ftl/FTLWeightedTarget.h

   1 /*
   2  * Copyright (C) 2014 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
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   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
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  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef FTLWeightedTarget_h
  27 #define FTLWeightedTarget_h
  28
  29 #if ENABLE(FTL_JIT)
  30
  31 #include "FTLAbbreviatedTypes.h"
  32 #include "FTLWeight.h"
  33
  34 namespace JSC { namespace FTL {
  35
  36 class WeightedTarget {
  37 public:
  38     WeightedTarget()
  39         : m_target(nullptr)
  40     {
  41     }
  42
  43     WeightedTarget(LBasicBlock target, Weight weight)
  44         : m_target(target)
  45         , m_weight(weight)
  46     {
  47     }
  48
  49     WeightedTarget(LBasicBlock target, float weight)
  50         : m_target(target)
  51         , m_weight(weight)
  52     {
  53     }
  54
  55     LBasicBlock target() const { return m_target; }
  56     Weight weight() const { return m_weight; }
  57
  58 private:
  59     LBasicBlock m_target;
  60     Weight m_weight;
  61 };
  62
  63 // Helpers for creating weighted targets for statically known (or unknown) branch
  64 // profiles.
  65
  66 inline WeightedTarget usually(LBasicBlock block)
  67 {
  68     return WeightedTarget(block, 1);
  69 }
  70
  71 inline WeightedTarget rarely(LBasicBlock block)
  72 {
  73     return WeightedTarget(block, 0);
  74 }
  75
  76 // This means we let LLVM figure it out basic on its static estimates. LLVM's static
  77 // estimates are usually pretty darn good, so there's generally nothing wrong with
  78 // using this.
  79 inline WeightedTarget unsure(LBasicBlock block)
  80 {
  81     return WeightedTarget(block, Weight());
  82 }
  83
  84 } } // namespace JSC::FTL
  85
  86 #endif // ENABLE(FTL_JIT)
  87
  88 #endif // FTLWeightedTarget_h
  89