de.tuberlin.uebb.jbop.optimizer.loop.ForLoopUnrollerTest.java Source code

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/*
 * Copyright (C) 2013 uebb.tu-berlin.de.
 * 
 * This file is part of JBOP (Java Bytecode OPtimizer).
 * 
 * JBOP is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * JBOP 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with JBOP. If not, see <http://www.gnu.org/licenses/>.
 */
package de.tuberlin.uebb.jbop.optimizer.loop;

import static org.junit.Assert.assertEquals;
import static org.objectweb.asm.Opcodes.GOTO;
import static org.objectweb.asm.Opcodes.ICONST_0;
import static org.objectweb.asm.Opcodes.ICONST_5;
import static org.objectweb.asm.Opcodes.IF_ICMPGT;
import static org.objectweb.asm.Opcodes.IF_ICMPLT;
import static org.objectweb.asm.Opcodes.IINC;
import static org.objectweb.asm.Opcodes.ILOAD;
import static org.objectweb.asm.Opcodes.ISTORE;
import static org.objectweb.asm.Opcodes.NOP;

import org.junit.Before;
import org.junit.Test;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.IincInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;

import de.tuberlin.uebb.jbop.optimizer.ClassNodeBuilder;
import de.tuberlin.uebb.jbop.optimizer.utils.NodeHelper;

/**
 * Tests for {@link ForLoopUnroller}.
 * 
 * @author Christopher Ewest
 */
public class ForLoopUnrollerTest {

    private ClassNodeBuilder builder;
    private MethodNode method;
    private final ForLoopUnroller optimizer = new ForLoopUnroller();

    /**
     * Init for every test.
     */
    @Before
    public void before() {
        builder = ClassNodeBuilder.createClass("de.tuberlin.uebb.jbop.optimizer.loop.ForLoopTestClass").//
                addMethod("testLoop", "()V");//
        method = builder.getMethod("testLoop");
    }

    /**
     * Tests that ForLoopUnroller is working correctly.
     * 
     * Used is a loop of the kind:
     * 
     * for(int i=0; i< 3; ++i)
     */
    @Test
    public void testForLoopUnrollerStrictForward() {
        // INIT
        final LabelNode label1 = new LabelNode();
        final LabelNode label2 = new LabelNode();
        builder.addInsn(new InsnNode(Opcodes.ICONST_0)).//
                addInsn(new VarInsnNode(Opcodes.ISTORE, 1)).//
                addInsn(new JumpInsnNode(Opcodes.GOTO, label1)).//
                addInsn(label2).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new InsnNode(Opcodes.IADD)).//
                addInsn(new IincInsnNode(1, 1)).//
                addInsn(label1).//
                addInsn(NodeHelper.getInsnNodeFor(3)).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new JumpInsnNode(Opcodes.IF_ICMPLT, label2)).//
                addInsn(new InsnNode(Opcodes.RETURN));

        // RUN
        assertEquals(13, method.instructions.size());
        final InsnList optimized = optimizer.optimize(method.instructions, method);

        // ASSERT
        assertEquals(19, optimized.size());

        int node = 0;
        for (int i = 0; i < 3; ++i) {
            assertEquals(i, NodeHelper.getNumberValue(optimized.get(node)).intValue());
            node++;
            assertEquals(Opcodes.ISTORE, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.ILOAD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.ILOAD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.IADD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode()); // this is the SkipMarkNode
            node++;
        }
    }

    /**
     * Tests that ForLoopUnroller is working correctly.
     * 
     * Used is a loop of the kind:
     * 
     * for(int i=6; i> 0; i=i-2)
     */
    @Test
    public void testForLoopUnrollerBackward() {
        // INIT
        final LabelNode label1 = new LabelNode();
        final LabelNode label2 = new LabelNode();
        builder.addInsn(NodeHelper.getInsnNodeFor(6)).//
                addInsn(new VarInsnNode(Opcodes.ISTORE, 1)).//
                addInsn(new JumpInsnNode(Opcodes.GOTO, label1)).//
                addInsn(label2).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new InsnNode(Opcodes.IADD)).//
                addInsn(new IincInsnNode(1, -2)).//
                addInsn(label1).//
                addInsn(new VarInsnNode(Opcodes.ILOAD, 1)).//
                addInsn(new JumpInsnNode(Opcodes.IFGT, label2)).//
                addInsn(new InsnNode(Opcodes.RETURN));

        // RUN
        assertEquals(12, method.instructions.size());
        final InsnList optimized = optimizer.optimize(method.instructions, method);

        // ASSERT
        assertEquals(19, optimized.size());

        int node = 0;
        for (int i = 6; i > 0; i -= 2) {
            assertEquals(i, NodeHelper.getNumberValue(optimized.get(node)).intValue());
            node++;
            assertEquals(Opcodes.ISTORE, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.ILOAD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.ILOAD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.IADD, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
            node++;
        }
    }

    /**
     * Tests the LoopUnroller for an empty loop.
     */
    @Test
    public void testForLoopUnrollerEmptyLoop() {
        // INIT
        final LabelNode label1 = new LabelNode();
        final LabelNode label2 = new LabelNode();
        builder.add(ICONST_0).//
                add(ISTORE, 1).//
                add(GOTO, label1).//
                addInsn(label2).//
                add(IINC, 1, 1).//
                addInsn(label1).//
                add(ICONST_5).//
                add(ILOAD, 1).//
                add(IF_ICMPLT, label2).//
                addReturn();

        // RUN
        assertEquals(10, method.instructions.size());
        final InsnList optimized = optimizer.optimize(method.instructions, method);

        // ASSERT
        assertEquals(1, optimized.size()); //
    }

    /**
     * Tests the Loopunroller for a loop with the test-instructions at the beginning.
     */
    @Test
    public void testForLoopTypeTwo() {
        // INIT
        final LabelNode check = new LabelNode();
        final LabelNode ende = new LabelNode();
        builder.add(ICONST_0)//
                .add(ISTORE, 1)//
                .addInsn(check)//
                .add(ICONST_5)//
                .add(ILOAD, 1)//
                .add(IF_ICMPGT, ende)//
                .add(NOP)//
                .add(NOP)//
                .add(NOP)//
                .add(IINC, 1, 1)//
                .add(GOTO, check)//
                .addInsn(ende)//
                .add(NOP)//
                .addReturn();

        // RUN
        assertEquals(14, method.instructions.size());
        final InsnList optimized = optimizer.optimize(method.instructions, method);

        // ASSERT
        assertEquals(38, optimized.size()); //
        int node = 0;
        for (int i = 0; i < 6; ++i) {
            assertEquals(i, NodeHelper.getNumberValue(optimized.get(node)).intValue());
            node++;
            assertEquals(Opcodes.ISTORE, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
            node++;
            assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
            node++;
        }
        assertEquals(Opcodes.NOP, optimized.get(node).getOpcode());
        node++;
        assertEquals(Opcodes.RETURN, optimized.get(node).getOpcode());
        node++;
    }
}