[Bug fortran/52012] New: [4.6/4.7 Regression] Wrong-code with RESHAPE

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52012

             Bug #: 52012
           Summary: [4.6/4.7 Regression] Wrong-code with RESHAPE
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: critical
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: pault@gcc.gnu.org


The following program prints with GCC 4.6 and 4.7:

   0.0000   0.0000   1.0000   0.0000   0.0000
   0.0000   0.0000   0.0000

Expected: The following result - as with GCC 4.5:

   0.0000   0.0000   1.0000   0.0000   0.0000
   0.0000   0.0000   1.0000

Doing a simple   print '(10f3.0)', a  shows the correct result. Thus, depending
how one accesses an array element, the result is correct or wrong.


The issue was reported by Reinhold Bader; I added the abort checks (both fail).


program gf
  implicit none
  real, allocatable :: a(:,:,:)
!  real :: a(5,4,3)
  real :: b(3,4,5) = 0.0
  b(1,2,3) = 1.0
  allocate(a(size(b,3),size(b,2),size(b,1)))
  a = reshape(b,shape(a),order=[3,2,1])
  write(*,*) a(:,2,1)
! the following line prints an incorrect value of a(3,2,1)
! even though the above one works correctly
  write(*,*) a(1,2,1), a(2,2,1), a(3,2,1)
  if (a(3,2,1) /= 1) call abort()
  if (sum(abs(a)) /= 1.0) call abort()
end program