org.formulacompiler.compiler.internal.bytecode.HelperCompilerForFoldChained.java Source code

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Here is the source code for org.formulacompiler.compiler.internal.bytecode.HelperCompilerForFoldChained.java

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/*
 * Copyright (c) 2006-2009 by Abacus Research AG, Switzerland.
 * All rights reserved.
 *
 * This file is part of the Abacus Formula Compiler (AFC).
 *
 * For commercial licensing, please contact sales(at)formulacompiler.com.
 *
 * AFC is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * AFC 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with AFC.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.formulacompiler.compiler.internal.bytecode;

import java.util.Collection;

import org.formulacompiler.compiler.CompilerException;
import org.formulacompiler.compiler.internal.expressions.DataType;
import org.formulacompiler.compiler.internal.expressions.ExpressionNode;
import org.formulacompiler.compiler.internal.expressions.ExpressionNodeForFoldApply;
import org.formulacompiler.compiler.internal.expressions.LetDictionary.LetEntry;
import org.formulacompiler.compiler.internal.model.ExpressionNodeForSubSectionModel;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

@SuppressWarnings("unqualified-field-access")
final class HelperCompilerForFoldChained extends HelperCompilerForFolds {
    static final Compilable TOP_OF_STACK = new Compilable() {
        public void compile(final ExpressionCompiler _exp) throws CompilerException {
            // Nothing to do here.
        }

        public boolean isArray() {
            return false;
        }
    };

    private final ChainedFoldCompiler chainedCompiler;

    public HelperCompilerForFoldChained(SectionCompiler _section, ExpressionNodeForFoldApply _applyNode,
            Iterable<LetEntry<Compilable>> _closure) {
        super(_section, _applyNode, _closure);
        this.chainedCompiler = new ChainedFoldCompiler(expressionCompiler(), _applyNode);
    }

    @Override
    protected void compileBody() throws CompilerException {
        assert ChainedFoldCompiler.isChainable(fold) && !fold.isSpecialWhenEmpty();
        final ExpressionNode initNode = fold.accuInit(0);
        final DataType initType = initNode.getDataType();
        final Iterable<ExpressionNode> elts = apply.elements();
        final ExpressionNode initialElt = fold.mayReduceAndRearrange() ? firstLocalElementIn(elts) : null;
        final ExpressionNode initial = (null != initialElt) ? initialElt : initNode;

        expressionCompiler().compile(initial);

        final String accName = fold.accuName(0);
        letDict().let(accName, initType, TOP_OF_STACK);

        chainedCompiler.compileFoldOverLocalValues(elts, initialElt);

        if (expressionCompiler().isSubSectionIn(elts)) {
            setupAccumulator(initType);
            compileAccumulatorStore();

            compileFoldOverSubSections(elts);

            compileAccumulatorLoad();
        }
        mv().returnValue();

        letDict().unlet(accName);
    }

    private void compileFoldOverSubSections(Iterable<ExpressionNode> _elts) throws CompilerException {
        final int reuseLocalsAt = localsOffset();
        for (final ExpressionNode elt : _elts) {
            if (elt instanceof ExpressionNodeForSubSectionModel) {
                resetLocalsTo(reuseLocalsAt);

                expressionCompiler().compileSubSectionTraversal((ExpressionNodeForSubSectionModel) elt,
                        new ExpressionCompiler.SubSectionTraversal() {

                            public void compile(Collection<ExpressionNode> _elements, int _indexLocalOffset)
                                    throws CompilerException {
                                if (null != firstLocalElementIn(_elements)) {
                                    compileAccumulatorLoad();
                                    chainedCompiler.compileFoldOverLocalValues(_elements, null);
                                    compileAccumulatorStore();
                                }
                                compileFoldOverSubSections(_elements);
                            }

                        });

            }
        }
    }

    private Type accuType;
    private int accuVar;

    private void setupAccumulator(DataType _type) {
        accuType = section().engineCompiler().typeCompiler(_type).type();
        accuVar = newLocal(accuType.getSize());
    }

    private void compileAccumulatorStore() {
        mv().visitVarInsn(accuType.getOpcode(Opcodes.ISTORE), accuVar);
    }

    private void compileAccumulatorLoad() {
        mv().visitVarInsn(accuType.getOpcode(Opcodes.ILOAD), accuVar);
    }

}