/*

 * Copyright (c) 2012, 2016, 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.r10;

import static jdk.vm.ci.amd64.AMD64.rax;

import static jdk.vm.ci.amd64.AMD64.rsp;

import static jdk.vm.ci.code.ValueUtil.asRegister;

import static org.graalvm.compiler.core.common.GraalOptions.CanOmitFrame;

import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;

import static org.graalvm.compiler.core.common.GraalOptions.ZapStackOnMethodEntry;

import org.graalvm.compiler.asm.Assembler;

import org.graalvm.compiler.asm.Label;

import org.graalvm.compiler.asm.amd64.AMD64Address;

import org.graalvm.compiler.asm.amd64.AMD64Assembler.ConditionFlag;

import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;

import org.graalvm.compiler.code.CompilationResult;

import org.graalvm.compiler.core.amd64.AMD64NodeMatchRules;

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

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

import org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig;

import org.graalvm.compiler.core.target.Backend;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;

import org.graalvm.compiler.hotspot.HotSpotDataBuilder;

import org.graalvm.compiler.hotspot.HotSpotGraalRuntimeProvider;

import org.graalvm.compiler.hotspot.HotSpotHostBackend;

import org.graalvm.compiler.hotspot.HotSpotLIRGenerationResult;

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

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

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.amd64.AMD64Call;

import org.graalvm.compiler.lir.amd64.AMD64FrameMap;

import org.graalvm.compiler.lir.amd64.AMD64FrameMapBuilder;

import org.graalvm.compiler.lir.asm.CompilationResultBuilder;

import org.graalvm.compiler.lir.asm.CompilationResultBuilderFactory;

import org.graalvm.compiler.lir.asm.DataBuilder;

import org.graalvm.compiler.lir.asm.FrameContext;

import org.graalvm.compiler.lir.framemap.FrameMap;

import org.graalvm.compiler.lir.framemap.FrameMapBuilder;

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

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

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;

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.StackSlot;

import jdk.vm.ci.hotspot.HotSpotCallingConventionType;

import jdk.vm.ci.hotspot.HotSpotSentinelConstant;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.JavaType;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**

 * HotSpot AMD64 specific backend.

 */

public class AMD64HotSpotBackend extends HotSpotHostBackend {

    public AMD64HotSpotBackend(GraalHotSpotVMConfig config, HotSpotGraalRuntimeProvider runtime, HotSpotProviders providers) {

        super(config, runtime, providers);

    }

    @Override

    public FrameMapBuilder newFrameMapBuilder(RegisterConfig registerConfig) {

        RegisterConfig registerConfigNonNull = registerConfig == null ? getCodeCache().getRegisterConfig() : registerConfig;

        return new AMD64FrameMapBuilder(newFrameMap(registerConfigNonNull), getCodeCache(), registerConfigNonNull);

    }

    @Override

    public FrameMap newFrameMap(RegisterConfig registerConfig) {

        return new AMD64FrameMap(getCodeCache(), registerConfig, this);

    }

    @Override

    public LIRGeneratorTool newLIRGenerator(LIRGenerationResult lirGenRes) {

        return new AMD64HotSpotLIRGenerator(getProviders(), config, lirGenRes);

    }

    @Override

    public LIRGenerationResult newLIRGenerationResult(CompilationIdentifier compilationId, LIR lir, FrameMapBuilder frameMapBuilder, StructuredGraph graph, Object stub) {

        return new HotSpotLIRGenerationResult(compilationId, lir, frameMapBuilder, makeCallingConvention(graph, (Stub) stub), stub);

    }

    @Override

    public NodeLIRBuilderTool newNodeLIRBuilder(StructuredGraph graph, LIRGeneratorTool lirGen) {

        return new AMD64HotSpotNodeLIRBuilder(graph, lirGen, new AMD64NodeMatchRules(lirGen));

    }

    @Override

    protected void bangStackWithOffset(CompilationResultBuilder crb, int bangOffset) {

        AMD64MacroAssembler asm = (AMD64MacroAssembler) crb.asm;

        int pos = asm.position();

        asm.movl(new AMD64Address(rsp, -bangOffset), AMD64.rax);

        assert asm.position() - pos >= PATCHED_VERIFIED_ENTRY_POINT_INSTRUCTION_SIZE;

    }

    /**

     * The size of the instruction used to patch the verified entry point of an nmethod when the

     * nmethod is made non-entrant or a zombie (e.g. during deopt or class unloading). The first

     * instruction emitted at an nmethod's verified entry point must be at least this length to

     * ensure mt-safe patching.

     */

    public static final int PATCHED_VERIFIED_ENTRY_POINT_INSTRUCTION_SIZE = 5;

    /**

     * Emits code at the verified entry point and return point(s) of a method.

     */

    class HotSpotFrameContext implements FrameContext {

        final boolean isStub;

        final boolean omitFrame;

        HotSpotFrameContext(boolean isStub, boolean omitFrame) {

            this.isStub = isStub;

            this.omitFrame = omitFrame;

        }

        @Override

        public boolean hasFrame() {

            return !omitFrame;

        }

        @Override

        public void enter(CompilationResultBuilder crb) {

            FrameMap frameMap = crb.frameMap;

            int frameSize = frameMap.frameSize();

            AMD64MacroAssembler asm = (AMD64MacroAssembler) crb.asm;

            if (omitFrame) {

                if (!isStub) {

                    asm.nop(PATCHED_VERIFIED_ENTRY_POINT_INSTRUCTION_SIZE);

                }

            } else {

                int verifiedEntryPointOffset = asm.position();

                if (!isStub) {

                    emitStackOverflowCheck(crb);

                    // assert asm.position() - verifiedEntryPointOffset >=

                    // PATCHED_VERIFIED_ENTRY_POINT_INSTRUCTION_SIZE;

                }

                if (!isStub && asm.position() == verifiedEntryPointOffset) {

                    asm.subqWide(rsp, frameSize);

                    assert asm.position() - verifiedEntryPointOffset >= PATCHED_VERIFIED_ENTRY_POINT_INSTRUCTION_SIZE;

                } else {

                    asm.decrementq(rsp, frameSize);

                }

                if (ZapStackOnMethodEntry.getValue(crb.getOptions())) {

                    final int intSize = 4;

                    for (int i = 0; i < frameSize / intSize; ++i) {

                        asm.movl(new AMD64Address(rsp, i * intSize), 0xC1C1C1C1);

                    }

                }

                assert frameMap.getRegisterConfig().getCalleeSaveRegisters() == null;

            }

        }

        @Override

        public void leave(CompilationResultBuilder crb) {

            if (!omitFrame) {

                AMD64MacroAssembler asm = (AMD64MacroAssembler) crb.asm;

                assert crb.frameMap.getRegisterConfig().getCalleeSaveRegisters() == null;

                int frameSize = crb.frameMap.frameSize();

                asm.incrementq(rsp, frameSize);

            }

        }

    }

    @Override

    protected Assembler createAssembler(FrameMap frameMap) {

        return new AMD64MacroAssembler(getTarget());

    }

    @Override

    public CompilationResultBuilder newCompilationResultBuilder(LIRGenerationResult lirGenRen, FrameMap frameMap, CompilationResult compilationResult, CompilationResultBuilderFactory factory) {

        // Omit the frame if the method:

        // - has no spill slots or other slots allocated during register allocation

        // - has no callee-saved registers

        // - has no incoming arguments passed on the stack

        // - has no deoptimization points

        // - makes no foreign calls (which require an aligned stack)

        HotSpotLIRGenerationResult gen = (HotSpotLIRGenerationResult) lirGenRen;

        LIR lir = gen.getLIR();

        assert gen.getDeoptimizationRescueSlot() == null || frameMap.frameNeedsAllocating() : "method that can deoptimize must have a frame";

        OptionValues options = lir.getOptions();

        DebugContext debug = lir.getDebug();

        boolean omitFrame = CanOmitFrame.getValue(options) && !frameMap.frameNeedsAllocating() && !lir.hasArgInCallerFrame() && !gen.hasForeignCall();

        Stub stub = gen.getStub();

        Assembler masm = createAssembler(frameMap);

        HotSpotFrameContext frameContext = new HotSpotFrameContext(stub != null, omitFrame);

        DataBuilder dataBuilder = new HotSpotDataBuilder(getCodeCache().getTarget());

        CompilationResultBuilder crb = factory.createBuilder(getCodeCache(), getForeignCalls(), frameMap, masm, dataBuilder, frameContext, options, debug, compilationResult);

        crb.setTotalFrameSize(frameMap.totalFrameSize());

        crb.setMaxInterpreterFrameSize(gen.getMaxInterpreterFrameSize());

        StackSlot deoptimizationRescueSlot = gen.getDeoptimizationRescueSlot();

        if (deoptimizationRescueSlot != null && stub == null) {

            crb.compilationResult.setCustomStackAreaOffset(deoptimizationRescueSlot);

        }

        if (stub != null) {

            EconomicSet<Register> destroyedCallerRegisters = gatherDestroyedCallerRegisters(lir);

            updateStub(stub, destroyedCallerRegisters, gen.getCalleeSaveInfo(), frameMap);

        }

        return crb;

    }

    @Override

    public void emitCode(CompilationResultBuilder crb, LIR lir, ResolvedJavaMethod installedCodeOwner) {

        AMD64MacroAssembler asm = (AMD64MacroAssembler) crb.asm;

        FrameMap frameMap = crb.frameMap;

        RegisterConfig regConfig = frameMap.getRegisterConfig();

        Label verifiedEntry = new Label();

        // Emit the prefix

        emitCodePrefix(installedCodeOwner, crb, asm, regConfig, verifiedEntry);

        // Emit code for the LIR

        emitCodeBody(installedCodeOwner, crb, lir);

        // Emit the suffix

        emitCodeSuffix(installedCodeOwner, crb, asm, frameMap);

        // Profile assembler instructions

        profileInstructions(lir, crb);

    }

    /**

     * Emits the code prior to the verified entry point.

     *

     * @param installedCodeOwner see {@link Backend#emitCode}

     */

    public void emitCodePrefix(ResolvedJavaMethod installedCodeOwner, CompilationResultBuilder crb, AMD64MacroAssembler asm, RegisterConfig regConfig, Label verifiedEntry) {

        HotSpotProviders providers = getProviders();

        if (installedCodeOwner != null && !installedCodeOwner.isStatic()) {

            crb.recordMark(config.MARKID_UNVERIFIED_ENTRY);

            CallingConvention cc = regConfig.getCallingConvention(HotSpotCallingConventionType.JavaCallee, null, new JavaType[]{providers.getMetaAccess().lookupJavaType(Object.class)}, this);

            Register inlineCacheKlass = rax; // see definition of IC_Klass in

                                             // c1_LIRAssembler_x86.cpp

            Register receiver = asRegister(cc.getArgument(0));

            AMD64Address src = new AMD64Address(receiver, config.hubOffset);

            if (config.useCompressedClassPointers) {

                Register register = r10;

                AMD64HotSpotMove.decodeKlassPointer(crb, asm, register, providers.getRegisters().getHeapBaseRegister(), src, config);

                if (GeneratePIC.getValue(crb.getOptions())) {

                    asm.movq(providers.getRegisters().getHeapBaseRegister(), asm.getPlaceholder(-1));

                    crb.recordMark(config.MARKID_NARROW_OOP_BASE_ADDRESS);

                } else {

                    if (config.narrowKlassBase != 0) {

                        // The heap base register was destroyed above, so restore it

                        asm.movq(providers.getRegisters().getHeapBaseRegister(), config.narrowOopBase);

                    }

                }

                asm.cmpq(inlineCacheKlass, register);

            } else {

                asm.cmpq(inlineCacheKlass, src);

            }

            AMD64Call.directConditionalJmp(crb, asm, getForeignCalls().lookupForeignCall(IC_MISS_HANDLER), ConditionFlag.NotEqual);

        }

        asm.align(config.codeEntryAlignment);

        crb.recordMark(config.MARKID_OSR_ENTRY);

        asm.bind(verifiedEntry);

        crb.recordMark(config.MARKID_VERIFIED_ENTRY);

        if (GeneratePIC.getValue(crb.getOptions())) {

            // Check for method state

            HotSpotFrameContext frameContext = (HotSpotFrameContext) crb.frameContext;

            if (!frameContext.isStub) {

                crb.recordInlineDataInCodeWithNote(new HotSpotSentinelConstant(LIRKind.value(AMD64Kind.QWORD), JavaKind.Long), HotSpotConstantLoadAction.MAKE_NOT_ENTRANT);

                asm.movq(AMD64.rax, asm.getPlaceholder(-1));

                asm.testq(AMD64.rax, AMD64.rax);

                AMD64Call.directConditionalJmp(crb, asm, getForeignCalls().lookupForeignCall(WRONG_METHOD_HANDLER), ConditionFlag.NotZero);

            }

        }

    }

    /**

     * Emits the code which starts at the verified entry point.

     *

     * @param installedCodeOwner see {@link Backend#emitCode}

     */

    public void emitCodeBody(ResolvedJavaMethod installedCodeOwner, CompilationResultBuilder crb, LIR lir) {

        crb.emit(lir);

    }

    /**

     * @param installedCodeOwner see {@link Backend#emitCode}

     */

    public void emitCodeSuffix(ResolvedJavaMethod installedCodeOwner, CompilationResultBuilder crb, AMD64MacroAssembler asm, FrameMap frameMap) {

        HotSpotProviders providers = getProviders();

        HotSpotFrameContext frameContext = (HotSpotFrameContext) crb.frameContext;

        if (!frameContext.isStub) {

            HotSpotForeignCallsProvider foreignCalls = providers.getForeignCalls();

            crb.recordMark(config.MARKID_EXCEPTION_HANDLER_ENTRY);

            AMD64Call.directCall(crb, asm, foreignCalls.lookupForeignCall(EXCEPTION_HANDLER), null, false, null);

            crb.recordMark(config.MARKID_DEOPT_HANDLER_ENTRY);

            AMD64Call.directCall(crb, asm, foreignCalls.lookupForeignCall(DEOPTIMIZATION_HANDLER), null, false, null);

        } else {

            // No need to emit the stubs for entries back into the method since

            // it has no calls that can cause such "return" entries

            if (frameContext.omitFrame) {

                // Cannot access slots in caller's frame if my frame is omitted

                assert !frameMap.accessesCallerFrame();

            }

        }

    }

    @Override

    public RegisterAllocationConfig newRegisterAllocationConfig(RegisterConfig registerConfig, String[] allocationRestrictedTo) {

        RegisterConfig registerConfigNonNull = registerConfig == null ? getCodeCache().getRegisterConfig() : registerConfig;

        return new AMD64HotSpotRegisterAllocationConfig(registerConfigNonNull, allocationRestrictedTo);

    }

    @Override

    public EconomicSet<Register> translateToCallerRegisters(EconomicSet<Register> calleeRegisters) {

        return calleeRegisters;

    }

}