Source/JavaScriptCore/ftl/FTLCompile.cpp

/*
 * Copyright (C) 2015-2021 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice, this list of conditions and the following disclaimer in the
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#include "config.h"
#include "FTLCompile.h"

#if ENABLE(FTL_JIT)

#include "AirCode.h"
#include "AirDisassembler.h"
#include "AirStackSlot.h"
#include "B3Generate.h"
#include "B3Value.h"
#include "B3ValueInlines.h"
#include "CodeBlockWithJITType.h"
#include "CCallHelpers.h"
#include "DFGGraphSafepoint.h"
#include "FTLJITCode.h"
#include "LinkBuffer.h"
#include "PCToCodeOriginMap.h"
#include "ThunkGenerators.h"
#include <wtf/RecursableLambda.h>

namespace JSC { namespace FTL {

const char* const tierName = "FTL ";

using namespace DFG;

void compile(State& state, Safepoint::Result& safepointResult)
{
    Graph& graph = state.graph;
    CodeBlock* codeBlock = graph.m_codeBlock;
    VM& vm = graph.m_vm;

    if (shouldDumpDisassembly() || vm.m_perBytecodeProfiler)
        state.proc->code().setDisassembler(makeUnique<B3::Air::Disassembler>());

    if (!shouldDumpDisassembly() && !Options::asyncDisassembly() && !graph.compilation() && !state.proc->needsPCToOriginMap())
        graph.freeDFGIRAfterLowering();

    {
        GraphSafepoint safepoint(state.graph, safepointResult);

        B3::prepareForGeneration(*state.proc);
    }

    if (safepointResult.didGetCancelled())
        return;
    RELEASE_ASSERT(!state.graph.m_vm.heap.worldIsStopped());
    
    if (state.allocationFailed)
        return;
    
    RegisterAtOffsetList registerOffsets = state.proc->calleeSaveRegisterAtOffsetList();
    if (shouldDumpDisassembly())
        dataLog(tierName, "Unwind info for ", CodeBlockWithJITType(codeBlock, JITType::FTLJIT), ": ", registerOffsets, "\n");
    codeBlock->setCalleeSaveRegisters(WTFMove(registerOffsets));
    ASSERT(!(state.proc->frameSize() % sizeof(EncodedJSValue)));
    state.jitCode->common.frameRegisterCount = state.proc->frameSize() / sizeof(EncodedJSValue);

    int localsOffset =
        state.capturedValue->offsetFromFP() / sizeof(EncodedJSValue) + graph.m_nextMachineLocal;
    if (shouldDumpDisassembly()) {
        dataLog(tierName,
            "localsOffset = ", localsOffset, " for stack slot: ",
            pointerDump(state.capturedValue), " at ", RawPointer(state.capturedValue), "\n");
    }
    
    for (unsigned i = graph.m_inlineVariableData.size(); i--;) {
        InlineCallFrame* inlineCallFrame = graph.m_inlineVariableData[i].inlineCallFrame;
        
        if (inlineCallFrame->argumentCountRegister.isValid())
            inlineCallFrame->argumentCountRegister += localsOffset;
        
        for (unsigned argument = inlineCallFrame->m_argumentsWithFixup.size(); argument-- > 1;) {
            inlineCallFrame->m_argumentsWithFixup[argument] =
                inlineCallFrame->m_argumentsWithFixup[argument].withLocalsOffset(localsOffset);
        }
        
        if (inlineCallFrame->isClosureCall) {
            inlineCallFrame->calleeRecovery =
                inlineCallFrame->calleeRecovery.withLocalsOffset(localsOffset);
        }

    }

    // Note that the scope register could be invalid here if the original code had CallEval but it
    // got killed. That's because it takes the CallEval to cause the scope register to be kept alive
    // unless the debugger is also enabled.
    if (graph.needsScopeRegister() && codeBlock->scopeRegister().isValid())
        codeBlock->setScopeRegister(codeBlock->scopeRegister() + localsOffset);

    for (OSRExitDescriptor& descriptor : state.jitCode->osrExitDescriptors) {
        for (unsigned i = descriptor.m_values.size(); i--;)
            descriptor.m_values[i] = descriptor.m_values[i].withLocalsOffset(localsOffset);
        for (ExitTimeObjectMaterialization* materialization : descriptor.m_materializations)
            materialization->accountForLocalsOffset(localsOffset);
    }

    // We will add exception handlers while generating.
    codeBlock->clearExceptionHandlers();

    CCallHelpers jit(codeBlock);
    B3::generate(*state.proc, jit);

    // Emit the exception handler.
    *state.exceptionHandler = jit.label();
#if ENABLE(EXTRA_CTI_THUNKS)
    CCallHelpers::Jump handler = jit.jump();
    VM* vmPtr = &vm;
    jit.addLinkTask(
        [=] (LinkBuffer& linkBuffer) {
            linkBuffer.link(handler, CodeLocationLabel(vmPtr->getCTIStub(handleExceptionGenerator).retaggedCode<NoPtrTag>()));
        });
#else
    jit.copyCalleeSavesToEntryFrameCalleeSavesBuffer(vm.topEntryFrame);
    jit.move(MacroAssembler::TrustedImmPtr(&vm), GPRInfo::argumentGPR0);
    jit.prepareCallOperation(vm);
    CCallHelpers::Call call = jit.call(OperationPtrTag);
    jit.jumpToExceptionHandler(vm);
    jit.addLinkTask(
        [=] (LinkBuffer& linkBuffer) {
            linkBuffer.link(call, FunctionPtr<OperationPtrTag>(operationLookupExceptionHandler));
        });
#endif // ENABLE(EXTRA_CTI_THUNKS)

    state.finalizer->b3CodeLinkBuffer = makeUnique<LinkBuffer>(jit, codeBlock, LinkBuffer::Profile::FTL, JITCompilationCanFail);

    if (state.finalizer->b3CodeLinkBuffer->didFailToAllocate()) {
        state.allocationFailed = true;
        return;
    }

    if (vm.shouldBuilderPCToCodeOriginMapping()) {
        B3::PCToOriginMap originMap = state.proc->releasePCToOriginMap();
        state.jitCode->common.m_pcToCodeOriginMap = makeUnique<PCToCodeOriginMap>(PCToCodeOriginMapBuilder(vm, WTFMove(originMap)), *state.finalizer->b3CodeLinkBuffer);
    }

    CodeLocationLabel<JSEntryPtrTag> label = state.finalizer->b3CodeLinkBuffer->locationOf<JSEntryPtrTag>(state.proc->code().entrypointLabel(0));
    state.generatedFunction = label;
    state.jitCode->initializeB3Byproducts(state.proc->releaseByproducts());

    for (auto pair : state.graph.m_entrypointIndexToCatchBytecodeIndex) {
        BytecodeIndex catchBytecodeIndex = pair.value;
        unsigned entrypointIndex = pair.key;
        Vector<FlushFormat> argumentFormats = state.graph.m_argumentFormats[entrypointIndex];
        state.graph.appendCatchEntrypoint(catchBytecodeIndex, state.finalizer->b3CodeLinkBuffer->locationOf<ExceptionHandlerPtrTag>(state.proc->code().entrypointLabel(entrypointIndex)), WTFMove(argumentFormats));
    }
    state.jitCode->common.finalizeCatchEntrypoints(WTFMove(state.graph.m_catchEntrypoints));

    if (shouldDumpDisassembly())
        state.dumpDisassembly(WTF::dataFile());

    Profiler::Compilation* compilation = graph.compilation();
    if (UNLIKELY(compilation)) {
        compilation->addDescription(
            Profiler::OriginStack(),
            toCString("Generated FTL DFG IR for ", CodeBlockWithJITType(codeBlock, JITType::FTLJIT), ", instructions size = ", graph.m_codeBlock->instructionsSize(), ":\n"));

        graph.ensureSSADominators();
        graph.ensureSSANaturalLoops();

        const char* prefix = "    ";

        DumpContext dumpContext;
        StringPrintStream out;
        Node* lastNode = nullptr;
        for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); ++blockIndex) {
            DFG::BasicBlock* block = graph.block(blockIndex);
            if (!block)
                continue;

            graph.dumpBlockHeader(out, prefix, block, Graph::DumpLivePhisOnly, &dumpContext);
            compilation->addDescription(Profiler::OriginStack(), out.toCString());
            out.reset();

            for (size_t nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
                Node* node = block->at(nodeIndex);

                Profiler::OriginStack stack;

                if (node->origin.semantic.isSet()) {
                    stack = Profiler::OriginStack(
                        *vm.m_perBytecodeProfiler, codeBlock, node->origin.semantic);
                }

                if (graph.dumpCodeOrigin(out, prefix, lastNode, node, &dumpContext)) {
                    compilation->addDescription(stack, out.toCString());
                    out.reset();
                }

                graph.dump(out, prefix, node, &dumpContext);
                compilation->addDescription(stack, out.toCString());
                out.reset();

                if (node->origin.semantic.isSet())
                    lastNode = node;
            }
        }

        dumpContext.dump(out, prefix);
        compilation->addDescription(Profiler::OriginStack(), out.toCString());
        out.reset();

        out.print("\n\n\n    FTL B3/Air Disassembly:\n");
        compilation->addDescription(Profiler::OriginStack(), out.toCString());
        out.reset();

        state.dumpDisassembly(out, scopedLambda<void(Node*)>([&] (Node*) {
            compilation->addDescription({ }, out.toCString());
            out.reset();
        }));
        compilation->addDescription({ }, out.toCString());
        out.reset();

        state.jitCode->common.compilation = compilation;
    }

}

} } // namespace JSC::FTL

#endif // ENABLE(FTL_JIT)