Merge pull request #6851 from ethereum/makeOptimizerWorkForWasm

Make Yul optimizer not fail for wasm.

Changelog.md

@@ -7,6 +7,7 @@ Language Features:
 Compiler Features:
  * Optimizer: Add rule to simplify SUB(~0, X) to NOT(X).
  * Commandline Interface: Experimental parser error recovery via the ``--error-recovery`` commandline switch.
+ * Yul Optimizer: Make the optimizer work for all dialects of Yul including eWasm.
 
 
 

libsolidity/codegen/CompilerContext.cpp

@@ -32,8 +32,8 @@
 #include <libyul/AsmAnalysisInfo.h>
 #include <libyul/backends/evm/AsmCodeGen.h>
 #include <libyul/backends/evm/EVMDialect.h>
+#include <libyul/backends/evm/EVMMetrics.h>
 #include <libyul/optimiser/Suite.h>
-#include <libyul/optimiser/Metrics.h>
 #include <libyul/YulString.h>
 
 #include <liblangutil/ErrorReporter.h>

libyul/AssemblyStack.cpp

@@ -31,6 +31,7 @@
 #include <libyul/backends/evm/EVMCodeTransform.h>
 #include <libyul/backends/evm/EVMDialect.h>
 #include <libyul/backends/evm/EVMObjectCompiler.h>
+#include <libyul/backends/evm/EVMMetrics.h>
 #include <libyul/backends/wasm/WasmDialect.h>
 #include <libyul/backends/wasm/EWasmObjectCompiler.h>
 #include <libyul/optimiser/Metrics.h>
@@ -146,15 +147,17 @@ void AssemblyStack::optimize(Object& _object, bool _isCreation)
 	for (auto& subNode: _object.subObjects)
 		if (auto subObject = dynamic_cast<Object*>(subNode.get()))
 			optimize(*subObject, false);
-	EVMDialect const& dialect = dynamic_cast<EVMDialect const&>(languageToDialect(m_language, m_evmVersion));
+	if (EVMDialect const* dialect = dynamic_cast<EVMDialect const*>(&languageToDialect(m_language, m_evmVersion)))
-	GasMeter meter(dialect, _isCreation, m_optimiserSettings.expectedExecutionsPerDeployment);
+	{
-	OptimiserSuite::run(
+		GasMeter meter(*dialect, _isCreation, m_optimiserSettings.expectedExecutionsPerDeployment);
-		dialect,
+		OptimiserSuite::run(
-		meter,
+			*dialect,
-		*_object.code,
+			meter,
-		*_object.analysisInfo,
+			*_object.code,
-		m_optimiserSettings.optimizeStackAllocation
+			*_object.analysisInfo,
-	);
+			m_optimiserSettings.optimizeStackAllocation
+		);
+	}
 }
 
 MachineAssemblyObject AssemblyStack::assemble(Machine _machine) const

libyul/CMakeLists.txt

@@ -28,6 +28,8 @@ add_library(yul
 	backends/evm/AbstractAssembly.h
 	backends/evm/AsmCodeGen.h
 	backends/evm/AsmCodeGen.cpp
+	backends/evm/ConstantOptimiser.cpp
+	backends/evm/ConstantOptimiser.h
 	backends/evm/EVMAssembly.cpp
 	backends/evm/EVMAssembly.h
 	backends/evm/EVMCodeTransform.cpp
@@ -36,6 +38,8 @@ add_library(yul
 	backends/evm/EVMDialect.h
 	backends/evm/EVMObjectCompiler.cpp
 	backends/evm/EVMObjectCompiler.h
+	backends/evm/EVMMetrics.cpp
+	backends/evm/EVMMetrics.h
 	backends/evm/NoOutputAssembly.h
 	backends/evm/NoOutputAssembly.cpp
 	backends/wasm/EWasmCodeTransform.cpp
@@ -58,8 +62,6 @@ add_library(yul
 	optimiser/BlockHasher.h
 	optimiser/CommonSubexpressionEliminator.cpp
 	optimiser/CommonSubexpressionEliminator.h
-	optimiser/ConstantOptimiser.cpp
-	optimiser/ConstantOptimiser.h
 	optimiser/ControlFlowSimplifier.cpp
 	optimiser/ControlFlowSimplifier.h
 	optimiser/DataFlowAnalyzer.cpp

libyul/CompilabilityChecker.cpp

@@ -43,27 +43,31 @@ map<YulString, int> CompilabilityChecker::run(
 
 	solAssert(_dialect.flavour == AsmFlavour::Strict, "");
 
-	solAssert(dynamic_cast<EVMDialect const*>(&_dialect), "");
+	if (EVMDialect const* evmDialect = dynamic_cast<EVMDialect const*>(&_dialect))
-	NoOutputEVMDialect noOutputDialect(dynamic_cast<EVMDialect const&>(_dialect));
-	BuiltinContext builtinContext;
-
-	yul::AsmAnalysisInfo analysisInfo =
-		yul::AsmAnalyzer::analyzeStrictAssertCorrect(noOutputDialect, _ast);
-
-	NoOutputAssembly assembly;
-	CodeTransform transform(assembly, analysisInfo, _ast, noOutputDialect, builtinContext, _optimizeStackAllocation);
-	try
 	{
-		transform(_ast);
+		NoOutputEVMDialect noOutputDialect(*evmDialect);
-	}
+		BuiltinContext builtinContext;
-	catch (StackTooDeepError const&)
-	{
-		solAssert(!transform.stackErrors().empty(), "Got stack too deep exception that was not stored.");
-	}
 
-	std::map<YulString, int> functions;
+		yul::AsmAnalysisInfo analysisInfo =
-	for (StackTooDeepError const& error: transform.stackErrors())
+			yul::AsmAnalyzer::analyzeStrictAssertCorrect(noOutputDialect, _ast);
-		functions[error.functionName] = max(error.depth, functions[error.functionName]);
 
-	return functions;
+		NoOutputAssembly assembly;
+		CodeTransform transform(assembly, analysisInfo, _ast, noOutputDialect, builtinContext, _optimizeStackAllocation);
+		try
+		{
+			transform(_ast);
+		}
+		catch (StackTooDeepError const&)
+		{
+			solAssert(!transform.stackErrors().empty(), "Got stack too deep exception that was not stored.");
+		}
+
+		std::map<YulString, int> functions;
+		for (StackTooDeepError const& error: transform.stackErrors())
+			functions[error.functionName] = max(error.depth, functions[error.functionName]);
+
+		return functions;
+	}
+	else
+		return {};
 }

libyul/Dialect.h

@@ -66,6 +66,9 @@ struct Dialect: boost::noncopyable
 	/// @returns the builtin function of the given name or a nullptr if it is not a builtin function.
 	virtual BuiltinFunction const* builtin(YulString /*_name*/) const { return nullptr; }
 
+	virtual BuiltinFunction const* discardFunction() const { return nullptr; }
+	virtual BuiltinFunction const* equalityFunction() const { return nullptr; }
+
 	Dialect(AsmFlavour _flavour): flavour(_flavour) {}
 	virtual ~Dialect() = default;
 

libyul/backends/evm/ConstantOptimiser.cpp

@@ -18,14 +18,12 @@
  * Optimisation stage that replaces constants by expressions that compute them.
  */
 
-#include <libyul/optimiser/ConstantOptimiser.h>
+#include <libyul/backends/evm/ConstantOptimiser.h>
 
 #include <libyul/optimiser/ASTCopier.h>
-#include <libyul/optimiser/Metrics.h>
+#include <libyul/backends/evm/EVMMetrics.h>
 #include <libyul/AsmData.h>
-#include <libyul/AsmPrinter.h>
 #include <libyul/Utilities.h>
-#include <libyul/AsmParser.h>
 
 #include <libdevcore/CommonData.h>
 

libyul/backends/evm/EVMDialect.h

@@ -68,6 +68,9 @@ struct EVMDialect: public Dialect
 	/// @returns the builtin function of the given name or a nullptr if it is not a builtin function.
 	BuiltinFunctionForEVM const* builtin(YulString _name) const override;
 
+	BuiltinFunctionForEVM const* discardFunction() const override { return builtin("pop"_yulstring); }
+	BuiltinFunctionForEVM const* equalityFunction() const override { return builtin("eq"_yulstring); }
+
 	static EVMDialect const& looseAssemblyForEVM(langutil::EVMVersion _version);
 	static EVMDialect const& strictAssemblyForEVM(langutil::EVMVersion _version);
 	static EVMDialect const& strictAssemblyForEVMObjects(langutil::EVMVersion _version);

libyul/backends/evm/EVMMetrics.cpp

@@ -0,0 +1,123 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+* Module providing metrics for the EVM optimizer.
+*/
+
+#include <libyul/backends/evm/EVMMetrics.h>
+
+#include <libyul/AsmData.h>
+#include <libyul/Exceptions.h>
+#include <libyul/Utilities.h>
+#include <libyul/backends/evm/EVMDialect.h>
+
+#include <libevmasm/Instruction.h>
+#include <libevmasm/GasMeter.h>
+
+#include <libdevcore/Visitor.h>
+#include <libdevcore/CommonData.h>
+
+using namespace std;
+using namespace dev;
+using namespace yul;
+
+size_t GasMeter::costs(Expression const& _expression) const
+{
+	return combineCosts(GasMeterVisitor::costs(_expression, m_dialect, m_isCreation));
+}
+
+size_t GasMeter::instructionCosts(eth::Instruction _instruction) const
+{
+	return combineCosts(GasMeterVisitor::instructionCosts(_instruction, m_dialect, m_isCreation));
+}
+
+size_t GasMeter::combineCosts(std::pair<size_t, size_t> _costs) const
+{
+	return _costs.first * m_runs + _costs.second;
+}
+
+
+pair<size_t, size_t> GasMeterVisitor::costs(
+	Expression const& _expression,
+	EVMDialect const& _dialect,
+	bool _isCreation
+)
+{
+	GasMeterVisitor gmv(_dialect, _isCreation);
+	gmv.visit(_expression);
+	return {gmv.m_runGas, gmv.m_dataGas};
+}
+
+pair<size_t, size_t> GasMeterVisitor::instructionCosts(
+	dev::eth::Instruction _instruction,
+	EVMDialect const& _dialect,
+	bool _isCreation
+)
+{
+	GasMeterVisitor gmv(_dialect, _isCreation);
+	gmv.instructionCostsInternal(_instruction);
+	return {gmv.m_runGas, gmv.m_dataGas};
+}
+
+void GasMeterVisitor::operator()(FunctionCall const& _funCall)
+{
+	ASTWalker::operator()(_funCall);
+	if (BuiltinFunctionForEVM const* f = m_dialect.builtin(_funCall.functionName.name))
+		if (f->instruction)
+		{
+			instructionCostsInternal(*f->instruction);
+			return;
+		}
+	yulAssert(false, "Functions not implemented.");
+}
+
+void GasMeterVisitor::operator()(FunctionalInstruction const& _fun)
+{
+	ASTWalker::operator()(_fun);
+	instructionCostsInternal(_fun.instruction);
+}
+
+void GasMeterVisitor::operator()(Literal const& _lit)
+{
+	m_runGas += dev::eth::GasMeter::runGas(dev::eth::Instruction::PUSH1);
+	m_dataGas +=
+		singleByteDataGas() +
+		size_t(dev::eth::GasMeter::dataGas(dev::toCompactBigEndian(valueOfLiteral(_lit), 1), m_isCreation));
+}
+
+void GasMeterVisitor::operator()(Identifier const&)
+{
+	m_runGas += dev::eth::GasMeter::runGas(dev::eth::Instruction::DUP1);
+	m_dataGas += singleByteDataGas();
+}
+
+size_t GasMeterVisitor::singleByteDataGas() const
+{
+	if (m_isCreation)
+		return dev::eth::GasCosts::txDataNonZeroGas;
+	else
+		return dev::eth::GasCosts::createDataGas;
+}
+
+void GasMeterVisitor::instructionCostsInternal(dev::eth::Instruction _instruction)
+{
+	if (_instruction == eth::Instruction::EXP)
+		m_runGas += dev::eth::GasCosts::expGas + dev::eth::GasCosts::expByteGas(m_dialect.evmVersion());
+	else
+		m_runGas += dev::eth::GasMeter::runGas(_instruction);
+	m_dataGas += singleByteDataGas();
+}

libyul/backends/evm/EVMMetrics.h

@@ -0,0 +1,101 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Module providing metrics for the optimizer.
+ */
+
+#pragma once
+
+#include <libyul/optimiser/ASTWalker.h>
+#include <liblangutil/EVMVersion.h>
+#include <libevmasm/Instruction.h>
+
+namespace yul
+{
+
+struct EVMDialect;
+
+/**
+ * Gas meter for expressions only involving literals, identifiers and
+ * EVM instructions.
+ *
+ * Assumes that EXP is not used with exponents larger than a single byte.
+ * Is not particularly exact for anything apart from arithmetic.
+ */
+class GasMeter
+{
+public:
+	GasMeter(EVMDialect const& _dialect, bool _isCreation, size_t _runs):
+		m_dialect(_dialect),
+		m_isCreation{_isCreation},
+		m_runs(_runs)
+	{}
+
+	/// @returns the full combined costs of deploying and evaluating the expression.
+	size_t costs(Expression const& _expression) const;
+	/// @returns the combined costs of deploying and running the instruction, not including
+	/// the costs for its arguments.
+	size_t instructionCosts(dev::eth::Instruction _instruction) const;
+
+private:
+	size_t combineCosts(std::pair<size_t, size_t> _costs) const;
+
+	EVMDialect const& m_dialect;
+	bool m_isCreation = false;
+	size_t m_runs;
+};
+
+class GasMeterVisitor: public ASTWalker
+{
+public:
+	static std::pair<size_t, size_t> costs(
+		Expression const& _expression,
+		EVMDialect const& _dialect,
+		bool _isCreation
+	);
+
+	static std::pair<size_t, size_t> instructionCosts(
+		dev::eth::Instruction _instruction,
+		EVMDialect const& _dialect,
+		bool _isCreation = false
+	);
+
+public:
+	GasMeterVisitor(EVMDialect const& _dialect, bool _isCreation):
+		m_dialect(_dialect),
+		m_isCreation{_isCreation}
+	{}
+
+	void operator()(FunctionCall const& _funCall) override;
+	void operator()(FunctionalInstruction const& _instr) override;
+	void operator()(Literal const& _literal) override;
+	void operator()(Identifier const& _identifier) override;
+
+private:
+	size_t singleByteDataGas() const;
+	/// Computes the cost of storing and executing the single instruction (excluding its arguments).
+	/// For EXP, it assumes that the exponent is at most 255.
+	/// Does not work particularly exact for anything apart from arithmetic.
+	void instructionCostsInternal(dev::eth::Instruction _instruction);
+
+	EVMDialect const& m_dialect;
+	bool m_isCreation = false;
+	size_t m_runGas = 0;
+	size_t m_dataGas = 0;
+};
+
+}

libyul/backends/wasm/WasmDialect.h

@@ -45,6 +45,8 @@ struct WasmDialect: public Dialect
 	WasmDialect();
 
 	BuiltinFunction const* builtin(YulString _name) const override;
+	BuiltinFunction const* discardFunction() const override { return builtin("drop"_yulstring); }
+	BuiltinFunction const* equalityFunction() const override { return builtin("i64.eq"_yulstring); }
 
 	static WasmDialect const& instance();
 

libyul/optimiser/ControlFlowSimplifier.cpp

@@ -18,6 +18,7 @@
 #include <libyul/optimiser/Semantics.h>
 #include <libyul/AsmData.h>
 #include <libyul/Utilities.h>
+#include <libyul/Dialect.h>
 #include <libdevcore/CommonData.h>
 #include <libdevcore/Visitor.h>
 
@@ -33,11 +34,16 @@ using OptionalStatements = boost::optional<vector<Statement>>;
 namespace
 {
 
-ExpressionStatement makePopExpressionStatement(langutil::SourceLocation const& _location, Expression&& _expression)
+ExpressionStatement makeDiscardCall(
+	langutil::SourceLocation const& _location,
+	Dialect const& _dialect,
+	Expression&& _expression
+)
 {
+	yulAssert(_dialect.discardFunction(), "No discard function available.");
 	return {_location, FunctionCall{
 		_location,
-		Identifier{_location, "pop"_yulstring},
+		Identifier{_location, _dialect.discardFunction()->name},
 		{std::move(_expression)}
 	}};
 }
@@ -66,36 +72,55 @@ void removeEmptyCasesFromSwitch(Switch& _switchStmt)
 	);
 }
 
-OptionalStatements reduceNoCaseSwitch(Switch& _switchStmt)
+OptionalStatements reduceNoCaseSwitch(Dialect const& _dialect, Switch& _switchStmt)
 {
 	yulAssert(_switchStmt.cases.empty(), "Expected no case!");
+	if (!_dialect.discardFunction())
+		return {};
 
 	auto loc = locationOf(*_switchStmt.expression);
 
-	return make_vector<Statement>(makePopExpressionStatement(loc, std::move(*_switchStmt.expression)));
+	return make_vector<Statement>(makeDiscardCall(
+		loc,
+		_dialect,
+		std::move(*_switchStmt.expression)
+	));
 }
 
-OptionalStatements reduceSingleCaseSwitch(Switch& _switchStmt)
+OptionalStatements reduceSingleCaseSwitch(Dialect const& _dialect, Switch& _switchStmt)
 {
 	yulAssert(_switchStmt.cases.size() == 1, "Expected only one case!");
 
 	auto& switchCase = _switchStmt.cases.front();
 	auto loc = locationOf(*_switchStmt.expression);
 	if (switchCase.value)
+	{
+		if (!_dialect.equalityFunction())
+			return {};
 		return make_vector<Statement>(If{
 			std::move(_switchStmt.location),
 			make_unique<Expression>(FunctionCall{
 				loc,
-				Identifier{loc, "eq"_yulstring},
+				Identifier{loc, _dialect.equalityFunction()->name},
 				{std::move(*switchCase.value), std::move(*_switchStmt.expression)}
 			}),
 			std::move(switchCase.body)
 		});
+	}
 	else
+	{
+		if (!_dialect.discardFunction())
+			return {};
+
 		return make_vector<Statement>(
-			makePopExpressionStatement(loc, std::move(*_switchStmt.expression)),
+			makeDiscardCall(
+				loc,
+				_dialect,
+				std::move(*_switchStmt.expression)
+			),
 			std::move(switchCase.body)
 		);
+	}
 }
 
 }
@@ -151,10 +176,14 @@ void ControlFlowSimplifier::simplify(std::vector<yul::Statement>& _statements)
 {
 	GenericFallbackReturnsVisitor<OptionalStatements, If, Switch> const visitor(
 		[&](If& _ifStmt) -> OptionalStatements {
-			if (_ifStmt.body.statements.empty())
+			if (_ifStmt.body.statements.empty() && m_dialect.discardFunction())
 			{
 				OptionalStatements s = vector<Statement>{};
-				s->emplace_back(makePopExpressionStatement(_ifStmt.location, std::move(*_ifStmt.condition)));
+				s->emplace_back(makeDiscardCall(
+					_ifStmt.location,
+					m_dialect,
+					std::move(*_ifStmt.condition)
+				));
 				return s;
 			}
 			return {};
@@ -164,9 +193,9 @@ void ControlFlowSimplifier::simplify(std::vector<yul::Statement>& _statements)
 			removeEmptyCasesFromSwitch(_switchStmt);
 
 			if (_switchStmt.cases.empty())
-				return reduceNoCaseSwitch(_switchStmt);
+				return reduceNoCaseSwitch(m_dialect, _switchStmt);
 			else if (_switchStmt.cases.size() == 1)
-				return reduceSingleCaseSwitch(_switchStmt);
+				return reduceSingleCaseSwitch(m_dialect, _switchStmt);
 
 			return {};
 		}

libyul/optimiser/Metrics.cpp

@@ -169,93 +169,6 @@ void CodeCost::addInstructionCost(eth::Instruction _instruction)
 		m_cost += 49;
 }
 
-size_t GasMeter::costs(Expression const& _expression) const
-{
-	return combineCosts(GasMeterVisitor::costs(_expression, m_dialect, m_isCreation));
-}
-
-size_t GasMeter::instructionCosts(eth::Instruction _instruction) const
-{
-	return combineCosts(GasMeterVisitor::instructionCosts(_instruction, m_dialect, m_isCreation));
-}
-
-size_t GasMeter::combineCosts(std::pair<size_t, size_t> _costs) const
-{
-	return _costs.first * m_runs + _costs.second;
-}
-
-
-pair<size_t, size_t> GasMeterVisitor::costs(
-	Expression const& _expression,
-	EVMDialect const& _dialect,
-	bool _isCreation
-)
-{
-	GasMeterVisitor gmv(_dialect, _isCreation);
-	gmv.visit(_expression);
-	return {gmv.m_runGas, gmv.m_dataGas};
-}
-
-pair<size_t, size_t> GasMeterVisitor::instructionCosts(
-	dev::eth::Instruction _instruction,
-	EVMDialect const& _dialect,
-	bool _isCreation
-)
-{
-	GasMeterVisitor gmv(_dialect, _isCreation);
-	gmv.instructionCostsInternal(_instruction);
-	return {gmv.m_runGas, gmv.m_dataGas};
-}
-
-void GasMeterVisitor::operator()(FunctionCall const& _funCall)
-{
-	ASTWalker::operator()(_funCall);
-	if (BuiltinFunctionForEVM const* f = m_dialect.builtin(_funCall.functionName.name))
-		if (f->instruction)
-		{
-			instructionCostsInternal(*f->instruction);
-			return;
-		}
-	yulAssert(false, "Functions not implemented.");
-}
-
-void GasMeterVisitor::operator()(FunctionalInstruction const& _fun)
-{
-	ASTWalker::operator()(_fun);
-	instructionCostsInternal(_fun.instruction);
-}
-
-void GasMeterVisitor::operator()(Literal const& _lit)
-{
-	m_runGas += dev::eth::GasMeter::runGas(dev::eth::Instruction::PUSH1);
-	m_dataGas +=
-		singleByteDataGas() +
-		size_t(dev::eth::GasMeter::dataGas(dev::toCompactBigEndian(valueOfLiteral(_lit), 1), m_isCreation));
-}
-
-void GasMeterVisitor::operator()(Identifier const&)
-{
-	m_runGas += dev::eth::GasMeter::runGas(dev::eth::Instruction::DUP1);
-	m_dataGas += singleByteDataGas();
-}
-
-size_t GasMeterVisitor::singleByteDataGas() const
-{
-	if (m_isCreation)
-		return dev::eth::GasCosts::txDataNonZeroGas;
-	else
-		return dev::eth::GasCosts::createDataGas;
-}
-
-void GasMeterVisitor::instructionCostsInternal(dev::eth::Instruction _instruction)
-{
-	if (_instruction == eth::Instruction::EXP)
-		m_runGas += dev::eth::GasCosts::expGas + dev::eth::GasCosts::expByteGas(m_dialect.evmVersion());
-	else
-		m_runGas += dev::eth::GasMeter::runGas(_instruction);
-	m_dataGas += singleByteDataGas();
-}
-
 void AssignmentCounter::operator()(Assignment const& _assignment)
 {
 	for (auto const& variable: _assignment.variableNames)

libyul/optimiser/Metrics.h

@@ -22,9 +22,6 @@
 
 #include <libyul/optimiser/ASTWalker.h>
 #include <liblangutil/EVMVersion.h>
-#include <libevmasm/Instruction.h>
-
-#include <libevmasm/Instruction.h>
 
 namespace yul
 {
@@ -96,75 +93,6 @@ private:
 	size_t m_cost = 0;
 };
 
-/**
- * Gas meter for expressions only involving literals, identifiers and
- * EVM instructions.
- *
- * Assumes that EXP is not used with exponents larger than a single byte.
- * Is not particularly exact for anything apart from arithmetic.
- */
-class GasMeter
-{
-public:
-	GasMeter(EVMDialect const& _dialect, bool _isCreation, size_t _runs):
-		m_dialect(_dialect),
-		m_isCreation{_isCreation},
-		m_runs(_runs)
-	{}
-
-	/// @returns the full combined costs of deploying and evaluating the expression.
-	size_t costs(Expression const& _expression) const;
-	/// @returns the combined costs of deploying and running the instruction, not including
-	/// the costs for its arguments.
-	size_t instructionCosts(dev::eth::Instruction _instruction) const;
-
-private:
-	size_t combineCosts(std::pair<size_t, size_t> _costs) const;
-
-	EVMDialect const& m_dialect;
-	bool m_isCreation = false;
-	size_t m_runs;
-};
-
-class GasMeterVisitor: public ASTWalker
-{
-public:
-	static std::pair<size_t, size_t> costs(
-		Expression const& _expression,
-		EVMDialect const& _dialect,
-		bool _isCreation
-	);
-
-	static std::pair<size_t, size_t> instructionCosts(
-		dev::eth::Instruction _instruction,
-		EVMDialect const& _dialect,
-		bool _isCreation = false
-	);
-
-public:
-	GasMeterVisitor(EVMDialect const& _dialect, bool _isCreation):
-		m_dialect(_dialect),
-		m_isCreation{_isCreation}
-	{}
-
-	void operator()(FunctionCall const& _funCall) override;
-	void operator()(FunctionalInstruction const& _instr) override;
-	void operator()(Literal const& _literal) override;
-	void operator()(Identifier const& _identifier) override;
-
-private:
-	size_t singleByteDataGas() const;
-	/// Computes the cost of storing and executing the single instruction (excluding its arguments).
-	/// For EXP, it assumes that the exponent is at most 255.
-	/// Does not work particularly exact for anything apart from arithmetic.
-	void instructionCostsInternal(dev::eth::Instruction _instruction);
-
-	EVMDialect const& m_dialect;
-	bool m_isCreation = false;
-	size_t m_runGas = 0;
-	size_t m_dataGas = 0;
-};
-
 /**
  * Counts the number of assignments to every variable.
  * Only works after running the Disambiguator.

libyul/optimiser/Suite.cpp

@@ -24,7 +24,6 @@
 #include <libyul/optimiser/VarDeclInitializer.h>
 #include <libyul/optimiser/BlockFlattener.h>
 #include <libyul/optimiser/ControlFlowSimplifier.h>
-#include <libyul/optimiser/ConstantOptimiser.h>
 #include <libyul/optimiser/DeadCodeEliminator.h>
 #include <libyul/optimiser/FunctionGrouper.h>
 #include <libyul/optimiser/FunctionHoister.h>
@@ -45,6 +44,7 @@
 #include <libyul/optimiser/RedundantAssignEliminator.h>
 #include <libyul/optimiser/VarNameCleaner.h>
 #include <libyul/optimiser/Metrics.h>
+#include <libyul/backends/evm/ConstantOptimiser.h>
 #include <libyul/AsmAnalysis.h>
 #include <libyul/AsmAnalysisInfo.h>
 #include <libyul/AsmData.h>
@@ -209,7 +209,8 @@ void OptimiserSuite::run(
 
 	FunctionGrouper{}(ast);
 
-	ConstantOptimiser{dynamic_cast<EVMDialect const&>(_dialect), _meter}(ast);
+	if (EVMDialect const* dialect = dynamic_cast<EVMDialect const*>(&_dialect))
+		ConstantOptimiser{*dialect, _meter}(ast);
 	VarNameCleaner{ast, _dialect, reservedIdentifiers}(ast);
 	yul::AsmAnalyzer::analyzeStrictAssertCorrect(_dialect, ast);
 

test/libyul/YulOptimizerTest.cpp

@@ -23,7 +23,6 @@
 #include <libyul/optimiser/VarDeclInitializer.h>
 #include <libyul/optimiser/VarNameCleaner.h>
 #include <libyul/optimiser/ControlFlowSimplifier.h>
-#include <libyul/optimiser/ConstantOptimiser.h>
 #include <libyul/optimiser/DeadCodeEliminator.h>
 #include <libyul/optimiser/Disambiguator.h>
 #include <libyul/optimiser/CommonSubexpressionEliminator.h>
@@ -47,8 +46,9 @@
 #include <libyul/optimiser/StructuralSimplifier.h>
 #include <libyul/optimiser/StackCompressor.h>
 #include <libyul/optimiser/Suite.h>
-#include <libyul/optimiser/Metrics.h>
+#include <libyul/backends/evm/ConstantOptimiser.h>
 #include <libyul/backends/evm/EVMDialect.h>
+#include <libyul/backends/evm/EVMMetrics.h>
 #include <libyul/backends/wasm/WordSizeTransform.h>
 #include <libyul/AsmPrinter.h>
 #include <libyul/AsmParser.h>