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			87 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			87 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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	This file is part of solidity.
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	solidity is free software: you can redistribute it and/or modify
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	it under the terms of the GNU General Public License as published by
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	the Free Software Foundation, either version 3 of the License, or
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	(at your option) any later version.
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	solidity is distributed in the hope that it will be useful,
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	but WITHOUT ANY WARRANTY; without even the implied warranty of
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	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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	GNU General Public License for more details.
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	You should have received a copy of the GNU General Public License
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	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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 * Optimisation stage that replaces expressions of type ``sload(x)`` by the value
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 * currently stored in storage, if known.
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 */
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#include <libyul/optimiser/LoadResolver.h>
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#include <libyul/backends/evm/EVMDialect.h>
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#include <libyul/optimiser/Semantics.h>
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#include <libyul/optimiser/CallGraphGenerator.h>
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#include <libyul/SideEffects.h>
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#include <libyul/AsmData.h>
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using namespace std;
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using namespace dev;
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using namespace yul;
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void LoadResolver::run(OptimiserStepContext& _context, Block& _ast)
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{
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	bool containsMSize = MSizeFinder::containsMSize(_context.dialect, _ast);
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	LoadResolver{
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		_context.dialect,
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		SideEffectsPropagator::sideEffects(_context.dialect, CallGraphGenerator::callGraph(_ast)),
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		!containsMSize
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	}(_ast);
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}
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void LoadResolver::visit(Expression& _e)
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{
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	DataFlowAnalyzer::visit(_e);
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	if (!dynamic_cast<EVMDialect const*>(&m_dialect))
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		return;
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	if (holds_alternative<FunctionCall>(_e))
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	{
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		FunctionCall const& funCall = std::get<FunctionCall>(_e);
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		if (auto const* builtin = dynamic_cast<EVMDialect const&>(m_dialect).builtin(funCall.functionName.name))
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			if (builtin->instruction)
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				tryResolve(_e, *builtin->instruction, funCall.arguments);
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	}
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	else if (holds_alternative<FunctionalInstruction>(_e))
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	{
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		FunctionalInstruction const& instruction = std::get<FunctionalInstruction>(_e);
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		tryResolve(_e, instruction.instruction, instruction.arguments);
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	}
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}
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void LoadResolver::tryResolve(
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	Expression& _e,
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	dev::eth::Instruction _instruction,
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	vector<Expression> const& _arguments
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)
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{
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	if (_arguments.empty() || !holds_alternative<Identifier>(_arguments.at(0)))
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		return;
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	YulString key = std::get<Identifier>(_arguments.at(0)).name;
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	if (
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		_instruction == dev::eth::Instruction::SLOAD &&
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		m_storage.values.count(key)
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	)
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		_e = Identifier{locationOf(_e), m_storage.values[key]};
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	else if (
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		m_optimizeMLoad &&
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		_instruction == dev::eth::Instruction::MLOAD &&
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		m_memory.values.count(key)
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	)
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		_e = Identifier{locationOf(_e), m_memory.values[key]};
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}
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