[Bug fortran/46087] New: Double precision values, when read in from data file, include random trailing numbers

[kyle.s.willis at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46087

           Summary: Double precision values, when read in from data file,
                    include random trailing numbers
           Product: gcc
           Version: 4.5.1
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: fortran
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: kyle.s.wil...@gmail.com


Example code:

      program test_dble

      real(8) :: a,b
      integer :: x,y

      open(unit=11,file='testdble.dat',status='old')

      read(11,*) a
      read(11,*) x
      read(11,*) b
      read(11,*) y

      write(*,'(f22.20)') a
      write(*,'(f22.20)') b
      print*, a
      print*, b
      print *, x
      print *, y

      close(11)

      end program test_dble

testdble.dat:
2.18
5
4.2
55

I am converting from using Absoft f77 compiler to the lastest version of
gfortran and when comparing the results, gfortran adds random trailing numbers
onto the end of the double precision numbers. The number SHOULD have all
trailing zeros and no other numbers.

Results using gfortran 4.5.1:

2.18000000000000015987
4.20000000000000017764
   2.1800000000000002
   4.2000000000000002
           5
          55

Results using f77:

2.18000000000000000000
4.20000000000000000000
   2.18000000000000
   4.20000000000000
   5
   55

The program was not compiiled using any compiler flags.

Thanks.