Merge pull request #4068 from ethereum/gasEstimatorPerformance

Gas estimator performance

1 files changed, 9 insertions, 1 deletions

diff --git a/libevmasm/PathGasMeter.h b/libevmasm/PathGasMeter.h
index 2527d7fb..9537b176 100644
--- a/libevmasm/PathGasMeter.h
+++ b/libevmasm/PathGasMeter.h
@@ -58,9 +58,17 @@ public:
 	GasMeter::GasConsumption estimateMax(size_t _startIndex, std::shared_ptr<KnownState> const& _state);
 
 private:
+	/// Adds a new path item to the queue, but only if we do not already have
+	/// a higher gas usage at that point.
+	/// This is not exact as different state might influence higher gas costs at a later
+	/// point in time, but it greatly reduces computational overhead.
+	void queue(std::unique_ptr<GasPath>&& _newPath);
 	GasMeter::GasConsumption handleQueueItem();
 
-	std::vector<std::unique_ptr<GasPath>> m_queue;
+	/// Map of jumpdest -> gas path, so not really a queue. We only have one queued up
+	/// item per jumpdest, because of the behaviour of `queue` above.
+	std::map<size_t, std::unique_ptr<GasPath>> m_queue;
+	std::map<size_t, GasMeter::GasConsumption> m_highestGasUsagePerJumpdest;
 	std::map<u256, size_t> m_tagPositions;
 	AssemblyItems const& m_items;
 	solidity::EVMVersion m_evmVersion;