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Q216747: FIX: Incorrect Code Generated With /Og and /G6

Article: Q216747
Product(s): Microsoft C Compiler
Version(s): winnt:6.0
Operating System(s): 
Keyword(s): kbservicepack kbVC600 kbVS600sp2 kbVS600SP1 kbVS600sp3fix
Last Modified: 06-MAY-2001

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The information in this article applies to:

- Microsoft Visual C++, 32-bit Professional Edition, version 6.0 
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SYMPTOMS
========

Incorrect code may be generated with the /Og and /G6 compiler optimizations.

CAUSE
=====

The compiler incorrectly moves an .inc file, .add file, .sub file, or .lea file
across an instruction that references memory.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information
about Visual Studio service packs, please see the following articles in the
Microsoft Knowledge Base:

  Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

  Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

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

The following code illustrates one way the compiler can handle moving an
instruction:

     inc eax
     mov [eax + 2*ebx + 3]

The compiler needs to update the displacement to swap the instructions. For
example:

     mov [eax + 2*ebx + (3 + 1)]
     inc eax

Additional query words:

======================================================================
Keywords          : kbservicepack kbVC600 kbVS600sp2 kbVS600SP1 kbVS600sp3fix 
Technology        : kbVCsearch kbAudDeveloper kbVC600 kbVC32bitSearch
Version           : winnt:6.0
Issue type        : kbbug
Solution Type     : kbfix

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