Function ffclock_convert_delta

freebsd/kern/kern_tc.c:569–588

* Sub-routine to convert a time interval measured in RAW counter units to time * in seconds stored in bintime format. * NOTE: bintime_mul requires u_int, but the value of the ffcounter may be * larger than the max value of u_int (on 32 bit architecture). Loop to consume * extra cycles. */

 * extra cycles.
 */
static void
ffclock_convert_delta(ffcounter ffdelta, uint64_t period, struct bintime *bt)
{
	struct bintime bt2;
	ffcounter delta, delta_max;

	delta_max = (1ULL << (8 * sizeof(unsigned int))) - 1;
	bintime_clear(bt);
	do {
		if (ffdelta > delta_max)
			delta = delta_max;
		else
			delta = ffdelta;
		bt2.sec = 0;
		bt2.frac = period;
		bintime_mul(&bt2, (unsigned int)delta);
		bintime_add(bt, &bt2);
		ffdelta -= delta;
	} while (ffdelta > 0);
}

/*
 * Update the fftimehands.