libyul/optimiser/Metrics.cpp


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126

/*(
    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);
}