path: root/libyul/optimiser/Metrics.cpp

/*(
    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 <libevmasm/Instruction.h>

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;
}

void CodeSize::visit(Statement const& _statement)
{
    if (_statement.type() == typeid(FunctionDefinition))
        return;

    ++m_size;
    ASTWalker::visit(_statement);
}

void CodeSize::visit(Expression const& _expression)
{
    ++m_size;
    ASTWalker::visit(_expression);
}


size_t CodeCost::codeCost(Expression const& _expr)
{
    CodeCost cc;
    cc.visit(_expr);
    return cc.m_cost;
}


void CodeCost::operator()(FunctionCall const& _funCall)
{
    yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
    m_cost += 49;
    ASTWalker::operator()(_funCall);
}

void CodeCost::operator()(FunctionalInstruction const& _instr)
{
    using namespace dev::solidity;
    yulAssert(m_cost >= 1, "Should assign cost one in visit(Expression).");
    Tier gasPriceTier = instructionInfo(_instr.instruction).gasPriceTier;
    if (gasPriceTier < Tier::VeryLow)
        m_cost -= 1;
    else if (gasPriceTier < Tier::High)
        m_cost += 1;
    else
        m_cost += 49;
    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);
}