1#include <stdio.h>
2#include <stdlib.h>
3#include <time.h>
4#include <math.h>
5#include <string.h>
6#include <unistd.h>
7#include <sys/types.h>
8#include <sys/stat.h>
9
10#include "../lib/lfsr.h"
11#include "../gettime.h"
12#include "../fio_time.h"
13
14void usage()
15{
16	printf("Usage: lfsr-test 0x<numbers> [seed] [spin] [verify]\n");
17	printf("-------------------------------------------------------------\n");
18	printf("*numbers: how many random numbers to produce (in hex)\n"
19		   "seed:     initial value\n"
20		   "spin:     how many iterations before we produce a number\n"
21		   "verify:   check if LFSR has iterated correctly\n\n"
22		   "Only <numbers> is required. The rest are evaluated to 0 or false\n"
23		   "Elapsed/mean time and verification results are printed at the"
24	       "end of the test\n");
25}
26
27int main(int argc, char *argv[])
28{
29	int r;
30	struct timeval start, end;
31	struct fio_lfsr *fl;
32	int verify = 0;
33	unsigned int spin = 0;
34	uint64_t seed = 0;
35	uint64_t numbers;
36	uint64_t v_size;
37	uint64_t i;
38	void *v = NULL, *v_start;
39	double total, mean;
40
41	arch_init(argv);
42
43	/* Read arguments */
44	switch (argc) {
45		case 5: if (strncmp(argv[4], "verify", 7) == 0)
46					verify = 1;
47		case 4: spin = atoi(argv[3]);
48		case 3: seed = atol(argv[2]);
49		case 2: numbers = strtol(argv[1], NULL, 16);
50				break;
51		default: usage();
52				 return 1;
53	}
54
55	/* Initialize LFSR */
56	fl = malloc(sizeof(struct fio_lfsr));
57	if (!fl) {
58		perror("malloc");
59		return 1;
60	}
61
62	r = lfsr_init(fl, numbers, seed, spin);
63	if (r) {
64		printf("Initialization failed.\n");
65		return r;
66	}
67
68	/* Print specs */
69	printf("LFSR specs\n");
70	printf("==========================\n");
71	printf("Size is         %u\n", 64 - __builtin_clzl(fl->cached_bit));
72	printf("Max val is      %lu\n", (unsigned long) fl->max_val);
73	printf("XOR-mask is     0x%lX\n", (unsigned long) fl->xormask);
74	printf("Seed is         %lu\n", (unsigned long) fl->last_val);
75	printf("Spin is         %u\n", fl->spin);
76	printf("Cycle length is %lu\n", (unsigned long) fl->cycle_length);
77
78	/* Create verification table */
79	if (verify) {
80		v_size = numbers * sizeof(uint8_t);
81		v = malloc(v_size);
82		memset(v, 0, v_size);
83		printf("\nVerification table is %lf KiB\n", (double)(v_size) / 1024);
84	}
85	v_start = v;
86
87	/*
88	 * Iterate over a tight loop until we have produced all the requested
89	 * numbers. Verifying the results should introduce some small yet not
90	 * negligible overhead.
91	 */
92	fprintf(stderr, "\nTest initiated... ");
93	fio_gettime(&start, NULL);
94	while (!lfsr_next(fl, &i)) {
95		if (verify)
96			*(uint8_t *)(v + i) += 1;
97	}
98	fio_gettime(&end, NULL);
99	fprintf(stderr, "finished.\n");
100
101
102	/* Check if all expected numbers within range have been calculated */
103	r = 0;
104	if (verify) {
105		fprintf(stderr, "Verifying results... ");
106		for (i = 0; i < numbers; i++) {
107			if (*(uint8_t *)(v + i) != 1) {
108				fprintf(stderr, "failed (%lu = %d).\n",
109						(unsigned long) i,
110						*(uint8_t *)(v + i));
111				r = 1;
112				break;
113			}
114		}
115		if (!r)
116			fprintf(stderr, "OK!\n");
117	}
118
119	/* Calculate elapsed time and mean time per number */
120	total = utime_since(&start, &end);
121	mean = total / fl->num_vals;
122
123	printf("\nTime results ");
124	if (verify)
125		printf("(slower due to verification)");
126	printf("\n==============================\n");
127	printf("Elapsed: %lf s\n", total / pow(10,6));
128	printf("Mean:    %lf us\n", mean);
129
130	free(v_start);
131	free(fl);
132	return r;
133}
134