edu.mit.streamjit.util.bytecode.insts.SwitchInst.java Source code

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Here is the source code for edu.mit.streamjit.util.bytecode.insts.SwitchInst.java

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/*
 * Copyright (c) 2013-2014 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package edu.mit.streamjit.util.bytecode.insts;

import com.google.common.base.Function;
import static com.google.common.base.Preconditions.*;
import com.google.common.base.Predicates;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.Iterables;
import edu.mit.streamjit.util.bytecode.BasicBlock;
import edu.mit.streamjit.util.bytecode.Constant;
import edu.mit.streamjit.util.bytecode.Value;
import java.util.Iterator;

/**
 * Transfers control to one of several possible blocks by comparing a value
 * against a map of integer constants to blocks.
 * @author Jeffrey Bosboom <jbosboom@csail.mit.edu>
 * @since 4/15/2013
 */
public final class SwitchInst extends TerminatorInst {
    public SwitchInst(Value expr, BasicBlock defaultBlock) {
        super(defaultBlock.getType().getTypeFactory(), 2);
        setValue(expr);
        setDefault(defaultBlock);
    }

    public Value getValue() {
        return getOperand(0);
    }

    public void setValue(Value v) {
        setOperand(0, v);
    }

    public BasicBlock getDefault() {
        return (BasicBlock) getOperand(1);
    }

    public void setDefault(BasicBlock bb) {
        setOperand(1, bb);
    }

    public BasicBlock get(Constant<Integer> cst) {
        int ci = Iterables.indexOf(operands(), Predicates.<Value>equalTo(cst));
        return ci != -1 ? (BasicBlock) getOperand(ci + 1) : null;
    }

    public BasicBlock put(Constant<Integer> cst, BasicBlock bb) {
        BasicBlock oldVal = get(cst);
        int ci = Iterables.indexOf(operands(), Predicates.<Value>equalTo(cst));
        if (ci != -1)
            setOperand(ci + 1, bb);
        else {
            addOperand(Iterables.size(operands()), cst);
            addOperand(Iterables.size(operands()), bb);
        }
        return oldVal;
    }

    @SuppressWarnings("unchecked")
    public FluentIterable<Constant<Integer>> cases() {
        return (FluentIterable<Constant<Integer>>) (FluentIterable) operands().filter(Constant.class);
    }

    @Override
    public SwitchInst clone(Function<Value, Value> operandMap) {
        SwitchInst i = new SwitchInst(operandMap.apply(getValue()), (BasicBlock) operandMap.apply(getDefault()));
        for (Constant<Integer> c : cases())
            i.put(((Constant<?>) (operandMap.apply(c))).as(Integer.class), (BasicBlock) operandMap.apply(get(c)));
        return i;
    }

    @Override
    protected void checkOperand(int i, Value v) {
        checkArgument(v instanceof BasicBlock
                || v.getType().isSubtypeOf(v.getType().getTypeFactory().getType(int.class)));
        super.checkOperand(i, v);
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder(getName());
        sb.append(": = switch ").append(getValue().getName());
        sb.append(" default ").append(getDefault().getName()).append(" ");
        for (Iterator<Value> i = operands().iterator(); i.hasNext();)
            sb.append("[").append(i.next().getName()).append(", ").append(i.next().getName()).append("], ");
        sb.delete(sb.length() - 2, sb.length());
        return sb.toString();
    }
}