//-------------------------------------------------------------------
//	overflow.cpp
//
//	This program attempts to trigger an 'interrupt-on-overflow'
//	exception (Interrupt 4) by executing the 'into' instruction 
//	following a calculation which will set the OF-bit (Overflow 
//	Flag) in the processor's EFLAGS register.  For this purpose
//	we can simply square the largest (unsigned) 32-bit integer. 
//
//		to compile:  $ g++ overflow.cpp -o overflow
//		to execute:  $ ./overflow
//
//	NOTES: The 'into' instruction is not supported when the CPU
//	is executing in 64-bit mode.  Linux's exception-handler for
//	the 'interrupt-on-overfow' exception displays the incorrect 
//	diagnostic message "Segmentation fault" (kernel 2.6.27.10).
//
//	programmer: ALLAN CRUSE
//	written on: 14 SEP 2009
//-------------------------------------------------------------------


int main( int argc, char **argv )
{
	// square the largest unsigned 32-bit integer
	asm(" mov $-1, %eax \n mul %eax \n into ");
}