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			72 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			72 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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| 	This file is part of solidity.
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| 
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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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| 
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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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| 
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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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|  * Optimiser component that combines syntactically equivalent functions.
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|  */
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| #pragma once
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| 
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| #include <libyul/optimiser/ASTWalker.h>
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| #include <libyul/AsmDataForward.h>
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| 
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| namespace yul
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| {
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| 
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| /**
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|  * Optimiser component that detects syntactically equivalent functions.
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|  *
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|  * Prerequisite: Disambiguator
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|  */
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| class EquivalentFunctionDetector: public ASTWalker
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| {
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| public:
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| 	static std::map<YulString, FunctionDefinition const*> run(Block& _block)
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| 	{
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| 		EquivalentFunctionDetector detector{};
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| 		detector(_block);
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| 		return std::move(detector.m_duplicates);
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| 	}
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| 
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| 	using ASTWalker::operator();
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| 	void operator()(FunctionDefinition const& _fun) override;
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| 
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| private:
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| 	EquivalentFunctionDetector() = default;
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| 	/**
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| 	 * Fast heuristic to detect distinct, resp. potentially equal functions.
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| 	 *
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| 	 * Defines a partial order on function definitions. If two functions
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| 	 * are comparable (one is "less" than the other), they are distinct.
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| 	 * If not (neither is "less" than the other), they are *potentially* equal.
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| 	 */
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| 	class RoughHeuristic
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| 	{
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| 	public:
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| 		RoughHeuristic(FunctionDefinition const& _fun): m_fun(_fun) {}
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| 		bool operator<(RoughHeuristic const& _rhs) const;
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| 	private:
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| 		std::size_t codeSize() const;
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| 		FunctionDefinition const& m_fun;
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| 		mutable boost::optional<std::size_t> m_codeSize;
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| 		// In case the heuristic doesn't turn out to be good enough, we might want to define a hash function for code blocks.
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| 	};
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| 	std::map<RoughHeuristic, std::vector<FunctionDefinition const*>> m_candidates;
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| 	std::map<YulString, FunctionDefinition const*> m_duplicates;
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| };
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| 
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| 
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| }
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