mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
85 lines
2.6 KiB
C++
85 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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// SPDX-License-Identifier: GPL-3.0
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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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#pragma once
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#include <libyul/optimiser/DataFlowAnalyzer.h>
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#include <libyul/optimiser/OptimiserStep.h>
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namespace solidity::yul
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{
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/**
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* Optimisation stage that replaces expressions of type ``sload(x)`` and ``mload(x)`` by the value
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* currently stored in storage resp. memory, if known.
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*
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* Also evaluates simple ``keccak256(a, c)`` when the value at memory location `a` is known and `c`
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* is a constant `<= 32`.
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*
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* Works best if the code is in SSA form.
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*
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* Prerequisite: Disambiguator, ForLoopInitRewriter.
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*/
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class LoadResolver: public DataFlowAnalyzer
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{
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public:
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static constexpr char const* name{"LoadResolver"};
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/// Run the load resolver on the given complete AST.
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static void run(OptimiserStepContext&, Block& _ast);
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private:
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LoadResolver(
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Dialect const& _dialect,
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std::map<YulString, SideEffects> _functionSideEffects,
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bool _containsMSize,
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std::optional<size_t> _expectedExecutionsPerDeployment
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):
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DataFlowAnalyzer(_dialect, MemoryAndStorage::Analyze, std::move(_functionSideEffects)),
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m_containsMSize(_containsMSize),
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m_expectedExecutionsPerDeployment(std::move(_expectedExecutionsPerDeployment))
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{}
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protected:
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using ASTModifier::visit;
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void visit(Expression& _e) override;
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void tryResolve(
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Expression& _e,
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StoreLoadLocation _location,
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std::vector<Expression> const& _arguments
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);
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/// Evaluates simple ``keccak256(a, c)`` when the value at memory location ``a`` is known and
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/// `c` is a constant `<= 32`.
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void tryEvaluateKeccak(
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Expression& _e,
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std::vector<Expression> const& _arguments
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);
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/// If the AST contains `msize`, then we skip resolving `mload` and `keccak256`.
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bool m_containsMSize = false;
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/// The --optimize-runs parameter. Value `nullopt` represents creation code.
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std::optional<size_t> m_expectedExecutionsPerDeployment;
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};
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}
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