/*

 * Copyright (c) 2018, Red Hat Inc. 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.aarch64;

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_DYNAMIC_INVOKE;

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.meta.HotSpotConstantLoadAction.INITIALIZE;

import static org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction.LOAD_COUNTERS;

import static org.graalvm.compiler.hotspot.meta.HotSpotConstantLoadAction.RESOLVE;

import static org.graalvm.compiler.lir.LIRValueUtil.asConstant;

import static org.graalvm.compiler.lir.LIRValueUtil.isConstantValue;

import java.util.function.Function;

import org.graalvm.compiler.asm.Label;

import org.graalvm.compiler.asm.aarch64.AArch64Address.AddressingMode;

import org.graalvm.compiler.asm.aarch64.AArch64Assembler.ConditionFlag;

import org.graalvm.compiler.asm.aarch64.AArch64Assembler.PrefetchMode;

import org.graalvm.compiler.core.aarch64.AArch64ArithmeticLIRGenerator;

import org.graalvm.compiler.core.aarch64.AArch64LIRGenerator;

import org.graalvm.compiler.core.aarch64.AArch64LIRKindTool;

import org.graalvm.compiler.core.common.CompressEncoding;

import org.graalvm.compiler.core.common.LIRKind;

import org.graalvm.compiler.core.common.calc.Condition;

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.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.meta.HotSpotConstantLoadAction;

import org.graalvm.compiler.hotspot.meta.HotSpotProviders;

import org.graalvm.compiler.hotspot.meta.HotSpotRegistersProvider;

import org.graalvm.compiler.hotspot.stubs.Stub;

import org.graalvm.compiler.lir.LIRFrameState;

import org.graalvm.compiler.lir.LIRInstruction;

import org.graalvm.compiler.lir.LabelRef;

import org.graalvm.compiler.lir.SwitchStrategy;

import org.graalvm.compiler.lir.Variable;

import org.graalvm.compiler.lir.VirtualStackSlot;

import org.graalvm.compiler.lir.aarch64.AArch64AddressValue;

import org.graalvm.compiler.lir.aarch64.AArch64CCall;

import org.graalvm.compiler.lir.aarch64.AArch64Call;

import org.graalvm.compiler.lir.aarch64.AArch64ControlFlow.StrategySwitchOp;

import org.graalvm.compiler.lir.aarch64.AArch64FrameMapBuilder;

import org.graalvm.compiler.lir.aarch64.AArch64Move;

import org.graalvm.compiler.lir.aarch64.AArch64Move.StoreOp;

import org.graalvm.compiler.lir.aarch64.AArch64PrefetchOp;

import org.graalvm.compiler.lir.aarch64.AArch64RestoreRegistersOp;

import org.graalvm.compiler.lir.aarch64.AArch64SaveRegistersOp;

import org.graalvm.compiler.lir.gen.LIRGenerationResult;

import org.graalvm.compiler.options.OptionValues;

import jdk.vm.ci.aarch64.AArch64;

import jdk.vm.ci.aarch64.AArch64Kind;

import jdk.vm.ci.code.CallingConvention;

import jdk.vm.ci.code.Register;

import jdk.vm.ci.code.RegisterValue;

import jdk.vm.ci.code.StackSlot;

import jdk.vm.ci.hotspot.HotSpotCompressedNullConstant;

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.SpeculationLog;

import jdk.vm.ci.meta.Value;

/**

 * LIR generator specialized for AArch64 HotSpot.

 */

public class AArch64HotSpotLIRGenerator extends AArch64LIRGenerator implements HotSpotLIRGenerator {

    final GraalHotSpotVMConfig config;

    private HotSpotDebugInfoBuilder debugInfoBuilder;

    protected AArch64HotSpotLIRGenerator(HotSpotProviders providers, GraalHotSpotVMConfig config, LIRGenerationResult lirGenRes) {

        this(new AArch64LIRKindTool(), new AArch64ArithmeticLIRGenerator(null), new AArch64HotSpotMoveFactory(), providers, config, lirGenRes);

    }

    protected AArch64HotSpotLIRGenerator(LIRKindTool lirKindTool, AArch64ArithmeticLIRGenerator arithmeticLIRGen, MoveFactory moveFactory, HotSpotProviders providers, GraalHotSpotVMConfig config,

                    LIRGenerationResult lirGenRes) {

        super(lirKindTool, arithmeticLIRGen, moveFactory, providers, lirGenRes);

        this.config = config;

    }

    @Override

    public HotSpotProviders getProviders() {

        return (HotSpotProviders) super.getProviders();

    }

    @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;

        if (AArch64Call.isNearCall(linkage)) {

            append(new AArch64Call.DirectNearForeignCallOp(linkage, result, arguments, temps, info, label));

        } else {

            append(new AArch64Call.DirectFarForeignCallOp(linkage, result, arguments, temps, info, label));

        }

    }

    @Override

    public void emitTailcall(Value[] args, Value address) {

        throw GraalError.unimplemented();

    }

    @Override

    public void emitCCall(long address, CallingConvention nativeCallingConvention, Value[] args) {

        Value[] argLocations = new Value[args.length];

        getResult().getFrameMapBuilder().callsMethod(nativeCallingConvention);

        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(AArch64Kind.QWORD), JavaConstant.forLong(address));

        append(new AArch64CCall(nativeCallingConvention.getReturn(), ptr, argLocations));

    }

    /**

     * @param savedRegisters the registers saved by this operation which may be subject to pruning

     * @param savedRegisterLocations the slots to which the registers are saved

     */

        append(save);

        return save;

    }

    /**

     * 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

        }

        return getResult().getFrameMapBuilder().allocateSpillSlot(LIRKind.value(kind));

    }

    /**

     * Adds a node to the graph that saves all allocatable registers to the stack.

     *

     * @return the register save node

     */

        AllocatableValue[] savedRegisterLocations = new AllocatableValue[savedRegisters.length];

        for (int i = 0; i < savedRegisters.length; i++) {

            savedRegisterLocations[i] = allocateSaveRegisterLocation(savedRegisters[i]);

        }

    }

    protected void emitRestoreRegisters(AArch64SaveRegistersOp save) {

        append(new AArch64RestoreRegistersOp(save.getSlots().clone(), save));

    }

    @Override

    public VirtualStackSlot getLockSlot(int lockDepth) {

        return getLockStack().makeLockSlot(lockDepth);

    }

    private HotSpotLockStack getLockStack() {

        assert debugInfoBuilder != null && debugInfoBuilder.lockStack() != null;

        return debugInfoBuilder.lockStack();

    }

    @Override

    public void emitCompareBranch(PlatformKind cmpKind, Value x, Value y, Condition cond, boolean unorderedIsTrue, LabelRef trueDestination, LabelRef falseDestination,

                    double trueDestinationProbability) {

        Value localX = x;

        Value localY = y;

        if (localX instanceof HotSpotObjectConstant) {

            localX = load(localX);

        }

        if (localY instanceof HotSpotObjectConstant) {

            localY = load(localY);

        }

        super.emitCompareBranch(cmpKind, localX, localY, cond, unorderedIsTrue, trueDestination, falseDestination, trueDestinationProbability);

    }

    @Override

    protected boolean emitCompare(PlatformKind cmpKind, Value a, Value b, Condition condition, boolean unorderedIsTrue) {

        Value localA = a;

        Value localB = b;

        if (isConstantValue(a)) {

            Constant c = asConstant(a);

            if (HotSpotCompressedNullConstant.COMPRESSED_NULL.equals(c)) {

                localA = AArch64.zr.asValue(LIRKind.value(AArch64Kind.DWORD));

            } else if (c instanceof HotSpotObjectConstant) {

                localA = load(localA);

            }

        }

        if (isConstantValue(b)) {

            Constant c = asConstant(b);

            if (HotSpotCompressedNullConstant.COMPRESSED_NULL.equals(c)) {

                localB = AArch64.zr.asValue(LIRKind.value(AArch64Kind.DWORD));

            } else if (c instanceof HotSpotObjectConstant) {

                localB = load(localB);

            }

        }

        return super.emitCompare(cmpKind, localA, localB, condition, unorderedIsTrue);

    }

    @Override

    public Value emitCompress(Value pointer, CompressEncoding encoding, boolean nonNull) {

        LIRKind inputKind = pointer.getValueKind(LIRKind.class);

        LIRKindTool lirKindTool = getLIRKindTool();

        assert inputKind.getPlatformKind() == AArch64Kind.QWORD;

        if (inputKind.isReference(0)) {

            // oop

            Variable result = newVariable(LIRKind.compressedReference(AArch64Kind.DWORD));

            append(new AArch64HotSpotMove.CompressPointer(result, asAllocatable(pointer), getProviders().getRegisters().getHeapBaseRegister().asValue(), encoding, nonNull));

            return result;

        } else {

            // metaspace pointer

            Variable result = newVariable(LIRKind.value(AArch64Kind.DWORD));

            AllocatableValue base = Value.ILLEGAL;

            OptionValues options = getResult().getLIR().getOptions();

            if (encoding.hasBase() || GeneratePIC.getValue(options)) {

                if (GeneratePIC.getValue(options)) {

                    Variable baseAddress = newVariable(lirKindTool.getWordKind());

                    AArch64HotSpotMove.BaseMove move = new AArch64HotSpotMove.BaseMove(baseAddress, config);

                    append(move);

                    base = baseAddress;

                } else {

                    base = emitLoadConstant(LIRKind.value(AArch64Kind.QWORD), JavaConstant.forLong(encoding.getBase()));

                }

            }

            append(new AArch64HotSpotMove.CompressPointer(result, asAllocatable(pointer), base, encoding, nonNull));

            return result;

        }

    }

    @Override

    public Value emitUncompress(Value pointer, CompressEncoding encoding, boolean nonNull) {

        LIRKind inputKind = pointer.getValueKind(LIRKind.class);

        assert inputKind.getPlatformKind() == AArch64Kind.DWORD;

        if (inputKind.isReference(0)) {

            // oop

            Variable result = newVariable(LIRKind.reference(AArch64Kind.QWORD));

            append(new AArch64HotSpotMove.UncompressPointer(result, asAllocatable(pointer), getProviders().getRegisters().getHeapBaseRegister().asValue(), encoding, nonNull));

            return result;

        } else {

            // metaspace pointer

            Variable result = newVariable(LIRKind.value(AArch64Kind.QWORD));

            AllocatableValue base = Value.ILLEGAL;

            OptionValues options = getResult().getLIR().getOptions();

            if (encoding.hasBase() || GeneratePIC.getValue(options)) {

                if (GeneratePIC.getValue(options)) {

                    Variable baseAddress = newVariable(LIRKind.value(AArch64Kind.QWORD));

                    AArch64HotSpotMove.BaseMove move = new AArch64HotSpotMove.BaseMove(baseAddress, config);

                    append(move);

                    base = baseAddress;

                } else {

                    base = emitLoadConstant(LIRKind.value(AArch64Kind.QWORD), JavaConstant.forLong(encoding.getBase()));

                }

            }

            append(new AArch64HotSpotMove.UncompressPointer(result, asAllocatable(pointer), base, encoding, nonNull));

            return result;

        }

    }

    @Override

    public void emitNullCheck(Value address, LIRFrameState state) {

        if (address.getValueKind().getPlatformKind() == AArch64Kind.DWORD) {

            CompressEncoding encoding = config.getOopEncoding();

            Value uncompressed = emitUncompress(address, encoding, false);

            append(new AArch64Move.NullCheckOp(asAddressValue(uncompressed), state));

        } else {

            super.emitNullCheck(address, state);

        }

    }

    @Override

    public void emitPrefetchAllocate(Value address) {

        append(new AArch64PrefetchOp(asAddressValue(address), PrefetchMode.PSTL1KEEP));

    }

    @Override

    public void beforeRegisterAllocation() {

        super.beforeRegisterAllocation();

        boolean hasDebugInfo = getResult().getLIR().hasDebugInfo();

        if (hasDebugInfo) {

            getResult().setDeoptimizationRescueSlot(((AArch64FrameMapBuilder) getResult().getFrameMapBuilder()).allocateDeoptimizationRescueSlot());

        }

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

    }

    private Label label;

    @Override

    public Variable emitForeignCall(ForeignCallLinkage linkage, LIRFrameState state, Value... args) {

        HotSpotForeignCallLinkage hotspotLinkage = (HotSpotForeignCallLinkage) linkage;

        boolean destroysRegisters = hotspotLinkage.destroysRegisters();

        AArch64SaveRegistersOp save = null;

        Stub stub = getStub();

        }

        Variable result;

        LIRFrameState debugInfo = null;

        if (hotspotLinkage.needsDebugInfo()) {

            debugInfo = state;

            assert debugInfo != null || getStub() != null;

        }

        if (destroysRegisters || hotspotLinkage.needsJavaFrameAnchor()) {

            HotSpotRegistersProvider registers = getProviders().getRegisters();

            Register thread = registers.getThreadRegister();

            Variable scratch = newVariable(LIRKind.value(target().arch.getWordKind()));

            // We need a label for the return address.

            label = new Label();

            append(new AArch64HotSpotCRuntimeCallPrologueOp(config.threadLastJavaSpOffset(), config.threadLastJavaPcOffset(), thread, scratch, label));

            result = super.emitForeignCall(hotspotLinkage, debugInfo, args);

            append(new AArch64HotSpotCRuntimeCallEpilogueOp(config.threadLastJavaSpOffset(), config.threadLastJavaPcOffset(), thread, label));

            // Clear it out so it's not being reused later.

            label = null;

        } else {

            result = super.emitForeignCall(hotspotLinkage, debugInfo, args);

        }

            }

        }

        return result;

    }

    @Override

    public void emitDeoptimizeCaller(DeoptimizationAction action, DeoptimizationReason reason) {

        Value actionAndReason = emitJavaConstant(getMetaAccess().encodeDeoptActionAndReason(action, reason, 0));

        Value speculation = emitJavaConstant(getMetaAccess().encodeSpeculation(SpeculationLog.NO_SPECULATION));

        moveDeoptValuesToThread(actionAndReason, speculation);

        append(new AArch64HotSpotDeoptimizeCallerOp(config));

    }

    @Override

    public void emitDeoptimize(Value actionAndReason, Value failedSpeculation, LIRFrameState state) {

        moveDeoptValuesToThread(actionAndReason, failedSpeculation);

        append(new AArch64HotSpotDeoptimizeOp(state));

    }

    private void moveDeoptValuesToThread(Value actionAndReason, Value speculation) {

        moveValueToThread(actionAndReason, config.pendingDeoptimizationOffset);

        moveValueToThread(speculation, config.pendingFailedSpeculationOffset);

    }

    private void moveValueToThread(Value value, int offset) {

        LIRKind wordKind = LIRKind.value(target().arch.getWordKind());

        RegisterValue thread = getProviders().getRegisters().getThreadRegister().asValue(wordKind);

        final int transferSize = value.getValueKind().getPlatformKind().getSizeInBytes();

        AArch64AddressValue address = new AArch64AddressValue(value.getValueKind(), thread, Value.ILLEGAL, offset, transferSize, AddressingMode.IMMEDIATE_SCALED);

        append(new StoreOp((AArch64Kind) value.getPlatformKind(), address, loadReg(value), null));

    }

    @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 AArch64HotSpotUnwindOp(config, exceptionParameter));

    }

    @Override

    public Value emitLoadObjectAddress(Constant constant) {

        HotSpotObjectConstant objectConstant = (HotSpotObjectConstant) constant;

        LIRKind kind = objectConstant.isCompressed() ? getLIRKindTool().getNarrowOopKind() : getLIRKindTool().getObjectKind();

        Variable result = newVariable(kind);

        append(new AArch64HotSpotLoadAddressOp(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 AArch64HotSpotLoadAddressOp(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 AArch64HotSpotConstantRetrievalOp(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);

    }

    @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 AArch64HotSpotLoadConfigValueOp(markId, result));

        return result;

    }

    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 void emitReturn(JavaKind kind, Value input) {

        AllocatableValue operand = Value.ILLEGAL;

        if (input != null) {

            operand = resultOperandFor(kind, input.getValueKind());

            emitMove(operand, input);

        }

        Register thread = getProviders().getRegisters().getThreadRegister();

        append(new AArch64HotSpotReturnOp(operand, getStub() != null, config, thread, getResult().requiresReservedStackAccessCheck()));

    }

    @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)};