1/*
2 * Copyright (C) 2011, 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 DFGOSRExit_h
27#define DFGOSRExit_h
28
29#if ENABLE(DFG_JIT)
30
31#include "CodeOrigin.h"
32#include "DFGCommon.h"
33#include "DFGExitProfile.h"
34#include "DFGOSRExitBase.h"
35#include "DFGValueRecoveryOverride.h"
36#include "GPRInfo.h"
37#include "MacroAssembler.h"
38#include "MethodOfGettingAValueProfile.h"
39#include "Operands.h"
40#include "ValueProfile.h"
41#include "ValueRecovery.h"
42#include <wtf/Vector.h>
43
44namespace JSC { namespace DFG {
45
46class SpeculativeJIT;
47struct BasicBlock;
48struct Node;
49
50// This enum describes the types of additional recovery that
51// may need be performed should a speculation check fail.
52enum SpeculationRecoveryType {
53    SpeculativeAdd,
54    BooleanSpeculationCheck
55};
56
57// === SpeculationRecovery ===
58//
59// This class provides additional information that may be associated with a
60// speculation check - for example
61class SpeculationRecovery {
62public:
63    SpeculationRecovery(SpeculationRecoveryType type, GPRReg dest, GPRReg src)
64        : m_type(type)
65        , m_dest(dest)
66        , m_src(src)
67    {
68    }
69
70    SpeculationRecoveryType type() { return m_type; }
71    GPRReg dest() { return m_dest; }
72    GPRReg src() { return m_src; }
73
74private:
75    // Indicates the type of additional recovery to be performed.
76    SpeculationRecoveryType m_type;
77    // different recovery types may required different additional information here.
78    GPRReg m_dest;
79    GPRReg m_src;
80};
81
82// === OSRExit ===
83//
84// This structure describes how to exit the speculative path by
85// going into baseline code.
86struct OSRExit : public OSRExitBase {
87    OSRExit(ExitKind, JSValueSource, MethodOfGettingAValueProfile, SpeculativeJIT*, unsigned streamIndex, unsigned recoveryIndex = UINT_MAX);
88
89    MacroAssemblerCodeRef m_code;
90
91    JSValueSource m_jsValueSource;
92    MethodOfGettingAValueProfile m_valueProfile;
93
94    unsigned m_patchableCodeOffset;
95
96    unsigned m_recoveryIndex;
97
98    void setPatchableCodeOffset(MacroAssembler::PatchableJump);
99    MacroAssembler::Jump getPatchableCodeOffsetAsJump() const;
100    CodeLocationJump codeLocationForRepatch(CodeBlock*) const;
101    void correctJump(LinkBuffer&);
102
103    unsigned m_streamIndex;
104
105    RefPtr<ValueRecoveryOverride> m_valueRecoveryOverride;
106
107    bool considerAddingAsFrequentExitSite(CodeBlock* profiledCodeBlock)
108    {
109        return OSRExitBase::considerAddingAsFrequentExitSite(profiledCodeBlock, ExitFromDFG);
110    }
111};
112
113struct SpeculationFailureDebugInfo {
114    CodeBlock* codeBlock;
115    ExitKind kind;
116    unsigned bytecodeOffset;
117};
118
119} } // namespace JSC::DFG
120
121#endif // ENABLE(DFG_JIT)
122
123#endif // DFGOSRExit_h
124
125