DOCUMENT:Q316090  23-JUL-2002  [visualc]
TITLE   :BUG: Fatal Error C1001 When You Compile with Global Optimizer
PRODUCT :Microsoft C Compiler
PROD/VER::
OPER/SYS:
KEYWORDS:kbCompilerkbbuglist

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

 - The C/C++ Compiler (CL.EXE), included with:
    - Microsoft Visual C++.NET (2002) 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you compile a program with global optimizer, you receive the following
error message:

   "fatal error C1001: INTERNAL COMPILER ERROR (compiler file
   'f:\vs70builds\9466\vc\Compiler\Utc\src\P2\emit.c', line 937)
   Please choose the Technical Support command on the Visual Help menu, or open
   the Technical Support help file for more information."

CAUSE
=====

The behavior occurs because optimizer puts too many instructions in the function
prolog for a particular optimization (frame pointer omission).

RESOLUTION
==========

To work around the problem, you must prevent instructions from being scheduled
in the prolog. To do this, do one of the following:

 - Make a function call to an external function that is contained in another
   object file (may not work when "Whole program optimization" (/GL) is enabled)
   or DLL.

   -or-

 - Use the undocumented _ReadWriteBarrier() intrinsic at the beginning of the
   affected function. This intrinsic does not generate any code but prevents
   optimizations across the intrinsic. To do this, add the following declaration
   to the file:

   void _ReadWriteBarrier();
   #pragma intrinsic(_ReadWriteBarrier) 

Add the following code at the beginning of the function that causes the C1001
error:

   #if _MSC_VER==1300
     _ReadWriteBarrier();
   #endif

NOTE: The use of undocumented intrinsics is not guaranteed to work in future
versions of the compiler.

STATUS
======

Microsoft has confirmed that this is a bug in the Microsoft products that are
listed at the beginning of this article.

Additional query words: Og ICE KbCpp KbNative

======================================================================
Keywords          : kbCompiler kbbuglist
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :
Issue type        : kbbug
Solution Type     : kbpending

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

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