Source/JavaScriptCore/b3/B3StackmapSpecial.h

/*
 * Copyright (C) 2015-2017 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
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 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
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 *
 * 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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 */

#pragma once

#if ENABLE(B3_JIT)

#include "AirArg.h"
#include "AirSpecial.h"
#include "B3ValueRep.h"

namespace JSC { namespace B3 {

namespace Air { class Code; }

// This is a base class for specials that have stackmaps. Note that it can find the Stackmap by
// asking for the Inst's origin. Hence, these objects don't need to even hold a reference to the
// Stackmap.

class StackmapSpecial : public Air::Special {
public:
    StackmapSpecial();
    virtual ~StackmapSpecial();

    enum RoleMode : int8_t {
        SameAsRep,
        ForceLateUseUnlessRecoverable,
        ForceLateUse
    };

protected:
    void reportUsedRegisters(Air::Inst&, const RegisterSet&) final;
    RegisterSet extraEarlyClobberedRegs(Air::Inst&) final;
    RegisterSet extraClobberedRegs(Air::Inst&) final;

    // Note that this does not override generate() or dumpImpl()/deepDumpImpl(). We have many
    // subclasses that implement that.
    void forEachArgImpl(
        unsigned numIgnoredB3Args, unsigned numIgnoredAirArgs,
        Air::Inst&, RoleMode, Optional<unsigned> firstRecoverableIndex,
        const ScopedLambda<Air::Inst::EachArgCallback>&, Optional<Width> optionalDefArgWidth);

    bool isValidImpl(
        unsigned numIgnoredB3Args, unsigned numIgnoredAirArgs,
        Air::Inst&);
    bool admitsStackImpl(
        unsigned numIgnoredB3Args, unsigned numIgnoredAirArgs,
        Air::Inst&, unsigned argIndex);

    // Appends the reps for the Inst's args, starting with numIgnoredArgs, to the given vector.
    Vector<ValueRep> repsImpl(
        Air::GenerationContext&, unsigned numIgnoredB3Args, unsigned numIgnoredAirArgs, Air::Inst&);

    static bool isArgValidForValue(const Air::Arg&, Value*);
    static bool isArgValidForRep(Air::Code&, const Air::Arg&, const ValueRep&);
    static ValueRep repForArg(Air::Code&, const Air::Arg&);
};

} } // namespace JSC::B3

namespace WTF {

void printInternal(PrintStream&, JSC::B3::StackmapSpecial::RoleMode);

} // namespace WTF

#endif // ENABLE(B3_JIT)