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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package com.oracle.graal.lir.profiling;

import static com.oracle.graal.api.code.ValueUtil.*;

import java.util.*;

import com.oracle.graal.api.code.*;
import com.oracle.graal.api.meta.*;
import com.oracle.graal.compiler.common.cfg.*;
import com.oracle.graal.lir.*;
import com.oracle.graal.lir.StandardOp.BlockEndOp;
import com.oracle.graal.lir.StandardOp.LabelOp;
import com.oracle.graal.lir.StandardOp.MoveOp;
import com.oracle.graal.lir.gen.*;
import com.oracle.graal.lir.phases.*;
import com.oracle.jvmci.common.*;

public class MoveProfiling extends PostAllocationOptimizationPhase {

    @Override
    protected <B extends AbstractBlockBase<B>> void run(TargetDescription target, LIRGenerationResult lirGenRes, List<B> codeEmittingOrder, List<B> linearScanOrder,
                    BenchmarkCounterFactory counterFactory) {
        new Analyzer(lirGenRes.getLIR(), counterFactory).run();
    }

    private static enum MoveType {
        REG2REG("Reg", "Reg"),
        STACK2REG("Reg", "Stack"),
        CONST2REG("Reg", "Const"),
        REG2STACK("Stack", "Reg"),
        CONST2STACK("Stack", "Const");

        private final String name;

        MoveType(String dst, String src) {
            this.name = String.format("%5s <- %s", dst, src);
        }

        @Override
        public String toString() {
            return name;
        }

        public static MoveType get(MoveOp move) {
            AllocatableValue dst = move.getResult();
            Value src = move.getInput();
            if (isRegister(dst)) {
                if (isRegister(src)) {
                    return REG2REG;
                }
                if (isStackSlot(src)) {
                    return STACK2REG;
                }
                if (isConstant(src)) {
                    return CONST2REG;
                }
            } else if (isStackSlot(dst)) {
                if (isRegister(src)) {
                    return REG2STACK;
                }
                if (isConstant(src)) {
                    return CONST2STACK;
                }
            }
            throw JVMCIError.shouldNotReachHere(String.format("Unrecognized Move: %s dst=%s, src=%s", move, dst, src));
        }
    }

    private static class Analyzer {
        private final LIR lir;
        private final BenchmarkCounterFactory counterFactory;
        private final LIRInsertionBuffer buffer;
        private final int[] cnt;

        public Analyzer(LIR lir, BenchmarkCounterFactory counterFactory) {
            this.lir = lir;
            this.counterFactory = counterFactory;
            this.buffer = new LIRInsertionBuffer();
            cnt = new int[MoveType.values().length];
        }

        public void run() {
            for (AbstractBlockBase<?> block : lir.getControlFlowGraph().getBlocks()) {
                doBlock(block);
            }
        }

        public void doBlock(AbstractBlockBase<?> block) {
            List<LIRInstruction> instructions = lir.getLIRforBlock(block);
            assert instructions.size() >= 2 : "Malformed block: " + block + ", " + instructions;
            assert instructions.get(instructions.size() - 1) instanceof BlockEndOp : "Not a BlockEndOp: " + instructions.get(instructions.size() - 1);
            assert !(instructions.get(instructions.size() - 2) instanceof BlockEndOp) : "Is a BlockEndOp: " + instructions.get(instructions.size() - 2);
            assert instructions.get(0) instanceof LabelOp : "Not a LabelOp: " + instructions.get(0);
            assert !(instructions.get(1) instanceof LabelOp) : "Is a LabelOp: " + instructions.get(1);

            // reset counters
            Arrays.fill(cnt, 0);
            // analysis phase
            for (LIRInstruction inst : instructions) {
                if (inst instanceof MoveOp) {
                    cnt[MoveType.get((MoveOp) inst).ordinal()]++;
                }
            }

            // counter insertion phase
            List<String> names = new ArrayList<>();
            List<Value> increments = new ArrayList<>();
            for (MoveType type : MoveType.values()) {
                int i = cnt[type.ordinal()];
                if (i > 0) {
                    names.add(type.toString());
                    increments.add(JavaConstant.forInt(i));
                }
            }
            String[] groups = new String[names.size()];
            Arrays.fill(groups, "Move Operations");
            if (names.size() > 0) { // Don't pollute LIR when nothing has to be done
                LIRInstruction inst = counterFactory.createMultiBenchmarkCounter(names.toArray(new String[0]), groups, increments.toArray(new Value[0]));
                assert inst != null;
                buffer.init(instructions);
                buffer.append(1, inst);
                buffer.finish();
            }
        }
    }

}