FIX: Optimization Problem, $STORAGE:2 and Multiplication (73392)

The information in this article applies to:

Microsoft FORTRAN Compiler for MS-DOS 5.0
Microsoft FORTRAN Compiler for MS-DOS 5.1
Microsoft FORTRAN compiler for OS/2 5.0
Microsoft FORTRAN compiler for OS/2 5.1

This article was previously published under Q73392

SYMPTOMS

The sample code below produces the output:

  6     0

instead of the expected output

  6     1280

RESOLUTION

Use one of the following to work around the problem in the sample code:

Disable optimization by compiling with /Od -or-
Delete $storage:2 so that the default $storage:4 is used -or-
Assign the result of (iy - 1) in line 10 to a temporary variable and use the temporary variable in line 20.

STATUS

Microsoft has confirmed this to be a bug in the products listed above. This problem was corrected in FORTRAN PowerStation, version 1.0.

MORE INFORMATION

The following sample code can be used to demonstrate the problem.

Sample code

$storage:2
       call subs(6, 1)
       end

       subroutine subs(iy, ipage)
       integer bx, dx, tmp
10     bx = (ipage - 1) * 256
20     dx = (iy - 1) * 256
       write (*, *) iy, dx
       return
       end

Modification Type:	Major	Last Reviewed:	12/1/2003
Keywords:	kbfix KB73392