kc3-lang/angle/src/third_party/compiler/ArrayBoundsClamper.cpp

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• Author : Olli Etuaho
  Date : 2015-06-01 12:16:36
  Hash : 3d0d9a48
  Message : Clean up TIntermTraverser usage Remove default parameters from TIntermTraverser. Also clean up a few dead function declarations in traversers. TEST=angle_unittests, angle_end2end_tests BUG=angleproject:1037 Change-Id: I8d126c6c2d5b53e8b14e23e3d102f204a59323b3 Reviewed-on: https://chromium-review.googlesource.com/275184 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org> Tested-by: Olli Etuaho <oetuaho@nvidia.com>

• src/third_party/compiler/ArrayBoundsClamper.cpp

• /*
   * Copyright (C) 2012 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE, INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE, INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "third_party/compiler/ArrayBoundsClamper.h"
  
  // The built-in 'clamp' instruction only accepts floats and returns a float.  I
  // iterated a few times with our driver team who examined the output from our
  // compiler - they said the multiple casts generates more code than a single
  // function call.  An inline ternary operator might have been better, but since
  // the index value might be an expression itself, we'd have to make temporary
  // variables to avoid evaluating the expression multiple times.  And making
  // temporary variables was difficult because ANGLE would then need to make more
  // brutal changes to the expression tree.
  
  const char* kIntClampBegin = "// BEGIN: Generated code for array bounds clamping\n\n";
  const char* kIntClampEnd = "// END: Generated code for array bounds clamping\n\n";
  const char* kIntClampDefinition = "int webgl_int_clamp(int value, int minValue, int maxValue) { return ((value < minValue) ? minValue : ((value > maxValue) ? maxValue : value)); }\n\n";
  
  namespace {
  
  class ArrayBoundsClamperMarker : public TIntermTraverser {
  public:
      ArrayBoundsClamperMarker()
          : TIntermTraverser(true, false, false),
            mNeedsClamp(false)
     {
     }
  
     virtual bool visitBinary(Visit visit, TIntermBinary* node)
     {
         if (node->getOp() == EOpIndexIndirect)
         {
             TIntermTyped* left = node->getLeft();
             if (left->isArray() || left->isVector() || left->isMatrix())
             {
                 node->setAddIndexClamp();
                 mNeedsClamp = true;
             }
         }
         return true;
     }
  
      bool GetNeedsClamp() { return mNeedsClamp; }
  
  private:
      bool mNeedsClamp;
  };
  
  }  // anonymous namespace
  
  ArrayBoundsClamper::ArrayBoundsClamper()
      : mClampingStrategy(SH_CLAMP_WITH_CLAMP_INTRINSIC)
      , mArrayBoundsClampDefinitionNeeded(false)
  {
  }
  
  void ArrayBoundsClamper::SetClampingStrategy(ShArrayIndexClampingStrategy clampingStrategy)
  {
      mClampingStrategy = clampingStrategy;
  }
  
  void ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping(TIntermNode* root)
  {
      ASSERT(root);
  
      ArrayBoundsClamperMarker clamper;
      root->traverse(&clamper);
      if (clamper.GetNeedsClamp())
      {
          SetArrayBoundsClampDefinitionNeeded();
      }
  }
  
  void ArrayBoundsClamper::OutputClampingFunctionDefinition(TInfoSinkBase& out) const
  {
      if (!mArrayBoundsClampDefinitionNeeded)
      {
          return;
      }
      if (mClampingStrategy != SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION)
      {
          return;
      }
      out << kIntClampBegin << kIntClampDefinition << kIntClampEnd;
  }