solidity/libyul/optimiser/LoadResolver.cpp

67 lines
2.0 KiB
C++

/*
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 <http://www.gnu.org/licenses/>.
*/
/**
* Optimisation stage that replaces expressions of type ``sload(x)`` by the value
* currently stored in storage, if known.
*/
#include <libyul/optimiser/LoadResolver.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/AsmData.h>
using namespace std;
using namespace dev;
using namespace yul;
void LoadResolver::run(Dialect const& _dialect, Block& _ast)
{
bool containsMSize = MSizeFinder::containsMSize(_dialect, _ast);
LoadResolver{_dialect, !containsMSize}(_ast);
}
void LoadResolver::visit(Expression& _e)
{
if (_e.type() == typeid(FunctionCall))
{
FunctionCall const& funCall = boost::get<FunctionCall>(_e);
if (auto const* builtin = dynamic_cast<EVMDialect const&>(m_dialect).builtin(funCall.functionName.name))
if (!builtin->parameters.empty() && funCall.arguments.at(0).type() == typeid(Identifier))
{
YulString key = boost::get<Identifier>(funCall.arguments.at(0)).name;
if (
builtin->instruction == dev::eth::Instruction::SLOAD &&
m_storage.values.count(key)
)
{
_e = Identifier{locationOf(_e), m_storage.values[key]};
return;
}
else if (
m_optimizeMLoad &&
builtin->instruction == dev::eth::Instruction::MLOAD &&
m_memory.values.count(key)
)
{
_e = Identifier{locationOf(_e), m_memory.values[key]};
return;
}
}
}
}