diff --git a/libyul/AsmAnalysis.cpp b/libyul/AsmAnalysis.cpp
index eee3beacb..07db82095 100644
--- a/libyul/AsmAnalysis.cpp
+++ b/libyul/AsmAnalysis.cpp
@@ -137,7 +137,7 @@ vector<YulString> AsmAnalyzer::operator()(Identifier const& _identifier)
 		{
 			bool insideFunction = m_currentScope->insideFunction();
 			size_t stackSize = m_resolver(_identifier, yul::IdentifierContext::RValue, insideFunction);
-			if (stackSize != size_t(-1))
+			if (stackSize != numeric_limits<size_t>::max())
 			{
 				found = true;
 				yulAssert(stackSize == 1, "Invalid stack size of external reference.");
@@ -479,7 +479,7 @@ void AsmAnalyzer::checkAssignment(Identifier const& _variable, YulString _valueT
 	{
 		bool insideFunction = m_currentScope->insideFunction();
 		size_t variableSize = m_resolver(_variable, yul::IdentifierContext::LValue, insideFunction);
-		if (variableSize != size_t(-1))
+		if (variableSize != numeric_limits<size_t>::max())
 		{
 			found = true;
 			variableType = &m_dialect.defaultType;
diff --git a/libyul/Utilities.cpp b/libyul/Utilities.cpp
index a797258eb..59e0adce3 100644
--- a/libyul/Utilities.cpp
+++ b/libyul/Utilities.cpp
@@ -45,7 +45,7 @@ string solidity::yul::reindent(string const& _code)
 	auto const static countBraces = [](string const& _s) noexcept -> int
 	{
 		auto const i = _s.find("//");
-		auto const e = i == _s.npos ? end(_s) : next(begin(_s), i);
+		auto const e = i == _s.npos ? end(_s) : next(begin(_s), static_cast<ptrdiff_t>(i));
 		auto const opening = count_if(begin(_s), e, [](auto ch) { return ch == '{' || ch == '('; });
 		auto const closing = count_if(begin(_s), e, [](auto ch) { return ch == '}' || ch == ')'; });
 		return opening - closing;
diff --git a/libyul/YulString.h b/libyul/YulString.h
index 9166cff3d..0abe1f38d 100644
--- a/libyul/YulString.h
+++ b/libyul/YulString.h
@@ -71,10 +71,10 @@ public:
 	{
 		// FNV hash - can be replaced by a better one, e.g. xxhash64
 		std::uint64_t hash = emptyHash();
-		for (auto c: v)
+		for (char c: v)
 		{
 			hash *= 1099511628211u;
-			hash ^= c;
+			hash ^= static_cast<uint64_t>(c);
 		}
 
 		return hash;
diff --git a/libyul/backends/evm/AsmCodeGen.cpp b/libyul/backends/evm/AsmCodeGen.cpp
index eefff5b18..6775214e8 100644
--- a/libyul/backends/evm/AsmCodeGen.cpp
+++ b/libyul/backends/evm/AsmCodeGen.cpp
@@ -143,14 +143,14 @@ pair<shared_ptr<AbstractAssembly>, AbstractAssembly::SubID> EthAssemblyAdapter::
 {
 	shared_ptr<evmasm::Assembly> assembly{make_shared<evmasm::Assembly>()};
 	auto sub = m_assembly.newSub(assembly);
-	return {make_shared<EthAssemblyAdapter>(*assembly), size_t(sub.data())};
+	return {make_shared<EthAssemblyAdapter>(*assembly), static_cast<size_t>(sub.data())};
 }
 
 void EthAssemblyAdapter::appendDataOffset(AbstractAssembly::SubID _sub)
 {
 	auto it = m_dataHashBySubId.find(_sub);
 	if (it == m_dataHashBySubId.end())
-		m_assembly.pushSubroutineOffset(size_t(_sub));
+		m_assembly.pushSubroutineOffset(_sub);
 	else
 		m_assembly << evmasm::AssemblyItem(evmasm::PushData, it->second);
 }
@@ -159,7 +159,7 @@ void EthAssemblyAdapter::appendDataSize(AbstractAssembly::SubID _sub)
 {
 	auto it = m_dataHashBySubId.find(_sub);
 	if (it == m_dataHashBySubId.end())
-		m_assembly.pushSubroutineSize(size_t(_sub));
+		m_assembly.pushSubroutineSize(static_cast<size_t>(_sub));
 	else
 		m_assembly << u256(m_assembly.data(h256(it->second)).size());
 }
diff --git a/libyul/backends/evm/EVMAssembly.cpp b/libyul/backends/evm/EVMAssembly.cpp
index 47f7509a3..c13a16083 100644
--- a/libyul/backends/evm/EVMAssembly.cpp
+++ b/libyul/backends/evm/EVMAssembly.cpp
@@ -74,7 +74,7 @@ void EVMAssembly::appendLabelReference(LabelID _labelId)
 
 EVMAssembly::LabelID EVMAssembly::newLabelId()
 {
-	m_labelPositions[m_nextLabelId] = size_t(-1);
+	m_labelPositions[m_nextLabelId] = numeric_limits<size_t>::max();
 	return m_nextLabelId++;
 }
 
@@ -165,7 +165,7 @@ evmasm::LinkerObject EVMAssembly::finalize()
 		size_t referencePos = ref.first;
 		yulAssert(m_labelPositions.count(ref.second), "");
 		size_t labelPos = m_labelPositions.at(ref.second);
-		yulAssert(labelPos != size_t(-1), "Undefined but allocated label used.");
+		yulAssert(labelPos != numeric_limits<size_t>::max(), "Undefined but allocated label used.");
 		updateReference(referencePos, labelReferenceSize, u256(labelPos));
 	}
 
@@ -177,7 +177,7 @@ evmasm::LinkerObject EVMAssembly::finalize()
 void EVMAssembly::setLabelToCurrentPosition(LabelID _labelId)
 {
 	yulAssert(m_labelPositions.count(_labelId), "Label not found.");
-	yulAssert(m_labelPositions[_labelId] == size_t(-1), "Label already set.");
+	yulAssert(m_labelPositions[_labelId] == numeric_limits<size_t>::max(), "Label already set.");
 	m_labelPositions[_labelId] = m_bytecode.size();
 }
 
diff --git a/libyul/backends/evm/EVMCodeTransform.cpp b/libyul/backends/evm/EVMCodeTransform.cpp
index a4e19998f..f57fd35f3 100644
--- a/libyul/backends/evm/EVMCodeTransform.cpp
+++ b/libyul/backends/evm/EVMCodeTransform.cpp
@@ -175,28 +175,29 @@ void CodeTransform::operator()(VariableDeclaration const& _varDecl)
 {
 	yulAssert(m_scope, "");
 
-	int const numVariables = _varDecl.variables.size();
-	int heightAtStart = m_assembly.stackHeight();
+	size_t const numVariables = _varDecl.variables.size();
+	auto heightAtStart = static_cast<size_t>(m_assembly.stackHeight());
 	if (_varDecl.value)
 	{
 		std::visit(*this, *_varDecl.value);
-		expectDeposit(numVariables, heightAtStart);
+		expectDeposit(static_cast<int>(numVariables), static_cast<int>(heightAtStart));
 	}
 	else
 	{
 		m_assembly.setSourceLocation(_varDecl.location);
-		int variablesLeft = numVariables;
+		size_t variablesLeft = numVariables;
 		while (variablesLeft--)
 			m_assembly.appendConstant(u256(0));
 	}
 
 	m_assembly.setSourceLocation(_varDecl.location);
 	bool atTopOfStack = true;
-	for (int varIndex = numVariables - 1; varIndex >= 0; --varIndex)
+	for (size_t varIndex = 0; varIndex < numVariables; ++varIndex)
 	{
-		YulString varName = _varDecl.variables[varIndex].name;
+		size_t varIndexReverse = numVariables - 1 - varIndex;
+		YulString varName = _varDecl.variables[varIndexReverse].name;
 		auto& var = std::get<Scope::Variable>(m_scope->identifiers.at(varName));
-		m_context->variableStackHeights[&var] = heightAtStart + varIndex;
+		m_context->variableStackHeights[&var] = heightAtStart + varIndexReverse;
 		if (!m_allowStackOpt)
 			continue;
 
@@ -214,10 +215,10 @@ void CodeTransform::operator()(VariableDeclaration const& _varDecl)
 			atTopOfStack = false;
 		else
 		{
-			int slot = *m_unusedStackSlots.begin();
+			auto slot = static_cast<size_t>(*m_unusedStackSlots.begin());
 			m_unusedStackSlots.erase(m_unusedStackSlots.begin());
 			m_context->variableStackHeights[&var] = slot;
-			if (int heightDiff = variableHeightDiff(var, varName, true))
+			if (size_t heightDiff = variableHeightDiff(var, varName, true))
 				m_assembly.appendInstruction(evmasm::swapInstruction(heightDiff - 1));
 			m_assembly.appendInstruction(evmasm::Instruction::POP);
 		}
@@ -240,7 +241,7 @@ void CodeTransform::operator()(Assignment const& _assignment)
 {
 	int height = m_assembly.stackHeight();
 	std::visit(*this, *_assignment.value);
-	expectDeposit(_assignment.variableNames.size(), height);
+	expectDeposit(static_cast<int>(_assignment.variableNames.size()), height);
 
 	m_assembly.setSourceLocation(_assignment.location);
 	generateMultiAssignment(_assignment.variableNames);
@@ -263,7 +264,7 @@ void CodeTransform::operator()(FunctionCall const& _call)
 	else
 	{
 		m_assembly.setSourceLocation(_call.location);
-		EVMAssembly::LabelID returnLabel(-1); // only used for evm 1.0
+		EVMAssembly::LabelID returnLabel(numeric_limits<EVMAssembly::LabelID>::max()); // only used for evm 1.0
 		if (!m_evm15)
 		{
 			returnLabel = m_assembly.newLabelId();
@@ -281,10 +282,17 @@ void CodeTransform::operator()(FunctionCall const& _call)
 			visitExpression(arg);
 		m_assembly.setSourceLocation(_call.location);
 		if (m_evm15)
-			m_assembly.appendJumpsub(functionEntryID(_call.functionName.name, *function), function->arguments.size(), function->returns.size());
+			m_assembly.appendJumpsub(
+				functionEntryID(_call.functionName.name, *function),
+				static_cast<int>(function->arguments.size()),
+				static_cast<int>(function->returns.size())
+			);
 		else
 		{
-			m_assembly.appendJumpTo(functionEntryID(_call.functionName.name, *function), function->returns.size() - function->arguments.size() - 1);
+			m_assembly.appendJumpTo(
+				functionEntryID(_call.functionName.name, *function),
+				static_cast<int>(function->returns.size() - function->arguments.size()) - 1
+			);
 			m_assembly.appendLabel(returnLabel);
 		}
 	}
@@ -300,7 +308,7 @@ void CodeTransform::operator()(Identifier const& _identifier)
 		{
 			// TODO: opportunity for optimization: Do not DUP if this is the last reference
 			// to the top most element of the stack
-			if (int heightDiff = variableHeightDiff(_var, _identifier.name, false))
+			if (size_t heightDiff = variableHeightDiff(_var, _identifier.name, false))
 				m_assembly.appendInstruction(evmasm::dupInstruction(heightDiff));
 			else
 				// Store something to balance the stack
@@ -407,7 +415,7 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
 	int const stackHeightBefore = m_assembly.stackHeight();
 
 	if (m_evm15)
-		m_assembly.appendBeginsub(functionEntryID(_function.name, function), _function.parameters.size());
+		m_assembly.appendBeginsub(functionEntryID(_function.name, function), static_cast<int>(_function.parameters.size()));
 	else
 		m_assembly.appendLabel(functionEntryID(_function.name, function));
 
@@ -465,15 +473,15 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
 		// modified parallel to the actual stack.
 		vector<int> stackLayout;
 		if (!m_evm15)
-			stackLayout.push_back(_function.returnVariables.size()); // Move return label to the top
+			stackLayout.push_back(static_cast<int>(_function.returnVariables.size())); // Move return label to the top
 		stackLayout += vector<int>(_function.parameters.size(), -1); // discard all arguments
 
 		for (size_t i = 0; i < _function.returnVariables.size(); ++i)
-			stackLayout.push_back(i); // Move return values down, but keep order.
+			stackLayout.push_back(static_cast<int>(i)); // Move return values down, but keep order.
 
 		if (stackLayout.size() > 17)
 		{
-			StackTooDeepError error(_function.name, YulString{}, stackLayout.size() - 17);
+			StackTooDeepError error(_function.name, YulString{}, static_cast<int>(stackLayout.size()) - 17);
 			error << errinfo_comment(
 				"The function " +
 				_function.name.str() +
@@ -481,11 +489,11 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
 				to_string(stackLayout.size() - 17) +
 				" parameters or return variables too many to fit the stack size."
 			);
-			stackError(std::move(error), m_assembly.stackHeight() - _function.parameters.size());
+			stackError(std::move(error), m_assembly.stackHeight() - static_cast<int>(_function.parameters.size()));
 		}
 		else
 		{
-			while (!stackLayout.empty() && stackLayout.back() != int(stackLayout.size() - 1))
+			while (!stackLayout.empty() && stackLayout.back() != static_cast<int>(stackLayout.size() - 1))
 				if (stackLayout.back() < 0)
 				{
 					m_assembly.appendInstruction(evmasm::Instruction::POP);
@@ -493,17 +501,17 @@ void CodeTransform::operator()(FunctionDefinition const& _function)
 				}
 				else
 				{
-					m_assembly.appendInstruction(evmasm::swapInstruction(stackLayout.size() - stackLayout.back() - 1));
-					swap(stackLayout[stackLayout.back()], stackLayout.back());
+					m_assembly.appendInstruction(evmasm::swapInstruction(stackLayout.size() - static_cast<size_t>(stackLayout.back()) - 1));
+					swap(stackLayout[static_cast<size_t>(stackLayout.back())], stackLayout.back());
 				}
-			for (int i = 0; size_t(i) < stackLayout.size(); ++i)
-				yulAssert(i == stackLayout[i], "Error reshuffling stack.");
+			for (size_t i = 0; i < stackLayout.size(); ++i)
+				yulAssert(i == static_cast<size_t>(stackLayout[i]), "Error reshuffling stack.");
 		}
 	}
 	if (m_evm15)
-		m_assembly.appendReturnsub(_function.returnVariables.size(), stackHeightBefore);
+		m_assembly.appendReturnsub(static_cast<int>(_function.returnVariables.size()), stackHeightBefore);
 	else
-		m_assembly.appendJump(stackHeightBefore - _function.returnVariables.size());
+		m_assembly.appendJump(stackHeightBefore - static_cast<int>(_function.returnVariables.size()));
 	m_assembly.setStackHeight(stackHeightBefore);
 }
 
@@ -683,7 +691,7 @@ void CodeTransform::generateAssignment(Identifier const& _variableName)
 	if (auto var = m_scope->lookup(_variableName.name))
 	{
 		Scope::Variable const& _var = std::get<Scope::Variable>(*var);
-		if (int heightDiff = variableHeightDiff(_var, _variableName.name, true))
+		if (size_t heightDiff = variableHeightDiff(_var, _variableName.name, true))
 			m_assembly.appendInstruction(evmasm::swapInstruction(heightDiff - 1));
 		m_assembly.appendInstruction(evmasm::Instruction::POP);
 		decreaseReference(_variableName.name, _var);
@@ -698,12 +706,12 @@ void CodeTransform::generateAssignment(Identifier const& _variableName)
 	}
 }
 
-int CodeTransform::variableHeightDiff(Scope::Variable const& _var, YulString _varName, bool _forSwap)
+size_t CodeTransform::variableHeightDiff(Scope::Variable const& _var, YulString _varName, bool _forSwap)
 {
 	yulAssert(m_context->variableStackHeights.count(&_var), "");
-	int heightDiff = m_assembly.stackHeight() - m_context->variableStackHeights[&_var];
+	size_t heightDiff = static_cast<size_t>(m_assembly.stackHeight()) - m_context->variableStackHeights[&_var];
 	yulAssert(heightDiff > (_forSwap ? 1 : 0), "Negative stack difference for variable.");
-	int limit = _forSwap ? 17 : 16;
+	size_t limit = _forSwap ? 17 : 16;
 	if (heightDiff > limit)
 	{
 		m_stackErrors.emplace_back(_varName, heightDiff - limit);
@@ -723,4 +731,3 @@ void CodeTransform::expectDeposit(int _deposit, int _oldHeight) const
 {
 	yulAssert(m_assembly.stackHeight() == _oldHeight + _deposit, "Invalid stack deposit.");
 }
-
diff --git a/libyul/backends/evm/EVMCodeTransform.h b/libyul/backends/evm/EVMCodeTransform.h
index 6447aa7b1..3c9506b47 100644
--- a/libyul/backends/evm/EVMCodeTransform.h
+++ b/libyul/backends/evm/EVMCodeTransform.h
@@ -54,7 +54,7 @@ struct StackTooDeepError: virtual YulException
 struct CodeTransformContext
 {
 	std::map<Scope::Function const*, AbstractAssembly::LabelID> functionEntryIDs;
-	std::map<Scope::Variable const*, int> variableStackHeights;
+	std::map<Scope::Variable const*, size_t> variableStackHeights;
 	std::map<Scope::Variable const*, unsigned> variableReferences;
 
 	struct JumpInfo
@@ -200,7 +200,7 @@ private:
 	/// Determines the stack height difference to the given variables. Throws
 	/// if it is not yet in scope or the height difference is too large. Returns
 	/// the (positive) stack height difference otherwise.
-	int variableHeightDiff(Scope::Variable const& _var, YulString _name, bool _forSwap);
+	size_t variableHeightDiff(Scope::Variable const& _var, YulString _name, bool _forSwap);
 
 	void expectDeposit(int _deposit, int _oldHeight) const;
 
diff --git a/libyul/backends/evm/EVMDialect.cpp b/libyul/backends/evm/EVMDialect.cpp
index b5b5eda6e..6875df234 100644
--- a/libyul/backends/evm/EVMDialect.cpp
+++ b/libyul/backends/evm/EVMDialect.cpp
@@ -63,8 +63,8 @@ pair<YulString, BuiltinFunctionForEVM> createEVMFunction(
 	evmasm::InstructionInfo info = evmasm::instructionInfo(_instruction);
 	BuiltinFunctionForEVM f;
 	f.name = YulString{_name};
-	f.parameters.resize(info.args);
-	f.returns.resize(info.ret);
+	f.parameters.resize(static_cast<size_t>(info.args));
+	f.returns.resize(static_cast<size_t>(info.ret));
 	f.sideEffects = EVMDialect::sideEffectsOfInstruction(_instruction);
 	f.controlFlowSideEffects.terminates = evmasm::SemanticInformation::terminatesControlFlow(_instruction);
 	f.controlFlowSideEffects.reverts = evmasm::SemanticInformation::reverts(_instruction);
diff --git a/libyul/backends/evm/EVMMetrics.cpp b/libyul/backends/evm/EVMMetrics.cpp
index 4d1103578..f3508afb3 100644
--- a/libyul/backends/evm/EVMMetrics.cpp
+++ b/libyul/backends/evm/EVMMetrics.cpp
@@ -91,7 +91,11 @@ void GasMeterVisitor::operator()(Literal const& _lit)
 	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::PUSH1);
 	m_dataGas +=
 		singleByteDataGas() +
-		size_t(evmasm::GasMeter::dataGas(toCompactBigEndian(valueOfLiteral(_lit), 1), m_isCreation, m_dialect.evmVersion()));
+		static_cast<size_t>(evmasm::GasMeter::dataGas(
+			toCompactBigEndian(valueOfLiteral(_lit), 1),
+			m_isCreation,
+			m_dialect.evmVersion()
+		));
 }
 
 void GasMeterVisitor::operator()(Identifier const&)
diff --git a/libyul/backends/wasm/BinaryTransform.cpp b/libyul/backends/wasm/BinaryTransform.cpp
index b305b9c55..82de96b51 100644
--- a/libyul/backends/wasm/BinaryTransform.cpp
+++ b/libyul/backends/wasm/BinaryTransform.cpp
@@ -376,12 +376,12 @@ bytes BinaryTransform::operator()(BuiltinCall const& _call)
 	if (_call.functionName == "dataoffset")
 	{
 		string name = get<StringLiteral>(_call.arguments.at(0)).value;
-		return toBytes(Opcode::I64Const) + lebEncodeSigned(m_subModulePosAndSize.at(name).first);
+		return toBytes(Opcode::I64Const) + lebEncodeSigned(static_cast<int64_t>(m_subModulePosAndSize.at(name).first));
 	}
 	else if (_call.functionName == "datasize")
 	{
 		string name = get<StringLiteral>(_call.arguments.at(0)).value;
-		return toBytes(Opcode::I64Const) + lebEncodeSigned(m_subModulePosAndSize.at(name).second);
+		return toBytes(Opcode::I64Const) + lebEncodeSigned(static_cast<int64_t>(m_subModulePosAndSize.at(name).second));
 	}
 
 	bytes args = visit(_call.arguments);
diff --git a/libyul/backends/wasm/WordSizeTransform.cpp b/libyul/backends/wasm/WordSizeTransform.cpp
index edcc08923..473f7324f 100644
--- a/libyul/backends/wasm/WordSizeTransform.cpp
+++ b/libyul/backends/wasm/WordSizeTransform.cpp
@@ -112,7 +112,7 @@ void WordSizeTransform::operator()(Block& _block)
 							yulAssert(varDecl.variables.size() == 1, "");
 							auto newLhs = generateU64IdentifierNames(varDecl.variables[0].name);
 							vector<Statement> ret;
-							for (int i = 0; i < 3; i++)
+							for (size_t i = 0; i < 3; i++)
 								ret.emplace_back(VariableDeclaration{
 									varDecl.location,
 									{TypedName{varDecl.location, newLhs[i], m_targetDialect.defaultType}},
@@ -143,7 +143,7 @@ void WordSizeTransform::operator()(Block& _block)
 					auto newRhs = expandValue(*varDecl.value);
 					auto newLhs = generateU64IdentifierNames(varDecl.variables[0].name);
 					vector<Statement> ret;
-					for (int i = 0; i < 4; i++)
+					for (size_t i = 0; i < 4; i++)
 						ret.emplace_back(VariableDeclaration{
 								varDecl.location,
 								{TypedName{varDecl.location, newLhs[i], m_targetDialect.defaultType}},
@@ -172,7 +172,7 @@ void WordSizeTransform::operator()(Block& _block)
 							yulAssert(assignment.variableNames.size() == 1, "");
 							auto newLhs = generateU64IdentifierNames(assignment.variableNames[0].name);
 							vector<Statement> ret;
-							for (int i = 0; i < 3; i++)
+							for (size_t i = 0; i < 3; i++)
 								ret.emplace_back(Assignment{
 									assignment.location,
 									{Identifier{assignment.location, newLhs[i]}},
@@ -203,7 +203,7 @@ void WordSizeTransform::operator()(Block& _block)
 					auto newRhs = expandValue(*assignment.value);
 					YulString lhsName = assignment.variableNames[0].name;
 					vector<Statement> ret;
-					for (int i = 0; i < 4; i++)
+					for (size_t i = 0; i < 4; i++)
 						ret.emplace_back(Assignment{
 								assignment.location,
 								{Identifier{assignment.location, m_variableMapping.at(lhsName)[i]}},
@@ -382,7 +382,7 @@ std::vector<Statement> WordSizeTransform::handleSwitch(Switch& _switch)
 array<YulString, 4> WordSizeTransform::generateU64IdentifierNames(YulString const& _s)
 {
 	yulAssert(m_variableMapping.find(_s) == m_variableMapping.end(), "");
-	for (int i = 0; i < 4; i++)
+	for (size_t i = 0; i < 4; i++)
 		m_variableMapping[_s][i] = m_nameDispenser.newName(YulString{_s.str() + "_" + to_string(i)});
 	return m_variableMapping[_s];
 }
@@ -392,19 +392,20 @@ array<unique_ptr<Expression>, 4> WordSizeTransform::expandValue(Expression const
 	array<unique_ptr<Expression>, 4> ret;
 	if (holds_alternative<Identifier>(_e))
 	{
-		Identifier const& id = std::get<Identifier>(_e);
-		for (int i = 0; i < 4; i++)
+		auto const& id = std::get<Identifier>(_e);
+		for (size_t i = 0; i < 4; i++)
 			ret[i] = make_unique<Expression>(Identifier{id.location, m_variableMapping.at(id.name)[i]});
 	}
 	else if (holds_alternative<Literal>(_e))
 	{
-		Literal const& lit = std::get<Literal>(_e);
+		auto const& lit = std::get<Literal>(_e);
 		u256 val = valueOfLiteral(lit);
-		for (int i = 3; i >= 0; i--)
+		for (size_t exprIndex = 0; exprIndex < 4; ++exprIndex)
 		{
+			size_t exprIndexReverse = 3 - exprIndex;
 			u256 currentVal = val & std::numeric_limits<uint64_t>::max();
 			val >>= 64;
-			ret[i] = make_unique<Expression>(
+			ret[exprIndexReverse] = make_unique<Expression>(
 				Literal{
 					lit.location,
 					LiteralKind::Number,
@@ -426,4 +427,3 @@ vector<Expression> WordSizeTransform::expandValueToVector(Expression const& _e)
 		ret.emplace_back(std::move(*val));
 	return ret;
 }
-
diff --git a/libyul/optimiser/DeadCodeEliminator.cpp b/libyul/optimiser/DeadCodeEliminator.cpp
index 890161bf0..2416af514 100644
--- a/libyul/optimiser/DeadCodeEliminator.cpp
+++ b/libyul/optimiser/DeadCodeEliminator.cpp
@@ -51,10 +51,10 @@ void DeadCodeEliminator::operator()(Block& _block)
 	tie(controlFlowChange, index) = TerminationFinder{m_dialect}.firstUnconditionalControlFlowChange(_block.statements);
 
 	// Erase everything after the terminating statement that is not a function definition.
-	if (controlFlowChange != TerminationFinder::ControlFlow::FlowOut && index != size_t(-1))
+	if (controlFlowChange != TerminationFinder::ControlFlow::FlowOut && index != std::numeric_limits<size_t>::max())
 		_block.statements.erase(
 			remove_if(
-				_block.statements.begin() + index + 1,
+				_block.statements.begin() + static_cast<ptrdiff_t>(index) + 1,
 				_block.statements.end(),
 				[] (Statement const& _s) { return !holds_alternative<yul::FunctionDefinition>(_s); }
 			),
@@ -63,4 +63,3 @@ void DeadCodeEliminator::operator()(Block& _block)
 
 	ASTModifier::operator()(_block);
 }
-
diff --git a/libyul/optimiser/ExpressionJoiner.cpp b/libyul/optimiser/ExpressionJoiner.cpp
index ba38fa86e..45c23dcc3 100644
--- a/libyul/optimiser/ExpressionJoiner.cpp
+++ b/libyul/optimiser/ExpressionJoiner.cpp
@@ -119,7 +119,7 @@ void ExpressionJoiner::decrementLatestStatementPointer()
 void ExpressionJoiner::resetLatestStatementPointer()
 {
 	m_currentBlock = nullptr;
-	m_latestStatementInBlock = size_t(-1);
+	m_latestStatementInBlock = numeric_limits<size_t>::max();
 }
 
 Statement* ExpressionJoiner::latestStatement()
diff --git a/libyul/optimiser/Semantics.cpp b/libyul/optimiser/Semantics.cpp
index a6f41b844..f9d831b7a 100644
--- a/libyul/optimiser/Semantics.cpp
+++ b/libyul/optimiser/Semantics.cpp
@@ -180,7 +180,7 @@ pair<TerminationFinder::ControlFlow, size_t> TerminationFinder::firstUncondition
 		if (controlFlow != ControlFlow::FlowOut)
 			return {controlFlow, i};
 	}
-	return {ControlFlow::FlowOut, size_t(-1)};
+	return {ControlFlow::FlowOut, numeric_limits<size_t>::max()};
 }
 
 TerminationFinder::ControlFlow TerminationFinder::controlFlowKind(Statement const& _statement)
diff --git a/libyul/optimiser/StackCompressor.cpp b/libyul/optimiser/StackCompressor.cpp
index cfb2fef82..d011c64b8 100644
--- a/libyul/optimiser/StackCompressor.cpp
+++ b/libyul/optimiser/StackCompressor.cpp
@@ -178,14 +178,14 @@ bool StackCompressor::run(
 			eliminateVariables(
 				_dialect,
 				std::get<Block>(_object.code->statements.at(0)),
-				stackSurplus.at({}),
+				static_cast<size_t>(stackSurplus.at({})),
 				allowMSizeOptimzation
 			);
 		}
 
 		for (size_t i = 1; i < _object.code->statements.size(); ++i)
 		{
-			FunctionDefinition& fun = std::get<FunctionDefinition>(_object.code->statements[i]);
+			auto& fun = std::get<FunctionDefinition>(_object.code->statements[i]);
 			if (!stackSurplus.count(fun.name))
 				continue;
 
@@ -193,7 +193,7 @@ bool StackCompressor::run(
 			eliminateVariables(
 				_dialect,
 				fun,
-				stackSurplus.at(fun.name),
+				static_cast<size_t>(stackSurplus.at(fun.name)),
 				allowMSizeOptimzation
 			);
 		}