Unique vector

Author: nikola-matic

libsolutil/CommonData.h

@@ -159,14 +159,6 @@ inline std::multiset<T...>& operator-=(std::multiset<T...>& _a, C const& _b)
 	return _a;
 }
 
-/// Remove the elements of a container from a vector
-template <class T, class U> std::vector<T>& operator-=(std::vector<T>& _a, U& _b)
-{
-	for (auto const& i: _b)
-		_a.erase(std::find(_a.begin(), _a.end(), i));
-	return _a;
-}
-
 namespace solidity::util
 {
 
@@ -351,6 +343,49 @@ void joinMap(std::map<K, V>& _a, std::map<K, V>&& _b, F _conflictSolver)
 	}
 }
 
+template<typename T>
+class UniqueVector
+{
+public:
+	std::vector<T>& contents() { return m_contents; }
+	size_t size() const { return m_contents.size(); }
+	bool empty() const { return m_contents.empty(); }
+	auto begin() const { return m_contents.begin(); }
+	auto end() const { return m_contents.end(); }
+	void clear() { m_contents.clear(); }
+	bool contains(T const& _value) const
+	{
+		return std::find(m_contents.begin(), m_contents.end(), _value) != m_contents.end();
+	}
+
+	void pushBack(T _value)
+	{
+		if (!contains(_value))
+			m_contents.emplace_back(std::move(_value));
+	}
+
+	void pushBack(UniqueVector<T> const& _values)
+	{
+		for (auto&& value: _values)
+			pushBack(value);
+	}
+
+	void removeAll(std::vector<T> const& _values)
+	{
+		for (auto const& value: _values)
+			m_contents.erase(std::find(m_contents.begin(), m_contents.end(), value));
+	}
+
+private:
+	std::vector<T> m_contents;
+};
+
+template<typename T>
+void swap(UniqueVector<T>& _lhs, UniqueVector<T>& _rhs)
+{
+	std::swap(_lhs.contents(), _rhs.contents());
+}
+
 namespace detail
 {
 
@@ -458,24 +493,6 @@ bool contains_if(T const& _t, Predicate const& _p)
 	return std::end(_t) != std::find_if(std::begin(_t), std::end(_t), _p);
 }
 
-/// Function that insert @param _elem into a vector @param _destination only if _elem is not
-/// already present in _destination vector.
-template <class T>
-void tryEmplaceBack(std::vector<T>& _destination, T _elem)
-{
-	if (!contains(_destination, _elem))
-		_destination.emplace_back(std::move(_elem));
-}
-
-/// Function that takes vector @param _destination and appends vector @param _source,
-/// whilst only taking into account unique elements of _source.
-template <class T>
-void appendMissing(std::vector<T>& _destination, std::vector<T> const& _source)
-{
-	for (auto&& elem: _source)
-		tryEmplaceBack(_destination, elem);
-}
-
 /// Function that iterates over a vector, calling a function on each of its
 /// elements. If that function returns a vector, the element is replaced by
 /// the returned vector. During the iteration, the original vector is only valid

libyul/optimiser/SSATransform.cpp

@@ -167,22 +167,22 @@ class IntroduceControlFlowSSA: public ASTModifier
 	/// Variables (that are to be replaced) currently in scope.
 	std::set<YulString> m_variablesInScope;
 	/// Variables that do not have a specific value.
-	std::vector<YulString> m_variablesToReassign;
+	util::UniqueVector<YulString> m_variablesToReassign;
 	TypeInfo const& m_typeInfo;
 };
 
 void IntroduceControlFlowSSA::operator()(FunctionDefinition& _function)
 {
 	std::set<YulString> varsInScope;
 	std::swap(varsInScope, m_variablesInScope);
-	std::vector<YulString> toReassign;
+	util::UniqueVector<YulString> toReassign;
 	std::swap(toReassign, m_variablesToReassign);
 
 	for (auto const& param: _function.parameters)
 		if (m_variablesToReplace.count(param.name))
 		{
 			m_variablesInScope.insert(param.name);
-			m_variablesToReassign.push_back(param.name);
+			m_variablesToReassign.pushBack(param.name);
 		}
 
 	ASTModifier::operator()(_function);
@@ -196,8 +196,8 @@ void IntroduceControlFlowSSA::operator()(ForLoop& _for)
 	yulAssert(_for.pre.statements.empty(), "For loop init rewriter not run.");
 
 	for (auto const& var: assignedVariableNames(_for.body) + assignedVariableNames(_for.post))
-		if (util::contains(m_variablesInScope,var) && !util::contains(m_variablesToReassign, var))
-			m_variablesToReassign.push_back(var);
+		if (util::contains(m_variablesInScope,var))
+			m_variablesToReassign.pushBack(var);
 
 	(*this)(_for.body);
 	(*this)(_for.post);
@@ -207,20 +207,20 @@ void IntroduceControlFlowSSA::operator()(Switch& _switch)
 {
 	yulAssert(m_variablesToReassign.empty(), "");
 
-	std::vector<YulString> toReassign;
+	util::UniqueVector<YulString> toReassign;
 	for (auto& c: _switch.cases)
 	{
 		(*this)(c.body);
-		util::appendMissing(toReassign, m_variablesToReassign);
+		toReassign.pushBack(m_variablesToReassign);
 	}
 
-	util::appendMissing(m_variablesToReassign, toReassign);
+	m_variablesToReassign.pushBack(toReassign);
 }
 
 void IntroduceControlFlowSSA::operator()(Block& _block)
 {
-	std::vector<YulString> variablesDeclaredHere;
-	std::vector<YulString> assignedVariables;
+	util::UniqueVector<YulString> variablesDeclaredHere;
+	util::UniqueVector<YulString> assignedVariables;
 
 	util::iterateReplacing(
 		_block.statements,
@@ -235,8 +235,7 @@ void IntroduceControlFlowSSA::operator()(Block& _block)
 					{TypedName{debugDataOf(_s), newName, m_typeInfo.typeOfVariable(toReassign)}},
 					std::make_unique<Expression>(Identifier{debugDataOf(_s), toReassign})
 				});
-				if (!util::contains(assignedVariables, toReassign))
-					assignedVariables.push_back(toReassign);
+				assignedVariables.pushBack(toReassign);
 			}
 			m_variablesToReassign.clear();
 
@@ -246,16 +245,16 @@ void IntroduceControlFlowSSA::operator()(Block& _block)
 				for (auto const& var: varDecl.variables)
 					if (m_variablesToReplace.count(var.name))
 					{
-						util::tryEmplaceBack(variablesDeclaredHere, var.name);
+						variablesDeclaredHere.pushBack(var.name);
 						m_variablesInScope.insert(var.name);
 					}
 			}
 			else if (std::holds_alternative<Assignment>(_s))
 			{
 				Assignment& assignment = std::get<Assignment>(_s);
 				for (auto const& var: assignment.variableNames)
-					if (m_variablesToReplace.count(var.name) && !util::contains(assignedVariables, var.name))
-						assignedVariables.push_back(var.name);
+					if (m_variablesToReplace.count(var.name))
+						assignedVariables.pushBack(var.name);
 			}
 			else
 				visit(_s);
@@ -270,9 +269,9 @@ void IntroduceControlFlowSSA::operator()(Block& _block)
 		}
 	);
 
-	util::appendMissing(m_variablesToReassign, assignedVariables);
-	m_variablesInScope -= variablesDeclaredHere;
-	m_variablesToReassign -= variablesDeclaredHere;
+	m_variablesToReassign.pushBack(assignedVariables);
+	m_variablesInScope -= variablesDeclaredHere.contents();
+	m_variablesToReassign.removeAll(variablesDeclaredHere.contents());
 }
 
 /**