bytecode/BytecodeLivenessAnalysis.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 BytecodeLivenessAnalysis_h
  27 #define BytecodeLivenessAnalysis_h
  28
  29 #include "BytecodeBasicBlock.h"
  30 #include <wtf/FastBitVector.h>
  31 #include <wtf/HashMap.h>
  32 #include <wtf/Vector.h>
  33
  34 namespace JSC {
  35
  36 class CodeBlock;
  37 class FullBytecodeLiveness;
  38
  39 class BytecodeLivenessAnalysis {
  40 public:
  41     BytecodeLivenessAnalysis(CodeBlock*);
  42
  43     bool operandIsLiveAtBytecodeOffset(int operand, unsigned bytecodeOffset);
  44     FastBitVector getLivenessInfoAtBytecodeOffset(unsigned bytecodeOffset);
  45
  46     void computeFullLiveness(FullBytecodeLiveness& result);
  47
  48 private:
  49     void compute();
  50     void runLivenessFixpoint();
  51     void dumpResults();
  52
  53     void getLivenessInfoForNonCapturedVarsAtBytecodeOffset(unsigned bytecodeOffset, FastBitVector&);
  54
  55     CodeBlock* m_codeBlock;
  56     Vector<RefPtr<BytecodeBasicBlock> > m_basicBlocks;
  57 };
  58
  59 inline bool operandIsAlwaysLive(CodeBlock*, int operand);
  60 inline bool operandThatIsNotAlwaysLiveIsLive(CodeBlock*, const FastBitVector& out, int operand);
  61 inline bool operandIsLive(CodeBlock*, const FastBitVector& out, int operand);
  62
  63 FastBitVector getLivenessInfo(CodeBlock*, const FastBitVector& out);
  64
  65 } // namespace JSC
  66
  67 #endif // BytecodeLivenessAnalysis_h