Symptoms
Consider the following scenario:
-
You develop a Microsoft Visual C++ 2010 application that uses bit field members in a struct in Microsoft Visual Studio 2010.
-
You enable an optimization compiler option for the application, and then you build the application.
-
You run the application.
In this scenario, incorrect machine code may be generated for certain bit field member operations in the struct.
Resolution
Hotfix information
A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that this article describes. Apply it only to systems that are experiencing this specific problem.
To resolve this problem, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft website:
http://support.microsoft.com/contactus/?ws=supportNote In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
Prerequisites
To apply this hotfix, you must have Microsoft Visual Studio 2010 SP1 installed.
Restart requirement
You do not have to restart the computer after you install the hotfix if the affected files are not being used at the time of installation. We recommend that you close all Visual Studio 2010-related components before you install the hotfix.
The global version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
|
File name |
File version |
File size |
Date |
Time |
Platform |
Path |
|---|---|---|---|---|---|---|
|
C2.dll |
16.0.40219.449 |
2,606,728 |
18-Apr-2013 |
18:09 |
x86 |
Microsoft Visual Studio 10.0\VC\bin |
|
C2.dll |
16.0.40219.449 |
2,493,576 |
19-Apr-2013 |
21:19 |
x86 |
Microsoft Visual Studio 10.0\VC\bin\x86_amd64 |
|
C2.dll |
16.0.40219.449 |
2,593,928 |
19-Apr-2013 |
21:19 |
x86 |
Microsoft Visual Studio 10.0\VC\bin\x86_ia64 |
|
C2.dll |
16.0.40219.449 |
2,960,008 |
19-Apr-2013 |
21:19 |
x64 |
Microsoft Visual Studio 10.0\VC\bin\amd64 |
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Workaround
To work around this issue, use one of the following methods:
-
Use the /Od optimization compiler option to turn off optimization.
-
Use the optimize pragma to turn on or turn off the optimization on a function-by-function basis.
-
Upgrade to Microsoft Visual Studio 2012.
References
For more information about the optimize pragma, go to the following MSDN website:
General information about the optimize pragmaFor more information about /O optimization options, go to the following MSDN website:
