测试代码运行效率

#include <time.h>
#define BEGIN_COUNT(mark) __int64 __begin_count##mark;\
    QueryPerformanceCounter((LARGE_INTEGER*)&__begin_count##mark);\

#define END_COUNT(mark) __int64 __end_count##mark;\
    QueryPerformanceCounter((LARGE_INTEGER*)&__end_count##mark);\
    __int64 __Frequency##mark;\
    QueryPerformanceFrequency((LARGE_INTEGER*)&__Frequency##mark);\
    double __interval##mark;\
    __interval##mark = __end_count##mark - __begin_count##mark;\
    double __begin##mark;\
    __begin##mark = __begin_count##mark * 1000000 /__Frequency##mark;\
    double  __end##mark;\
    __end##mark   =   __end_count##mark * 1000000 /__Frequency##mark;\
    double   __usec##mark;\
    __usec##mark   =   __interval##mark * 1000000 /__Frequency##mark;\
    ATLTRACE("From begin %10.2lf\n to end %10.2lf,\nCPU elapsed time %10.2lf microseconds",__begin##mark,__end##mark,__usec##mark);\