ftl/FTLForOSREntryJITCode.h

   1 /*
   2  * Copyright (C) 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 FTLForOSREntryJITCode_h
  27 #define FTLForOSREntryJITCode_h
  28
  29 #if ENABLE(FTL_JIT)
  30
  31 #include "FTLJITCode.h"
  32
  33 namespace JSC { namespace FTL {
  34
  35 // OSR entry into the FTL has a number of quirks:
  36 //
  37 // - OSR entry only happens through special OSR entry compilations. They have their
  38 //   own CodeBlock and their own JITCode.
  39 //
  40 // - We only OSR enter in loop headers that have a null inline call frame.
  41 //
  42 // - Each OSR entry compilation allows entry through only one bytecode index.
  43
  44 class ForOSREntryJITCode : public FTL::JITCode {
  45 public:
  46     ForOSREntryJITCode();
  47     ~ForOSREntryJITCode();
  48
  49     void initializeEntryBuffer(VM&, unsigned numCalleeRegisters);
  50     ScratchBuffer* entryBuffer() const { return m_entryBuffer; }
  51
  52     void setBytecodeIndex(unsigned value) { m_bytecodeIndex = value; }
  53     unsigned bytecodeIndex() const { return m_bytecodeIndex; }
  54
  55     void countEntryFailure() { m_entryFailureCount++; }
  56     unsigned entryFailureCount() const { return m_entryFailureCount; }
  57
  58     ForOSREntryJITCode* ftlForOSREntry();
  59
  60 private:
  61     ScratchBuffer* m_entryBuffer; // Only for OSR entry code blocks.
  62     unsigned m_bytecodeIndex;
  63     unsigned m_entryFailureCount;
  64 };
  65
  66 } } // namespace JSC::FTL
  67
  68 #endif // ENABLE(FLT_JIT)
  69
  70 #endif // FTLForOSREntryJITCode_h
  71