bytecode/BytecodeBasicBlock.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 BytecodeBasicBlock_h
  27 #define BytecodeBasicBlock_h
  28
  29 #include <limits.h>
  30 #include <wtf/FastBitVector.h>
  31 #include <wtf/HashMap.h>
  32 #include <wtf/RefCounted.h>
  33 #include <wtf/Vector.h>
  34
  35 namespace JSC {
  36
  37 class CodeBlock;
  38
  39 class BytecodeBasicBlock : public RefCounted<BytecodeBasicBlock> {
  40 public:
  41     enum SpecialBlockType { EntryBlock, ExitBlock };
  42     BytecodeBasicBlock(unsigned start, unsigned length);
  43     BytecodeBasicBlock(SpecialBlockType);
  44
  45     bool isEntryBlock() { return !m_leaderBytecodeOffset && !m_totalBytecodeLength; }
  46     bool isExitBlock() { return m_leaderBytecodeOffset == UINT_MAX && m_totalBytecodeLength == UINT_MAX; }
  47
  48     unsigned leaderBytecodeOffset() { return m_leaderBytecodeOffset; }
  49     unsigned totalBytecodeLength() { return m_totalBytecodeLength; }
  50
  51     Vector<unsigned>& bytecodeOffsets() { return m_bytecodeOffsets; }
  52     void addBytecodeLength(unsigned);
  53
  54     void addPredecessor(BytecodeBasicBlock* block) { m_predecessors.append(block); }
  55     void addSuccessor(BytecodeBasicBlock* block) { m_successors.append(block); }
  56
  57     Vector<BytecodeBasicBlock*>& predecessors() { return m_predecessors; }
  58     Vector<BytecodeBasicBlock*>& successors() { return m_successors; }
  59
  60     FastBitVector& in() { return m_in; }
  61     FastBitVector& out() { return m_out; }
  62
  63 private:
  64     unsigned m_leaderBytecodeOffset;
  65     unsigned m_totalBytecodeLength;
  66
  67     Vector<unsigned> m_bytecodeOffsets;
  68
  69     Vector<BytecodeBasicBlock*> m_predecessors;
  70     Vector<BytecodeBasicBlock*> m_successors;
  71
  72     FastBitVector m_in;
  73     FastBitVector m_out;
  74 };
  75
  76 void computeBytecodeBasicBlocks(CodeBlock*, Vector<RefPtr<BytecodeBasicBlock> >&);
  77
  78 inline BytecodeBasicBlock::BytecodeBasicBlock(unsigned start, unsigned length)
  79     : m_leaderBytecodeOffset(start)
  80     , m_totalBytecodeLength(length)
  81 {
  82     m_bytecodeOffsets.append(m_leaderBytecodeOffset);
  83 }
  84
  85 inline BytecodeBasicBlock::BytecodeBasicBlock(BytecodeBasicBlock::SpecialBlockType blockType)
  86     : m_leaderBytecodeOffset(blockType == BytecodeBasicBlock::EntryBlock ? 0 : UINT_MAX)
  87     , m_totalBytecodeLength(blockType == BytecodeBasicBlock::EntryBlock ? 0 : UINT_MAX)
  88 {
  89 }
  90
  91 inline void BytecodeBasicBlock::addBytecodeLength(unsigned bytecodeLength)
  92 {
  93     m_bytecodeOffsets.append(m_leaderBytecodeOffset + m_totalBytecodeLength);
  94     m_totalBytecodeLength += bytecodeLength;
  95 }
  96
  97 } // namespace JSC
  98
  99 #endif // BytecodeBasicBlock_h