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More flexible way to approach unknown stack elements.

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This commit is contained in:
chriseth 2015-04-30 11:40:43 +02:00
parent 9106d72a02
commit 3ebb7d99c4
3 changed files with 34 additions and 12 deletions
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30
ExpressionClasses.cpp
View File

@ -37,6 +37,7 @@ using namespace dev::eth;
bool ExpressionClasses::Expression::operator<(ExpressionClasses::Expression const& _other) const bool ExpressionClasses::Expression::operator<(ExpressionClasses::Expression const& _other) const
{ {
assertThrow(!!item && !!_other.item, OptimizerException, "");
auto type = item->type(); auto type = item->type();
auto otherType = _other.item->type(); auto otherType = _other.item->type();
return std::tie(type, item->data(), arguments, sequenceNumber) < return std::tie(type, item->data(), arguments, sequenceNumber) <
@ -78,6 +79,15 @@ ExpressionClasses::Id ExpressionClasses::find(
return exp.id; return exp.id;
} }
ExpressionClasses::Id ExpressionClasses::newId()
{
// Note that we cannot insert it in m_expressions because this requires item to be set.
Expression exp;
exp.id = m_representatives.size();
m_representatives.push_back(exp);
return exp.id;
}
bool ExpressionClasses::knownToBeDifferent(ExpressionClasses::Id _a, ExpressionClasses::Id _b) bool ExpressionClasses::knownToBeDifferent(ExpressionClasses::Id _a, ExpressionClasses::Id _b)
{ {
// Try to simplify "_a - _b" and return true iff the value is a non-zero constant. // Try to simplify "_a - _b" and return true iff the value is a non-zero constant.
@ -122,10 +132,16 @@ string ExpressionClasses::fullDAGToString(ExpressionClasses::Id _id) const
{ {
Expression const& expr = representative(_id); Expression const& expr = representative(_id);
stringstream str; stringstream str;
str << dec << expr.id << ":" << *expr.item << "("; str << dec << expr.id << ":";
if (expr.item)
{
str << *expr.item << "(";
for (Id arg: expr.arguments) for (Id arg: expr.arguments)
str << fullDAGToString(arg) << ","; str << fullDAGToString(arg) << ",";
str << ")"; str << ")";
}
else
str << " UNIQUE";
return str.str(); return str.str();
} }
@ -279,7 +295,7 @@ ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr,
{ {
static Rules rules; static Rules rules;
if (_expr.item->type() != Operation) if (!_expr.item || _expr.item->type() != Operation)
return -1; return -1;
for (auto const& rule: rules.rules()) for (auto const& rule: rules.rules())
@ -337,7 +353,7 @@ void Pattern::setMatchGroup(unsigned _group, map<unsigned, Expression const*>& _
bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const
{ {
if (!matchesBaseItem(*_expr.item)) if (!matchesBaseItem(_expr.item))
return false; return false;
if (m_matchGroup) if (m_matchGroup)
{ {
@ -387,13 +403,15 @@ string Pattern::toString() const
return s.str(); return s.str();
} }
bool Pattern::matchesBaseItem(AssemblyItem const& _item) const bool Pattern::matchesBaseItem(AssemblyItem const* _item) const
{ {
if (m_type == UndefinedItem) if (m_type == UndefinedItem)
return true; return true;
if (m_type != _item.type()) if (!_item)
return false; return false;
if (m_requireDataMatch && m_data != _item.data()) if (m_type != _item->type())
return false;
if (m_requireDataMatch && m_data != _item->data())
return false; return false;
return true; return true;
} }

8
ExpressionClasses.h
View File

@ -50,7 +50,7 @@ public:
struct Expression struct Expression
{ {
Id id; Id id;
AssemblyItem const* item; AssemblyItem const* item = nullptr;
Ids arguments; Ids arguments;
unsigned sequenceNumber; ///< Storage modification sequence, only used for SLOAD/SSTORE instructions. unsigned sequenceNumber; ///< Storage modification sequence, only used for SLOAD/SSTORE instructions.
/// Behaves as if this was a tuple of (item->type(), item->data(), arguments, sequenceNumber). /// Behaves as if this was a tuple of (item->type(), item->data(), arguments, sequenceNumber).
@ -68,6 +68,10 @@ public:
bool _copyItem = true, bool _copyItem = true,
unsigned _sequenceNumber = 0 unsigned _sequenceNumber = 0
); );
/// @returns a new unique class id which does not and will never have a representative containing
/// an AssemblyItem, i.e. its value cannot be generated, instead it has to be assumed to be
/// already present.
Id newId();
/// @returns the canonical representative of an expression class. /// @returns the canonical representative of an expression class.
Expression const& representative(Id _id) const { return m_representatives.at(_id); } Expression const& representative(Id _id) const { return m_representatives.at(_id); }
/// @returns the number of classes. /// @returns the number of classes.
@ -149,7 +153,7 @@ public:
std::string toString() const; std::string toString() const;
private: private:
bool matchesBaseItem(AssemblyItem const& _item) const; bool matchesBaseItem(AssemblyItem const* _item) const;
Expression const& matchGroupValue() const; Expression const& matchGroupValue() const;
AssemblyItemType m_type; AssemblyItemType m_type;

2
KnownState.cpp
View File

@ -136,7 +136,7 @@ ExpressionClasses::Id KnownState::stackElement(int _stackHeight, SourceLocation
if (m_stackElements.count(_stackHeight)) if (m_stackElements.count(_stackHeight))
return m_stackElements.at(_stackHeight); return m_stackElements.at(_stackHeight);
// Stack element not found (not assigned yet), create new equivalence class. // Stack element not found (not assigned yet), create new equivalence class.
return m_stackElements[_stackHeight] = initialStackElement(_stackHeight, _location); return m_stackElements[_stackHeight] = m_expressionClasses->newId();
} }
ExpressionClasses::Id KnownState::initialStackElement( ExpressionClasses::Id KnownState::initialStackElement(