[Bug middle-end/37150] New: vectorizer issue

[jv244 at cam dot ac dot uk]

As pointed out :

http://gcc.gnu.org/ml/gcc/2008-08/msg00290.html

The attached testcase yields (on a core2 duo, gcc trunk):

    gfortran -O3 -ftree-vectorize -ffast-math -march=native test.f90
    time ./a.out

real 0m3.414s

    ifort -xT -O3  test.f90
    time ./a.out

real 0m1.556s

The assembly contains:

        ifort   gfortran
mulpd     140          0
mulsd       0        280


so the reason seems that ifort vectorizes the attached testcase


-- 
           Summary: vectorizer issue
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jv244 at cam dot ac dot uk
  GCC host triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37150