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
146
|
//===-- Use.cpp - Implement the Use class ---------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the algorithm for finding the User of a Use.
//
//===----------------------------------------------------------------------===//
#include "llvm/Value.h"
namespace llvm {
//===----------------------------------------------------------------------===//
// Use swap Implementation
//===----------------------------------------------------------------------===//
void Use::swap(Use &RHS) {
Value *V1(Val);
Value *V2(RHS.Val);
if (V1 != V2) {
if (V1) {
removeFromList();
}
if (V2) {
RHS.removeFromList();
Val = V2;
V2->addUse(*this);
} else {
Val = 0;
}
if (V1) {
RHS.Val = V1;
V1->addUse(RHS);
} else {
RHS.Val = 0;
}
}
}
//===----------------------------------------------------------------------===//
// Use getImpliedUser Implementation
//===----------------------------------------------------------------------===//
const Use *Use::getImpliedUser() const {
const Use *Current = this;
while (true) {
unsigned Tag = (Current++)->Prev.getInt();
switch (Tag) {
case zeroDigitTag:
case oneDigitTag:
continue;
case stopTag: {
++Current;
ptrdiff_t Offset = 1;
while (true) {
unsigned Tag = Current->Prev.getInt();
switch (Tag) {
case zeroDigitTag:
case oneDigitTag:
++Current;
Offset = (Offset << 1) + Tag;
continue;
default:
return Current + Offset;
}
}
}
case fullStopTag:
return Current;
}
}
}
//===----------------------------------------------------------------------===//
// Use initTags Implementation
//===----------------------------------------------------------------------===//
Use *Use::initTags(Use * const Start, Use *Stop) {
ptrdiff_t Done = 0;
while (Done < 20) {
if (Start == Stop--)
return Start;
static const PrevPtrTag tags[20] = { fullStopTag, oneDigitTag, stopTag,
oneDigitTag, oneDigitTag, stopTag,
zeroDigitTag, oneDigitTag, oneDigitTag,
stopTag, zeroDigitTag, oneDigitTag,
zeroDigitTag, oneDigitTag, stopTag,
oneDigitTag, oneDigitTag, oneDigitTag,
oneDigitTag, stopTag
};
new(Stop) Use(tags[Done++]);
}
ptrdiff_t Count = Done;
while (Start != Stop) {
--Stop;
if (!Count) {
new(Stop) Use(stopTag);
++Done;
Count = Done;
} else {
new(Stop) Use(PrevPtrTag(Count & 1));
Count >>= 1;
++Done;
}
}
return Start;
}
//===----------------------------------------------------------------------===//
// Use zap Implementation
//===----------------------------------------------------------------------===//
void Use::zap(Use *Start, const Use *Stop, bool del) {
while (Start != Stop)
(--Stop)->~Use();
if (del)
::operator delete(Start);
}
//===----------------------------------------------------------------------===//
// Use getUser Implementation
//===----------------------------------------------------------------------===//
User *Use::getUser() const {
const Use *End = getImpliedUser();
const PointerIntPair<User*, 1, unsigned>&
ref(static_cast<const AugmentedUse*>(End - 1)->ref);
User *She = ref.getPointer();
return ref.getInt()
? She
: (User*)End;
}
} // End llvm namespace
|
