1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
// Copyright (c) 2018 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_REDUCE_REMOVE_UNREFERENCED_INSTRUCTION_REDUCTION_OPPORTUNITY_FINDER_H_
#define SOURCE_REDUCE_REMOVE_UNREFERENCED_INSTRUCTION_REDUCTION_OPPORTUNITY_FINDER_H_
#include "source/reduce/reduction_opportunity_finder.h"
namespace spvtools {
namespace reduce {
// A finder for opportunities to remove non-control-flow instructions in blocks
// in cases where the instruction's id is either not referenced at all, or
// referenced only in a trivial manner (for example, we regard a struct type as
// unused if it is referenced only by struct layout decorations). As well as
// making the module smaller, removing an instruction that references particular
// ids may create opportunities for subsequently removing the instructions that
// generated those ids.
class RemoveUnusedInstructionReductionOpportunityFinder
: public ReductionOpportunityFinder {
public:
explicit RemoveUnusedInstructionReductionOpportunityFinder(
bool remove_constants_and_undefs);
~RemoveUnusedInstructionReductionOpportunityFinder() override = default;
std::string GetName() const final;
std::vector<std::unique_ptr<ReductionOpportunity>> GetAvailableOpportunities(
opt::IRContext* context, uint32_t target_function) const final;
private:
// Returns true if and only if the only uses of |inst| are by decorations that
// relate intimately to the instruction (as opposed to decorations that could
// be removed independently), or by interface ids in OpEntryPoint.
bool OnlyReferencedByIntimateDecorationOrEntryPointInterface(
opt::IRContext* context, const opt::Instruction& inst) const;
// Returns true if and only if |inst| is a decoration instruction that can
// legitimately be removed on its own (rather than one that has to be removed
// simultaneously with other instructions).
bool IsIndependentlyRemovableDecoration(const opt::Instruction& inst) const;
bool remove_constants_and_undefs_;
};
} // namespace reduce
} // namespace spvtools
#endif // SOURCE_REDUCE_REMOVE_UNREFERENCED_INSTRUCTION_REDUCTION_OPPORTUNITY_FINDER_H_
|
