1/*
2 * Copyright (C) 2011 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#include <wtf/Platform.h>
30
31#if ENABLE(DFG_JIT)
32
33#include "CodeOrigin.h"
34#include "DFGCommon.h"
35#include "DFGExitProfile.h"
36#include "DFGGPRInfo.h"
37#include "DFGValueRecoveryOverride.h"
38#include "MacroAssembler.h"
39#include "MethodOfGettingAValueProfile.h"
40#include "Operands.h"
41#include "ValueProfile.h"
42#include "ValueRecovery.h"
43#include <wtf/Vector.h>
44
45namespace JSC { namespace DFG {
46
47class SpeculativeJIT;
48
49// This enum describes the types of additional recovery that
50// may need be performed should a speculation check fail.
51enum SpeculationRecoveryType {
52    SpeculativeAdd,
53    BooleanSpeculationCheck
54};
55
56// === SpeculationRecovery ===
57//
58// This class provides additional information that may be associated with a
59// speculation check - for example
60class SpeculationRecovery {
61public:
62    SpeculationRecovery(SpeculationRecoveryType type, GPRReg dest, GPRReg src)
63        : m_type(type)
64        , m_dest(dest)
65        , m_src(src)
66    {
67    }
68
69    SpeculationRecoveryType type() { return m_type; }
70    GPRReg dest() { return m_dest; }
71    GPRReg src() { return m_src; }
72
73private:
74    // Indicates the type of additional recovery to be performed.
75    SpeculationRecoveryType m_type;
76    // different recovery types may required different additional information here.
77    GPRReg m_dest;
78    GPRReg m_src;
79};
80
81// === OSRExit ===
82//
83// This structure describes how to exit the speculative path by
84// going into baseline code.
85struct OSRExit {
86    OSRExit(ExitKind, JSValueSource, MethodOfGettingAValueProfile, SpeculativeJIT*, unsigned streamIndex, unsigned recoveryIndex = 0);
87
88    MacroAssemblerCodeRef m_code;
89
90    JSValueSource m_jsValueSource;
91    MethodOfGettingAValueProfile m_valueProfile;
92
93    unsigned m_patchableCodeOffset;
94    CodeOrigin m_codeOrigin;
95    CodeOrigin m_codeOriginForExitProfile;
96
97    unsigned m_recoveryIndex;
98    unsigned m_watchpointIndex;
99
100    ExitKind m_kind;
101    uint32_t m_count;
102
103    bool considerAddingAsFrequentExitSite(CodeBlock* profiledCodeBlock)
104    {
105        if (!m_count || !exitKindIsCountable(m_kind))
106            return false;
107        return considerAddingAsFrequentExitSiteSlow(profiledCodeBlock);
108    }
109
110    void setPatchableCodeOffset(MacroAssembler::PatchableJump);
111    MacroAssembler::Jump getPatchableCodeOffsetAsJump() const;
112    CodeLocationJump codeLocationForRepatch(CodeBlock*) const;
113    void correctJump(LinkBuffer&);
114
115    unsigned m_streamIndex;
116    int m_lastSetOperand;
117
118    RefPtr<ValueRecoveryOverride> m_valueRecoveryOverride;
119
120private:
121    bool considerAddingAsFrequentExitSiteSlow(CodeBlock* profiledCodeBlock);
122};
123
124struct SpeculationFailureDebugInfo {
125    CodeBlock* codeBlock;
126};
127
128} } // namespace JSC::DFG
129
130#endif // ENABLE(DFG_JIT)
131
132#endif // DFGOSRExit_h
133
134