1 /*
2  * Copyright (C) 2015 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_INSTRUCTION_SIMPLIFIER_ARM_H_
18 #define ART_COMPILER_OPTIMIZING_INSTRUCTION_SIMPLIFIER_ARM_H_
19 
20 #include "nodes.h"
21 #include "optimization.h"
22 
23 namespace art {
24 namespace arm {
25 
26 class InstructionSimplifierArmVisitor : public HGraphVisitor {
27  public:
InstructionSimplifierArmVisitor(HGraph * graph,OptimizingCompilerStats * stats)28   InstructionSimplifierArmVisitor(HGraph* graph, OptimizingCompilerStats* stats)
29       : HGraphVisitor(graph), stats_(stats) {}
30 
31  private:
RecordSimplification()32   void RecordSimplification() {
33     if (stats_ != nullptr) {
34       stats_->RecordStat(kInstructionSimplificationsArch);
35     }
36   }
37 
38   bool TryMergeIntoUsersShifterOperand(HInstruction* instruction);
39   bool TryMergeIntoShifterOperand(HInstruction* use, HInstruction* bitfield_op, bool do_merge);
CanMergeIntoShifterOperand(HInstruction * use,HInstruction * bitfield_op)40   bool CanMergeIntoShifterOperand(HInstruction* use, HInstruction* bitfield_op) {
41     return TryMergeIntoShifterOperand(use, bitfield_op, /* do_merge */ false);
42   }
MergeIntoShifterOperand(HInstruction * use,HInstruction * bitfield_op)43   bool MergeIntoShifterOperand(HInstruction* use, HInstruction* bitfield_op) {
44     DCHECK(CanMergeIntoShifterOperand(use, bitfield_op));
45     return TryMergeIntoShifterOperand(use, bitfield_op, /* do_merge */ true);
46   }
47 
48   /**
49    * This simplifier uses a special-purpose BB visitor.
50    * (1) No need to visit Phi nodes.
51    * (2) Since statements can be removed in a "forward" fashion,
52    *     the visitor should test if each statement is still there.
53    */
VisitBasicBlock(HBasicBlock * block)54   void VisitBasicBlock(HBasicBlock* block) OVERRIDE {
55     // TODO: fragile iteration, provide more robust iterators?
56     for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
57       HInstruction* instruction = it.Current();
58       if (instruction->IsInBlock()) {
59         instruction->Accept(this);
60       }
61     }
62   }
63 
64   void VisitAnd(HAnd* instruction) OVERRIDE;
65   void VisitArrayGet(HArrayGet* instruction) OVERRIDE;
66   void VisitArraySet(HArraySet* instruction) OVERRIDE;
67   void VisitMul(HMul* instruction) OVERRIDE;
68   void VisitOr(HOr* instruction) OVERRIDE;
69   void VisitShl(HShl* instruction) OVERRIDE;
70   void VisitShr(HShr* instruction) OVERRIDE;
71   void VisitTypeConversion(HTypeConversion* instruction) OVERRIDE;
72   void VisitUShr(HUShr* instruction) OVERRIDE;
73 
74   OptimizingCompilerStats* stats_;
75 };
76 
77 
78 class InstructionSimplifierArm : public HOptimization {
79  public:
InstructionSimplifierArm(HGraph * graph,OptimizingCompilerStats * stats)80   InstructionSimplifierArm(HGraph* graph, OptimizingCompilerStats* stats)
81       : HOptimization(graph, kInstructionSimplifierArmPassName, stats) {}
82 
83   static constexpr const char* kInstructionSimplifierArmPassName = "instruction_simplifier_arm";
84 
Run()85   void Run() OVERRIDE {
86     InstructionSimplifierArmVisitor visitor(graph_, stats_);
87     visitor.VisitReversePostOrder();
88   }
89 };
90 
91 }  // namespace arm
92 }  // namespace art
93 
94 #endif  // ART_COMPILER_OPTIMIZING_INSTRUCTION_SIMPLIFIER_ARM_H_
95