Source/JavaScriptCore/wasm/WasmOpcodeOrigin.h

/*
 * Copyright (C) 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
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    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
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if ENABLE(WEBASSEMBLY_OMGJIT)

#include "WasmFormat.h"

#include <wtf/ForbidHeapAllocation.h>

namespace JSC {

namespace B3 {
class Origin;
}

namespace Wasm {

class OpcodeOrigin {
    WTF_FORBID_HEAP_ALLOCATION;

public:
    void dump(PrintStream&) const;

    OpcodeOrigin() = default;

    friend bool operator==(const OpcodeOrigin&, const OpcodeOrigin&) = default;

    OpcodeOrigin(OpType opcode, size_t offset)
    {
        ASSERT(static_cast<uint32_t>(offset) == offset);
        ASSERT(static_cast<OpType>(static_cast<uint8_t>(opcode)) == opcode);
        packedData = (static_cast<uint64_t>(opcode) << 32) | offset;
    }
    OpcodeOrigin(OpType prefix, uint32_t opcode, size_t offset)
    {
        ASSERT(static_cast<uint32_t>(offset) == offset);
        ASSERT(static_cast<OpType>(static_cast<uint8_t>(prefix)) == prefix);
        // We must leave the top 4 bits free for tagging inside B3::Origin
        // If the spec ever numbers opcodes this aggressively, we will need to consider heap allocation.
        ASSERT((opcode & ((1 << 17) - 1)) == opcode);
        packedData = (static_cast<uint64_t>(opcode) << 40) | (static_cast<uint64_t>(prefix) << 32) | offset;
    }

    OpcodeOrigin(B3::Origin);

    OpType opcode() const
    {
        return static_cast<OpType>(packedData >> 32 & 0xff);
    }

    Ext1OpType ext1Opcode() const
    {
        return static_cast<Ext1OpType>(packedData >> 40);
    }

    ExtSIMDOpType simdOpcode() const
    {
        return static_cast<ExtSIMDOpType>(packedData >> 40);
    }

    ExtGCOpType gcOpcode() const
    {
        return static_cast<ExtGCOpType>(packedData >> 40);
    }

    ExtAtomicOpType atomicOpcode() const
    {
        return static_cast<ExtAtomicOpType>(packedData >> 40);
    }

    size_t location() const
    {
        return static_cast<uint32_t>(packedData);
    }

    B3::Origin asB3Origin();

private:
    uint64_t packedData { 0 };
};

} } // namespace JSC::Wasm

#endif // ENABLE(WEBASSEMBLY_OMGJIT)