[Bug fortran/17568] New: ISHFT intrinsic: bogus overflow error

[anlauf at hep dot tu-darmstadt dot de]

Hi,

the following code

program gfcbug9
  implicit none
  integer, parameter :: nbits = bit_size (1)
  integer            :: res
  res = ishft (1, nbits-1)
  print *, res
end program gfcbug9


fails to compile with the error message:


 In file gfcbug9.f90:5

  res = ishft (1, nbits-1)
              1
Error: Result of ISHFT overflows its kind at (1)


This is a bug.  AFAIK all bits that drop out left or right just
should get lost.  The only constraint (abs(shift) < bit_size) is
satisfied.

Cheers,
-ha

-- 
           Summary: ISHFT intrinsic: bogus overflow error
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: anlauf at hep dot tu-darmstadt dot de
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-cygwin


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17568