[Bug fortran/36599] New: major execution regression for induct.f90 polyhedron benchmark in 4.3.1 on Intel

["howarth at nitro dot med dot uc dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

There is a 20% execution regression on the polyhedron induct.f90 benchmark when
compiled with gfortran in gcc 4.3.1 compared to gcc 4.2.4. This reduction
appears
to be triggered by the -fassociative-math (which appears to require
-fno-signed-zeros -fno-trapping-math to actually be used by gfortran).
I am attaching induct.s.good generated by...

gfortran -fno-signed-zeros -fno-trapping-math --save-temps -O3 induct.f90

which doesn't show the speed regression and induct.s.bad generated by...

gfortran -fassociative-math -fno-signed-zeros -fno-trapping-math --save-temps
-O3 induct.f90

The induct.f90 and induct.inp data files for compiling this benchmark can be
downloaded from
http://www.polyhedron.com/web_images/documents/pb05.zip.


-- 
           Summary: major execution regression for induct.f90 polyhedron
                    benchmark in 4.3.1 on Intel
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: howarth at nitro dot med dot uc dot edu
 GCC build triplet: i686-apple-darwin9
  GCC host triplet: i686-apple-darwin9
GCC target triplet: i686-apple-darwin9


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36599