001/*
002 * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.api.directives.test;
024
025import org.junit.*;
026
027import com.oracle.graal.api.directives.*;
028import com.oracle.graal.compiler.test.*;
029import com.oracle.graal.graph.iterators.*;
030import com.oracle.graal.nodes.*;
031
032public class ProbabilityDirectiveTest extends GraalCompilerTest {
033
034    public static int branchProbabilitySnippet(int arg) {
035        if (GraalDirectives.injectBranchProbability(0.125, arg > 0)) {
036            GraalDirectives.controlFlowAnchor(); // prevent removal of the if
037            return 1;
038        } else {
039            GraalDirectives.controlFlowAnchor(); // prevent removal of the if
040            return 2;
041        }
042    }
043
044    @Test
045    public void testBranchProbability() {
046        test("branchProbabilitySnippet", 5);
047    }
048
049    @Override
050    protected boolean checkLowTierGraph(StructuredGraph graph) {
051        NodeIterable<IfNode> ifNodes = graph.getNodes(IfNode.TYPE);
052        Assert.assertEquals("IfNode count", 1, ifNodes.count());
053
054        IfNode ifNode = ifNodes.first();
055        AbstractBeginNode trueSuccessor = ifNode.trueSuccessor();
056        Assert.assertEquals("branch probability of " + ifNode, 0.125, ifNode.probability(trueSuccessor), 0);
057
058        return true;
059    }
060}