/*

 * Copyright (c) 2015, 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.aarch64;

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.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.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.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.StandardOp.SaveRegistersOp;

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.gen.LIRGenerationResult;

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.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.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(), 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;

    }

    @SuppressWarnings("unused") 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));

    }

    public SaveRegistersOp emitSaveAllRegisters() {

        throw GraalError.unimplemented();

    }

    @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);

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

        if (inputKind.isReference(0)) {

            // oop

            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;

            if (encoding.hasBase()) {

                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;

            if (encoding.hasBase()) {

                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;

        Variable result;

        LIRFrameState debugInfo = null;

        if (hotspotLinkage.needsDebugInfo()) {

            debugInfo = state;

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

        }

        if (linkage.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(), config.threadLastJavaFpOffset(), thread, scratch, label));

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

            append(new AArch64HotSpotCRuntimeCallEpilogueOp(config.threadLastJavaSpOffset(), config.threadLastJavaFpOffset(), thread));

            // 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 nullValue = emitConstant(LIRKind.reference(AArch64Kind.QWORD), JavaConstant.NULL_POINTER);

        moveDeoptValuesToThread(actionAndReason, nullValue);

        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 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));

    }

    /**

     * 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());

    }

    @Override

    protected StrategySwitchOp createStrategySwitchOp(SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Variable key, AllocatableValue scratchValue,

                    Function<Condition, ConditionFlag> converter) {

        return new AArch64HotSpotStrategySwitchOp(strategy, keyTargets, defaultTarget, key, scratchValue, converter);

    }

    public void setDebugInfoBuilder(HotSpotDebugInfoBuilder debugInfoBuilder) {

        this.debugInfoBuilder = debugInfoBuilder;

    }

    @Override

    public SaveRegistersOp createZapRegisters(Register[] zappedRegisters, JavaConstant[] zapValues) {

        throw GraalError.unimplemented();

    }

    @Override

    public LIRInstruction createZapArgumentSpace(StackSlot[] zappedStack, JavaConstant[] zapValues) {

        throw GraalError.unimplemented();

    }

}