/*

 * Copyright (c) 2012, 2019, 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_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 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.SpeculationLog;

import jdk.vm.ci.meta.Value;

/**

 * 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 AMD64ArithmeticLIRGenerator(null), 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();

    }

    @Override

    protected int getMaxVectorSize() {

        return config.maxVectorSize;

    }

    /**

     * Utility for emitting the instruction to save RBP.

     */

    class SaveRbp {

        final NoOp placeholder;

        /**

         * The slot reserved for saving RBP.

         */

        final StackSlot reservedSlot;

        SaveRbp(NoOp placeholder) {

            this.placeholder = placeholder;

            AMD64FrameMapBuilder frameMapBuilder = (AMD64FrameMapBuilder) getResult().getFrameMapBuilder();

        }

        /**

         * 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);

    }

    /**

     * 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<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, getResult().requiresReservedStackAccessCheck()));

    }

    @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, getRegisterConfig()));

        }

        super.emitForeignCallOp(linkage, result, arguments, temps, info);

    }

    /**

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

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

     */

    protected AMD64SaveRegistersOp emitSaveRegisters(Register[] savedRegisters, AllocatableValue[] savedRegisterLocations) {

        AMD64SaveRegistersOp save = new AMD64SaveRegistersOp(savedRegisters, savedRegisterLocations);

        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

            kind = AMD64Kind.DOUBLE;

        }

        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

     */

    private AMD64SaveRegistersOp emitSaveAllRegisters() {

        Register[] savedRegisters = getSaveableRegisters();

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

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

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

        }

        return emitSaveRegisters(savedRegisters, savedRegisterLocations);

    }

    protected Register[] getSaveableRegisters() {

        return getResult().getRegisterAllocationConfig().getAllocatableRegisters().toArray();

    }

    protected void emitRestoreRegisters(AMD64SaveRegistersOp save) {

        append(new AMD64RestoreRegistersOp(save.getSlots().clone(), save));

    }

    /**

     * 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 && stub != null && stub.shouldSaveRegistersAroundCalls()) {

            save = emitSaveAllRegisters();

        }

        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 (save != null) {

            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));

    }