1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_COMPILER_OPTIMIZING_REGISTER_ALLOCATION_RESOLVER_H_
18 #define ART_COMPILER_OPTIMIZING_REGISTER_ALLOCATION_RESOLVER_H_
19 
20 #include "base/array_ref.h"
21 #include "base/value_object.h"
22 #include "data_type.h"
23 
24 namespace art {
25 
26 class ArenaAllocator;
27 class CodeGenerator;
28 class HBasicBlock;
29 class HInstruction;
30 class HParallelMove;
31 class LiveInterval;
32 class Location;
33 class SsaLivenessAnalysis;
34 
35 /**
36  * Reconciles the locations assigned to live intervals with the location
37  * summary of each instruction, and inserts moves to resolve split intervals,
38  * nonlinear control flow, and phi inputs.
39  */
40 class RegisterAllocationResolver : ValueObject {
41  public:
42   RegisterAllocationResolver(CodeGenerator* codegen, const SsaLivenessAnalysis& liveness);
43 
44   void Resolve(ArrayRef<HInstruction* const> safepoints,
45                size_t reserved_out_slots,  // Includes slot(s) for the art method.
46                size_t int_spill_slots,
47                size_t long_spill_slots,
48                size_t float_spill_slots,
49                size_t double_spill_slots,
50                size_t catch_phi_spill_slots,
51                ArrayRef<LiveInterval* const> temp_intervals);
52 
53  private:
54   // Update live registers of safepoint location summary.
55   void UpdateSafepointLiveRegisters();
56 
57   // Calculate the maximum size of the spill area for safepoints.
58   size_t CalculateMaximumSafepointSpillSize(ArrayRef<HInstruction* const> safepoints);
59 
60   // Connect adjacent siblings within blocks, and resolve inputs along the way.
61   void ConnectSiblings(LiveInterval* interval);
62 
63   // Connect siblings between block entries and exits.
64   void ConnectSplitSiblings(LiveInterval* interval, HBasicBlock* from, HBasicBlock* to) const;
65 
66   // Helper methods for inserting parallel moves in the graph.
67   void InsertParallelMoveAtExitOf(HBasicBlock* block,
68                                   HInstruction* instruction,
69                                   Location source,
70                                   Location destination) const;
71   void InsertParallelMoveAtEntryOf(HBasicBlock* block,
72                                    HInstruction* instruction,
73                                    Location source,
74                                    Location destination) const;
75   void InsertMoveAfter(HInstruction* instruction, Location source, Location destination) const;
76   void AddInputMoveFor(HInstruction* input,
77                        HInstruction* user,
78                        Location source,
79                        Location destination) const;
80   void InsertParallelMoveAt(size_t position,
81                             HInstruction* instruction,
82                             Location source,
83                             Location destination) const;
84   void AddMove(HParallelMove* move,
85                Location source,
86                Location destination,
87                HInstruction* instruction,
88                DataType::Type type) const;
89 
90   ArenaAllocator* const allocator_;
91   CodeGenerator* const codegen_;
92   const SsaLivenessAnalysis& liveness_;
93 
94   DISALLOW_COPY_AND_ASSIGN(RegisterAllocationResolver);
95 };
96 
97 }  // namespace art
98 
99 #endif  // ART_COMPILER_OPTIMIZING_REGISTER_ALLOCATION_RESOLVER_H_
100