The Tor Browser / file comparison
comparison: gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp
gfx/angle/src/third_party/compiler/ArrayBoundsClamper.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:c6f496634a62 |
|---|---|
| 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 */ | |
| 25 | |
| 26 #include "third_party/compiler/ArrayBoundsClamper.h" | |
| 27 | |
| 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. | |
| 36 | |
| 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"; | |
| 40 | |
| 41 namespace { | |
| 42 | |
| 43 class ArrayBoundsClamperMarker : public TIntermTraverser { | |
| 44 public: | |
| 45 ArrayBoundsClamperMarker() | |
| 46 : mNeedsClamp(false) | |
| 47 { | |
| 48 } | |
| 49 | |
| 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 } | |
| 63 | |
| 64 bool GetNeedsClamp() { return mNeedsClamp; } | |
| 65 | |
| 66 private: | |
| 67 bool mNeedsClamp; | |
| 68 }; | |
| 69 | |
| 70 } // anonymous namespace | |
| 71 | |
| 72 ArrayBoundsClamper::ArrayBoundsClamper() | |
| 73 : mClampingStrategy(SH_CLAMP_WITH_CLAMP_INTRINSIC) | |
| 74 , mArrayBoundsClampDefinitionNeeded(false) | |
| 75 { | |
| 76 } | |
| 77 | |
| 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); | |
| 82 | |
| 83 mClampingStrategy = clampingStrategy; | |
| 84 } | |
| 85 | |
| 86 void ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping(TIntermNode* root) | |
| 87 { | |
| 88 ASSERT(root); | |
| 89 | |
| 90 ArrayBoundsClamperMarker clamper; | |
| 91 root->traverse(&clamper); | |
| 92 if (clamper.GetNeedsClamp()) | |
| 93 { | |
| 94 SetArrayBoundsClampDefinitionNeeded(); | |
| 95 } | |
| 96 } | |
| 97 | |
| 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 } |
