> There's the "inexact" exception. But contrary to invalid operations
> (and overflows, at least in rounding to nearest), the only way to
> detect it is to test the exception status flags; the numerical
> value won't say anything about the exception (unless you have some
> knowledge about it, such as you know that the value is an integer
> but you don't get an integer... But not all inexact exceptions can
> be detected in such a way).
Thanks, interesting.
P.S.: Looks like David is right: Doing a runtime conversion raises the
Exception:
#include <stdio.h>
#include <fenv.h>
int main (void) {
volatile int b = 0x7fffffbf;
volatile float c = b;
printf ("inexact = %d\n", fetestexcept (FE_INEXACT));
c /= 123;
printf ("inexact = %d\n", fetestexcept (FE_INEXACT));
return 0;
}
$ ./a.exe
inexact = 32
inexact = 32
