Source/JavaScriptCore/jit/JITBitXorGenerator.cpp

/*
 * Copyright (C) 2015-2019 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "JITBitXorGenerator.h"

#if ENABLE(JIT)

namespace JSC {

void JITBitXorGenerator::generateFastPath(CCallHelpers& jit)
{
    ASSERT(!m_leftOperand.isConstInt32() || !m_rightOperand.isConstInt32());
    
    m_didEmitFastPath = true;
    
    if (m_leftOperand.isConstInt32() || m_rightOperand.isConstInt32()) {
        JSValueRegs var = m_leftOperand.isConstInt32() ? m_right : m_left;
        SnippetOperand& constOpr = m_leftOperand.isConstInt32() ? m_leftOperand : m_rightOperand;
        
        // Try to do intVar ^ intConstant.
        m_slowPathJumpList.append(jit.branchIfNotInt32(var));
        
        jit.moveValueRegs(var, m_result);
#if USE(JSVALUE64)
        jit.xor32(CCallHelpers::Imm32(constOpr.asConstInt32()), m_result.payloadGPR());
        jit.or64(GPRInfo::numberTagRegister, m_result.payloadGPR());
#else
        jit.xor32(CCallHelpers::Imm32(constOpr.asConstInt32()), m_result.payloadGPR());
#endif
        
    } else {
        ASSERT(!m_leftOperand.isConstInt32() && !m_rightOperand.isConstInt32());
        
        // Try to do intVar ^ intVar.
        m_slowPathJumpList.append(jit.branchIfNotInt32(m_left));
        m_slowPathJumpList.append(jit.branchIfNotInt32(m_right));
        
        jit.moveValueRegs(m_left, m_result);
#if USE(JSVALUE64)
        jit.xor64(m_right.payloadGPR(), m_result.payloadGPR());
        jit.or64(GPRInfo::numberTagRegister, m_result.payloadGPR());
#else
        jit.xor32(m_right.payloadGPR(), m_result.payloadGPR());
#endif
    }
}

} // namespace JSC

#endif // ENABLE(JIT)