DOCUMENT:Q87549  26-JUN-2001  [utilities]
TITLE   :FIX: ESP Not Updated Correctly After PUSHFD, POPFD
PRODUCT :Microsoft Programming Utilities
PROD/VER::
OPER/SYS:
KEYWORDS:kb16bitonly

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

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

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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