Line data    Source code

       1             : // Copyright (c) 2018-2023  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 lib
      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