bpf: allow self-xor operation
[dpdk.git] / app / test / test_rand_perf.c
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2019 Ericsson AB
3  */
4
5 #include <inttypes.h>
6 #include <stdio.h>
7
8 #include <rte_common.h>
9 #include <rte_cycles.h>
10 #include <rte_random.h>
11
12 #include "test.h"
13
14 static volatile uint64_t vsum;
15
16 #define ITERATIONS (100000000)
17
18 #define BEST_CASE_BOUND (1<<16)
19 #define WORST_CASE_BOUND (BEST_CASE_BOUND + 1)
20
21 enum rand_type {
22         rand_type_64,
23         rand_type_bounded_best_case,
24         rand_type_bounded_worst_case
25 };
26
27 static const char *
28 rand_type_desc(enum rand_type rand_type)
29 {
30         switch (rand_type) {
31         case rand_type_64:
32                 return "Full 64-bit [rte_rand()]";
33         case rand_type_bounded_best_case:
34                 return "Bounded average best-case [rte_rand_max()]";
35         case rand_type_bounded_worst_case:
36                 return "Bounded average worst-case [rte_rand_max()]";
37         default:
38                 return NULL;
39         }
40 }
41
42 static __rte_always_inline void
43 test_rand_perf_type(enum rand_type rand_type)
44 {
45         uint64_t start;
46         uint32_t i;
47         uint64_t end;
48         uint64_t sum = 0;
49         uint64_t op_latency;
50
51         start = rte_rdtsc();
52
53         for (i = 0; i < ITERATIONS; i++) {
54                 switch (rand_type) {
55                 case rand_type_64:
56                         sum += rte_rand();
57                         break;
58                 case rand_type_bounded_best_case:
59                         sum += rte_rand_max(BEST_CASE_BOUND);
60                         break;
61                 case rand_type_bounded_worst_case:
62                         sum += rte_rand_max(WORST_CASE_BOUND);
63                         break;
64                 }
65         }
66
67         end = rte_rdtsc();
68
69         /* to avoid an optimizing compiler removing the whole loop */
70         vsum = sum;
71
72         op_latency = (end - start) / ITERATIONS;
73
74         printf("%s: %"PRId64" TSC cycles/op\n", rand_type_desc(rand_type),
75                op_latency);
76 }
77
78 static int
79 test_rand_perf(void)
80 {
81         rte_srand(42);
82
83         printf("Pseudo-random number generation latencies:\n");
84
85         test_rand_perf_type(rand_type_64);
86         test_rand_perf_type(rand_type_bounded_best_case);
87         test_rand_perf_type(rand_type_bounded_worst_case);
88
89         return 0;
90 }
91
92 REGISTER_TEST_COMMAND(rand_perf_autotest, test_rand_perf);