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author | Tobias Hunger <tobias.hunger@qt.io> | 2019-04-16 16:32:08 +0200 |
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committer | Tobias Hunger <tobias.hunger@qt.io> | 2019-04-16 16:32:08 +0200 |
commit | 6630937e63ae5797487b86743a7733c8ae5cc42c (patch) | |
tree | 3d53dacf6430f9099e1fb20835881205de674961 /src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp | |
parent | 37ed6dae00640f9cc980ffda05347c12a7eb5d7e (diff) | |
parent | c7af193d2e49e9f10b86262e63d8d13abf72b5cf (diff) |
Merge commit 'dev' into 'wip/cmake-merge'
Change-Id: I176c40d031be26a1dd1cf08843e448a660598783
Diffstat (limited to 'src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp')
-rw-r--r-- | src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp b/src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp new file mode 100644 index 0000000000..f17dd73657 --- /dev/null +++ b/src/3rdparty/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp @@ -0,0 +1,153 @@ +// +// Copyright (c) 2016 The ANGLE Project Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. +// +// Implementation of the integer pow expressions HLSL bug workaround. +// See header for more info. + +#include "compiler/translator/ExpandIntegerPowExpressions.h" + +#include <cmath> +#include <cstdlib> + +#include "compiler/translator/IntermTraverse.h" + +namespace sh +{ + +namespace +{ + +class Traverser : public TIntermTraverser +{ + public: + static void Apply(TIntermNode *root, TSymbolTable *symbolTable); + + private: + Traverser(TSymbolTable *symbolTable); + bool visitAggregate(Visit visit, TIntermAggregate *node) override; + void nextIteration(); + + bool mFound = false; +}; + +// static +void Traverser::Apply(TIntermNode *root, TSymbolTable *symbolTable) +{ + Traverser traverser(symbolTable); + do + { + traverser.nextIteration(); + root->traverse(&traverser); + if (traverser.mFound) + { + traverser.updateTree(); + } + } while (traverser.mFound); +} + +Traverser::Traverser(TSymbolTable *symbolTable) : TIntermTraverser(true, false, false, symbolTable) +{ +} + +void Traverser::nextIteration() +{ + mFound = false; + nextTemporaryId(); +} + +bool Traverser::visitAggregate(Visit visit, TIntermAggregate *node) +{ + if (mFound) + { + return false; + } + + // Test 0: skip non-pow operators. + if (node->getOp() != EOpPow) + { + return true; + } + + const TIntermSequence *sequence = node->getSequence(); + ASSERT(sequence->size() == 2u); + const TIntermConstantUnion *constantNode = sequence->at(1)->getAsConstantUnion(); + + // Test 1: check for a single constant. + if (!constantNode || constantNode->getNominalSize() != 1) + { + return true; + } + + const TConstantUnion *constant = constantNode->getUnionArrayPointer(); + + TConstantUnion asFloat; + asFloat.cast(EbtFloat, *constant); + + float value = asFloat.getFConst(); + + // Test 2: value is in the problematic range. + if (value < -5.0f || value > 9.0f) + { + return true; + } + + // Test 3: value is integer or pretty close to an integer. + float absval = std::abs(value); + float frac = absval - std::round(absval); + if (frac > 0.0001f) + { + return true; + } + + // Test 4: skip -1, 0, and 1 + int exponent = static_cast<int>(value); + int n = std::abs(exponent); + if (n < 2) + { + return true; + } + + // Potential problem case detected, apply workaround. + nextTemporaryId(); + + TIntermTyped *lhs = sequence->at(0)->getAsTyped(); + ASSERT(lhs); + + TIntermDeclaration *init = createTempInitDeclaration(lhs); + TIntermTyped *current = createTempSymbol(lhs->getType()); + + insertStatementInParentBlock(init); + + // Create a chain of n-1 multiples. + for (int i = 1; i < n; ++i) + { + TIntermBinary *mul = new TIntermBinary(EOpMul, current, createTempSymbol(lhs->getType())); + mul->setLine(node->getLine()); + current = mul; + } + + // For negative pow, compute the reciprocal of the positive pow. + if (exponent < 0) + { + TConstantUnion *oneVal = new TConstantUnion(); + oneVal->setFConst(1.0f); + TIntermConstantUnion *oneNode = new TIntermConstantUnion(oneVal, node->getType()); + TIntermBinary *div = new TIntermBinary(EOpDiv, oneNode, current); + current = div; + } + + queueReplacement(current, OriginalNode::IS_DROPPED); + mFound = true; + return false; +} + +} // anonymous namespace + +void ExpandIntegerPowExpressions(TIntermNode *root, TSymbolTable *symbolTable) +{ + Traverser::Apply(root, symbolTable); +} + +} // namespace sh |