Line data    Source code

       1              : // Copyright (c) 2018-2025  Made to Order Software Corp.  All Rights Reserved
       2              : //
       3              : // https://snapwebsites.org/project/snapdev
       4              : // contact@m2osw.com
       5              : //
       6              : // This program is free software: you can redistribute it and/or modify
       7              : // it under the terms of the GNU General Public License as published by
       8              : // the Free Software Foundation, either version 3 of the License, or
       9              : // (at your option) any later version.
      10              : //
      11              : // This program is distributed in the hope that it will be useful,
      12              : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13              : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14              : // GNU General Public License for more details.
      15              : //
      16              : // You should have received a copy of the GNU General Public License
      17              : // along with this program.  If not, see <https://www.gnu.org/licenses/>.
      18              : 
      19              : /** \file
      20              :  * \brief Verify that the log2() function.
      21              :  *
      22              :  * This file implements test for the log2() function.
      23              :  */
      24              : 
      25              : // self
      26              : //
      27              : #include    "catch_main.h"
      28              : 
      29              : 
      30              : 
      31              : // snapdev
      32              : //
      33              : #include    <snapdev/log2.h>
      34              : 
      35              : 
      36              : // last include
      37              : //
      38              : #include    <snapdev/poison.h>
      39              : 
      40              : 
      41              : 
      42              : 
      43              : 
      44              : 
      45            3 : CATCH_TEST_CASE("log2", "[math]")
      46              : {
      47            3 :     CATCH_START_SECTION("log2: zero")
      48              :     {
      49            1 :         CATCH_REQUIRE(snapdev::log2(0) == -1);
      50              :     }
      51            3 :     CATCH_END_SECTION()
      52              : 
      53            3 :     CATCH_START_SECTION("log2: powers of 2")
      54              :     {
      55           65 :         for(int i = 0; i < 64; ++i)
      56              :         {
      57           64 :             std::uint64_t const v = 1ULL << i;
      58           64 :             CATCH_REQUIRE(snapdev::log2(v) == i);
      59              :         }
      60              :     }
      61            3 :     CATCH_END_SECTION()
      62              : 
      63            3 :     CATCH_START_SECTION("log2: random numbers")
      64              :     {
      65           65 :         for(int i = 0; i < 64; ++i)
      66              :         {
      67           64 :             std::uint64_t r = (static_cast<std::uint64_t>(rand()) << 32) ^ static_cast<std::uint64_t>(rand());
      68           64 :             r &= (1ULL << i) - 1ULL;
      69           64 :             std::uint64_t const v = (1ULL << i) | r;
      70              : 
      71              :             // same difference, all the lower bits are ignored in the
      72              :             // computation
      73              :             //
      74           64 :             CATCH_REQUIRE(snapdev::log2(v) == i);
      75              :         }
      76              :     }
      77            3 :     CATCH_END_SECTION()
      78            3 : }
      79              : 
      80              : 
      81              : 
      82              : // vim: ts=4 sw=4 et