mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
60 lines
1.9 KiB
C++
60 lines
1.9 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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* Optimiser component that uses the simplification rules to simplify expressions.
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*/
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#include <libyul/optimiser/ExpressionSimplifier.h>
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#include <libyul/optimiser/SimplificationRules.h>
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#include <libyul/optimiser/Semantics.h>
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#include <libyul/optimiser/SSAValueTracker.h>
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#include <libyul/AsmData.h>
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#include <libdevcore/CommonData.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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using namespace dev::solidity;
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void ExpressionSimplifier::visit(Expression& _expression)
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{
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ASTModifier::visit(_expression);
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while (auto match = SimplificationRules::findFirstMatch(_expression, m_ssaValues))
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{
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// Do not apply the rule if it removes non-constant parts of the expression.
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// TODO: The check could actually be less strict than "movable".
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// We only require "Does not cause side-effects".
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// Note: References to variables that are only assigned once are always movable,
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// so if the value of the variable is not movable, the expression that references
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// the variable still is.
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if (match->removesNonConstants && !MovableChecker(_expression).movable())
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return;
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_expression = match->action().toExpression(locationOf(_expression));
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}
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}
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void ExpressionSimplifier::run(Block& _ast)
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{
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SSAValueTracker ssaValues;
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ssaValues(_ast);
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ExpressionSimplifier{ssaValues.values()}(_ast);
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}
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