[Bug tree-optimization/37021] New: Fortran Complex reduction / multiplication not vectorized

[rguenth at gcc dot gnu dot org]

subroutine to_product_of(self,a,b,a1,a2)
  complex(kind=8) :: self (:)
  complex(kind=8), intent(in) :: a(:,:)
  complex(kind=8), intent(in) :: b(:)
  integer a1,a2
  self = ZERO
  do i = 1,a1
    do j = 1,a2
      self(i) = self(i) + a(i,j)*b(j)
    end do
  end do
end subroutine

There are numerous reasons this is not vectorized at the moment:
 1) aliasing doesn't tell apart the data of self, a and b
 2) the reduction is obfuscated by extra SSA_NAME copies from store-motion
    (after you fix 1)
 3) REALPART_EXPR < (*ptr)[i] > is not handled by data dependency analysis
 4) ... ?


-- 
           Summary: Fortran Complex reduction / multiplication not
                    vectorized
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, alias
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37021