/*
 * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package org.graalvm.compiler.hotspot.amd64;

import static jdk.vm.ci.amd64.AMD64.rbp;
import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
import static org.graalvm.compiler.hotspot.HotSpotBackend.INITIALIZE_KLASS_BY_SYMBOL;
import static org.graalvm.compiler.hotspot.HotSpotBackend.RESOLVE_KLASS_BY_SYMBOL;
import static org.graalvm.compiler.hotspot.HotSpotBackend.RESOLVE_METHOD_BY_SYMBOL_AND_LOAD_COUNTERS;
import static org.graalvm.compiler.hotspot.HotSpotBackend.RESOLVE_STRING_BY_SYMBOL;
import static org.graalvm.compiler.hotspot.HotSpotBackend.RESOLVE_DYNAMIC_INVOKE;
import static org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction.RESOLVE;
import static org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction.INITIALIZE;
import static org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction.LOAD_COUNTERS;

import java.util.ArrayList;
import java.util.List;

import org.graalvm.compiler.asm.amd64.AMD64Address.Scale;
import org.graalvm.compiler.core.amd64.AMD64ArithmeticLIRGenerator;
import org.graalvm.compiler.core.amd64.AMD64LIRGenerator;
import org.graalvm.compiler.core.amd64.AMD64MoveFactoryBase.BackupSlotProvider;
import org.graalvm.compiler.core.common.CompressEncoding;
import org.graalvm.compiler.core.common.LIRKind;
import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
import org.graalvm.compiler.core.common.spi.ForeignCallLinkage;
import org.graalvm.compiler.core.common.spi.LIRKindTool;
import org.graalvm.compiler.debug.DebugContext;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
import org.graalvm.compiler.hotspot.HotSpotBackend;
import org.graalvm.compiler.hotspot.HotSpotDebugInfoBuilder;
import org.graalvm.compiler.hotspot.HotSpotForeignCallLinkage;
import org.graalvm.compiler.hotspot.HotSpotLIRGenerationResult;
import org.graalvm.compiler.hotspot.HotSpotLIRGenerator;
import org.graalvm.compiler.hotspot.HotSpotLockStack;
import org.graalvm.compiler.hotspot.debug.BenchmarkCounters;
import org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.hotspot.stubs.Stub;
import org.graalvm.compiler.lir.LIR;
import org.graalvm.compiler.lir.LIRFrameState;
import org.graalvm.compiler.lir.LIRInstruction;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.LabelRef;
import org.graalvm.compiler.lir.StandardOp.NoOp;
import org.graalvm.compiler.lir.SwitchStrategy;
import org.graalvm.compiler.lir.Variable;
import org.graalvm.compiler.lir.VirtualStackSlot;
import org.graalvm.compiler.lir.amd64.AMD64AddressValue;
import org.graalvm.compiler.lir.amd64.AMD64CCall;
import org.graalvm.compiler.lir.amd64.AMD64ControlFlow.StrategySwitchOp;
import org.graalvm.compiler.lir.amd64.AMD64FrameMapBuilder;
import org.graalvm.compiler.lir.amd64.AMD64Move;
import org.graalvm.compiler.lir.amd64.AMD64Move.MoveFromRegOp;
import org.graalvm.compiler.lir.amd64.AMD64PrefetchOp;
import org.graalvm.compiler.lir.amd64.AMD64ReadTimestampCounter;
import org.graalvm.compiler.lir.amd64.AMD64RestoreRegistersOp;
import org.graalvm.compiler.lir.amd64.AMD64SaveRegistersOp;
import org.graalvm.compiler.lir.amd64.AMD64VZeroUpper;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
import org.graalvm.compiler.lir.framemap.FrameMapBuilder;
import org.graalvm.compiler.lir.gen.LIRGenerationResult;
import org.graalvm.compiler.options.OptionValues;

import jdk.vm.ci.amd64.AMD64;
import jdk.vm.ci.amd64.AMD64Kind;
import jdk.vm.ci.code.CallingConvention;
import jdk.vm.ci.code.Register;
import jdk.vm.ci.code.RegisterConfig;
import jdk.vm.ci.code.RegisterValue;
import jdk.vm.ci.code.StackSlot;
import jdk.vm.ci.hotspot.HotSpotMetaspaceConstant;
import jdk.vm.ci.hotspot.HotSpotObjectConstant;
import jdk.vm.ci.meta.AllocatableValue;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.DeoptimizationAction;
import jdk.vm.ci.meta.DeoptimizationReason;
import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.PlatformKind;
import jdk.vm.ci.meta.PrimitiveConstant;
import jdk.vm.ci.meta.Value;

LIR generator specialized for AMD64 HotSpot.
/**
 * LIR generator specialized for AMD64 HotSpot.
 */
public class AMD64HotSpotLIRGenerator extends AMD64LIRGenerator implements HotSpotLIRGenerator {

    final GraalHotSpotVMConfig config;
    private HotSpotDebugInfoBuilder debugInfoBuilder;

    protected AMD64HotSpotLIRGenerator(HotSpotProviders providers, GraalHotSpotVMConfig config, LIRGenerationResult lirGenRes) {
        this(providers, config, lirGenRes, new BackupSlotProvider(lirGenRes.getFrameMapBuilder()));
    }

    private AMD64HotSpotLIRGenerator(HotSpotProviders providers, GraalHotSpotVMConfig config, LIRGenerationResult lirGenRes, BackupSlotProvider backupSlotProvider) {
        this(new AMD64HotSpotLIRKindTool(), new AMD64HotSpotArithmeticLIRGenerator(), new AMD64HotSpotMoveFactory(backupSlotProvider), providers, config, lirGenRes);
    }

    protected AMD64HotSpotLIRGenerator(LIRKindTool lirKindTool, AMD64ArithmeticLIRGenerator arithmeticLIRGen, MoveFactory moveFactory, HotSpotProviders providers, GraalHotSpotVMConfig config,
                    LIRGenerationResult lirGenRes) {
        super(lirKindTool, arithmeticLIRGen, moveFactory, providers, lirGenRes);
        assert config.basicLockSize == 8;
        this.config = config;
    }

    @Override
    public HotSpotProviders getProviders() {
        return (HotSpotProviders) super.getProviders();
    }

    
Utility for emitting the instruction to save RBP.
/**
     * Utility for emitting the instruction to save RBP.
     */
    class SaveRbp {

        final NoOp placeholder;

        
The slot reserved for saving RBP.
/**
         * The slot reserved for saving RBP.
         */
        final StackSlot reservedSlot;

        SaveRbp(NoOp placeholder) {
            this.placeholder = placeholder;
            AMD64FrameMapBuilder frameMapBuilder = (AMD64FrameMapBuilder) getResult().getFrameMapBuilder();
            this.reservedSlot = frameMapBuilder.allocateRBPSpillSlot();
        }

        
Replaces this operation with the appropriate move for saving rbp.
Params:
useStack – specifies if rbp must be saved to the stack/**
         * Replaces this operation with the appropriate move for saving rbp.
         *
         * @param useStack specifies if rbp must be saved to the stack
         */
        public AllocatableValue finalize(boolean useStack) {
            AllocatableValue dst;
            if (useStack) {
                dst = reservedSlot;
            } else {
                ((AMD64FrameMapBuilder) getResult().getFrameMapBuilder()).freeRBPSpillSlot();
                dst = newVariable(LIRKind.value(AMD64Kind.QWORD));
            }

            placeholder.replace(getResult().getLIR(), new MoveFromRegOp(AMD64Kind.QWORD, dst, rbp.asValue(LIRKind.value(AMD64Kind.QWORD))));
            return dst;
        }
    }

    private SaveRbp saveRbp;

    protected void emitSaveRbp() {
        NoOp placeholder = new NoOp(getCurrentBlock(), getResult().getLIR().getLIRforBlock(getCurrentBlock()).size());
        append(placeholder);
        saveRbp = new SaveRbp(placeholder);
    }

    protected SaveRbp getSaveRbp() {
        return saveRbp;
    }

    
Helper instruction to reserve a stack slot for the whole method. Note that the actual users
of the stack slot might be inserted after stack slot allocation. This dummy instruction
ensures that the stack slot is alive and gets a real stack slot assigned.
/**
     * Helper instruction to reserve a stack slot for the whole method. Note that the actual users
     * of the stack slot might be inserted after stack slot allocation. This dummy instruction
     * ensures that the stack slot is alive and gets a real stack slot assigned.
     */
    private static final class RescueSlotDummyOp extends LIRInstruction {
        public static final LIRInstructionClass<RescueSlotDummyOp> TYPE = LIRInstructionClass.create(RescueSlotDummyOp.class);

        @Alive({OperandFlag.STACK, OperandFlag.UNINITIALIZED}) private AllocatableValue slot;

        RescueSlotDummyOp(FrameMapBuilder frameMapBuilder, LIRKind kind) {
            super(TYPE);
            slot = frameMapBuilder.allocateSpillSlot(kind);
        }

        public AllocatableValue getSlot() {
            return slot;
        }

        @Override
        public void emitCode(CompilationResultBuilder crb) {
        }
    }

    private RescueSlotDummyOp rescueSlotOp;

    private AllocatableValue getOrInitRescueSlot() {
        RescueSlotDummyOp op = getOrInitRescueSlotOp();
        return op.getSlot();
    }

    private RescueSlotDummyOp getOrInitRescueSlotOp() {
        if (rescueSlotOp == null) {
            // create dummy instruction to keep the rescue slot alive
            rescueSlotOp = new RescueSlotDummyOp(getResult().getFrameMapBuilder(), getLIRKindTool().getWordKind());
        }
        return rescueSlotOp;
    }

    
List of epilogue operations that need to restore RBP.
/**
     * List of epilogue operations that need to restore RBP.
     */
    List<AMD64HotSpotRestoreRbpOp> epilogueOps = new ArrayList<>(2);

    @Override
    public <I extends LIRInstruction> I append(I op) {
        I ret = super.append(op);
        if (op instanceof AMD64HotSpotRestoreRbpOp) {
            epilogueOps.add((AMD64HotSpotRestoreRbpOp) op);
        }
        return ret;
    }

    @Override
    public VirtualStackSlot getLockSlot(int lockDepth) {
        return getLockStack().makeLockSlot(lockDepth);
    }

    private HotSpotLockStack getLockStack() {
        assert debugInfoBuilder != null && debugInfoBuilder.lockStack() != null;
        return debugInfoBuilder.lockStack();
    }

    private Register findPollOnReturnScratchRegister() {
        RegisterConfig regConfig = getProviders().getCodeCache().getRegisterConfig();
        for (Register r : regConfig.getAllocatableRegisters()) {
            if (!r.equals(regConfig.getReturnRegister(JavaKind.Long)) && !r.equals(AMD64.rbp)) {
                return r;
            }
        }
        throw GraalError.shouldNotReachHere();
    }

    private Register pollOnReturnScratchRegister;

    @Override
    public void emitReturn(JavaKind kind, Value input) {
        AllocatableValue operand = Value.ILLEGAL;
        if (input != null) {
            operand = resultOperandFor(kind, input.getValueKind());
            emitMove(operand, input);
        }
        if (pollOnReturnScratchRegister == null) {
            pollOnReturnScratchRegister = findPollOnReturnScratchRegister();
        }
        Register thread = getProviders().getRegisters().getThreadRegister();
        append(new AMD64HotSpotReturnOp(operand, getStub() != null, thread, pollOnReturnScratchRegister, config));
    }

    @Override
    public boolean needOnlyOopMaps() {
        // Stubs only need oop maps
        return getResult().getStub() != null;
    }

    private LIRFrameState currentRuntimeCallInfo;

    @Override
    protected void emitForeignCallOp(ForeignCallLinkage linkage, Value result, Value[] arguments, Value[] temps, LIRFrameState info) {
        currentRuntimeCallInfo = info;
        HotSpotForeignCallLinkage hsLinkage = (HotSpotForeignCallLinkage) linkage;
        AMD64 arch = (AMD64) target().arch;
        if (arch.getFeatures().contains(AMD64.CPUFeature.AVX) && hsLinkage.mayContainFP() && !hsLinkage.isCompiledStub()) {
            /*
             * If the target may contain FP ops, and it is not compiled by us, we may have an
             * AVX-SSE transition.
             *
             * We exclude the argument registers from the zeroing LIR instruction since it violates
             * the LIR semantics of @Temp that values must not be live. Note that the emitted
             * machine instruction actually zeros _all_ XMM registers which is fine since we know
             * that their upper half is not used.
             */
            append(new AMD64VZeroUpper(arguments));
        }
        super.emitForeignCallOp(linkage, result, arguments, temps, info);
    }

    
Params:
savedRegisters – the registers saved by this operation which may be subject to pruning
savedRegisterLocations – the slots to which the registers are saved
supportsRemove – determines if registers can be pruned/**
     * @param savedRegisters the registers saved by this operation which may be subject to pruning
     * @param savedRegisterLocations the slots to which the registers are saved
     * @param supportsRemove determines if registers can be pruned
     */
    protected AMD64SaveRegistersOp emitSaveRegisters(Register[] savedRegisters, AllocatableValue[] savedRegisterLocations, boolean supportsRemove) {
        AMD64SaveRegistersOp save = new AMD64SaveRegistersOp(savedRegisters, savedRegisterLocations, supportsRemove);
        append(save);
        return save;
    }

    
Allocate a stack slot for saving a register.
/**
     * Allocate a stack slot for saving a register.
     */
    protected VirtualStackSlot allocateSaveRegisterLocation(Register register) {
        PlatformKind kind = target().arch.getLargestStorableKind(register.getRegisterCategory());
        if (kind.getVectorLength() > 1) {
            // we don't use vector registers, so there is no need to save them
            kind = AMD64Kind.DOUBLE;
        }
        return getResult().getFrameMapBuilder().allocateSpillSlot(LIRKind.value(kind));
    }

    
Adds a node to the graph that saves all allocatable registers to the stack.
Params:
supportsRemove – determines if registers can be pruned
Returns:
the register save node/**
     * Adds a node to the graph that saves all allocatable registers to the stack.
     *
     * @param supportsRemove determines if registers can be pruned
     * @return the register save node
     */
    private AMD64SaveRegistersOp emitSaveAllRegisters(Register[] savedRegisters, boolean supportsRemove) {
        AllocatableValue[] savedRegisterLocations = new AllocatableValue[savedRegisters.length];
        for (int i = 0; i < savedRegisters.length; i++) {
            savedRegisterLocations[i] = allocateSaveRegisterLocation(savedRegisters[i]);
        }
        return emitSaveRegisters(savedRegisters, savedRegisterLocations, supportsRemove);
    }

    protected void emitRestoreRegisters(AMD64SaveRegistersOp save) {
        append(new AMD64RestoreRegistersOp(save.getSlots().clone(), save));
    }

    
Gets the Stub this generator is generating code for or null if a stub is not being generated. /**
     * Gets the {@link Stub} this generator is generating code for or {@code null} if a stub is not
     * being generated.
     */
    public Stub getStub() {
        return getResult().getStub();
    }

    @Override
    public HotSpotLIRGenerationResult getResult() {
        return ((HotSpotLIRGenerationResult) super.getResult());
    }

    public void setDebugInfoBuilder(HotSpotDebugInfoBuilder debugInfoBuilder) {
        this.debugInfoBuilder = debugInfoBuilder;
    }

    @Override
    public Variable emitForeignCall(ForeignCallLinkage linkage, LIRFrameState state, Value... args) {
        HotSpotForeignCallLinkage hotspotLinkage = (HotSpotForeignCallLinkage) linkage;
        boolean destroysRegisters = hotspotLinkage.destroysRegisters();

        AMD64SaveRegistersOp save = null;
        Stub stub = getStub();
        if (destroysRegisters) {
            if (stub != null && stub.preservesRegisters()) {
                Register[] savedRegisters = getRegisterConfig().getAllocatableRegisters().toArray();
                save = emitSaveAllRegisters(savedRegisters, true);
            }
        }

        Variable result;
        LIRFrameState debugInfo = null;
        if (hotspotLinkage.needsDebugInfo()) {
            debugInfo = state;
            assert debugInfo != null || stub != null;
        }

        if (hotspotLinkage.needsJavaFrameAnchor()) {
            Register thread = getProviders().getRegisters().getThreadRegister();
            append(new AMD64HotSpotCRuntimeCallPrologueOp(config.threadLastJavaSpOffset(), thread));
            result = super.emitForeignCall(hotspotLinkage, debugInfo, args);
            append(new AMD64HotSpotCRuntimeCallEpilogueOp(config.threadLastJavaSpOffset(), config.threadLastJavaFpOffset(), config.threadLastJavaPcOffset(), thread));
        } else {
            result = super.emitForeignCall(hotspotLinkage, debugInfo, args);
        }

        if (destroysRegisters) {
            if (stub != null) {
                if (stub.preservesRegisters()) {
                    HotSpotLIRGenerationResult generationResult = getResult();
                    LIRFrameState key = currentRuntimeCallInfo;
                    if (key == null) {
                        key = LIRFrameState.NO_STATE;
                    }
                    assert !generationResult.getCalleeSaveInfo().containsKey(key);
                    generationResult.getCalleeSaveInfo().put(key, save);
                    emitRestoreRegisters(save);
                }
            }
        }

        return result;
    }

    @Override
    public Value emitLoadObjectAddress(Constant constant) {
        HotSpotObjectConstant objectConstant = (HotSpotObjectConstant) constant;
        LIRKind kind = objectConstant.isCompressed() ? getLIRKindTool().getNarrowOopKind() : getLIRKindTool().getObjectKind();
        Variable result = newVariable(kind);
        append(new AMD64HotSpotLoadAddressOp(result, constant, HotSpotConstantLoadAction.RESOLVE));
        return result;
    }

    @Override
    public Value emitLoadMetaspaceAddress(Constant constant, HotSpotConstantLoadAction action) {
        HotSpotMetaspaceConstant metaspaceConstant = (HotSpotMetaspaceConstant) constant;
        LIRKind kind = metaspaceConstant.isCompressed() ? getLIRKindTool().getNarrowPointerKind() : getLIRKindTool().getWordKind();
        Variable result = newVariable(kind);
        append(new AMD64HotSpotLoadAddressOp(result, constant, action));
        return result;
    }

    private Value emitConstantRetrieval(ForeignCallDescriptor foreignCall, Object[] notes, Constant[] constants, AllocatableValue[] constantDescriptions, LIRFrameState frameState) {
        ForeignCallLinkage linkage = getForeignCalls().lookupForeignCall(foreignCall);
        append(new AMD64HotSpotConstantRetrievalOp(constants, constantDescriptions, frameState, linkage, notes));
        AllocatableValue result = linkage.getOutgoingCallingConvention().getReturn();
        return emitMove(result);
    }

    private Value emitConstantRetrieval(ForeignCallDescriptor foreignCall, HotSpotConstantLoadAction action, Constant constant, AllocatableValue[] constantDescriptions, LIRFrameState frameState) {
        Constant[] constants = new Constant[]{constant};
        Object[] notes = new Object[]{action};
        return emitConstantRetrieval(foreignCall, notes, constants, constantDescriptions, frameState);
    }

    private Value emitConstantRetrieval(ForeignCallDescriptor foreignCall, HotSpotConstantLoadAction action, Constant constant, Value constantDescription, LIRFrameState frameState) {
        AllocatableValue[] constantDescriptions = new AllocatableValue[]{asAllocatable(constantDescription)};
        return emitConstantRetrieval(foreignCall, action, constant, constantDescriptions, frameState);
    }

    @Override
    public Value emitObjectConstantRetrieval(Constant constant, Value constantDescription, LIRFrameState frameState) {
        return emitConstantRetrieval(RESOLVE_STRING_BY_SYMBOL, RESOLVE, constant, constantDescription, frameState);
    }

    @Override
    public Value emitMetaspaceConstantRetrieval(Constant constant, Value constantDescription, LIRFrameState frameState) {
        return emitConstantRetrieval(RESOLVE_KLASS_BY_SYMBOL, RESOLVE, constant, constantDescription, frameState);
    }

    @Override
    public Value emitKlassInitializationAndRetrieval(Constant constant, Value constantDescription, LIRFrameState frameState) {
        return emitConstantRetrieval(INITIALIZE_KLASS_BY_SYMBOL, INITIALIZE, constant, constantDescription, frameState);
    }

    @Override
    public Value emitResolveMethodAndLoadCounters(Constant method, Value klassHint, Value methodDescription, LIRFrameState frameState) {
        AllocatableValue[] constantDescriptions = new AllocatableValue[]{asAllocatable(klassHint), asAllocatable(methodDescription)};
        return emitConstantRetrieval(RESOLVE_METHOD_BY_SYMBOL_AND_LOAD_COUNTERS, LOAD_COUNTERS, method, constantDescriptions, frameState);
    }

    @Override
    public Value emitResolveDynamicInvoke(Constant appendix, LIRFrameState frameState) {
        AllocatableValue[] constantDescriptions = new AllocatableValue[0];
        return emitConstantRetrieval(RESOLVE_DYNAMIC_INVOKE, INITIALIZE, appendix, constantDescriptions, frameState);
    }

    @Override
    public Value emitLoadConfigValue(int markId, LIRKind kind) {
        Variable result = newVariable(kind);
        append(new AMD64HotSpotLoadConfigValueOp(markId, result));
        return result;
    }

    @Override
    public Value emitRandomSeed() {
        AMD64ReadTimestampCounter timestamp = new AMD64ReadTimestampCounter();
        append(timestamp);
        return emitMove(timestamp.getLowResult());
    }

    @Override
    public void emitTailcall(Value[] args, Value address) {
        append(new AMD64TailcallOp(args, address));
    }

    @Override
    public void emitCCall(long address, CallingConvention nativeCallingConvention, Value[] args, int numberOfFloatingPointArguments) {
        Value[] argLocations = new Value[args.length];
        getResult().getFrameMapBuilder().callsMethod(nativeCallingConvention);
        // TODO(mg): in case a native function uses floating point varargs, the ABI requires that
        // RAX contains the length of the varargs
        PrimitiveConstant intConst = JavaConstant.forInt(numberOfFloatingPointArguments);
        AllocatableValue numberOfFloatingPointArgumentsRegister = AMD64.rax.asValue(LIRKind.value(AMD64Kind.DWORD));
        emitMoveConstant(numberOfFloatingPointArgumentsRegister, intConst);
        for (int i = 0; i < args.length; i++) {
            Value arg = args[i];
            AllocatableValue loc = nativeCallingConvention.getArgument(i);
            emitMove(loc, arg);
            argLocations[i] = loc;
        }
        Value ptr = emitLoadConstant(LIRKind.value(AMD64Kind.QWORD), JavaConstant.forLong(address));
        append(new AMD64CCall(nativeCallingConvention.getReturn(), ptr, numberOfFloatingPointArgumentsRegister, argLocations));
    }

    @Override
    public void emitUnwind(Value exception) {
        ForeignCallLinkage linkage = getForeignCalls().lookupForeignCall(HotSpotBackend.UNWIND_EXCEPTION_TO_CALLER);
        CallingConvention outgoingCc = linkage.getOutgoingCallingConvention();
        assert outgoingCc.getArgumentCount() == 2;
        RegisterValue exceptionParameter = (RegisterValue) outgoingCc.getArgument(0);
        emitMove(exceptionParameter, exception);
        append(new AMD64HotSpotUnwindOp(exceptionParameter));
    }

    private void moveDeoptValuesToThread(Value actionAndReason, Value speculation) {
        moveValueToThread(actionAndReason, config.pendingDeoptimizationOffset);
        moveValueToThread(speculation, config.pendingFailedSpeculationOffset);
    }

    private void moveValueToThread(Value v, int offset) {
        LIRKind wordKind = LIRKind.value(target().arch.getWordKind());
        RegisterValue thread = getProviders().getRegisters().getThreadRegister().asValue(wordKind);
        AMD64AddressValue address = new AMD64AddressValue(wordKind, thread, offset);
        arithmeticLIRGen.emitStore(v.getValueKind(), address, v, null);
    }

    @Override
    public void emitDeoptimize(Value actionAndReason, Value speculation, LIRFrameState state) {
        moveDeoptValuesToThread(actionAndReason, speculation);
        append(new AMD64DeoptimizeOp(state));
    }

    @Override
    public void emitDeoptimizeCaller(DeoptimizationAction action, DeoptimizationReason reason) {
        Value actionAndReason = emitJavaConstant(getMetaAccess().encodeDeoptActionAndReason(action, reason, 0));
        Value nullValue = emitConstant(LIRKind.reference(AMD64Kind.QWORD), JavaConstant.NULL_POINTER);
        moveDeoptValuesToThread(actionAndReason, nullValue);
        append(new AMD64HotSpotDeoptimizeCallerOp());
    }

    @Override
    public void beforeRegisterAllocation() {
        super.beforeRegisterAllocation();
        boolean hasDebugInfo = getResult().getLIR().hasDebugInfo();
        AllocatableValue savedRbp = saveRbp.finalize(hasDebugInfo);
        if (hasDebugInfo) {
            getResult().setDeoptimizationRescueSlot(((AMD64FrameMapBuilder) getResult().getFrameMapBuilder()).allocateDeoptimizationRescueSlot());
        }

        getResult().setMaxInterpreterFrameSize(debugInfoBuilder.maxInterpreterFrameSize());

        for (AMD64HotSpotRestoreRbpOp op : epilogueOps) {
            op.setSavedRbp(savedRbp);
        }
        if (BenchmarkCounters.enabled) {
            // ensure that the rescue slot is available
            LIRInstruction op = getOrInitRescueSlotOp();
            // insert dummy instruction into the start block
            LIR lir = getResult().getLIR();
            ArrayList<LIRInstruction> instructions = lir.getLIRforBlock(lir.getControlFlowGraph().getStartBlock());
            instructions.add(1, op);
            lir.getDebug().dump(DebugContext.INFO_LEVEL, lir, "created rescue dummy op");
        }
    }

    @Override
    public Value emitCompress(Value pointer, CompressEncoding encoding, boolean nonNull) {
        LIRKind inputKind = pointer.getValueKind(LIRKind.class);
        LIRKindTool lirKindTool = getLIRKindTool();
        assert inputKind.getPlatformKind() == lirKindTool.getObjectKind().getPlatformKind();
        if (inputKind.isReference(0)) {
            // oop
            Variable result = newVariable(lirKindTool.getNarrowOopKind());
            append(new AMD64Move.CompressPointer(result, asAllocatable(pointer), getProviders().getRegisters().getHeapBaseRegister().asValue(), encoding, nonNull, getLIRKindTool()));
            return result;
        } else {
            // metaspace pointer
            Variable result = newVariable(lirKindTool.getNarrowPointerKind());
            AllocatableValue base = Value.ILLEGAL;
            OptionValues options = getResult().getLIR().getOptions();
            if (encoding.hasBase() || GeneratePIC.getValue(options)) {
                if (GeneratePIC.getValue(options)) {
                    Variable baseAddress = newVariable(lirKindTool.getWordKind());
                    AMD64HotSpotMove.BaseMove move = new AMD64HotSpotMove.BaseMove(baseAddress, config);
                    append(move);
                    base = baseAddress;
                } else {
                    base = emitLoadConstant(lirKindTool.getWordKind(), JavaConstant.forLong(encoding.getBase()));
                }
            }
            append(new AMD64Move.CompressPointer(result, asAllocatable(pointer), base, encoding, nonNull, getLIRKindTool()));
            return result;
        }
    }

    @Override
    public Value emitUncompress(Value pointer, CompressEncoding encoding, boolean nonNull) {
        LIRKind inputKind = pointer.getValueKind(LIRKind.class);
        LIRKindTool lirKindTool = getLIRKindTool();
        assert inputKind.getPlatformKind() == lirKindTool.getNarrowOopKind().getPlatformKind();
        if (inputKind.isReference(0)) {
            // oop
            Variable result = newVariable(lirKindTool.getObjectKind());
            append(new AMD64Move.UncompressPointer(result, asAllocatable(pointer), getProviders().getRegisters().getHeapBaseRegister().asValue(), encoding, nonNull, lirKindTool));
            return result;
        } else {
            // metaspace pointer
            LIRKind uncompressedKind = lirKindTool.getWordKind();
            Variable result = newVariable(uncompressedKind);
            AllocatableValue base = Value.ILLEGAL;
            OptionValues options = getResult().getLIR().getOptions();
            if (encoding.hasBase() || GeneratePIC.getValue(options)) {
                if (GeneratePIC.getValue(options)) {
                    Variable baseAddress = newVariable(uncompressedKind);
                    AMD64HotSpotMove.BaseMove move = new AMD64HotSpotMove.BaseMove(baseAddress, config);
                    append(move);
                    base = baseAddress;
                } else {
                    base = emitLoadConstant(uncompressedKind, JavaConstant.forLong(encoding.getBase()));
                }
            }
            append(new AMD64Move.UncompressPointer(result, asAllocatable(pointer), base, encoding, nonNull, lirKindTool));
            return result;
        }
    }

    @Override
    public void emitNullCheck(Value address, LIRFrameState state) {
        if (address.getValueKind().getPlatformKind() == getLIRKindTool().getNarrowOopKind().getPlatformKind()) {
            CompressEncoding encoding = config.getOopEncoding();
            Value uncompressed;
            if (encoding.getShift() <= 3) {
                LIRKind wordKind = LIRKind.unknownReference(target().arch.getWordKind());
                uncompressed = new AMD64AddressValue(wordKind, getProviders().getRegisters().getHeapBaseRegister().asValue(wordKind), asAllocatable(address), Scale.fromInt(1 << encoding.getShift()),
                                0);
            } else {
                uncompressed = emitUncompress(address, encoding, false);
            }
            append(new AMD64Move.NullCheckOp(asAddressValue(uncompressed), state));
            return;
        }
        super.emitNullCheck(address, state);
    }

    @Override
    public LIRInstruction createBenchmarkCounter(String name, String group, Value increment) {
        if (BenchmarkCounters.enabled) {
            return new AMD64HotSpotCounterOp(name, group, increment, getProviders().getRegisters(), config, getOrInitRescueSlot());
        }
        throw GraalError.shouldNotReachHere("BenchmarkCounters are not enabled!");
    }

    @Override
    public LIRInstruction createMultiBenchmarkCounter(String[] names, String[] groups, Value[] increments) {
        if (BenchmarkCounters.enabled) {
            return new AMD64HotSpotCounterOp(names, groups, increments, getProviders().getRegisters(), config, getOrInitRescueSlot());
        }
        throw GraalError.shouldNotReachHere("BenchmarkCounters are not enabled!");
    }

    @Override
    public void emitPrefetchAllocate(Value address) {
        append(new AMD64PrefetchOp(asAddressValue(address), config.allocatePrefetchInstr));
    }

    @Override
    protected StrategySwitchOp createStrategySwitchOp(SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Variable key, AllocatableValue temp) {
        return new AMD64HotSpotStrategySwitchOp(strategy, keyTargets, defaultTarget, key, temp);
    }
}