[Bug fortran/54934] Invalid debug/ array bounds w/-fno-range-check and 32-bit target

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54934

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org

--- Comment #1 from kargl at gcc dot gnu.org 2012-10-15 15:40:28 UTC ---
Jan,

It's a convoluted problem.  In gfortran, to get
the maximum range of an integer type you need
to use [-huge(i)-1:huge(i)] where 'i' is of the
type of interest.  This is a result of gfortran
seeing a number like -4294967297 as a unary minus
with an operand of 4294967297.  4294967297 without
a kind suffix is of default integer kind, which is
a 32-bit signed int, and 4294967297 is slightly 
larger than huge(1) = 2147483647.  Note, Fortran
does not have unsigned integers.  If you don't
want to or cannot use the -fno-range-check option,
you can do 

        integer(8), parameter :: n = 2 * (huge(1_4) + 1_8) + 1
        dimension foo(n-1:n)
        dimension bar(-n-1:-n)
        bar = 42
        foo = bar
        print *, n
        stop
        end

where I correctly initialize bar to some value; otherwise, the
code is invalid Fortran.  You could also decorate the integers
with a integer kind suffix

        dimension foo(4294967296_8:4294967297_8)
        dimension bar(-4294967297_8:-4294967296_8)
        bar = 42
        foo=bar
        stop
        end

Here, the _8 tells gfortran to use a signed 64-bit int.

Both code snippets above compile on my x86_64-*-freebsd.
I don't know want happens on an i686 target.