Visual Studio C++ 2008 / 2010 - break on float NaN

Question

Is there any way to set up Visual Studio (just upgraded from 2008 to 2010) to break, as if an assertion failed, whenever any floating point number becomes NaN, QNAN

Answer 1

1) Go to project option and enable /fp:strict (C/C++ -> Code Generation -> Floating Pint Model).

2) Use _controlfp to set the floating-point control word (see code below).

#include 
unsigned int fp_control_state = _controlfp(_EM_INEXACT, _MCW_EM);

#include 

int main () {

    sqrtf(-1.0);    // floating point exception

    double x = 0.0;
    double y = 1.0/x;   // floating point exception

    return 0;
}