jdk-sandbox: test/hotspot/gtest/utilities/test_count_trailing

46437 cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	1	/*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	2	* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	4	*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	5	* This code is free software; you can redistribute it and/or modify it
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	6	* under the terms of the GNU General Public License version 2 only, as
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	7	* published by the Free Software Foundation.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	8	*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	9	* This code is distributed in the hope that it will be useful, but WITHOUT
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	12	* version 2 for more details (a copy is included in the LICENSE file that
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	13	* accompanied this code).
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	14	*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	15	* You should have received a copy of the GNU General Public License version
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	16	* 2 along with this work; if not, write to the Free Software Foundation,
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	18	*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	20	* or visit www.oracle.com if you need additional information or have any
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	21	* questions.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	22	*
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	23	*/
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	24
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	25	#include "precompiled.hpp"
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	26	#include "utilities/count_trailing_zeros.hpp"
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	27	#include "utilities/globalDefinitions.hpp"
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	28	#include "unittest.hpp"
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	29
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	30	TEST(count_trailing_zeros, one_or_two_set_bits) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	31	unsigned i = 0; // Position of a set bit.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	32	for (uintx ix = 1; ix != 0; ix <<= 1, ++i) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	33	unsigned j = 0; // Position of a set bit.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	34	for (uintx jx = 1; jx != 0; jx <<= 1, ++j) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	35	uintx value = ix \| jx;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	36	EXPECT_EQ(MIN2(i, j), count_trailing_zeros(value))
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	37	<< "value = " << value;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	38	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	39	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	40	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	41
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	42	TEST(count_trailing_zeros, all_ones_followed_by_all_zeros) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	43	unsigned i = BitsPerWord - 1; // Index of most significant set bit.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	44	uintx value = ~(uintx)0;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	45	for ( ; value != 0; value >>= 1, --i) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	46	EXPECT_EQ(0u, count_trailing_zeros(value))
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	47	<< "value = " << value;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	48	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	49	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	50
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	51	TEST(count_trailing_zeros, all_zeros_followed_by_all_ones) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	52	unsigned i = 0; // Index of least significant set bit.
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	53	uintx value = ~(uintx)0;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	54	for ( ; value != 0; value <<= 1, ++i) {
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	55	EXPECT_EQ(i, count_trailing_zeros(value))
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	56	<< "value = " << value;
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	57	}
cda23e690843 8179004: Add an efficient implementation of the "count trailing zeros" operation kbarrett parents: diff changeset	58	}

author	stuefe
	Mon, 23 Apr 2018 16:25:16 +0200
changeset 49852	4d3218e5f170
parent 47216	71c04702a3d5
child 53532	bc20d0376402
permissions	-rw-r--r--