darling-JavaScriptCore/dfg/DFGValueStrength.h
2017-08-12 09:48:01 -07:00

67 lines
2.3 KiB
C++

/*
* Copyright (C) 2014, 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.
* 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.
*/
#pragma once
#if ENABLE(DFG_JIT)
#include <wtf/PrintStream.h>
namespace JSC { namespace DFG {
enum ValueStrength {
// The value has been used for optimization and it arose through inference. We don't want the
// fact that we optimized the code to result in the GC keeping this value alive unnecessarily,
// so we'd rather kill the code and recompile than keep the object alive longer.
WeakValue,
// The code will keep this value alive. This is true of constants that were present in the
// source. String constants tend to be strong.
StrongValue
};
inline ValueStrength merge(ValueStrength a, ValueStrength b)
{
switch (a) {
case WeakValue:
return b;
case StrongValue:
return StrongValue;
}
RELEASE_ASSERT_NOT_REACHED();
return WeakValue;
}
} } // namespace JSC::DFG
namespace WTF {
void printInternal(PrintStream&, JSC::DFG::ValueStrength);
} // namespace WTF
#endif // ENABLE(DFG_JIT)