C로 수행시간 체크하기

간단하게 수행시간 체크하는 매크로를 만들어보았다.

### c++
#ifdef _WIN32
#define ENTER { \
    LARGE_INTEGER begin, end, freq; \
    QueryPerformanceFrequency(&freq); \
    QueryPerformanceCounter(&begin);
#define LEAVE \
    QueryPerformanceCounter(&end); \
    double elapsed_time = (double)(end.QuadPart - begin.QuadPart) / freq.QuadPart; \
    printf("%s:%d] %3.2f elapsed\n", __FUNCTION__, __LINE__, elapsed_time); \
#else
#include <sys/time.h>
#define ENTER { \
    struct timeval stime, etime; \
    unsigned int performed_time; \
    gettimeofday(&stime, NULL);
#define LEAVE \
    gettimeofday(&etime, NULL); \
    performed_time = etime.tv_sec - stime.tv_sec; \
    performed_time = performed_time * 1000000 + etime.tv_usec - stime.tv_usec; \
    printf("%s:%d] %d elapsed\n", __func__, __LINE__, performed_time); \
    }
#endif