mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
85 lines
2.5 KiB
C++
85 lines
2.5 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/>.
|
|
*/
|
|
// SPDX-License-Identifier: GPL-3.0
|
|
/**
|
|
* Optimisation stage that replaces expressions of type ``sload(x)`` by the value
|
|
* currently stored in storage, if known.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <libyul/optimiser/DataFlowAnalyzer.h>
|
|
#include <libyul/optimiser/OptimiserStep.h>
|
|
|
|
namespace solidity::yul
|
|
{
|
|
|
|
/**
|
|
* Optimisation stage that replaces expressions of type ``sload(x)`` and ``mload(x)`` by the value
|
|
* currently stored in storage resp. memory, if known.
|
|
*
|
|
* Also evaluates simple ``keccak256(a, c)`` when the value at memory location `a` is known and `c`
|
|
* is a constant `<= 32`.
|
|
*
|
|
* Works best if the code is in SSA form.
|
|
*
|
|
* Prerequisite: Disambiguator, ForLoopInitRewriter.
|
|
*/
|
|
class LoadResolver: public DataFlowAnalyzer
|
|
{
|
|
public:
|
|
static constexpr char const* name{"LoadResolver"};
|
|
/// Run the load resolver on the given complete AST.
|
|
static void run(OptimiserStepContext&, Block& _ast);
|
|
|
|
private:
|
|
LoadResolver(
|
|
Dialect const& _dialect,
|
|
std::map<YulString, SideEffects> _functionSideEffects,
|
|
bool _containsMSize,
|
|
std::optional<size_t> _expectedExecutionsPerDeployment
|
|
):
|
|
DataFlowAnalyzer(_dialect, std::move(_functionSideEffects)),
|
|
m_containsMSize(_containsMSize),
|
|
m_expectedExecutionsPerDeployment(std::move(_expectedExecutionsPerDeployment))
|
|
{}
|
|
|
|
protected:
|
|
using ASTModifier::visit;
|
|
void visit(Expression& _e) override;
|
|
|
|
void tryResolve(
|
|
Expression& _e,
|
|
StoreLoadLocation _location,
|
|
std::vector<Expression> const& _arguments
|
|
);
|
|
|
|
/// Evaluates simple ``keccak256(a, c)`` when the value at memory location ``a`` is known and
|
|
/// `c` is a constant `<= 32`.
|
|
void tryEvaluateKeccak(
|
|
Expression& _e,
|
|
std::vector<Expression> const& _arguments
|
|
);
|
|
|
|
/// If the AST contains `msize`, then we skip resolving `mload` and `keccak256`.
|
|
bool m_containsMSize = false;
|
|
/// The --optimize-runs parameter. Value `nullopt` represents creation code.
|
|
std::optional<size_t> m_expectedExecutionsPerDeployment;
|
|
};
|
|
|
|
}
|