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#define BENCH_LOOPS (16384)
#include <sys/time.h>
typedef struct {
int i;
int n;
int divisor;
struct timespec start;
struct timespec end;
struct timespec elapsed;
double average;
char *name;
char *doc;
char *units;
} bench_t;
#define bench_now(tsp) \
clock_gettime(CLOCK_REALTIME, (tsp))
/*
* Repeat the body of the loop 'max' times, with a few extra 'warm up'
* cycles to negate cache effects.
*/
#define bench_amortize(b, max) \
for ((b)->i = -64, \
(b)->n = (max); \
(b)->i < (b)->n; \
(b)->i ++, \
((b)->i == 0 ? bench_now(&(b)->start) : \
((b)->i == (b)->n ? bench_now(&(b)->end) \
:0))\
)
#define bench_init(b, nm, dc, un) do { \
(b)->name = (nm); \
(b)->doc = (dc); \
(b)->units = (un); \
timespecclear(&(b)->start); \
timespecclear(&(b)->end); \
timespecclear(&(b)->elapsed); \
(b)->n = (b)->i = 0; \
(b)->divisor = 1; \
} while (0)
#define bench_header(b) \
printf("----------------------------------------------------\n" \
"Name:\t%s\nDesc:%s\n", (b)->name, (b)->doc)
#define bench_report(b) do { \
struct timespec elapsed; \
bench_t overhead; \
\
/* compute the loop overhead */ \
bench_amortize(&overhead, BENCH_LOOPS) { /* nothing */ } \
\
timespecsub(&(b)->end, &(b)->start, &(b)->elapsed); \
(b)->average = ((double)(b)->elapsed.tv_sec * 1000000000.0 + \
(b)->elapsed.tv_nsec) / (double)((b)->divisor) / \
(double)((b)->n); \
\
printf("Time: %f usec %s\n", (b)->average, (b)->units); \
if ((b)->divisor != 1) \
printf("\t(%d operations per cycle)\n", (b)->divisor); \
} while (0)
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