elapsed.h (2144B)
1 #ifndef ELAPSED_H 2 #define ELAPSED_H 3 4 #ifdef __cplusplus 5 extern "C" { 6 #endif 7 8 #include <stdio.h> 9 10 /* Based on http://stackoverflow.com/a/8583395 */ 11 #if !defined(_WIN32) 12 #include <sys/time.h> 13 static double elapsed_realtime(void) { // returns 0 seconds first time called 14 static struct timeval t0; 15 struct timeval tv; 16 gettimeofday(&tv, 0); 17 if (!t0.tv_sec) 18 t0 = tv; 19 return (double)(tv.tv_sec - t0.tv_sec) + (double)(tv.tv_usec - t0.tv_usec) / 1e6; 20 } 21 #else 22 #include <windows.h> 23 #ifndef FatalError 24 #define FatalError(s) do { perror(s); exit(-1); } while(0) 25 #endif 26 static double elapsed_realtime(void) { // granularity about 50 microsecs on my machine 27 static LARGE_INTEGER freq, start; 28 LARGE_INTEGER count; 29 if (!QueryPerformanceCounter(&count)) 30 FatalError("QueryPerformanceCounter"); 31 if (!freq.QuadPart) { // one time initialization 32 if (!QueryPerformanceFrequency(&freq)) 33 FatalError("QueryPerformanceFrequency"); 34 start = count; 35 } 36 return (double)(count.QuadPart - start.QuadPart) / freq.QuadPart; 37 } 38 #endif 39 40 /* end Based on stackoverflow */ 41 42 static int show_benchmark(const char *descr, double t1, double t2, size_t size, int rep, const char *reptext) 43 { 44 double tdiff = t2 - t1; 45 double nstime; 46 47 printf("operation: %s\n", descr); 48 printf("elapsed time: %.3f (s)\n", tdiff); 49 printf("iterations: %d\n", rep); 50 printf("size: %lu (bytes)\n", (unsigned long)size); 51 printf("bandwidth: %.3f (MB/s)\n", (double)rep * (double)size / 1e6 / tdiff); 52 printf("throughput in ops per sec: %.3f\n", rep / tdiff); 53 if (reptext && rep != 1) { 54 printf("throughput in %s ops per sec: %.3f\n", reptext, 1 / tdiff); 55 } 56 nstime = tdiff * 1e9 / rep; 57 if (nstime < 1000) { 58 printf("time per op: %.3f (ns)\n", nstime); 59 } else if (nstime < 1e6) { 60 printf("time per op: %.3f (us)\n", nstime / 1000); 61 } else if (nstime < 1e9) { 62 printf("time per op: %.3f (ms)\n", nstime / 1e6); 63 } else { 64 printf("time per op: %.3f (s)\n", nstime / 1e9); 65 } 66 return 0; 67 } 68 69 #ifdef __cplusplus 70 } 71 #endif 72 73 #endif /* ELAPSED_H */