/*

 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "utilities/count_leading_zeros.hpp"

#include "utilities/globalDefinitions.hpp"

#include "unittest.hpp"

TEST(count_leading_zeros, one_or_two_set_bits) {

  unsigned i = 0;                  // Position of a set bit.

  for (uint32_t ix = 1; ix != 0; ix <<= 1, ++i) {

    unsigned j = 0;                // Position of a set bit.

    for (uint32_t jx = 1; jx != 0; jx <<= 1, ++j) {

      uint32_t value = ix | jx;

      EXPECT_EQ(31u - MAX2(i, j), count_leading_zeros(value))

        << "value = " << value;

    }

  }

}

TEST(count_leading_zeros, high_zeros_low_ones) {

  unsigned i = 0;                  // Number of leading zeros

  uint32_t value = ~(uint32_t)0;

  for ( ; value != 0; value >>= 1, ++i) {

    EXPECT_EQ(i, count_leading_zeros(value))

      << "value = " << value;

  }

}

TEST(count_leading_zeros, high_ones_low_zeros) {

  uint32_t value = ~(uint32_t)0;

  for ( ; value != 0; value <<= 1) {

    EXPECT_EQ(0u, count_leading_zeros(value))

      << "value = " << value;

  }

}