1/*
2 * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef DFGArgumentPosition_h
27#define DFGArgumentPosition_h
28
29#include "DFGDoubleFormatState.h"
30#include "DFGVariableAccessData.h"
31#include "DFGVariableAccessDataDump.h"
32#include "SpeculatedType.h"
33
34namespace JSC { namespace DFG {
35
36class ArgumentPosition {
37public:
38    ArgumentPosition()
39        : m_prediction(SpecNone)
40        , m_doubleFormatState(EmptyDoubleFormatState)
41        , m_isProfitableToUnbox(false)
42        , m_shouldNeverUnbox(false)
43    {
44    }
45
46    void addVariable(VariableAccessData* variable)
47    {
48        m_variables.append(variable);
49    }
50
51    bool mergeShouldNeverUnbox(bool shouldNeverUnbox)
52    {
53        return checkAndSet(m_shouldNeverUnbox, m_shouldNeverUnbox | shouldNeverUnbox);
54    }
55
56    bool mergeArgumentPredictionAwareness()
57    {
58        bool changed = false;
59        for (unsigned i = 0; i < m_variables.size(); ++i) {
60            VariableAccessData* variable = m_variables[i]->find();
61            changed |= mergeSpeculation(m_prediction, variable->argumentAwarePrediction());
62            changed |= mergeDoubleFormatState(m_doubleFormatState, variable->doubleFormatState());
63            changed |= mergeShouldNeverUnbox(variable->shouldNeverUnbox());
64        }
65        if (!changed)
66            return false;
67        changed = false;
68        for (unsigned i = 0; i < m_variables.size(); ++i) {
69            VariableAccessData* variable = m_variables[i]->find();
70            changed |= variable->mergeArgumentAwarePrediction(m_prediction);
71            changed |= variable->mergeDoubleFormatState(m_doubleFormatState);
72            changed |= variable->mergeShouldNeverUnbox(m_shouldNeverUnbox);
73        }
74        return changed;
75    }
76
77    bool mergeArgumentUnboxingAwareness()
78    {
79        bool changed = false;
80        for (unsigned i = 0; i < m_variables.size(); ++i) {
81            VariableAccessData* variable = m_variables[i]->find();
82            changed |= checkAndSet(m_isProfitableToUnbox, m_isProfitableToUnbox | variable->isProfitableToUnbox());
83        }
84        if (!changed)
85            return false;
86        changed = false;
87        for (unsigned i = 0; i < m_variables.size(); ++i) {
88            VariableAccessData* variable = m_variables[i]->find();
89            changed |= variable->mergeIsProfitableToUnbox(m_isProfitableToUnbox);
90        }
91        return changed;
92    }
93
94    bool shouldUnboxIfPossible() const { return m_isProfitableToUnbox && !m_shouldNeverUnbox; }
95
96    SpeculatedType prediction() const { return m_prediction; }
97    DoubleFormatState doubleFormatState() const { return m_doubleFormatState; }
98    bool shouldUseDoubleFormat() const
99    {
100        return doubleFormatState() == UsingDoubleFormat && shouldUnboxIfPossible();
101    }
102
103    void dump(PrintStream& out, Graph* graph)
104    {
105        for (unsigned i = 0; i < m_variables.size(); ++i) {
106            VariableAccessData* variable = m_variables[i]->find();
107            int operand = variable->operand();
108
109            if (i)
110                out.print(" ");
111
112            if (operandIsArgument(operand))
113                out.print("arg", operandToArgument(operand), "(", VariableAccessDataDump(*graph, variable), ")");
114            else
115                out.print("r", operand, "(", VariableAccessDataDump(*graph, variable), ")");
116        }
117        out.print("\n");
118    }
119
120private:
121    SpeculatedType m_prediction;
122    DoubleFormatState m_doubleFormatState;
123    bool m_isProfitableToUnbox;
124    bool m_shouldNeverUnbox;
125
126    Vector<VariableAccessData*, 2> m_variables;
127};
128
129} } // namespace JSC::DFG
130
131#endif // DFGArgumentPosition_h
132
133