void OSRExitCompiler::handleExitCounts(const OSRExit& exit)
{
    m_jit.add32(AssemblyHelpers::TrustedImm32(1), AssemblyHelpers::AbsoluteAddress(&exit.m_count));
    
    m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.codeBlock()), GPRInfo::regT0);
    
    AssemblyHelpers::JumpList tooFewFails;
    
    if (exit.m_kind == InadequateCoverage) {
        // Proceed based on the assumption that we can profitably optimize this code once
        // it has executed enough times.
        
        m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfForcedOSRExitCounter()), GPRInfo::regT2);
        m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()), GPRInfo::regT1);
        m_jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
        m_jit.add32(AssemblyHelpers::TrustedImm32(-1), GPRInfo::regT1);
        m_jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfForcedOSRExitCounter()));
        m_jit.store32(GPRInfo::regT1, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()));
        
        tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(Options::forcedOSRExitCountForReoptimization)));
    } else {
        // Proceed based on the assumption that we can handle these exits so long as they
        // don't get too frequent.
        
        m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeFailCounter()), GPRInfo::regT2);
        m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()), GPRInfo::regT1);
        m_jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
        m_jit.add32(AssemblyHelpers::TrustedImm32(-1), GPRInfo::regT1);
        m_jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeFailCounter()));
        m_jit.store32(GPRInfo::regT1, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()));
    
        m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.baselineCodeBlock()), GPRInfo::regT0);
    
        tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(m_jit.codeBlock()->largeFailCountThreshold())));
        m_jit.mul32(AssemblyHelpers::TrustedImm32(Options::desiredSpeculativeSuccessFailRatio), GPRInfo::regT2, GPRInfo::regT2);
    
        tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, GPRInfo::regT1));
    }

    // Reoptimize as soon as possible.
    m_jit.store32(AssemblyHelpers::TrustedImm32(0), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
    m_jit.store32(AssemblyHelpers::TrustedImm32(0), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
    AssemblyHelpers::Jump doneAdjusting = m_jit.jump();
    
    tooFewFails.link(&m_jit);
    
    // Adjust the execution counter such that the target is to only optimize after a while.
    int32_t targetValue =
        ExecutionCounter::applyMemoryUsageHeuristicsAndConvertToInt(
            m_jit.baselineCodeBlock()->counterValueForOptimizeAfterLongWarmUp(),
            m_jit.baselineCodeBlock());
    m_jit.store32(AssemblyHelpers::TrustedImm32(-targetValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
    m_jit.store32(AssemblyHelpers::TrustedImm32(targetValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
    m_jit.store32(AssemblyHelpers::TrustedImm32(ExecutionCounter::formattedTotalCount(targetValue)), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionTotalCount()));
    
    doneAdjusting.link(&m_jit);
}
Exemplo n.º 2
0
AssemblyHelpers::JumpList AssemblyHelpers::branchIfNotType(
    JSValueRegs regs, GPRReg tempGPR, const InferredType::Descriptor& descriptor, TagRegistersMode mode)
{
    AssemblyHelpers::JumpList result;

    switch (descriptor.kind()) {
    case InferredType::Bottom:
        result.append(jump());
        break;

    case InferredType::Boolean:
        result.append(branchIfNotBoolean(regs, tempGPR));
        break;

    case InferredType::Other:
        result.append(branchIfNotOther(regs, tempGPR));
        break;

    case InferredType::Int32:
        result.append(branchIfNotInt32(regs, mode));
        break;

    case InferredType::Number:
        result.append(branchIfNotNumber(regs, tempGPR, mode));
        break;

    case InferredType::String:
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotString(regs.payloadGPR()));
        break;

    case InferredType::ObjectWithStructure:
        result.append(branchIfNotCell(regs, mode));
        result.append(
            branchStructure(
                NotEqual,
                Address(regs.payloadGPR(), JSCell::structureIDOffset()),
                descriptor.structure()));
        break;

    case InferredType::ObjectWithStructureOrOther: {
        Jump ok = branchIfOther(regs, tempGPR);
        result.append(branchIfNotCell(regs, mode));
        result.append(
            branchStructure(
                NotEqual,
                Address(regs.payloadGPR(), JSCell::structureIDOffset()),
                descriptor.structure()));
        ok.link(this);
        break;
    }

    case InferredType::Object:
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotObject(regs.payloadGPR()));
        break;

    case InferredType::ObjectOrOther: {
        Jump ok = branchIfOther(regs, tempGPR);
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotObject(regs.payloadGPR()));
        ok.link(this);
        break;
    }

    case InferredType::Top:
        break;
    }

    return result;
}
void handleExitCounts(CCallHelpers& jit, const OSRExitBase& exit)
{
    jit.add32(AssemblyHelpers::TrustedImm32(1), AssemblyHelpers::AbsoluteAddress(&exit.m_count));

    jit.move(AssemblyHelpers::TrustedImmPtr(jit.codeBlock()), GPRInfo::regT0);

    AssemblyHelpers::Jump tooFewFails;

    jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()), GPRInfo::regT2);
    jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
    jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()));

    jit.move(AssemblyHelpers::TrustedImmPtr(jit.baselineCodeBlock()), GPRInfo::regT0);
    AssemblyHelpers::Jump reoptimizeNow = jit.branch32(
        AssemblyHelpers::GreaterThanOrEqual,
        AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()),
        AssemblyHelpers::TrustedImm32(0));

    // We want to figure out if there's a possibility that we're in a loop. For the outermost
    // code block in the inline stack, we handle this appropriately by having the loop OSR trigger
    // check the exit count of the replacement of the CodeBlock from which we are OSRing. The
    // problem is the inlined functions, which might also have loops, but whose baseline versions
    // don't know where to look for the exit count. Figure out if those loops are severe enough
    // that we had tried to OSR enter. If so, then we should use the loop reoptimization trigger.
    // Otherwise, we should use the normal reoptimization trigger.

    AssemblyHelpers::JumpList loopThreshold;

    for (InlineCallFrame* inlineCallFrame = exit.m_codeOrigin.inlineCallFrame; inlineCallFrame; inlineCallFrame = inlineCallFrame->caller.inlineCallFrame) {
        loopThreshold.append(
            jit.branchTest8(
                AssemblyHelpers::NonZero,
                AssemblyHelpers::AbsoluteAddress(
                    inlineCallFrame->executable->addressOfDidTryToEnterInLoop())));
    }

    jit.move(
        AssemblyHelpers::TrustedImm32(jit.codeBlock()->exitCountThresholdForReoptimization()),
        GPRInfo::regT1);

    if (!loopThreshold.empty()) {
        AssemblyHelpers::Jump done = jit.jump();

        loopThreshold.link(&jit);
        jit.move(
            AssemblyHelpers::TrustedImm32(
                jit.codeBlock()->exitCountThresholdForReoptimizationFromLoop()),
            GPRInfo::regT1);

        done.link(&jit);
    }

    tooFewFails = jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, GPRInfo::regT1);

    reoptimizeNow.link(&jit);

    // Reoptimize as soon as possible.
#if !NUMBER_OF_ARGUMENT_REGISTERS
    jit.poke(GPRInfo::regT0);
    jit.poke(AssemblyHelpers::TrustedImmPtr(&exit), 1);
#else
    jit.move(GPRInfo::regT0, GPRInfo::argumentGPR0);
    jit.move(AssemblyHelpers::TrustedImmPtr(&exit), GPRInfo::argumentGPR1);
#endif
    jit.move(AssemblyHelpers::TrustedImmPtr(bitwise_cast<void*>(triggerReoptimizationNow)), GPRInfo::nonArgGPR0);
    jit.call(GPRInfo::nonArgGPR0);
    AssemblyHelpers::Jump doneAdjusting = jit.jump();

    tooFewFails.link(&jit);

    // Adjust the execution counter such that the target is to only optimize after a while.
    int32_t activeThreshold =
        jit.baselineCodeBlock()->adjustedCounterValue(
            Options::thresholdForOptimizeAfterLongWarmUp());
    int32_t targetValue = applyMemoryUsageHeuristicsAndConvertToInt(
        activeThreshold, jit.baselineCodeBlock());
    int32_t clippedValue;
    switch (jit.codeBlock()->jitType()) {
    case JITCode::DFGJIT:
        clippedValue = BaselineExecutionCounter::clippedThreshold(jit.codeBlock()->globalObject(), targetValue);
        break;
    case JITCode::FTLJIT:
        clippedValue = UpperTierExecutionCounter::clippedThreshold(jit.codeBlock()->globalObject(), targetValue);
        break;
    default:
        RELEASE_ASSERT_NOT_REACHED();
#if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
        clippedValue = 0; // Make some compilers, and mhahnenberg, happy.
#endif
        break;
    }
    jit.store32(AssemblyHelpers::TrustedImm32(-clippedValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
    jit.store32(AssemblyHelpers::TrustedImm32(activeThreshold), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
    jit.store32(AssemblyHelpers::TrustedImm32(formattedTotalExecutionCount(clippedValue)), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionTotalCount()));

    doneAdjusting.link(&jit);
}