1 /* 2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "utilities/count_trailing_zeros.hpp" 27 #include "utilities/globalDefinitions.hpp" 28 #include "unittest.hpp" 29 30 TEST(count_trailing_zeros, one_or_two_set_bits) { 31 unsigned i = 0; // Position of a set bit. 32 for (uintx ix = 1; ix != 0; ix <<= 1, ++i) { 33 unsigned j = 0; // Position of a set bit. 34 for (uintx jx = 1; jx != 0; jx <<= 1, ++j) { 35 uintx value = ix | jx; 36 EXPECT_EQ(MIN2(i, j), count_trailing_zeros(value)) 37 << "value = " << value; 38 } 39 } 40 } 41 42 TEST(count_trailing_zeros, all_ones_followed_by_all_zeros) { 43 unsigned i = BitsPerWord - 1; // Index of most significant set bit. 44 uintx value = ~(uintx)0; 45 for ( ; value != 0; value >>= 1, --i) { 46 EXPECT_EQ(0u, count_trailing_zeros(value)) 47 << "value = " << value; 48 } 49 } 50 51 TEST(count_trailing_zeros, all_zeros_followed_by_all_ones) { 52 unsigned i = 0; // Index of least significant set bit. 53 uintx value = ~(uintx)0; 54 for ( ; value != 0; value <<= 1, ++i) { 55 EXPECT_EQ(i, count_trailing_zeros(value)) 56 << "value = " << value; 57 } 58 }