bytecode/FullBytecodeLiveness.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. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef FullBytecodeLiveness_h
  27 #define FullBytecodeLiveness_h
  28
  29 #include <wtf/FastBitVector.h>
  30
  31 namespace JSC {
  32
  33 class BytecodeLivenessAnalysis;
  34
  35 typedef HashMap<unsigned, FastBitVector, WTF::IntHash<unsigned>, WTF::UnsignedWithZeroKeyHashTraits<unsigned>> BytecodeToBitmapMap;
  36
  37 class FullBytecodeLiveness {
  38 public:
  39     FullBytecodeLiveness() : m_codeBlock(0) { }
  40
  41     // We say "out" to refer to the bitvector that contains raw results for a bytecode
  42     // instruction.
  43     const FastBitVector& getOut(unsigned bytecodeIndex) const
  44     {
  45         BytecodeToBitmapMap::const_iterator iter = m_map.find(bytecodeIndex);
  46         ASSERT(iter != m_map.end());
  47         return iter->value;
  48     }
  49
  50     bool operandIsLive(int operand, unsigned bytecodeIndex) const
  51     {
  52         return operandIsAlwaysLive(m_codeBlock, operand) || operandThatIsNotAlwaysLiveIsLive(m_codeBlock, getOut(bytecodeIndex), operand);
  53     }
  54
  55     FastBitVector getLiveness(unsigned bytecodeIndex) const
  56     {
  57         return getLivenessInfo(m_codeBlock, getOut(bytecodeIndex));
  58     }
  59
  60 private:
  61     friend class BytecodeLivenessAnalysis;
  62
  63     CodeBlock* m_codeBlock;
  64     BytecodeToBitmapMap m_map;
  65 };
  66
  67 } // namespace JSC
  68
  69 #endif // FullBytecodeLiveness_h
  70