Profile-guided optimization — различия между версиями

/****************************************************************************
 *	       File: PgoExample.c
 *
 * Description: Used to demonstrate the basic operation of Profile 
 *              Guided Optimization.  
 *
 *              Read incoming data from address 0xFFD00000 and count the 
 *              number of even values and odd values.  Supplying data files 
 *              with varying numbers of odd values vs. even values will 
 *              direct the compiler to optimize the conditional statement 
 *              with a bias for the branch most likely to be taken.
 ****************************************************************************/
unsigned int odds  = 0;
unsigned int evens = 0;
volatile int* data = (volatile int*)0xFFD00000;
 
int main( int argc, char* argv[] )
{
	int i;
 
	for( i=0; i<256; i++ )
	{
		if( (*data & 0xff) % 2 != 0 )
		{
			odds++;
		}
		else
		{
			evens++;
		}
	}
 
	return 0;
}