94 lines
3.2 KiB
C++
94 lines
3.2 KiB
C++
/*
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* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "utilities/count_trailing_zeros.hpp"
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#include "utilities/globalDefinitions.hpp"
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#include "unittest.hpp"
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template <typename T> static void test_one_or_two_set_bits() {
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unsigned i = 0; // Position of a set bit.
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unsigned max = sizeof(T) * BitsPerByte;
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for (T ix = T(1); i < max; ix <<= 1, ++i) {
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unsigned j = 0; // Position of a set bit.
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for (T jx = T(1); j < max; jx <<= 1, ++j) {
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T value = ix | jx;
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EXPECT_EQ(MIN2(i, j), count_trailing_zeros(value))
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<< "value = " << value;
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}
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}
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}
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TEST(count_trailing_zeros, one_or_two_set_bits) {
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test_one_or_two_set_bits<int8_t>();
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test_one_or_two_set_bits<int16_t>();
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test_one_or_two_set_bits<int32_t>();
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test_one_or_two_set_bits<int64_t>();
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test_one_or_two_set_bits<uint8_t>();
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test_one_or_two_set_bits<uint16_t>();
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test_one_or_two_set_bits<uint32_t>();
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test_one_or_two_set_bits<uint64_t>();
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}
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template <typename T> static void test_high_zeros_low_ones() {
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T value = std::numeric_limits<T>::max();
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for ( ; value != 0; value >>= 1) {
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EXPECT_EQ(0u, count_trailing_zeros(value))
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<< "value = " << value;
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}
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}
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TEST(count_trailing_zeros, high_zeros_low_ones) {
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test_high_zeros_low_ones<int8_t>();
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test_high_zeros_low_ones<int16_t>();
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test_high_zeros_low_ones<int32_t>();
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test_high_zeros_low_ones<int64_t>();
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test_high_zeros_low_ones<uint8_t>();
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test_high_zeros_low_ones<uint16_t>();
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test_high_zeros_low_ones<uint32_t>();
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test_high_zeros_low_ones<uint64_t>();
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}
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template <typename T> static void test_high_ones_low_zeros() {
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unsigned i = 0; // Index of least significant set bit.
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T value = ~T(0);
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unsigned max = sizeof(T) * BitsPerByte;
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for ( ; i < max; value <<= 1, ++i) {
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EXPECT_EQ(i, count_trailing_zeros(value))
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<< "value = " << value;
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}
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}
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TEST(count_trailing_zeros, high_ones_low_zeros) {
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test_high_ones_low_zeros<int8_t>();
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test_high_ones_low_zeros<int16_t>();
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test_high_ones_low_zeros<int32_t>();
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test_high_ones_low_zeros<int64_t>();
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test_high_ones_low_zeros<uint8_t>();
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test_high_ones_low_zeros<uint16_t>();
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test_high_ones_low_zeros<uint32_t>();
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test_high_ones_low_zeros<uint64_t>();
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}
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