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Q87549: FIX: ESP Not Updated Correctly After PUSHFD, POPFD

Article: Q87549
Product(s): Microsoft Programming Utilities
Version(s): 
Operating System(s): 
Keyword(s): kb16bitonly
Last Modified: 26-JUN-2001

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

- Microsoft CodeView for MS-DOS 
- Microsoft CodeView for OS/2 
- Microsoft CodeView for Windows 
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SYMPTOMS
========

When single-stepping through a PUSHFD or a POPFD in Microsoft CodeView versions
3.0, 3.11, 3.12, 3.14, 3.5, 4.0, 4.01, and 4.05 the ESP register is changed by
only 2 bytes rather than 4 bytes.

RESOLUTION
==========

The problem only occurs when single-stepping. Placing the cursor on the next
instruction and pressing F7 will result in CodeView correctly updating the ESP
register. If you use this workaround, make sure the next instruction does not
modify the stack pointer.

STATUS
======

Microsoft has confirmed this to be a problem in CodeView versions 3.0, 3.11,
3.12, 3.14, 3.5, 4.0, 4.01, and 4.05. This problem was corrected in CodeView
version 4.1.

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

The following sample code demonstrates the problem. Single-step over the
instructions to see ESP change by only 2 bytes. Restart and run to the first NOP
and then the second to see that ESP is then correctly updated.

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

  ; Assembly options needed: /Zi

  _text segment word public 'code'
     ASSUME cs:_text, ds:_text
  .386
     PUSHFD
     NOP
     POPFD
     NOP

     MOV ah, 4ch
     INT 21h
  _text ENDS
     END

Additional query words: 3.00 3.50 4.00

======================================================================
Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbCodeView kbZNotKeyword3
Version           : :
Solution Type     : kbfix

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

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