dfg/DFGOSRExit.h

   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 "GPRInfo.h"
  36 #include "MacroAssembler.h"
  37 #include "MethodOfGettingAValueProfile.h"
  38 #include "Operands.h"
  39 #include "ValueProfile.h"
  40 #include "ValueRecovery.h"
  41 #include <wtf/Vector.h>
  42
  43 namespace JSC { namespace DFG {
  44
  45 class SpeculativeJIT;
  46 struct BasicBlock;
  47 struct Node;
  48
  49 // This enum describes the types of additional recovery that
  50 // may need be performed should a speculation check fail.
  51 enum 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
  60 class SpeculationRecovery {
  61 public:
  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
  73 private:
  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.
  85 struct OSRExit : public OSRExitBase {
  86     OSRExit(ExitKind, JSValueSource, MethodOfGettingAValueProfile, SpeculativeJIT*, unsigned streamIndex, unsigned recoveryIndex = UINT_MAX);
  87
  88     MacroAssemblerCodeRef m_code;
  89
  90     JSValueSource m_jsValueSource;
  91     MethodOfGettingAValueProfile m_valueProfile;
  92
  93     unsigned m_patchableCodeOffset;
  94
  95     unsigned m_recoveryIndex;
  96
  97     void setPatchableCodeOffset(MacroAssembler::PatchableJump);
  98     MacroAssembler::Jump getPatchableCodeOffsetAsJump() const;
  99     CodeLocationJump codeLocationForRepatch(CodeBlock*) const;
 100     void correctJump(LinkBuffer&);
 101
 102     unsigned m_streamIndex;
 103
 104     void considerAddingAsFrequentExitSite(CodeBlock* profiledCodeBlock)
 105     {
 106         OSRExitBase::considerAddingAsFrequentExitSite(profiledCodeBlock, ExitFromDFG);
 107     }
 108 };
 109
 110 struct SpeculationFailureDebugInfo {
 111     CodeBlock* codeBlock;
 112     ExitKind kind;
 113     unsigned bytecodeOffset;
 114 };
 115
 116 } } // namespace JSC::DFG
 117
 118 #endif // ENABLE(DFG_JIT)
 119
 120 #endif // DFGOSRExit_h
 121