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_COMBINE_ACCESS_CHAINS_H_
16#define SOURCE_OPT_COMBINE_ACCESS_CHAINS_H_
17
18#include <vector>
19
20#include "source/opt/pass.h"
21
22namespace spvtools {
23namespace opt {
24
25// See optimizer.hpp for documentation.
26class CombineAccessChains : public Pass {
27 public:
28 const char* name() const override { return "combine-access-chains"; }
29 Status Process() override;
30
31 IRContext::Analysis GetPreservedAnalyses() override {
32 return IRContext::kAnalysisDefUse |
33 IRContext::kAnalysisInstrToBlockMapping |
34 IRContext::kAnalysisDecorations | IRContext::kAnalysisCombinators |
35 IRContext::kAnalysisCFG | IRContext::kAnalysisDominatorAnalysis |
36 IRContext::kAnalysisNameMap | IRContext::kAnalysisConstants |
37 IRContext::kAnalysisTypes;
38 }
39
40 private:
41 // Combine access chains in |function|. Blocks are processed in reverse
42 // post-order. Returns true if the function is modified.
43 bool ProcessFunction(Function& function);
44
45 // Combines an access chain (normal, in bounds or pointer) |inst| if its base
46 // pointer is another access chain. Returns true if the access chain was
47 // modified.
48 bool CombineAccessChain(Instruction* inst);
49
50 // Returns the value of |constant_inst| as a uint32_t.
51 uint32_t GetConstantValue(const analysis::Constant* constant_inst);
52
53 // Returns the array stride of |inst|'s type.
54 uint32_t GetArrayStride(const Instruction* inst);
55
56 // Returns the type by resolving the index operands |inst|. |inst| must be an
57 // access chain instruction.
58 const analysis::Type* GetIndexedType(Instruction* inst);
59
60 // Populates |new_operands| with the operands for the combined access chain.
61 // Returns false if the access chains cannot be combined.
62 bool CreateNewInputOperands(Instruction* ptr_input, Instruction* inst,
63 std::vector<Operand>* new_operands);
64
65 // Combines the last index of |ptr_input| with the element operand of |inst|.
66 // Adds the combined operand to |new_operands|.
67 bool CombineIndices(Instruction* ptr_input, Instruction* inst,
68 std::vector<Operand>* new_operands);
69
70 // Returns the opcode to use for the combined access chain.
71 SpvOp UpdateOpcode(SpvOp base_opcode, SpvOp input_opcode);
72
73 // Returns true if |opcode| is a pointer access chain.
74 bool IsPtrAccessChain(SpvOp opcode);
75
76 // Returns true if |inst| (an access chain) has 64-bit indices.
77 bool Has64BitIndices(Instruction* inst);
78};
79
80} // namespace opt
81} // namespace spvtools
82
83#endif // SOURCE_OPT_COMBINE_ACCESS_CHAINS_H_
84