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/*
* Copyright (C) 2013, 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 DFGAbstractInterpreter_h
#define DFGAbstractInterpreter_h
#if ENABLE(DFG_JIT)
#include "DFGAbstractValue.h"
#include "DFGBranchDirection.h"
#include "DFGGraph.h"
#include "DFGNode.h"
namespace JSC { namespace DFG {
template<typename AbstractStateType>
class AbstractInterpreter {
public:
AbstractInterpreter(Graph&, AbstractStateType&);
~AbstractInterpreter();
AbstractValue& forNode(Node* node)
{
return m_state.forNode(node);
}
AbstractValue& forNode(Edge edge)
{
return forNode(edge.node());
}
Operands<AbstractValue>& variables()
{
return m_state.variables();
}
bool needsTypeCheck(Node* node, SpeculatedType typesPassedThrough)
{
return !forNode(node).isType(typesPassedThrough);
}
bool needsTypeCheck(Edge edge, SpeculatedType typesPassedThrough)
{
return needsTypeCheck(edge.node(), typesPassedThrough);
}
bool needsTypeCheck(Edge edge)
{
return needsTypeCheck(edge, typeFilterFor(edge.useKind()));
}
// Abstractly executes the given node. The new abstract state is stored into an
// abstract stack stored in *this. Loads of local variables (that span
// basic blocks) interrogate the basic block's notion of the state at the head.
// Stores to local variables are handled in endBasicBlock(). This returns true
// if execution should continue past this node. Notably, it will return true
// for block terminals, so long as those terminals are not Return or Unreachable.
//
// This is guaranteed to be equivalent to doing:
//
// if (state.startExecuting(index)) {
// state.executeEdges(index);
// result = state.executeEffects(index);
// } else
// result = true;
bool execute(unsigned indexInBlock);
bool execute(Node*);
// Indicate the start of execution of the node. It resets any state in the node
// that is progressively built up by executeEdges() and executeEffects().
bool startExecuting(Node*);
bool startExecuting(unsigned indexInBlock);
// Abstractly execute the edges of the given node. This runs filterEdgeByUse()
// on all edges of the node. You can skip this step, if you have already used
// filterEdgeByUse() (or some equivalent) on each edge.
void executeEdges(Node*);
void executeEdges(unsigned indexInBlock);
ALWAYS_INLINE void filterEdgeByUse(Edge& edge)
{
ASSERT(mayHaveTypeCheck(edge.useKind()) || !needsTypeCheck(edge));
filterByType(edge, typeFilterFor(edge.useKind()));
}
ALWAYS_INLINE void filterEdgeByUse(Node*, Edge& edge)
{
filterEdgeByUse(edge);
}
// Abstractly execute the effects of the given node. This changes the abstract
// state assuming that edges have already been filtered.
bool executeEffects(unsigned indexInBlock);
bool executeEffects(unsigned clobberLimit, Node*);
void dump(PrintStream& out) const;
void dump(PrintStream& out);
template<typename T>
FiltrationResult filter(T node, const StructureSet& set)
{
return filter(forNode(node), set);
}
template<typename T>
FiltrationResult filterArrayModes(T node, ArrayModes arrayModes)
{
return filterArrayModes(forNode(node), arrayModes);
}
template<typename T>
FiltrationResult filter(T node, SpeculatedType type)
{
return filter(forNode(node), type);
}
template<typename T>
FiltrationResult filterByValue(T node, FrozenValue value)
{
return filterByValue(forNode(node), value);
}
FiltrationResult filter(AbstractValue&, const StructureSet&);
FiltrationResult filterArrayModes(AbstractValue&, ArrayModes);
FiltrationResult filter(AbstractValue&, SpeculatedType);
FiltrationResult filterByValue(AbstractValue&, FrozenValue);
private:
void clobberWorld(const CodeOrigin&, unsigned indexInBlock);
void clobberCapturedVars(const CodeOrigin&);
template<typename Functor>
void forAllValues(unsigned indexInBlock, Functor&);
void clobberStructures(unsigned indexInBlock);
void observeTransition(unsigned indexInBlock, Structure* from, Structure* to);
void observeTransitions(unsigned indexInBlock, const TransitionVector&);
void setDidClobber();
enum BooleanResult {
UnknownBooleanResult,
DefinitelyFalse,
DefinitelyTrue
};
BooleanResult booleanResult(Node*, AbstractValue&);
void setBuiltInConstant(Node* node, FrozenValue value)
{
AbstractValue& abstractValue = forNode(node);
abstractValue.set(m_graph, value, m_state.structureClobberState());
abstractValue.fixTypeForRepresentation(node);
}
void setConstant(Node* node, FrozenValue value)
{
setBuiltInConstant(node, value);
m_state.setFoundConstants(true);
}
ALWAYS_INLINE void filterByType(Edge& edge, SpeculatedType type)
{
AbstractValue& value = forNode(edge);
if (!value.isType(type))
edge.setProofStatus(NeedsCheck);
else
edge.setProofStatus(IsProved);
filter(value, type);
}
void verifyEdge(Node*, Edge);
void verifyEdges(Node*);
CodeBlock* m_codeBlock;
Graph& m_graph;
AbstractStateType& m_state;
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
#endif // DFGAbstractInterpreter_h
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