Source/JavaScriptCore/b3/B3PatchpointSpecial.cpp

/*
 * Copyright (C) 2015 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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#include "config.h"
#include "B3PatchpointSpecial.h"

#if ENABLE(B3_JIT)

#include "AirGenerationContext.h"
#include "B3ValueInlines.h"

namespace JSC { namespace B3 {

using namespace Air;

PatchpointSpecial::PatchpointSpecial()
{
}

PatchpointSpecial::~PatchpointSpecial()
{
}

void PatchpointSpecial::forEachArg(Inst& inst, const ScopedLambda<Inst::EachArgCallback>& callback)
{
    // FIXME: Allow B3 Patchpoints to specify LateUse.
    // https://bugs.webkit.org/show_bug.cgi?id=151335
    
    if (inst.origin->type() == Void) {
        forEachArgImpl(0, 1, inst, Arg::Use, callback);
        return;
    }

    callback(inst.args[1], Arg::Def, inst.origin->airType());
    forEachArgImpl(0, 2, inst, Arg::Use, callback);
}

bool PatchpointSpecial::isValid(Inst& inst)
{
    if (inst.origin->type() == Void)
        return isValidImpl(0, 1, inst);

    if (inst.args.size() < 2)
        return false;
    if (inst.args[1].kind() != Arg::Tmp)
        return false;
    if (!inst.args[1].isType(inst.origin->airType()))
        return false;

    return isValidImpl(0, 2, inst);
}

bool PatchpointSpecial::admitsStack(Inst& inst, unsigned argIndex)
{
    if (inst.origin->type() == Void)
        return admitsStackImpl(0, 1, inst, argIndex);

    if (argIndex == 1)
        return false;

    return admitsStackImpl(0, 2, inst, argIndex);
}

CCallHelpers::Jump PatchpointSpecial::generate(
    Inst& inst, CCallHelpers& jit, GenerationContext& context)
{
    StackmapValue* value = inst.origin->as<StackmapValue>();
    ASSERT(value);

    Vector<ValueRep> reps;
    unsigned offset = 1;
    if (inst.origin->type() != Void)
        reps.append(repForArg(*context.code, inst.args[offset++]));
    appendRepsImpl(context, offset, inst, reps);
    
    StackmapGenerationParams params;
    params.value = value;
    params.reps = reps;
    params.usedRegisters = value->m_usedRegisters;
    params.context = &context;

    value->m_generator->run(jit, params);

    return CCallHelpers::Jump();
}

void PatchpointSpecial::dumpImpl(PrintStream& out) const
{
    out.print("Patchpoint");
}

void PatchpointSpecial::deepDumpImpl(PrintStream& out) const
{
    out.print("Lowered B3::PatchpointValue.");
}

} } // namespace JSC::B3

#endif // ENABLE(B3_JIT)