From a38418f0d9c9698c537c88152f53f6a65f99580c Mon Sep 17 00:00:00 2001 From: chriseth Date: Fri, 2 Feb 2018 15:24:56 +0100 Subject: Common subexpression eliminator. --- .../optimiser/CommonSubexpressionEliminator.cpp | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 libjulia/optimiser/CommonSubexpressionEliminator.cpp (limited to 'libjulia/optimiser/CommonSubexpressionEliminator.cpp') diff --git a/libjulia/optimiser/CommonSubexpressionEliminator.cpp b/libjulia/optimiser/CommonSubexpressionEliminator.cpp new file mode 100644 index 00000000..229bd35e --- /dev/null +++ b/libjulia/optimiser/CommonSubexpressionEliminator.cpp @@ -0,0 +1,48 @@ +/*( + 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 . +*/ +/** + * Optimisation stage that replaces expressions known to be the current value of a variable + * in scope by a reference to that variable. + */ + +#include + +#include +#include + +#include + +using namespace std; +using namespace dev; +using namespace dev::julia; + +void CommonSubexpressionEliminator::visit(Expression& _e) +{ + // Single exception for substitution: We do not substitute one variable for another. + if (_e.type() != typeid(Identifier)) + // TODO this search rather inefficient. + for (auto const& var: m_value) + { + solAssert(var.second, ""); + if (SyntacticalEqualityChecker::equal(_e, *var.second)) + { + _e = Identifier{locationOf(_e), var.first}; + break; + } + } + DataFlowAnalyzer::visit(_e); +} -- cgit v1.2.3