HOWTO: Verify That Assembly Code Preserves Registers Correctly For Windows 2000

ID: Q232587

This article discusses a Beta release of a Microsoft product. The information in this article is provided as-is and is subject to change without notice.

No formal product support is available from Microsoft for this Beta product. For information about obtaining support for a Beta release, please see the documentation included with the Beta product files, or check the Web location from which you downloaded the release.

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API), included with:
- Microsoft Windows 2000
  on the following platforms: x86

SUMMARY

When your applications for Windows 2000 include assembly-language code that uses CPU registers, make sure that the following registers contain the same value when you leave a procedure as they did when you entered the procedure:

This is required both when you're developing modules that are written entirely in assembly language and also when you are using the Visual C compiler's inline assembler. This does not apply to programs written entirely in Visual C or Visual C++.

Registers are preserved on the stack with a PUSH instruction at the beginning of a procedure and restored from the stack with a POP instruction before the procedure returns.

REFERENCES

For more information about using assembly-language code and the inline assembler, see Assembler (Inline): Overview topic in the Adding Program Functionality section of the Visual C++ Programmer's Guide. This documentation is available online at:

http://msdn.microsoft.com/library/devprods/vs6/visualc/vccore/_core_assembler_.28.inline.293a_.overview.htm

Additional query words: compatguidestability

Keywords : kbKernBase kbWinOS2000 kbSDKPlatform kbSDKWin32
Version : winnt:
Platform : winnt
Issue type : kbhowto