t/rng-test.c

   1 /*
   2  * Simple random number generator for testing.
   3  * Copyright © 2022-2023 Nick Bowler
   4  *
   5  * Directly compare the test lib RNG against the reference implementation.
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include "tap.h"
  23
  24 #if !HAVE_FOR_DECLS
  25 int main(void)
  26 {
  27         tap_skip_all("cannot compile reference xoshiro256+");
  28 }
  29 #else
  30 #include "rng.c"
  31 #include "xos256p.c"
  32
  33 int main(void)
  34 {
  35         unsigned long long seed_state = 0xdeadbeeff00dcafe;
  36         unsigned long long test_result, ref_result;
  37         unsigned long long ref_state[4], test_state[4];
  38         int i, ret = 0;
  39
  40         tap_plan(200);
  41         for (i = 0; i < 100; i++) {
  42                 s[0] = ref_state[0] = test_state[0] = splitmix64(&seed_state);
  43                 s[1] = ref_state[1] = test_state[1] = splitmix64(&seed_state);
  44                 s[2] = ref_state[2] = test_state[2] = splitmix64(&seed_state);
  45                 s[3] = ref_state[3] = test_state[3] = splitmix64(&seed_state);
  46
  47                 ref_result = next();
  48                 test_result = xoshiro256p(test_state);
  49
  50                 if (!tap_result(ref_result == test_result, "rng output")) {
  51                         tap_diag("Failed, unexpected result");
  52                         tap_diag("   with initial state %llx %llx %llx %llx",
  53                                                   ref_state[0], ref_state[1],
  54                                                   ref_state[2], ref_state[3]);
  55                         tap_diag("   received: %llx", test_result);
  56                         tap_diag("   expected: %llx", ref_result);
  57                 }
  58
  59                 if (!tap_result(s[0] == test_state[0] && s[1] == test_state[1]
  60                              && s[2] == test_state[2] && s[3] == test_state[3],
  61                                 "rng state update"))
  62                 {
  63                         tap_diag("Failed, state update differed");
  64                         tap_diag("   with initial state %llx %llx %llx %llx",
  65                                                   ref_state[0], ref_state[1],
  66                                                   ref_state[2], ref_state[3]);
  67                         tap_diag("   received: %llx %llx %llx %llx",
  68                                        test_state[0], test_state[1],
  69                                        test_state[2], test_state[3]);
  70                         tap_diag("   expected: %llx %llx %llx %llx",
  71                                        (unsigned long long)s[0],
  72                                        (unsigned long long)s[1],
  73                                        (unsigned long long)s[2],
  74                                        (unsigned long long)s[3]);
  75                 }
  76         }
  77
  78         tap_done();
  79 }
  80 #endif