1// Copyright (c) 2018 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15#ifndef SOURCE_OPT_REDUCE_LOAD_SIZE_H_
16#define SOURCE_OPT_REDUCE_LOAD_SIZE_H_
17
18#include <unordered_map>
19
20#include "source/opt/ir_context.h"
21#include "source/opt/module.h"
22#include "source/opt/pass.h"
23
24namespace spvtools {
25namespace opt {
26
27// See optimizer.hpp for documentation.
28class ReduceLoadSize : public Pass {
29 public:
30 const char* name() const override { return "reduce-load-size"; }
31 Status Process() override;
32
33 // Return the mask of preserved Analyses.
34 IRContext::Analysis GetPreservedAnalyses() override {
35 return IRContext::kAnalysisDefUse |
36 IRContext::kAnalysisInstrToBlockMapping |
37 IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG |
38 IRContext::kAnalysisDominatorAnalysis |
39 IRContext::kAnalysisLoopAnalysis | IRContext::kAnalysisNameMap |
40 IRContext::kAnalysisConstants | IRContext::kAnalysisTypes;
41 }
42
43 private:
44 // Replaces |inst|, which must be an OpCompositeExtract instruction, with
45 // an OpAccessChain and a load if possible. This happens only if it is a load
46 // feeding |inst|. Returns true if the substitution happened. The position
47 // of the new instructions will be in the same place as the load feeding the
48 // extract.
49 bool ReplaceExtract(Instruction* inst);
50
51 // Returns true if the OpCompositeExtract instruction |inst| should be replace
52 // or not. This is determined by looking at the load that feeds |inst| if
53 // it is a load. |should_replace_cache_| is used to cache the results based
54 // on the load feeding |inst|.
55 bool ShouldReplaceExtract(Instruction* inst);
56
57 // Maps the result id of an OpLoad instruction to the result of whether or
58 // not the OpCompositeExtract that use the id should be replaced.
59 std::unordered_map<uint32_t, bool> should_replace_cache_;
60};
61
62} // namespace opt
63} // namespace spvtools
64
65#endif // SOURCE_OPT_REDUCE_LOAD_SIZE_H_
66