void calc_cycle_measure_overhead()
{
unsigned int cycle_cold, cycle_warm;
cycle_cold= TSCL;
cycle_cold = TSC_getDelay(cycle_cold);
cycle_warm= TSCL;
cycle_warm = TSC_getDelay(cycle_warm);
cycle_measure_overhead = (cycle_cold + cycle_warm)/2;
}
#define TSC_getDelay(startTSC) ((unsigned int)((0xFFFFFFFFl+TSCL)- (unsigned long long)startTSC)+ 1)
#define TSC_count_cycle_from(startTSC) (TSC_getDelay(startTSC)- cycle_measure_overhead)
问题：
1. cycle_measure_overhead = (cycle_cold + cycle_warm)/2;为什么要求一个均值？
2. #define TSC_getDelay(startTSC) ((unsigned int)((0xFFFFFFFFl+TSCL)- (unsigned long long)startTSC)+ 1)为什么要写成这种形式，不是直接用TSCL
