/*

* Copyright (C) 2014 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

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef FTLWeight_h

#define FTLWeight_h

#if ENABLE(FTL_JIT)

#include <wtf/MathExtras.h>

#include <wtf/StdLibExtras.h>

namespace JSC { namespace FTL {

class Weight {

public:

Weight()

: m_value(std::numeric_limits<float>::quiet_NaN())

{

}

explicit Weight(float value)

: m_value(value)

{

}

bool isSet() const { return m_value == m_value; }

bool operator!() const { return !isSet(); }

float value() const { return m_value; }

unsigned scaleToTotal(double total) const

{

// LLVM accepts 32-bit unsigned branch weights but in dumps it might display them

// as signed values. We don't need all 32 bits, so we just use the 31 bits.

double result = static_cast<double>(m_value) * INT_MAX / total;

if (result < 0)

return 0;

if (result > INT_MAX)

return INT_MAX;

return static_cast<unsigned>(result);

}

private:

float m_value;

};

} } // namespace JSC::FTL

#endif // ENABLE(FTL_JIT)

#endif // FTLWeight_h