/*

 * Copyright (c) 2013, 2015, 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

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 */

package org.graalvm.compiler.hotspot;

import static jdk.vm.ci.code.CodeUtil.getCallingConvention;

import static jdk.vm.ci.common.InitTimer.timer;

import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;

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

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

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

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

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

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

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

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

import org.graalvm.compiler.nodes.StructuredGraph;

import jdk.vm.ci.code.CallingConvention;

import jdk.vm.ci.common.InitTimer;

import jdk.vm.ci.hotspot.HotSpotCallingConventionType;

import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;

import jdk.vm.ci.meta.JavaType;

import jdk.vm.ci.runtime.JVMCICompiler;

/**

 * Common functionality of HotSpot host backends.

 */

public abstract class HotSpotHostBackend extends HotSpotBackend {

    /**

     * Descriptor for {@code SharedRuntime::deopt_blob()->unpack()} or

     * {@link DeoptimizationStub#deoptimizationHandler} depending on

     * {@link HotSpotBackend.Options#PreferGraalStubs}.

     */

    public static final ForeignCallDescriptor DEOPTIMIZATION_HANDLER = new ForeignCallDescriptor("deoptHandler", void.class);

    /**

     * Descriptor for {@code SharedRuntime::deopt_blob()->uncommon_trap()} or

     * {@link UncommonTrapStub#uncommonTrapHandler} depending on

     * {@link HotSpotBackend.Options#PreferGraalStubs}.

     */

    public static final ForeignCallDescriptor UNCOMMON_TRAP_HANDLER = new ForeignCallDescriptor("uncommonTrapHandler", void.class);

    protected final GraalHotSpotVMConfig config;

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

        super(runtime, providers);

        this.config = config;

    }

    @Override

    @SuppressWarnings("try")

    public void completeInitialization(HotSpotJVMCIRuntime jvmciRuntime) {

        final HotSpotProviders providers = getProviders();

        HotSpotHostForeignCallsProvider foreignCalls = (HotSpotHostForeignCallsProvider) providers.getForeignCalls();

        final HotSpotLoweringProvider lowerer = (HotSpotLoweringProvider) providers.getLowerer();

        try (InitTimer st = timer("foreignCalls.initialize")) {

            foreignCalls.initialize(providers);

        }

        try (InitTimer st = timer("lowerer.initialize")) {

            lowerer.initialize(providers, config);

        }

    }

    protected CallingConvention makeCallingConvention(StructuredGraph graph, Stub stub) {

        if (stub != null) {

            return stub.getLinkage().getIncomingCallingConvention();

        }

        CallingConvention cc = getCallingConvention(getCodeCache(), HotSpotCallingConventionType.JavaCallee, graph.method(), this);

        if (graph.getEntryBCI() != JVMCICompiler.INVOCATION_ENTRY_BCI) {

            // for OSR, only a pointer is passed to the method.

            JavaType[] parameterTypes = new JavaType[]{getMetaAccess().lookupJavaType(long.class)};

            CallingConvention tmp = getCodeCache().getRegisterConfig().getCallingConvention(HotSpotCallingConventionType.JavaCallee, getMetaAccess().lookupJavaType(void.class), parameterTypes, this);

            cc = new CallingConvention(cc.getStackSize(), cc.getReturn(), tmp.getArgument(0));

        }

        return cc;

    }

    public void emitStackOverflowCheck(CompilationResultBuilder crb) {

        if (config.useStackBanging) {

            // Each code entry causes one stack bang n pages down the stack where n

            // is configurable by StackShadowPages. The setting depends on the maximum

            // depth of VM call stack or native before going back into java code,

            // since only java code can raise a stack overflow exception using the

            // stack banging mechanism. The VM and native code does not detect stack

            // overflow.

            // The code in JavaCalls::call() checks that there is at least n pages

            // available, so all entry code needs to do is bang once for the end of

            // this shadow zone.

            // The entry code may need to bang additional pages if the framesize

            // is greater than a page.

            int pageSize = config.vmPageSize;

            int bangEnd = config.stackShadowPages * pageSize;

            // This is how far the previous frame's stack banging extended.

            int bangEndSafe = bangEnd;

            int frameSize = Math.max(crb.frameMap.frameSize(), crb.compilationResult.getMaxInterpreterFrameSize());

            if (frameSize > pageSize) {

                bangEnd += frameSize;

            }

            int bangOffset = bangEndSafe;

            if (bangOffset <= bangEnd) {

                crb.blockComment("[stack overflow check]");

            }

            while (bangOffset <= bangEnd) {

                // Need at least one stack bang at end of shadow zone.

                bangStackWithOffset(crb, bangOffset);

                bangOffset += pageSize;

            }

        }

    }

    protected abstract void bangStackWithOffset(CompilationResultBuilder crb, int bangOffset);

    @Override

    public ReferenceMapBuilder newReferenceMapBuilder(int totalFrameSize) {

        return new HotSpotReferenceMapBuilder(totalFrameSize, config.maxOopMapStackOffset);

    }

}