• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
22 namespace spvtools {
23 namespace opt {
24 
25 // See optimizer.hpp for documentation.
26 class CombineAccessChains : public Pass {
27  public:
name()28   const char* name() const override { return "combine-access-chains"; }
29   Status Process() override;
30 
GetPreservedAnalyses()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