DOCUMENT:Q104896  24-MAR-2000  [fortran]
TITLE   :FIX: F6100 Reading Maximal Negative Integers
PRODUCT :Microsoft Fortran Compiler
PROD/VER::1.0,1.0a
OPER/SYS:
KEYWORDS:kberrmsg kbFortranPS kbLangFortran

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0, 1.0a 
 - Microsoft Fortran Powerstation 32 for Windows NT, version 1.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

For any integer data type, reading the smallest negative integer of that range
generates the run-time error F6100 indicating that there was an INTEGER overflow
on input.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products listed at
the beginning of this article. This problem was corrected in Microsoft FORTRAN
PowerStation 32, version 4.0.

MORE INFORMATION
================

The smallest negative integer for each integer data type is:

   -128 Integer*1
   -32768 Integer*2
   -2147483648 Integer*4

The sample code below generates the 6100 error for all integer types when
compiled with PowerStation, but only generates the 6100 error for integer*4 with
FORTRAN 5.1 and earlier.

Sample Code
-----------

   C No Compiler options needed
         integer*1 i
         integer*2 j
         integer*4 k
         open(1,file='test.dat')
         do 10 n=3,5
           write(1,*) -2**((2**n-1))
    10   continue

         rewind(1)
         read(1,*,iostat=ierr) i
         if(ierr.eq.6100) then
           print*, 'error reading integer*1 was: ',ierr
         else
           print*, 'integer*1 input: ',i
         end if

         read(1,*,iostat=ierr) j
         if(ierr.eq.6100) then
           print*, 'error reading integer*2 was: ',ierr
         else
           print*, 'integer*2 input: ',j
         end if

         read(1,*,iostat=ierr) k
         if(ierr.eq.6100) then
           print*, 'error reading integer*4 was: ',ierr
         else
           print*, 'integer*4 input: ',k
         end if

         end

Additional query words: 1.00 5.10

======================================================================
Keywords          : kberrmsg kbFortranPS kbLangFortran 
Technology        : kbAudDeveloper kbFortranSearch kbZNotKeyword2 kbZNotKeyword3 kbFORTRANPower32100NT kbFORTRANPower100DOS kbFORTRANPower100aDOS
Version           : :1.0,1.0a
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2000.