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/*
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/>.
*/
/**
* @file ExpressionClasses.cpp
* @author Christian <c@ethdev.com>
* @date 2015
* Container for equivalence classes of expressions for use in common subexpression elimination.
*/
#include <libevmasm/ExpressionClasses.h>
#include <utility>
#include <tuple>
#include <functional>
#include <boost/range/adaptor/reversed.hpp>
#include <boost/noncopyable.hpp>
#include <libevmasm/Assembly.h>
#include <libevmasm/CommonSubexpressionEliminator.h>
#include <libevmasm/SimplificationRules.h>
#include <libevmasm/RuleList.h>
using namespace std;
using namespace dev;
using namespace dev::eth;
tuple<Pattern, function<Pattern()>, bool> const* Rules::findFirstMatch(
Expression const& _expr,
ExpressionClasses const& _classes
)
{
resetMatchGroups();
assertThrow(_expr.item, OptimizerException, "");
for (auto const& rule: m_rules[byte(_expr.item->instruction())])
{
if (std::get<0>(rule).matches(_expr, _classes))
return &rule;
resetMatchGroups();
}
return nullptr;
}
void Rules::addRules(std::vector<std::tuple<Pattern, std::function<Pattern ()>, bool>> const& _rules)
{
for (auto const& r: _rules)
addRule(r);
}
void Rules::addRule(std::tuple<Pattern, std::function<Pattern()>, bool> const& _rule)
{
m_rules[byte(std::get<0>(_rule).instruction())].push_back(_rule);
}
Rules::Rules()
{
// Multiple occurences of one of these inside one rule must match the same equivalence class.
// Constants.
Pattern A(Push);
Pattern B(Push);
Pattern C(Push);
// Anything.
Pattern X;
Pattern Y;
A.setMatchGroup(1, m_matchGroups);
B.setMatchGroup(2, m_matchGroups);
C.setMatchGroup(3, m_matchGroups);
X.setMatchGroup(4, m_matchGroups);
Y.setMatchGroup(5, m_matchGroups);
addRules(simplificationRuleList(A, B, C, X, Y));
}
Pattern::Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments):
m_type(Operation),
m_instruction(_instruction),
m_arguments(_arguments)
{
}
void Pattern::setMatchGroup(unsigned _group, map<unsigned, Expression const*>& _matchGroups)
{
m_matchGroup = _group;
m_matchGroups = &_matchGroups;
}
bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const
{
if (!matchesBaseItem(_expr.item))
return false;
if (m_matchGroup)
{
if (!m_matchGroups->count(m_matchGroup))
(*m_matchGroups)[m_matchGroup] = &_expr;
else if ((*m_matchGroups)[m_matchGroup]->id != _expr.id)
return false;
}
assertThrow(m_arguments.size() == 0 || _expr.arguments.size() == m_arguments.size(), OptimizerException, "");
for (size_t i = 0; i < m_arguments.size(); ++i)
if (!m_arguments[i].matches(_classes.representative(_expr.arguments[i]), _classes))
return false;
return true;
}
AssemblyItem Pattern::toAssemblyItem(SourceLocation const& _location) const
{
if (m_type == Operation)
return AssemblyItem(m_instruction, _location);
else
return AssemblyItem(m_type, data(), _location);
}
string Pattern::toString() const
{
stringstream s;
switch (m_type)
{
case Operation:
s << instructionInfo(m_instruction).name;
break;
case Push:
if (m_data)
s << "PUSH " << hex << data();
else
s << "PUSH ";
break;
case UndefinedItem:
s << "ANY";
break;
default:
if (m_data)
s << "t=" << dec << m_type << " d=" << hex << data();
else
s << "t=" << dec << m_type << " d: nullptr";
break;
}
if (!m_requireDataMatch)
s << " ~";
if (m_matchGroup)
s << "[" << dec << m_matchGroup << "]";
s << "(";
for (Pattern const& p: m_arguments)
s << p.toString() << ", ";
s << ")";
return s.str();
}
bool Pattern::matchesBaseItem(AssemblyItem const* _item) const
{
if (m_type == UndefinedItem)
return true;
if (!_item)
return false;
if (m_type != _item->type())
return false;
else if (m_type == Operation)
return m_instruction == _item->instruction();
else if (m_requireDataMatch)
return data() == _item->data();
return true;
}
Pattern::Expression const& Pattern::matchGroupValue() const
{
assertThrow(m_matchGroup > 0, OptimizerException, "");
assertThrow(!!m_matchGroups, OptimizerException, "");
assertThrow((*m_matchGroups)[m_matchGroup], OptimizerException, "");
return *(*m_matchGroups)[m_matchGroup];
}
u256 const& Pattern::data() const
{
assertThrow(m_data, OptimizerException, "");
return *m_data;
}
ExpressionTemplate::ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location)
{
if (_pattern.matchGroup())
{
hasId = true;
id = _pattern.id();
}
else
{
hasId = false;
item = _pattern.toAssemblyItem(_location);
}
for (auto const& arg: _pattern.arguments())
arguments.push_back(ExpressionTemplate(arg, _location));
}
string ExpressionTemplate::toString() const
{
stringstream s;
if (hasId)
s << id;
else
s << item;
s << "(";
for (auto const& arg: arguments)
s << arg.toString();
s << ")";
return s.str();
}
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