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    VariableAccessData* someVariable() const
52    {
53        if (m_variables.isEmpty())
54            return 0;
55        return m_variables[0]->find();
56    }
57
58    FlushFormat flushFormat() const
59    {
60        if (VariableAccessData* variable = someVariable())
61            return variable->flushFormat();
62        return DeadFlush;
63    }
64
65    bool mergeShouldNeverUnbox(bool shouldNeverUnbox)
66    {
67        return checkAndSet(m_shouldNeverUnbox, m_shouldNeverUnbox | shouldNeverUnbox);
68    }
69
70    bool mergeArgumentPredictionAwareness()
71    {
72        bool changed = false;
73        for (unsigned i = 0; i < m_variables.size(); ++i) {
74            VariableAccessData* variable = m_variables[i]->find();
75            changed |= mergeSpeculation(m_prediction, variable->argumentAwarePrediction());
76            changed |= mergeDoubleFormatState(m_doubleFormatState, variable->doubleFormatState());
77            changed |= mergeShouldNeverUnbox(variable->shouldNeverUnbox());
78        }
79        if (!changed)
80            return false;
81        changed = false;
82        for (unsigned i = 0; i < m_variables.size(); ++i) {
83            VariableAccessData* variable = m_variables[i]->find();
84            changed |= variable->mergeArgumentAwarePrediction(m_prediction);
85            changed |= variable->mergeDoubleFormatState(m_doubleFormatState);
86            changed |= variable->mergeShouldNeverUnbox(m_shouldNeverUnbox);
87        }
88        return changed;
89    }
90
91    bool mergeArgumentUnboxingAwareness()
92    {
93        bool changed = false;
94        for (unsigned i = 0; i < m_variables.size(); ++i) {
95            VariableAccessData* variable = m_variables[i]->find();
96            changed |= checkAndSet(m_isProfitableToUnbox, m_isProfitableToUnbox | variable->isProfitableToUnbox());
97        }
98        if (!changed)
99            return false;
100        changed = false;
101        for (unsigned i = 0; i < m_variables.size(); ++i) {
102            VariableAccessData* variable = m_variables[i]->find();
103            changed |= variable->mergeIsProfitableToUnbox(m_isProfitableToUnbox);
104        }
105        return changed;
106    }
107
108    bool shouldUnboxIfPossible() const { return m_isProfitableToUnbox && !m_shouldNeverUnbox; }
109
110    SpeculatedType prediction() const { return m_prediction; }
111    DoubleFormatState doubleFormatState() const { return m_doubleFormatState; }
112    bool shouldUseDoubleFormat() const
113    {
114        return doubleFormatState() == UsingDoubleFormat && shouldUnboxIfPossible();
115    }
116
117    void dump(PrintStream& out, Graph* graph)
118    {
119        for (unsigned i = 0; i < m_variables.size(); ++i) {
120            VariableAccessData* variable = m_variables[i]->find();
121            VirtualRegister operand = variable->local();
122
123            if (i)
124                out.print(" ");
125
126            if (operand.isArgument())
127                out.print("arg", operand.toArgument(), "(", VariableAccessDataDump(*graph, variable), ")");
128            else
129                out.print("r", operand.toLocal(), "(", VariableAccessDataDump(*graph, variable), ")");
130        }
131        out.print("\n");
132    }
133
134private:
135    SpeculatedType m_prediction;
136    DoubleFormatState m_doubleFormatState;
137    bool m_isProfitableToUnbox;
138    bool m_shouldNeverUnbox;
139
140    Vector<VariableAccessData*, 2> m_variables;
141};
142
143} } // namespace JSC::DFG
144
145#endif // DFGArgumentPosition_h
146
147