dfg/DFGOSREntry.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 DFGOSREntry_h
  27 #define DFGOSREntry_h
  28
  29 #include "DFGAbstractValue.h"
  30 #include "Operands.h"
  31 #include <wtf/BitVector.h>
  32
  33 namespace JSC {
  34
  35 class ExecState;
  36 class CodeBlock;
  37
  38 namespace DFG {
  39
  40 #if ENABLE(DFG_JIT)
  41 struct OSREntryReshuffling {
  42     OSREntryReshuffling() { }
  43
  44     OSREntryReshuffling(int fromOffset, int toOffset)
  45         : fromOffset(fromOffset)
  46         , toOffset(toOffset)
  47     {
  48     }
  49
  50     int fromOffset;
  51     int toOffset;
  52 };
  53
  54 struct OSREntryData {
  55     unsigned m_bytecodeIndex;
  56     unsigned m_machineCodeOffset;
  57     Operands<AbstractValue> m_expectedValues;
  58     // Use bitvectors here because they tend to only require one word.
  59     BitVector m_localsForcedDouble;
  60     BitVector m_localsForcedMachineInt;
  61     Vector<OSREntryReshuffling> m_reshufflings;
  62     BitVector m_machineStackUsed;
  63 };
  64
  65 inline unsigned getOSREntryDataBytecodeIndex(OSREntryData* osrEntryData)
  66 {
  67     return osrEntryData->m_bytecodeIndex;
  68 }
  69
  70 // Returns a pointer to a data buffer that the OSR entry thunk will recognize and
  71 // parse. If this returns null, it means
  72 void* prepareOSREntry(ExecState*, CodeBlock*, unsigned bytecodeIndex);
  73 #else
  74 inline void* prepareOSREntry(ExecState*, CodeBlock*, unsigned) { return 0; }
  75 #endif
  76
  77 } } // namespace JSC::DFG
  78
  79 #endif // DFGOSREntry_h
  80