/*
 * Copyright (C) 2011, 2014 Apple Inc. All rights reserved.
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#ifndef DFGCSEPhase_h
#define DFGCSEPhase_h

#if ENABLE(DFG_JIT)

#include "DFGCommon.h"

namespace JSC { namespace DFG {

class Graph;

// Block-local common subexpression elimination. It uses clobberize() for heap
// modeling, which is quite precise. This phase is known to produce big wins on
// a few benchmarks, and is relatively cheap to run.
//
// Note that this phase also gets rid of Identity nodes, which means that it's
// currently not an optional phase. Basically, DFG IR doesn't have use-lists,
// so there is no instantaneous replaceAllUsesWith operation. Instead, you turn
// a node into an Identity and wait for CSE to clean it up.
bool performLocalCSE(Graph&);

// Same, but global. Only works for SSA. This will find common subexpressions
// both in the same block and in any block that dominates the current block. It
// has no limits on how far it will look for load-elimination opportunities.
bool performGlobalCSE(Graph&);

} } // namespace JSC::DFG

#endif // ENABLE(DFG_JIT)

#endif // DFGCSEPhase_h