dfg/DFGArgumentPosition.h

   1 /*
   2  * Copyright (C) 2012 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 DFGArgumentPosition_h
  27 #define DFGArgumentPosition_h
  28
  29 #include "DFGDoubleFormatState.h"
  30 #include "DFGVariableAccessData.h"
  31 #include "PredictedType.h"
  32
  33 namespace JSC { namespace DFG {
  34
  35 class ArgumentPosition {
  36 public:
  37     ArgumentPosition()
  38         : m_prediction(PredictNone)
  39         , m_doubleFormatState(EmptyDoubleFormatState)
  40     {
  41     }
  42
  43     void addVariable(VariableAccessData* variable)
  44     {
  45         m_variables.append(variable);
  46     }
  47
  48     bool mergeArgumentAwareness()
  49     {
  50         bool changed = false;
  51         for (unsigned i = 0; i < m_variables.size(); ++i) {
  52             changed |= mergePrediction(m_prediction, m_variables[i]->argumentAwarePrediction());
  53             changed |= mergeDoubleFormatState(m_doubleFormatState, m_variables[i]->doubleFormatState());
  54         }
  55         if (!changed)
  56             return false;
  57         changed = false;
  58         for (unsigned i = 0; i < m_variables.size(); ++i) {
  59             changed |= m_variables[i]->mergeArgumentAwarePrediction(m_prediction);
  60             changed |= m_variables[i]->mergeDoubleFormatState(m_doubleFormatState);
  61         }
  62         return changed;
  63     }
  64
  65 private:
  66     PredictedType m_prediction;
  67     DoubleFormatState m_doubleFormatState;
  68
  69     Vector<VariableAccessData*, 2> m_variables;
  70 };
  71
  72 } } // namespace JSC::DFG
  73
  74 #endif // DFGArgumentPosition_h
  75