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.lir.ssa;
024
025import java.util.*;
026
027import jdk.internal.jvmci.code.*;
028
029import com.oracle.graal.compiler.common.cfg.*;
030import com.oracle.graal.lir.*;
031import com.oracle.graal.lir.gen.*;
032import com.oracle.graal.lir.phases.*;
033
034public final class SSADestructionPhase extends PreAllocationOptimizationPhase {
035
036    @Override
037    protected <B extends AbstractBlockBase<B>> void run(TargetDescription target, LIRGenerationResult lirGenRes, List<B> codeEmittingOrder, List<B> linearScanOrder, LIRGeneratorTool lirGen) {
038        LIR lir = lirGenRes.getLIR();
039        AbstractControlFlowGraph<?> cfg = lir.getControlFlowGraph();
040        for (AbstractBlockBase<?> block : cfg.getBlocks()) {
041            doBlock(block, lir, lirGen);
042        }
043    }
044
045    private static void doBlock(AbstractBlockBase<?> block, LIR lir, LIRGeneratorTool lirGen) {
046        if (block.getPredecessorCount() > 1) {
047            for (AbstractBlockBase<?> pred : block.getPredecessors()) {
048
049                List<LIRInstruction> instructions = lir.getLIRforBlock(pred);
050
051                int insertBefore = SSAUtil.phiOutIndex(lir, pred);
052
053                PhiResolver resolver = PhiResolver.create(lirGen, new LIRInsertionBuffer(), instructions, insertBefore);
054                SSAUtil.forEachPhiValuePair(lir, block, pred, resolver::move);
055                resolver.dispose();
056
057                SSAUtil.removePhiOut(lir, pred);
058            }
059            SSAUtil.removePhiIn(lir, block);
060        }
061    }
062
063}