SPIRV-Tools/source/opt/eliminate_dead_members_pass.h

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// 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_ELIMINATE_DEAD_MEMBERS_PASS_H_
#define SOURCE_OPT_ELIMINATE_DEAD_MEMBERS_PASS_H_
#include "source/opt/def_use_manager.h"
#include "source/opt/function.h"
#include "source/opt/mem_pass.h"
#include "source/opt/module.h"
namespace spvtools {
namespace opt {
// Remove unused members from structures. The remaining members will remain at
// the same offset.
class EliminateDeadMembersPass : public MemPass {
public:
const char* name() const override { return "eliminate-dead-members"; }
Status Process() override;
IRContext::Analysis GetPreservedAnalyses() override {
return IRContext::kAnalysisDefUse |
IRContext::kAnalysisInstrToBlockMapping |
IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG |
IRContext::kAnalysisDominatorAnalysis |
IRContext::kAnalysisLoopAnalysis |
IRContext::kAnalysisScalarEvolution |
IRContext::kAnalysisRegisterPressure |
IRContext::kAnalysisValueNumberTable |
IRContext::kAnalysisStructuredCFG |
IRContext::kAnalysisBuiltinVarId |
IRContext::kAnalysisIdToFuncMapping;
}
private:
// Populate |used_members_| with the member of structures that are live in the
// current context.
void FindLiveMembers();
// Add to |used_members_| the member of structures that are live in
// |function|.
void FindLiveMembers(const Function& function);
// Add to |used_members_| the member of structures that are live in |inst|.
void FindLiveMembers(const Instruction* inst);
// Add to |used_members_| the members that are live in the |OpStore|
// instruction |inst|.
void MarkMembersAsLiveForStore(const Instruction* inst);
// Add to |used_members_| the members that are live in the |OpCopyMemory*|
// instruction |inst|.
void MarkMembersAsLiveForCopyMemory(const Instruction* inst);
// Add to |used_members_| the members that are live in the
// |OpCompositeExtract| instruction |inst|.
void MarkMembersAsLiveForExtract(const Instruction* inst);
// Add to |used_members_| the members that are live in the |Op*AccessChain|
// instruction |inst|.
void MarkMembersAsLiveForAccessChain(const Instruction* inst);
// Add the member referenced by the OpArrayLength instruction |inst| to
// |uses_members_|.
void MarkMembersAsLiveForArrayLength(const Instruction* inst);
// Remove dead members from structs and updates any instructions that need to
// be updated as a consequence. Return true if something changed.
bool RemoveDeadMembers();
// Update |inst|, which must be an |OpMemberName| or |OpMemberDecorate|
// instruction, so it references the correct member after the struct is
// updated. Return true if something changed.
bool UpdateOpMemberNameOrDecorate(Instruction* inst);
// Update |inst|, which must be an |OpGroupMemberDecorate| instruction, so it
// references the correct member after the struct is updated. Return true if
// something changed.
bool UpdateOpGroupMemberDecorate(Instruction* inst);
// Update the |OpTypeStruct| instruction |inst| my removing the members that
// are not live. Return true if something changed.
bool UpdateOpTypeStruct(Instruction* inst);
// Update the |OpConstantComposite| instruction |inst| to match the change
// made to the type that was being generated. Return true if something
// changed.
bool UpdateConstantComposite(Instruction* inst);
// Update the |Op*AccessChain| instruction |inst| to reference the correct
// members. All members referenced in the access chain must be live. This
// function must be called after the |OpTypeStruct| instruction for the type
// has been updated. Return true if something changed.
bool UpdateAccessChain(Instruction* inst);
// Update the |OpCompositeExtract| instruction |inst| to reference the correct
// members. All members referenced in the instruction must be live. This
// function must be called after the |OpTypeStruct| instruction for the type
// has been updated. Return true if something changed.
bool UpdateCompsiteExtract(Instruction* inst);
// Update the |OpCompositeInsert| instruction |inst| to reference the correct
// members. If the member being inserted is not live, then |inst| is killed.
// This function must be called after the |OpTypeStruct| instruction for the
// type has been updated. Return true if something changed.
bool UpdateCompositeInsert(Instruction* inst);
// Update the |OpArrayLength| instruction |inst| to reference the correct
// member. The member referenced in the instruction must be live. Return true
// if something changed.
bool UpdateOpArrayLength(Instruction* inst);
// Add all of the members of type |type_id| and members of any subtypes to
// |used_members_|.
void MarkTypeAsFullyUsed(uint32_t type_id);
// Add all of the members of the type of the operand |in_idx| in |inst| and
// members of any subtypes to |uses_members_|.
void MarkOperandTypeAsFullyUsed(const Instruction* inst, uint32_t in_idx);
// Return the index of the member that use to be the |member_idx|th member of
// |type_id|. If the member has been removed, |kRemovedMember| is returned.
uint32_t GetNewMemberIndex(uint32_t type_id, uint32_t member_idx);
// A map from a type id to a set of indices representing the members of the
// type that are used, and must be kept.
std::unordered_map<uint32_t, std::set<uint32_t>> used_members_;
void MarkStructOperandsAsFullyUsed(const Instruction* inst);
void MarkPointeeTypeAsFullUsed(uint32_t ptr_type_id);
};
} // namespace opt
} // namespace spvtools
#endif // SOURCE_OPT_ELIMINATE_DEAD_MEMBERS_PASS_H_