Source/JavaScriptCore/jit/JITPlan.cpp

/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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#include "config.h"
#include "JITPlan.h"

#if ENABLE(JIT)

#include "AbstractSlotVisitor.h"
#include "CodeBlock.h"
#include "HeapInlines.h"
#include "VMInlines.h"
#include <wtf/CompilationThread.h>

namespace JSC {

extern Seconds totalBaselineCompileTime;
extern Seconds totalDFGCompileTime;
extern Seconds totalFTLCompileTime;
extern Seconds totalFTLDFGCompileTime;
extern Seconds totalFTLB3CompileTime;

JITPlan::JITPlan(JITCompilationMode mode, CodeBlock* codeBlock)
    : m_mode(mode)
    , m_vm(&codeBlock->vm())
    , m_codeBlock(codeBlock)
{
}

void JITPlan::cancel()
{
    RELEASE_ASSERT(m_stage != JITPlanStage::Canceled);
    ASSERT(m_vm);
    m_stage = JITPlanStage::Canceled;
    m_vm = nullptr;
    m_codeBlock = nullptr;
}

void JITPlan::notifyCompiling()
{
    m_stage = JITPlanStage::Compiling;
}

void JITPlan::notifyReady()
{
    m_stage = JITPlanStage::Ready;
}

auto JITPlan::tier() const -> Tier
{
    switch (m_mode) {
    case JITCompilationMode::InvalidCompilation:
        RELEASE_ASSERT_NOT_REACHED();
        return Tier::Baseline;
    case JITCompilationMode::Baseline:
        return Tier::Baseline;
    case JITCompilationMode::DFG:
        return Tier::DFG;
    case JITCompilationMode::FTL:
    case JITCompilationMode::FTLForOSREntry:
        return Tier::FTL;
    }
    RELEASE_ASSERT_NOT_REACHED();
}

JITCompilationKey JITPlan::key()
{
    JSCell* codeBlock;
    if (m_mode == JITCompilationMode::Baseline)
        codeBlock = m_codeBlock->unlinkedCodeBlock();
    else
        codeBlock = m_codeBlock->baselineAlternative();
    return JITCompilationKey(codeBlock, m_mode);
}

bool JITPlan::isKnownToBeLiveAfterGC()
{
    if (m_stage == JITPlanStage::Canceled)
        return false;
    if (!m_vm->heap.isMarked(m_codeBlock->ownerExecutable()))
        return false;
    return true;
}

bool JITPlan::isKnownToBeLiveDuringGC(AbstractSlotVisitor& visitor)
{
    if (m_stage == JITPlanStage::Canceled)
        return false;
    if (!visitor.isMarked(m_codeBlock->ownerExecutable()))
        return false;
    return true;
}

bool JITPlan::iterateCodeBlocksForGC(AbstractSlotVisitor& visitor, const Function<void(CodeBlock*)>& func)
{
    if (!isKnownToBeLiveDuringGC(visitor))
        return false;

    // Compilation writes lots of values to a CodeBlock without performing
    // an explicit barrier. So, we need to be pessimistic and assume that
    // all our CodeBlocks must be visited during GC.
    func(m_codeBlock);
    return true;
}

bool JITPlan::checkLivenessAndVisitChildren(AbstractSlotVisitor& visitor)
{
    if (!isKnownToBeLiveDuringGC(visitor))
        return false;

    visitor.appendUnbarriered(m_codeBlock);
    return true;
}

bool JITPlan::computeCompileTimes() const
{
    return reportCompileTimes()
        || Options::reportTotalCompileTimes()
        || (m_vm && m_vm->m_perBytecodeProfiler);
}

bool JITPlan::reportCompileTimes() const
{
    return Options::reportCompileTimes()
        || (Options::reportBaselineCompileTimes() && m_mode == JITCompilationMode::Baseline)
        || (Options::reportDFGCompileTimes() && m_mode == JITCompilationMode::DFG)
        || (Options::reportFTLCompileTimes() && isFTL());
}

void JITPlan::compileInThread(JITWorklistThread* thread)
{
    m_thread = thread;

    MonotonicTime before;
    CString codeBlockName;
    if (UNLIKELY(computeCompileTimes()))
        before = MonotonicTime::now();
    if (UNLIKELY(reportCompileTimes()))
        codeBlockName = toCString(*m_codeBlock);

    CompilationScope compilationScope;

#if ENABLE(DFG_JIT)
    if (DFG::logCompilationChanges(m_mode) || Options::logPhaseTimes())
        dataLog("DFG(Plan) compiling ", *m_codeBlock, " with ", m_mode, ", instructions size = ", m_codeBlock->instructionsSize(), "\n");
#endif // ENABLE(DFG_JIT)

    CompilationPath path = compileInThreadImpl();

    RELEASE_ASSERT((path == CancelPath) == (m_stage == JITPlanStage::Canceled));

    MonotonicTime after;
    if (UNLIKELY(computeCompileTimes())) {
        after = MonotonicTime::now();

        if (Options::reportTotalCompileTimes()) {
            if (isFTL()) {
                totalFTLCompileTime += after - before;
                totalFTLDFGCompileTime += m_timeBeforeFTL - before;
                totalFTLB3CompileTime += after - m_timeBeforeFTL;
            } else if (mode() == JITCompilationMode::Baseline)
                totalBaselineCompileTime += after - before;
            else
                totalDFGCompileTime += after - before;
        }
    }
    const char* pathName = nullptr;
    switch (path) {
    case FailPath:
        pathName = "N/A (fail)";
        break;
    case BaselinePath:
        pathName = "Baseline";
        break;
    case DFGPath:
        pathName = "DFG";
        break;
    case FTLPath:
        pathName = "FTL";
        break;
    case CancelPath:
        pathName = "Canceled";
        break;
    default:
        RELEASE_ASSERT_NOT_REACHED();
        break;
    }
    if (m_codeBlock) { // m_codeBlock will be null if the compilation was cancelled.
        if (path == FTLPath)
            CODEBLOCK_LOG_EVENT(m_codeBlock, "ftlCompile", ("took ", (after - before).milliseconds(), " ms (DFG: ", (m_timeBeforeFTL - before).milliseconds(), ", B3: ", (after - m_timeBeforeFTL).milliseconds(), ") with ", pathName));
        else
            CODEBLOCK_LOG_EVENT(m_codeBlock, "dfgCompile", ("took ", (after - before).milliseconds(), " ms with ", pathName));
    }
    if (UNLIKELY(reportCompileTimes())) {
        dataLog("Optimized ", codeBlockName, " using ", m_mode, " with ", pathName, " into ", codeSize(), " bytes in ", (after - before).milliseconds(), " ms");
        if (path == FTLPath)
            dataLog(" (DFG: ", (m_timeBeforeFTL - before).milliseconds(), ", B3: ", (after - m_timeBeforeFTL).milliseconds(), ")");
        dataLog(".\n");
    }
}

} // namespace JSC

#endif // ENABLE(DFG_JIT)