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https://github.com/KhronosGroup/SPIRV-Tools
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c2013e248b
Currently it is impossible to invalidate the constnat and type manager. However, the compact ids pass changes the ids for the types and constants, which makes them invalid. This change will make them analyses that have to been explicitly marked as preserved by passes. This will allow compact ids to invalidate them. Fixes #2220.
57 lines
1.8 KiB
C++
57 lines
1.8 KiB
C++
// Copyright (c) 2017 Google Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef SOURCE_OPT_DEAD_VARIABLE_ELIMINATION_H_
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#define SOURCE_OPT_DEAD_VARIABLE_ELIMINATION_H_
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#include <climits>
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#include <unordered_map>
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#include "source/opt/decoration_manager.h"
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#include "source/opt/mem_pass.h"
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namespace spvtools {
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namespace opt {
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class DeadVariableElimination : public MemPass {
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public:
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const char* name() const override { return "eliminate-dead-variables"; }
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Status Process() override;
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IRContext::Analysis GetPreservedAnalyses() override {
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return IRContext::kAnalysisDefUse | IRContext::kAnalysisConstants |
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IRContext::kAnalysisTypes;
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}
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private:
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// Deletes the OpVariable instruction who result id is |result_id|.
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void DeleteVariable(uint32_t result_id);
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// Keeps track of the number of references of an id. Once that value is 0, it
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// is safe to remove the corresponding instruction.
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//
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// Note that the special value kMustKeep is used to indicate that the
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// instruction cannot be deleted for reasons other that is being explicitly
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// referenced.
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std::unordered_map<uint32_t, size_t> reference_count_;
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// Special value used to indicate that an id cannot be safely deleted.
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enum { kMustKeep = INT_MAX };
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};
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} // namespace opt
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} // namespace spvtools
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#endif // SOURCE_OPT_DEAD_VARIABLE_ELIMINATION_H_
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