (with -O3).

P.S. -fregmove was used as an extra compiler flag.


-- 
           Summary: [4.1 Regression]: some loop optimizations no longer run
                    at -O2
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: regression
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: t dot artem at mailcity dot com
 GCC build triplet: i686-pc-linux-gnu-gcc
  GCC host triplet: i686-pc-linux-gnu-gcc
GCC target triplet: i686-pc-linux-gnu-gcc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26290