The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,109 @@
     1.4 +/*
     1.5 + * Copyright (C) 2012 Apple Inc. All rights reserved.
     1.6 + *
     1.7 + * Redistribution and use in source and binary forms, with or without
     1.8 + * modification, are permitted provided that the following conditions
     1.9 + * are met:
    1.10 + * 1. Redistributions of source code must retain the above copyright
    1.11 + *    notice, this list of conditions and the following disclaimer.
    1.12 + * 2. Redistributions in binary form must reproduce the above copyright
    1.13 + *    notice, this list of conditions and the following disclaimer in the
    1.14 + *    documentation and/or other materials provided with the distribution.
    1.15 + *
    1.16 + * THIS SOFTWARE IS PROVIDED BY APPLE, INC. ``AS IS'' AND ANY
    1.17 + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    1.18 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    1.19 + * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE, INC. OR
    1.20 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    1.21 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    1.22 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    1.23 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
    1.24 + * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    1.25 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    1.26 + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    1.27 + */
    1.28 +
    1.29 +#include "third_party/compiler/ArrayBoundsClamper.h"
    1.30 +
    1.31 +// The built-in 'clamp' instruction only accepts floats and returns a float.  I
    1.32 +// iterated a few times with our driver team who examined the output from our
    1.33 +// compiler - they said the multiple casts generates more code than a single
    1.34 +// function call.  An inline ternary operator might have been better, but since
    1.35 +// the index value might be an expression itself, we'd have to make temporary
    1.36 +// variables to avoid evaluating the expression multiple times.  And making
    1.37 +// temporary variables was difficult because ANGLE would then need to make more
    1.38 +// brutal changes to the expression tree.
    1.39 +
    1.40 +const char* kIntClampBegin = "// BEGIN: Generated code for array bounds clamping\n\n";
    1.41 +const char* kIntClampEnd = "// END: Generated code for array bounds clamping\n\n";
    1.42 +const char* kIntClampDefinition = "int webgl_int_clamp(int value, int minValue, int maxValue) { return ((value < minValue) ? minValue : ((value > maxValue) ? maxValue : value)); }\n\n";
    1.43 +
    1.44 +namespace {
    1.45 +
    1.46 +class ArrayBoundsClamperMarker : public TIntermTraverser {
    1.47 +public:
    1.48 +    ArrayBoundsClamperMarker()
    1.49 +        : mNeedsClamp(false)
    1.50 +   {
    1.51 +   }
    1.52 +
    1.53 +   virtual bool visitBinary(Visit visit, TIntermBinary* node)
    1.54 +   {
    1.55 +       if (node->getOp() == EOpIndexIndirect)
    1.56 +       {
    1.57 +           TIntermTyped* left = node->getLeft();
    1.58 +           if (left->isArray() || left->isVector() || left->isMatrix())
    1.59 +           {
    1.60 +               node->setAddIndexClamp();
    1.61 +               mNeedsClamp = true;
    1.62 +           }
    1.63 +       }
    1.64 +       return true;
    1.65 +   }
    1.66 +
    1.67 +    bool GetNeedsClamp() { return mNeedsClamp; }
    1.68 +
    1.69 +private:
    1.70 +    bool mNeedsClamp;
    1.71 +};
    1.72 +
    1.73 +}  // anonymous namespace
    1.74 +
    1.75 +ArrayBoundsClamper::ArrayBoundsClamper()
    1.76 +    : mClampingStrategy(SH_CLAMP_WITH_CLAMP_INTRINSIC)
    1.77 +    , mArrayBoundsClampDefinitionNeeded(false)
    1.78 +{
    1.79 +}
    1.80 +
    1.81 +void ArrayBoundsClamper::SetClampingStrategy(ShArrayIndexClampingStrategy clampingStrategy)
    1.82 +{
    1.83 +    ASSERT(clampingStrategy == SH_CLAMP_WITH_CLAMP_INTRINSIC ||
    1.84 +           clampingStrategy == SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION);
    1.85 +
    1.86 +    mClampingStrategy = clampingStrategy;
    1.87 +}
    1.88 +
    1.89 +void ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping(TIntermNode* root)
    1.90 +{
    1.91 +    ASSERT(root);
    1.92 +
    1.93 +    ArrayBoundsClamperMarker clamper;
    1.94 +    root->traverse(&clamper);
    1.95 +    if (clamper.GetNeedsClamp())
    1.96 +    {
    1.97 +        SetArrayBoundsClampDefinitionNeeded();
    1.98 +    }
    1.99 +}
   1.100 +
   1.101 +void ArrayBoundsClamper::OutputClampingFunctionDefinition(TInfoSinkBase& out) const
   1.102 +{
   1.103 +    if (!mArrayBoundsClampDefinitionNeeded)
   1.104 +    {
   1.105 +        return;
   1.106 +    }
   1.107 +    if (mClampingStrategy != SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION)
   1.108 +    {
   1.109 +        return;
   1.110 +    }
   1.111 +    out << kIntClampBegin << kIntClampDefinition << kIntClampEnd;
   1.112 +}