1 files changed, 88 insertions, 2 deletions

diff --git a/libyul/optimiser/Metrics.cpp b/libyul/optimiser/Metrics.cpp
index 8fc9476e..e13940aa 100644
--- a/libyul/optimiser/Metrics.cpp
+++ b/libyul/optimiser/Metrics.cpp
@@ -21,7 +21,13 @@
 #include <libyul/optimiser/Metrics.h>
 
 #include <libyul/AsmData.h>
+#include <libyul/Exceptions.h>
 
+#include <libevmasm/Instruction.h>
+
+#include <libdevcore/Visitor.h>
+
+using namespace std;
 using namespace dev;
 using namespace yul;
 
@@ -50,13 +56,93 @@ void CodeSize::visit(Statement const& _statement)
 {
 	if (_statement.type() == typeid(FunctionDefinition))
 		return;
+	else if (!(
+		_statement.type() == typeid(Block) ||
+		_statement.type() == typeid(ExpressionStatement) ||
+		_statement.type() == typeid(Assignment) ||
+		_statement.type() == typeid(VariableDeclaration)
+	))
+		++m_size;
 
-	++m_size;
 	ASTWalker::visit(_statement);
 }
 
 void CodeSize::visit(Expression const& _expression)
 {
-	++m_size;
+	if (_expression.type() != typeid(Identifier))
+		++m_size;
+	ASTWalker::visit(_expression);
+}
+
+
+size_t CodeCost::codeCost(Expression const& _expr)
+{
+	CodeCost cc;
+	cc.visit(_expr);
+	return cc.m_cost;
+}
+
+
+void CodeCost::operator()(FunctionCall const& _funCall)
+{
+	yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
+	m_cost += 49;
+	ASTWalker::operator()(_funCall);
+}
+
+void CodeCost::operator()(FunctionalInstruction const& _instr)
+{
+	using namespace dev::solidity;
+	yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
+	Tier gasPriceTier = instructionInfo(_instr.instruction).gasPriceTier;
+	if (gasPriceTier < Tier::VeryLow)
+		m_cost -= 1;
+	else if (gasPriceTier < Tier::High)
+		m_cost += 1;
+	else
+		m_cost += 49;
+	ASTWalker::operator()(_instr);
+}
+void CodeCost::operator()(Literal const& _literal)
+{
+	yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
+	size_t cost = 0;
+	switch (_literal.kind)
+	{
+	case LiteralKind::Boolean:
+		break;
+	case LiteralKind::Number:
+		for (u256 n = u256(_literal.value.str()); n >= 0x100; n >>= 8)
+			cost++;
+		break;
+	case LiteralKind::String:
+		cost = _literal.value.str().size();
+		break;
+	}
+
+	m_cost += cost;
+}
+
+void CodeCost::visit(Statement const& _statement)
+{
+	++m_cost;
+	ASTWalker::visit(_statement);
+}
+
+void CodeCost::visit(Expression const& _expression)
+{
+	++m_cost;
 	ASTWalker::visit(_expression);
 }
+
+void AssignmentCounter::operator()(Assignment const& _assignment)
+{
+	for (auto const& variable: _assignment.variableNames)
+		++m_assignmentCounters[variable.name];
+}
+
+size_t AssignmentCounter::assignmentCount(YulString _name) const
+{
+	auto it = m_assignmentCounters.find(_name);
+	return (it == m_assignmentCounters.end()) ? 0 : it->second;
+}