ftl/FTLLoweredNodeValue.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 FTLLoweredNodeValue_h
  27 #define FTLLoweredNodeValue_h
  28
  29 #if ENABLE(FTL_JIT)
  30
  31 #include "DFGBasicBlock.h"
  32 #include "FTLAbbreviatedTypes.h"
  33
  34 namespace JSC { namespace FTL {
  35
  36 // Represents the act of having lowered a DFG::Node to an LValue, and records the
  37 // DFG::BasicBlock that did the lowering. The LValue is what we use most often, but
  38 // we need to verify that we're in a block that is dominated by the one that did
  39 // the lowering. We're guaranteed that for each DFG::Node, there will be one
  40 // LoweredNodeValue that always dominates all uses of the DFG::Node; but there may
  41 // be others that don't dominate and we're effectively doing opportunistic GVN on
  42 // the lowering code.
  43
  44 class LoweredNodeValue {
  45 public:
  46     LoweredNodeValue()
  47         : m_value(0)
  48         , m_block(0)
  49     {
  50     }
  51
  52     LoweredNodeValue(LValue value, DFG::BasicBlock* block)
  53         : m_value(value)
  54         , m_block(block)
  55     {
  56         ASSERT(m_value);
  57         ASSERT(m_block);
  58     }
  59
  60     bool isSet() const { return !!m_value; }
  61     bool operator!() const { return !isSet(); }
  62
  63     LValue value() const { return m_value; }
  64     DFG::BasicBlock* block() const { return m_block; }
  65
  66 private:
  67     LValue m_value;
  68     DFG::BasicBlock* m_block;
  69 };
  70
  71 } } // namespace JSC::FTL
  72
  73 #endif // ENABLE(FTL_JIT)
  74
  75 #endif // FTLLoweredNodeValue_h
  76