compile.sh

#!/bin/sh -e

die() {
    echo "$@" >&2
    exit 1
}

test -n "$CC" || die '$CC not set'

$CC -O3 -std=c99 -c ./foo.c
$CC -O3 -std=c99 -c ./main.c
$CC *.o

# vim: set ts=4 sw=4 et:

foo.c

int foo(int p) {
    return p == 1 || p == 4 || p == 6 || p == 10 || p == 12 || p == 25;
}

main.c

#define _GNU_SOURCE

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdbool.h>
#include <unistd.h>

int foo(int);

#define E(call) do { if (__builtin_expect(call < 0, 0)) { perror(#call); exit(1); }; } while (false)

long long microseconds() {
    struct timeval tv;
    E(gettimeofday(&tv, NULL));
    return 1000000LL * tv.tv_sec + tv.tv_usec;
}

int main(void) {
    int random_data[1000000];
    for (int i = 0; i < 1000000; ++i) {
        random_data[i] = ((unsigned) random()) % 150;
    }

    for (;;) {
        long long start = microseconds();
        long long count = 0;
        while (microseconds() - start < 1000000) {
            int iter = 1000000;
            for (int i = 0; i < iter; ++i) {
                foo(random_data[i]);
            }
            count += iter;
        }
        long long dps = 1000000L * (microseconds() - start);
        long long ps_per_call = dps / count;
        printf("%lld ps per call\n", ps_per_call);
    }
    return 0;
}

// vim: set ts=4 sw=4 et: