The Tor Browser: gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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  */

    26 #include "third_party/compiler/ArrayBoundsClamper.h"

    28 // The built-in 'clamp' instruction only accepts floats and returns a float.  I

    29 // iterated a few times with our driver team who examined the output from our

    30 // compiler - they said the multiple casts generates more code than a single

    31 // function call.  An inline ternary operator might have been better, but since

    32 // the index value might be an expression itself, we'd have to make temporary

    33 // variables to avoid evaluating the expression multiple times.  And making

    34 // temporary variables was difficult because ANGLE would then need to make more

    35 // brutal changes to the expression tree.

    37 const char* kIntClampBegin = "// BEGIN: Generated code for array bounds clamping\n\n";

    38 const char* kIntClampEnd = "// END: Generated code for array bounds clamping\n\n";

    39 const char* kIntClampDefinition = "int webgl_int_clamp(int value, int minValue, int maxValue) { return ((value < minValue) ? minValue : ((value > maxValue) ? maxValue : value)); }\n\n";

    41 namespace {

    43 class ArrayBoundsClamperMarker : public TIntermTraverser {

    44 public:

    45     ArrayBoundsClamperMarker()

    46         : mNeedsClamp(false)

    47    {

    48    }

    50    virtual bool visitBinary(Visit visit, TIntermBinary* node)

    51    {

    52        if (node->getOp() == EOpIndexIndirect)

    53        {

    54            TIntermTyped* left = node->getLeft();

    55            if (left->isArray() || left->isVector() || left->isMatrix())

    56            {

    57                node->setAddIndexClamp();

    58                mNeedsClamp = true;

    59            }

    60        }

    61        return true;

    62    }

    64     bool GetNeedsClamp() { return mNeedsClamp; }

    66 private:

    67     bool mNeedsClamp;

    68 };

    70 }  // anonymous namespace

    72 ArrayBoundsClamper::ArrayBoundsClamper()

    73     : mClampingStrategy(SH_CLAMP_WITH_CLAMP_INTRINSIC)

    74     , mArrayBoundsClampDefinitionNeeded(false)

    75 {

    76 }

    78 void ArrayBoundsClamper::SetClampingStrategy(ShArrayIndexClampingStrategy clampingStrategy)

    79 {

    80     ASSERT(clampingStrategy == SH_CLAMP_WITH_CLAMP_INTRINSIC ||

    81            clampingStrategy == SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION);

    83     mClampingStrategy = clampingStrategy;

    84 }

    86 void ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping(TIntermNode* root)

    87 {

    88     ASSERT(root);

    90     ArrayBoundsClamperMarker clamper;

    91     root->traverse(&clamper);

    92     if (clamper.GetNeedsClamp())

    93     {

    94         SetArrayBoundsClampDefinitionNeeded();

    95     }

    96 }

    98 void ArrayBoundsClamper::OutputClampingFunctionDefinition(TInfoSinkBase& out) const

    99 {

   100     if (!mArrayBoundsClampDefinitionNeeded)

   101     {

   102         return;

   103     }

   104     if (mClampingStrategy != SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION)

   105     {

   106         return;

   107     }

   108     out << kIntClampBegin << kIntClampDefinition << kIntClampEnd;

   109 }

The Tor Browser / file revision

gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp@6474c204b198

gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp