blob: 49ca44331de783ff8a07b750d8fe894608a9b060 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "instruction_simplifier.h"
namespace art {
class InstructionSimplifierVisitor : public HGraphVisitor {
public:
explicit InstructionSimplifierVisitor(HGraph* graph) : HGraphVisitor(graph) {}
private:
void VisitSuspendCheck(HSuspendCheck* check) OVERRIDE;
void VisitEqual(HEqual* equal) OVERRIDE;
void VisitArraySet(HArraySet* equal) OVERRIDE;
void VisitTypeConversion(HTypeConversion* instruction) OVERRIDE;
};
void InstructionSimplifier::Run() {
InstructionSimplifierVisitor visitor(graph_);
visitor.VisitInsertionOrder();
}
void InstructionSimplifierVisitor::VisitSuspendCheck(HSuspendCheck* check) {
HBasicBlock* block = check->GetBlock();
// Currently always keep the suspend check at entry.
if (block->IsEntryBlock()) return;
// Currently always keep suspend checks at loop entry.
if (block->IsLoopHeader() && block->GetFirstInstruction() == check) {
DCHECK(block->GetLoopInformation()->GetSuspendCheck() == check);
return;
}
// Remove the suspend check that was added at build time for the baseline
// compiler.
block->RemoveInstruction(check);
}
void InstructionSimplifierVisitor::VisitEqual(HEqual* equal) {
HInstruction* input1 = equal->InputAt(0);
HInstruction* input2 = equal->InputAt(1);
if (input1->GetType() == Primitive::kPrimBoolean && input2->IsIntConstant()) {
if (input2->AsIntConstant()->GetValue() == 1) {
// Replace (bool_value == 1) with bool_value
equal->ReplaceWith(equal->InputAt(0));
equal->GetBlock()->RemoveInstruction(equal);
} else {
// Replace (bool_value == 0) with !bool_value
DCHECK_EQ(input2->AsIntConstant()->GetValue(), 0);
equal->GetBlock()->ReplaceAndRemoveInstructionWith(
equal, new (GetGraph()->GetArena()) HNot(Primitive::kPrimBoolean, input1));
}
}
}
void InstructionSimplifierVisitor::VisitArraySet(HArraySet* instruction) {
HInstruction* value = instruction->GetValue();
if (value->GetType() != Primitive::kPrimNot) return;
if (value->IsArrayGet()) {
if (value->AsArrayGet()->GetArray() == instruction->GetArray()) {
// If the code is just swapping elements in the array, no need for a type check.
instruction->ClearNeedsTypeCheck();
}
}
}
void InstructionSimplifierVisitor::VisitTypeConversion(HTypeConversion* instruction) {
if (instruction->GetResultType() == instruction->GetInputType()) {
// Remove the instruction if it's converting to the same type.
instruction->ReplaceWith(instruction->GetInput());
instruction->GetBlock()->RemoveInstruction(instruction);
}
}
} // namespace art
|
