.NET中的SEHException

Question

Setup:

• .Net-DLL written in C#
• C++/CLI Wrapper-Dll calling the .Net-DLL
• VS2013, Windows7 32Bit, .Net 4.5.2

Assigning a value larger than 2^31-1 to a double in the .Net-DLL will result in an SEHException, everything works fine with smaller values.

public void Foo()
{
    double foo = 2147483648d;
        ...
}

does throw an SEHexception when called from the C++/CLI, whereas

public void Foo()
{
    double foo = 2147483647d;
        ...
}

doesn't. Any ideas why this happens and how to avoid the exception?

Answer 1

The DLLs were called from an application which changed the FPU control world. Setting

_control87(_CW_DEFAULT, MCW_EM);

in the C++/CLI Wrapper-DLL before calling into the managed DLL is a quick fix.