quo, _ := bits.Div64(hi, lo, uint64(queryPerformanceFrequency))
	return time.Duration(quo)
}

var queryPerformanceFrequency int64

// highPrecisionTimeSince returns duration since a.
func highPrecisionTimeSince(a highPrecisionTime) time.Duration {
	return highPrecisionTimeNow().sub(a)

}

// highPrecisionTimeNow returns high precision time for benchmarking.
func highPrecisionTimeNow() highPrecisionTime {
	return highPrecisionTime{now: time.Now()}
}

// highPrecisionTimeSince returns duration since b.
func highPrecisionTimeSince(b highPrecisionTime) time.Duration {
	return time.Since(b.now)

				root.mu.Lock()
				root.duration += highPrecisionTimeSince(root.start)
				d := root.duration
				root.mu.Unlock()
				root.flushToParent(root.name, "--- FAIL: %s (%s)\n", root.name, fmtDuration(d))
			}
			didPanic = true
			panic(err)
		}
		if err != nil {
			doPanic(err)
		}

		// No panic or inappropriate Goexit.
		f.duration += highPrecisionTimeSince(f.start)

		if len(f.sub) > 0 {

// StopTimer stops timing a test. This can be used to pause the timer
// while performing complex initialization that you don't
// want to measure.
func (b *B) StopTimer() {
	if b.timerOn {
		b.duration += highPrecisionTimeSince(b.start)
		runtime.ReadMemStats(&memStats)
		b.netAllocs += memStats.Mallocs - b.startAllocs
		b.netBytes += memStats.TotalAlloc - b.startBytes
		b.timerOn = false
	}
}

		return
	}

	// We don't want to include the time we spend waiting for serial tests
	// in the test duration. Record the elapsed time thus far and reset the
	// timer afterwards.
	t.duration += highPrecisionTimeSince(t.start)

	// Add to the list of tests to be released by the parent.
	t.parent.sub = append(t.parent.sub, t)

	// Report any races during execution of this test up to this point.
	//