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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "../lib/lfsr.h"
#include "../gettime.h"
#include "../fio_time.h"
#include "../compiler/compiler.h"
static void usage(void)
{
printf("Usage: lfsr-test 0x<numbers> [seed] [spin] [verify]\n");
printf("-------------------------------------------------------------\n");
printf("*numbers: how many random numbers to produce (in hex)\n"
"seed: initial value\n"
"spin: how many iterations before we produce a number\n"
"verify: check if LFSR has iterated correctly\n\n"
"Only <numbers> is required. The rest are evaluated to 0 or false\n"
"Elapsed/mean time and verification results are printed at the"
"end of the test\n");
}
int main(int argc, char *argv[])
{
int r;
struct timespec start, end;
struct fio_lfsr *fl;
int verify = 0;
unsigned int spin = 0;
uint64_t seed = 0;
uint64_t numbers;
uint64_t v_size;
uint64_t i;
void *v = NULL, *v_start;
double total, mean;
arch_init(argv);
/* Read arguments */
switch (argc) {
case 5: if (strncmp(argv[4], "verify", 7) == 0)
verify = 1;
fio_fallthrough;
case 4: spin = atoi(argv[3]);
fio_fallthrough;
case 3: seed = atol(argv[2]);
fio_fallthrough;
case 2: numbers = strtol(argv[1], NULL, 16);
break;
default: usage();
return 1;
}
/* Initialize LFSR */
fl = malloc(sizeof(struct fio_lfsr));
if (!fl) {
perror("malloc");
return 1;
}
r = lfsr_init(fl, numbers, seed, spin);
if (r) {
printf("Initialization failed.\n");
return r;
}
/* Print specs */
printf("LFSR specs\n");
printf("==========================\n");
printf("Size is %u\n", 64 - __builtin_clzl(fl->cached_bit));
printf("Max val is %lu\n", (unsigned long) fl->max_val);
printf("XOR-mask is 0x%lX\n", (unsigned long) fl->xormask);
printf("Seed is %lu\n", (unsigned long) fl->last_val);
printf("Spin is %u\n", fl->spin);
printf("Cycle length is %lu\n", (unsigned long) fl->cycle_length);
/* Create verification table */
if (verify) {
v_size = numbers * sizeof(uint8_t);
v = calloc(1, v_size);
printf("\nVerification table is %lf KiB\n", (double)(v_size) / 1024);
}
v_start = v;
/*
* Iterate over a tight loop until we have produced all the requested
* numbers. Verifying the results should introduce some small yet not
* negligible overhead.
*/
fprintf(stderr, "\nTest initiated... ");
fio_gettime(&start, NULL);
while (!lfsr_next(fl, &i)) {
if (verify)
*(uint8_t *)(v + i) += 1;
}
fio_gettime(&end, NULL);
fprintf(stderr, "finished.\n");
/* Check if all expected numbers within range have been calculated */
r = 0;
if (verify) {
fprintf(stderr, "Verifying results... ");
for (i = 0; i < numbers; i++) {
if (*(uint8_t *)(v + i) != 1) {
fprintf(stderr, "failed (%lu = %d).\n",
(unsigned long) i,
*(uint8_t *)(v + i));
r = 1;
break;
}
}
if (!r)
fprintf(stderr, "OK!\n");
}
/* Calculate elapsed time and mean time per number */
total = utime_since(&start, &end);
mean = total / fl->num_vals;
printf("\nTime results ");
if (verify)
printf("(slower due to verification)");
printf("\n==============================\n");
printf("Elapsed: %lf s\n", total / pow(10,6));
printf("Mean: %lf us\n", mean);
free(v_start);
free(fl);
return r;
}
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