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Diffstat (limited to 'src/3rdparty/glslang/glslang/MachineIndependent/LiveTraverser.h')
| -rw-r--r-- | src/3rdparty/glslang/glslang/MachineIndependent/LiveTraverser.h | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/3rdparty/glslang/glslang/MachineIndependent/LiveTraverser.h b/src/3rdparty/glslang/glslang/MachineIndependent/LiveTraverser.h new file mode 100644 index 0000000..7333bc9 --- /dev/null +++ b/src/3rdparty/glslang/glslang/MachineIndependent/LiveTraverser.h @@ -0,0 +1,138 @@ +// +// Copyright (C) 2016 LunarG, Inc. +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// +// Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following +// disclaimer in the documentation and/or other materials provided +// with the distribution. +// +// Neither the name of 3Dlabs Inc. Ltd. nor the names of its +// contributors may be used to endorse or promote products derived +// from this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +// COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// + +#pragma once + +#include "../Include/Common.h" +#include "reflection.h" +#include "localintermediate.h" + +#include "gl_types.h" + +#include <list> +#include <unordered_set> + +namespace glslang { + +// +// The traverser: mostly pass through, except +// - processing function-call nodes to push live functions onto the stack of functions to process +// - processing selection nodes to trim semantically dead code +// +// This is in the glslang namespace directly so it can be a friend of TReflection. +// This can be derived from to implement reflection database traversers or +// binding mappers: anything that wants to traverse the live subset of the tree. +// + +class TLiveTraverser : public TIntermTraverser { +public: + TLiveTraverser(const TIntermediate& i, bool traverseAll = false, + bool preVisit = true, bool inVisit = false, bool postVisit = false) : + TIntermTraverser(preVisit, inVisit, postVisit), + intermediate(i), traverseAll(traverseAll) + { } + + // + // Given a function name, find its subroot in the tree, and push it onto the stack of + // functions left to process. + // + void pushFunction(const TString& name) + { + TIntermSequence& globals = intermediate.getTreeRoot()->getAsAggregate()->getSequence(); + for (unsigned int f = 0; f < globals.size(); ++f) { + TIntermAggregate* candidate = globals[f]->getAsAggregate(); + if (candidate && candidate->getOp() == EOpFunction && candidate->getName() == name) { + functions.push_back(candidate); + break; + } + } + } + + typedef std::list<TIntermAggregate*> TFunctionStack; + TFunctionStack functions; + +protected: + // To catch which function calls are not dead, and hence which functions must be visited. + virtual bool visitAggregate(TVisit, TIntermAggregate* node) + { + if (!traverseAll) + if (node->getOp() == EOpFunctionCall) + addFunctionCall(node); + + return true; // traverse this subtree + } + + // To prune semantically dead paths. + virtual bool visitSelection(TVisit /* visit */, TIntermSelection* node) + { + if (traverseAll) + return true; // traverse all code + + TIntermConstantUnion* constant = node->getCondition()->getAsConstantUnion(); + if (constant) { + // cull the path that is dead + if (constant->getConstArray()[0].getBConst() == true && node->getTrueBlock()) + node->getTrueBlock()->traverse(this); + if (constant->getConstArray()[0].getBConst() == false && node->getFalseBlock()) + node->getFalseBlock()->traverse(this); + + return false; // don't traverse any more, we did it all above + } else + return true; // traverse the whole subtree + } + + // Track live functions as well as uniforms, so that we don't visit dead functions + // and only visit each function once. + void addFunctionCall(TIntermAggregate* call) + { + // // just use the map to ensure we process each function at most once + if (liveFunctions.find(call->getName()) == liveFunctions.end()) { + liveFunctions.insert(call->getName()); + pushFunction(call->getName()); + } + } + + const TIntermediate& intermediate; + typedef std::unordered_set<TString> TLiveFunctions; + TLiveFunctions liveFunctions; + bool traverseAll; + +private: + // prevent copy & copy construct + TLiveTraverser(TLiveTraverser&); + TLiveTraverser& operator=(TLiveTraverser&); +}; + +} // namespace glslang |