solidity/libyul/optimiser/Metrics.cpp
2019-06-17 18:42:47 +02:00

183 lines
4.3 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/>.
*/
/**
* Module providing metrics for the optimizer.
*/
#include <libyul/optimiser/Metrics.h>
#include <libyul/AsmData.h>
#include <libyul/Exceptions.h>
#include <libyul/Utilities.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/GasMeter.h>
#include <libdevcore/Visitor.h>
#include <libdevcore/CommonData.h>
using namespace std;
using namespace dev;
using namespace yul;
size_t CodeSize::codeSize(Statement const& _statement)
{
CodeSize cs;
cs.visit(_statement);
return cs.m_size;
}
size_t CodeSize::codeSize(Expression const& _expression)
{
CodeSize cs;
cs.visit(_expression);
return cs.m_size;
}
size_t CodeSize::codeSize(Block const& _block)
{
CodeSize cs;
cs(_block);
return cs.m_size;
}
size_t CodeSize::codeSizeIncludingFunctions(Block const& _block)
{
CodeSize cs(false);
cs(_block);
return cs.m_size;
}
void CodeSize::visit(Statement const& _statement)
{
if (_statement.type() == typeid(FunctionDefinition) && m_ignoreFunctions)
return;
else if (
_statement.type() == typeid(If) ||
_statement.type() == typeid(Break) ||
_statement.type() == typeid(Continue)
)
m_size += 2;
else if (_statement.type() == typeid(ForLoop))
m_size += 3;
else if (_statement.type() == typeid(Switch))
m_size += 1 + 2 * boost::get<Switch>(_statement).cases.size();
else if (!(
_statement.type() == typeid(Block) ||
_statement.type() == typeid(ExpressionStatement) ||
_statement.type() == typeid(Assignment) ||
_statement.type() == typeid(VariableDeclaration)
))
++m_size;
ASTWalker::visit(_statement);
}
void CodeSize::visit(Expression const& _expression)
{
if (_expression.type() != typeid(Identifier))
++m_size;
ASTWalker::visit(_expression);
}
size_t CodeCost::codeCost(Dialect const& _dialect, Expression const& _expr)
{
CodeCost cc(_dialect);
cc.visit(_expr);
return cc.m_cost;
}
void CodeCost::operator()(FunctionCall const& _funCall)
{
ASTWalker::operator()(_funCall);
if (EVMDialect const* dialect = dynamic_cast<EVMDialect const*>(&m_dialect))
if (BuiltinFunctionForEVM const* f = dialect->builtin(_funCall.functionName.name))
if (f->instruction)
{
addInstructionCost(*f->instruction);
return;
}
m_cost += 49;
}
void CodeCost::operator()(FunctionalInstruction const& _instr)
{
yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
addInstructionCost(_instr.instruction);
ASTWalker::operator()(_instr);
}
void CodeCost::operator()(Literal const& _literal)
{
yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
size_t cost = 0;
switch (_literal.kind)
{
case LiteralKind::Boolean:
break;
case LiteralKind::Number:
for (u256 n = u256(_literal.value.str()); n >= 0x100; n >>= 8)
cost++;
break;
case LiteralKind::String:
cost = _literal.value.str().size();
break;
}
m_cost += cost;
}
void CodeCost::visit(Statement const& _statement)
{
++m_cost;
ASTWalker::visit(_statement);
}
void CodeCost::visit(Expression const& _expression)
{
++m_cost;
ASTWalker::visit(_expression);
}
void CodeCost::addInstructionCost(eth::Instruction _instruction)
{
dev::eth::Tier gasPriceTier = dev::eth::instructionInfo(_instruction).gasPriceTier;
if (gasPriceTier < dev::eth::Tier::VeryLow)
m_cost -= 1;
else if (gasPriceTier < dev::eth::Tier::High)
m_cost += 1;
else
m_cost += 49;
}
void AssignmentCounter::operator()(Assignment const& _assignment)
{
for (auto const& variable: _assignment.variableNames)
++m_assignmentCounters[variable.name];
}
size_t AssignmentCounter::assignmentCount(YulString _name) const
{
auto it = m_assignmentCounters.find(_name);
return (it == m_assignmentCounters.end()) ? 0 : it->second;
}