SPIRV-Tools/source/opt/desc_sroa.h
Steven Perron 4b64beb1ae
Add descriptor array scalar replacement (#2742)
Creates a pass that will replace a descriptor array with individual variables.  See #2740 for details.

Fixes #2740.
2019-08-08 10:53:19 -04:00

85 lines
3.0 KiB
C++

// Copyright (c) 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SOURCE_OPT_DESC_SROA_H_
#define SOURCE_OPT_DESC_SROA_H_
#include <cstdio>
#include <memory>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "source/opt/function.h"
#include "source/opt/pass.h"
#include "source/opt/type_manager.h"
namespace spvtools {
namespace opt {
// Documented in optimizer.hpp
class DescriptorScalarReplacement : public Pass {
public:
DescriptorScalarReplacement() {}
const char* name() const override { return "descriptor-scalar-replacement"; }
Status Process() override;
IRContext::Analysis GetPreservedAnalyses() override {
return IRContext::kAnalysisDefUse |
IRContext::kAnalysisInstrToBlockMapping |
IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG |
IRContext::kAnalysisConstants | IRContext::kAnalysisTypes;
}
private:
// Returns true if |var| is an OpVariable instruction that represents a
// descriptor array. These are the variables that we want to replace.
bool IsCandidate(Instruction* var);
// Replaces all references to |var| by new variables, one for each element of
// the array |var|. The binding for the new variables corresponding to
// element i will be the binding of |var| plus i. Returns true if successful.
bool ReplaceCandidate(Instruction* var);
// Replaces the base address |var| in the OpAccessChain or
// OpInBoundsAccessChain instruction |use| by the variable that the access
// chain accesses. The first index in |use| must be an |OpConstant|. Returns
// |true| if successful.
bool ReplaceAccessChain(Instruction* var, Instruction* use);
// Returns the id of the variable that will be used to replace the |idx|th
// element of |var|. The variable is created if it has not already been
// created.
uint32_t GetReplacementVariable(Instruction* var, uint32_t idx);
// Returns the id of a new variable that can be used to replace the |idx|th
// element of |var|.
uint32_t CreateReplacementVariable(Instruction* var, uint32_t idx);
// A map from an OpVariable instruction to the set of variables that will be
// used to replace it. The entry |replacement_variables_[var][i]| is the id of
// a variable that will be used in the place of the the ith element of the
// array |var|. If the entry is |0|, then the variable has not been
// created yet.
std::map<Instruction*, std::vector<uint32_t>> replacement_variables_;
};
} // namespace opt
} // namespace spvtools
#endif // SOURCE_OPT_DESC_SROA_H_