/*

 * Copyright (c) 2011, 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.

 */

package org.graalvm.compiler.core.test;

import org.graalvm.compiler.nodes.FrameState;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;

import org.graalvm.compiler.phases.common.CanonicalizerPhase;

import org.junit.Test;

public class IntegerEqualsCanonicalizerTest extends GraalCompilerTest {

    @Test

    public void testSubtractEqualsZero() {

        test("testSubtractEqualsZeroSnippet", "testSubtractEqualsZeroReference");

    }

    public static int testSubtractEqualsZeroReference(int a, int b) {

        if (a == b) {

            return 1;

        }

        return 0;

    }

    public static int testSubtractEqualsZeroSnippet(int a, int b) {

        if (a - b == 0) {

            return 1;

        }

        return 0;

    }

    @Test

    public void testSubtractEqualsZeroLong() {

        test("testSubtractEqualsZeroLongSnippet", "testSubtractEqualsZeroLongReference");

    }

    public static int testSubtractEqualsZeroLongReference(long a, long b) {

        if (a == b) {

            return 1;

        }

        return 0;

    }

    public static int testSubtractEqualsZeroLongSnippet(long a, long b) {

        if (a - b == 0) {

            return 1;

        }

        return 0;

    }

    /**

     * Tests the canonicalization of (x >>> const) == 0 to x |test| (-1 << const).

     */

    @Test

    public void testShiftEquals() {

        test("testShiftEqualsSnippet", "testShiftEqualsReference");

    }

    @SuppressWarnings("unused") private static int field;

    public static void testShiftEqualsSnippet(int x, int[] array, int y) {

        // optimize

        field = (x >>> 10) == 0 ? 1 : 0;

        field = (array.length >> 10) == 0 ? 1 : 0;

        field = (x << 10) == 0 ? 1 : 0;

        // don't optimize

        field = (x >> 10) == 0 ? 1 : 0;

        field = (x >>> y) == 0 ? 1 : 0;

        field = (x >> y) == 0 ? 1 : 0;

        field = (x << y) == 0 ? 1 : 0;

        field = (x >>> y) == 1 ? 1 : 0;

        field = (x >> y) == 1 ? 1 : 0;

        field = (x << y) == 1 ? 1 : 0;

    }

    public static void testShiftEqualsReference(int x, int[] array, int y) {

        field = (x & 0xfffffc00) == 0 ? 1 : 0;

        field = (array.length & 0xfffffc00) == 0 ? 1 : 0;

        field = (x & 0x3fffff) == 0 ? 1 : 0;

        // don't optimize signed right shifts

        field = (x >> 10) == 0 ? 1 : 0;

        // don't optimize no-constant shift amounts

        field = (x >>> y) == 0 ? 1 : 0;

        field = (x >> y) == 0 ? 1 : 0;

        field = (x << y) == 0 ? 1 : 0;

        // don't optimize non-zero comparisons

        field = (x >>> y) == 1 ? 1 : 0;

        field = (x >> y) == 1 ? 1 : 0;

        field = (x << y) == 1 ? 1 : 0;

    }

    @Test

    public void testCompare() {

        test("testCompareSnippet", "testCompareReference");

    }

    public static void testCompareSnippet(int x, int y, int[] array1, int[] array2) {

        int tempX = x;

        int array1Length = array1.length;

        int array2Length = array2.length;

        // optimize

        field = x == tempX ? 1 : 0;

        field = x != tempX ? 1 : 0;

        field = array1Length != (-1 - array2Length) ? 1 : 0;

        field = array1Length == (-1 - array2Length) ? 1 : 0;

        // don't optimize

        field = x == y ? 1 : 0;

        field = array1Length == array2Length ? 1 : 0;

        field = array1Length == (-array2Length) ? 1 : 0;

    }

    public static void testCompareReference(int x, int y, int[] array1, int[] array2) {

        int array1Length = array1.length;

        int array2Length = array2.length;

        // optimize

        field = 1;

        field = 0;

        field = 1;

        field = 0;

        // don't optimize (overlapping value ranges)

        field = x == y ? 1 : 0;

        field = array1Length == array2Length ? 1 : 0;

        field = array1Length == (-array2Length) ? 1 : 0;

    }

    public static boolean testNormalIntegerTest(int a) {

        return (a & 8) != 0;

    }

    public static boolean testAlternateIntegerTest(int a) {

        return (a & 8) == 8;

    }

    @Test

    public void testIntegerTest() {

        test("testNormalIntegerTest", "testAlternateIntegerTest");

    }

    private void test(String snippet, String referenceSnippet) {

        StructuredGraph graph = getCanonicalizedGraph(snippet);

        StructuredGraph referenceGraph = getCanonicalizedGraph(referenceSnippet);

        assertEquals(referenceGraph, graph);

    }

    private StructuredGraph getCanonicalizedGraph(String snippet) {

        StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES);

        new CanonicalizerPhase().apply(graph, getProviders());

        for (FrameState state : graph.getNodes(FrameState.TYPE).snapshot()) {

            state.replaceAtUsages(null);

            state.safeDelete();

        }

        return graph;

    }

}