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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/*
* 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.
*/
#ifndef ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_
#define ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_
#include "base/macros.h"
#include "base/scoped_arena_allocator.h"
#include "base/scoped_arena_containers.h"
#include "nodes.h"
#include "optimization.h"
namespace art HIDDEN {
/**
* Transforms a graph into SSA form. The liveness guarantees of
* this transformation are listed below. A DEX register
* being killed means its value at a given position in the code
* will not be available to its environment uses. A merge in the
* following text is materialized as a `HPhi`.
*
* (a) Dex registers that do not require merging (that is, they do not
* have different values at a join block) are available to all their
* environment uses. Note that it does not imply the instruction will
* have a physical location after register allocation. See the
* SsaLivenessAnalysis phase.
*
* (b) Dex registers that require merging, and the merging gives
* incompatible types, will be killed for environment uses of that merge.
*
* (c) When the `debuggable` flag is passed to the compiler, Dex registers
* that require merging and have a proper type after the merge, are
* available to all their environment uses. If the `debuggable` flag
* is not set, values of Dex registers only used by environments
* are killed.
*/
class SsaBuilder : public ValueObject {
public:
SsaBuilder(HGraph* graph,
Handle<mirror::ClassLoader> class_loader,
Handle<mirror::DexCache> dex_cache,
ScopedArenaAllocator* local_allocator)
: graph_(graph),
class_loader_(class_loader),
dex_cache_(dex_cache),
agets_fixed_(false),
local_allocator_(local_allocator),
ambiguous_agets_(local_allocator->Adapter(kArenaAllocGraphBuilder)),
ambiguous_asets_(local_allocator->Adapter(kArenaAllocGraphBuilder)),
uninitialized_strings_(local_allocator->Adapter(kArenaAllocGraphBuilder)),
uninitialized_string_phis_(local_allocator->Adapter(kArenaAllocGraphBuilder)) {
}
GraphAnalysisResult BuildSsa();
HInstruction* GetFloatOrDoubleEquivalent(HInstruction* instruction, DataType::Type type);
HInstruction* GetReferenceTypeEquivalent(HInstruction* instruction);
void MaybeAddAmbiguousArrayGet(HArrayGet* aget) {
DataType::Type type = aget->GetType();
DCHECK(!DataType::IsFloatingPointType(type));
if (DataType::IsIntOrLongType(type)) {
ambiguous_agets_.push_back(aget);
}
}
void MaybeAddAmbiguousArraySet(HArraySet* aset) {
DataType::Type type = aset->GetValue()->GetType();
if (DataType::IsIntOrLongType(type)) {
ambiguous_asets_.push_back(aset);
}
}
void AddUninitializedString(HNewInstance* string) {
// In some rare cases (b/27847265), the same NewInstance may be seen
// multiple times. We should only consider it once for removal, so we
// ensure it is not added more than once.
// Note that we cannot check whether this really is a NewInstance of String
// before RTP. We DCHECK that in RemoveRedundantUninitializedStrings.
if (!ContainsElement(uninitialized_strings_, string)) {
uninitialized_strings_.push_back(string);
}
}
void AddUninitializedStringPhi(HInvoke* invoke) {
uninitialized_string_phis_.push_back(invoke);
}
private:
void SetLoopHeaderPhiInputs();
void FixEnvironmentPhis();
void FixNullConstantType();
void EquivalentPhisCleanup();
void RunPrimitiveTypePropagation();
// Attempts to resolve types of aget(-wide) instructions and type values passed
// to aput(-wide) instructions from reference type information on the array
// input. Returns false if the type of an array is unknown.
bool FixAmbiguousArrayOps();
bool TypeInputsOfPhi(HPhi* phi, ScopedArenaVector<HPhi*>* worklist);
bool UpdatePrimitiveType(HPhi* phi, ScopedArenaVector<HPhi*>* worklist);
void ProcessPrimitiveTypePropagationWorklist(ScopedArenaVector<HPhi*>* worklist);
HFloatConstant* GetFloatEquivalent(HIntConstant* constant);
HDoubleConstant* GetDoubleEquivalent(HLongConstant* constant);
HPhi* GetFloatDoubleOrReferenceEquivalentOfPhi(HPhi* phi, DataType::Type type);
HArrayGet* GetFloatOrDoubleEquivalentOfArrayGet(HArrayGet* aget);
void RemoveRedundantUninitializedStrings();
bool ReplaceUninitializedStringPhis();
bool HasAliasInEnvironments(HInstruction* instruction);
HGraph* const graph_;
Handle<mirror::ClassLoader> class_loader_;
Handle<mirror::DexCache> dex_cache_;
// True if types of ambiguous ArrayGets have been resolved.
bool agets_fixed_;
ScopedArenaAllocator* const local_allocator_;
ScopedArenaVector<HArrayGet*> ambiguous_agets_;
ScopedArenaVector<HArraySet*> ambiguous_asets_;
ScopedArenaVector<HNewInstance*> uninitialized_strings_;
ScopedArenaVector<HInvoke*> uninitialized_string_phis_;
DISALLOW_COPY_AND_ASSIGN(SsaBuilder);
};
} // namespace art
#endif // ART_COMPILER_OPTIMIZING_SSA_BUILDER_H_
|
