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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'gfx/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp')
-rwxr-xr-xgfx/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp154
1 files changed, 154 insertions, 0 deletions
diff --git a/gfx/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp b/gfx/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp
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+++ b/gfx/angle/src/compiler/translator/ExpandIntegerPowExpressions.cpp
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+//
+// 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/IntermNode.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class Traverser : public TIntermTraverser
+{
+ public:
+ static void Apply(TIntermNode *root, unsigned int *tempIndex);
+
+ private:
+ Traverser();
+ bool visitAggregate(Visit visit, TIntermAggregate *node) override;
+ void nextIteration();
+
+ bool mFound = false;
+};
+
+// static
+void Traverser::Apply(TIntermNode *root, unsigned int *tempIndex)
+{
+ Traverser traverser;
+ traverser.useTemporaryIndex(tempIndex);
+ do
+ {
+ traverser.nextIteration();
+ root->traverse(&traverser);
+ if (traverser.mFound)
+ {
+ traverser.updateTree();
+ }
+ } while (traverser.mFound);
+}
+
+Traverser::Traverser() : TIntermTraverser(true, false, false)
+{
+}
+
+void Traverser::nextIteration()
+{
+ mFound = false;
+ nextTemporaryIndex();
+}
+
+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.
+ nextTemporaryIndex();
+
+ 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(node, current, OriginalNode::IS_DROPPED);
+ mFound = true;
+ return false;
+}
+
+} // anonymous namespace
+
+void ExpandIntegerPowExpressions(TIntermNode *root, unsigned int *tempIndex)
+{
+ Traverser::Apply(root, tempIndex);
+}
+
+} // namespace sh