Merge pull request #12831 from ethereum/cse-optimization

CSE optimization

libevmasm/CommonSubexpressionEliminator.h

@@ -179,9 +179,15 @@ AssemblyItemIterator CommonSubexpressionEliminator::feedItems(
 )
 {
 	assertThrow(!m_breakingItem, OptimizerException, "Invalid use of CommonSubexpressionEliminator.");
-	for (; _iterator != _end && !SemanticInformation::breaksCSEAnalysisBlock(*_iterator, _msizeImportant); ++_iterator)
+	unsigned const maxChunkSize = 2000;
+	unsigned chunkSize = 0;
+	for (
+		;
+		_iterator != _end && !SemanticInformation::breaksCSEAnalysisBlock(*_iterator, _msizeImportant) && chunkSize < maxChunkSize;
+		++_iterator, ++chunkSize
+	)
 		feedItem(*_iterator);
-	if (_iterator != _end)
+	if (_iterator != _end && chunkSize < maxChunkSize)
 		m_breakingItem = &(*_iterator++);
 	return _iterator;
 }

libevmasm/ExpressionClasses.cpp

@@ -23,38 +23,59 @@
  */
 
 #include <libevmasm/ExpressionClasses.h>
+
 #include <libevmasm/Assembly.h>
 #include <libevmasm/CommonSubexpressionEliminator.h>
 #include <libevmasm/SimplificationRules.h>
 
+#include <boost/container_hash/hash.hpp>
+
 #include <functional>
-#include <tuple>
 #include <limits>
+#include <tuple>
 
 using namespace std;
 using namespace solidity;
 using namespace solidity::evmasm;
 using namespace solidity::langutil;
 
-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 otherType = _other.item->type();
 	if (type != otherType)
-		return type < otherType;
+		return false;
 	else if (type == Operation)
 	{
 		auto instr = item->instruction();
 		auto otherInstr = _other.item->instruction();
-		return std::tie(instr, arguments, sequenceNumber) <
+		return std::tie(instr, arguments, sequenceNumber) ==
 			std::tie(otherInstr, _other.arguments, _other.sequenceNumber);
 	}
 	else
-		return std::tie(item->data(), arguments, sequenceNumber) <
+		return std::tie(item->data(), arguments, sequenceNumber) ==
 			std::tie(_other.item->data(), _other.arguments, _other.sequenceNumber);
 }
 
+std::size_t ExpressionClasses::Expression::ExpressionHash::operator()(Expression const& _expression) const
+{
+	assertThrow(!!_expression.item, OptimizerException, "");
+	std::size_t seed = 0;
+	auto type = _expression.item->type();
+	boost::hash_combine(seed, type);
+
+	if (type == Operation)
+		boost::hash_combine(seed, _expression.item->instruction());
+	else
+		boost::hash_combine(seed, _expression.item->data());
+
+	boost::hash_range(seed, _expression.arguments.begin(), _expression.arguments.end());
+	boost::hash_combine(seed, _expression.sequenceNumber);
+
+	return seed;
+}
+
 ExpressionClasses::Id ExpressionClasses::find(
 	AssemblyItem const& _item,
 	Ids const& _arguments,

libevmasm/ExpressionClasses.h

@@ -24,13 +24,13 @@
 
 #pragma once
 
-#include <libsolutil/Common.h>
 #include <libevmasm/AssemblyItem.h>
 
-#include <vector>
-#include <map>
+#include <libsolutil/Common.h>
+
 #include <memory>
-#include <set>
+#include <unordered_set>
+#include <vector>
 
 namespace solidity::langutil
 {
@@ -61,9 +61,15 @@ public:
 		/// Storage modification sequence, only used for storage and memory operations.
 		unsigned sequenceNumber = 0;
 		/// Behaves as if this was a tuple of (item->type(), item->data(), arguments, sequenceNumber).
-		bool operator<(Expression const& _other) const;
+		bool operator==(Expression const& _other) const;
+
+		struct ExpressionHash
+		{
+			std::size_t operator()(Expression const& _expression) const;
+		};
 	};
 
+
 	/// Retrieves the id of the expression equivalence class resulting from the given item applied to the
 	/// given classes, might also create a new one.
 	/// @param _copyItem if true, copies the assembly item to an internal storage instead of just
@@ -122,7 +128,7 @@ private:
 	/// Expression equivalence class representatives - we only store one item of an equivalence.
 	std::vector<Expression> m_representatives;
 	/// All expression ever encountered.
-	std::set<Expression> m_expressions;
+	std::unordered_set<Expression, Expression::ExpressionHash> m_expressions;
 	std::vector<std::shared_ptr<AssemblyItem>> m_spareAssemblyItems;
 };