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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
//===-- User.cpp - Implement the User class -------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/User.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/IntrinsicInst.h"
namespace llvm {
class BasicBlock;
//===----------------------------------------------------------------------===//
// User Class
//===----------------------------------------------------------------------===//
bool User::replaceUsesOfWith(Value *From, Value *To) {
bool Changed = false;
if (From == To) return Changed; // Duh what?
assert((!isa<Constant>(this) || isa<GlobalValue>(this)) &&
"Cannot call User::replaceUsesOfWith on a constant!");
for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
if (getOperand(i) == From) { // Is This operand is pointing to oldval?
// The side effects of this setOperand call include linking to
// "To", adding "this" to the uses list of To, and
// most importantly, removing "this" from the use list of "From".
setOperand(i, To);
Changed = true;
}
if (auto DVI = dyn_cast_or_null<DbgVariableIntrinsic>(this)) {
if (is_contained(DVI->location_ops(), From)) {
DVI->replaceVariableLocationOp(From, To);
Changed = true;
}
}
return Changed;
}
//===----------------------------------------------------------------------===//
// User allocHungoffUses Implementation
//===----------------------------------------------------------------------===//
void User::allocHungoffUses(unsigned N, bool IsPhi) {
assert(HasHungOffUses && "alloc must have hung off uses");
static_assert(alignof(Use) >= alignof(BasicBlock *),
"Alignment is insufficient for 'hung-off-uses' pieces");
// Allocate the array of Uses
size_t size = N * sizeof(Use);
if (IsPhi)
size += N * sizeof(BasicBlock *);
Use *Begin = static_cast<Use*>(::operator new(size));
Use *End = Begin + N;
setOperandList(Begin);
for (; Begin != End; Begin++)
new (Begin) Use(this);
}
void User::growHungoffUses(unsigned NewNumUses, bool IsPhi) {
assert(HasHungOffUses && "realloc must have hung off uses");
unsigned OldNumUses = getNumOperands();
// We don't support shrinking the number of uses. We wouldn't have enough
// space to copy the old uses in to the new space.
assert(NewNumUses > OldNumUses && "realloc must grow num uses");
Use *OldOps = getOperandList();
allocHungoffUses(NewNumUses, IsPhi);
Use *NewOps = getOperandList();
// Now copy from the old operands list to the new one.
std::copy(OldOps, OldOps + OldNumUses, NewOps);
// If this is a Phi, then we need to copy the BB pointers too.
if (IsPhi) {
auto *OldPtr = reinterpret_cast<char *>(OldOps + OldNumUses);
auto *NewPtr = reinterpret_cast<char *>(NewOps + NewNumUses);
std::copy(OldPtr, OldPtr + (OldNumUses * sizeof(BasicBlock *)), NewPtr);
}
Use::zap(OldOps, OldOps + OldNumUses, true);
}
// This is a private struct used by `User` to track the co-allocated descriptor
// section.
struct DescriptorInfo {
intptr_t SizeInBytes;
};
ArrayRef<const uint8_t> User::getDescriptor() const {
auto MutableARef = const_cast<User *>(this)->getDescriptor();
return {MutableARef.begin(), MutableARef.end()};
}
MutableArrayRef<uint8_t> User::getDescriptor() {
assert(HasDescriptor && "Don't call otherwise!");
assert(!HasHungOffUses && "Invariant!");
auto *DI = reinterpret_cast<DescriptorInfo *>(getIntrusiveOperands()) - 1;
assert(DI->SizeInBytes != 0 && "Should not have had a descriptor otherwise!");
return MutableArrayRef<uint8_t>(
reinterpret_cast<uint8_t *>(DI) - DI->SizeInBytes, DI->SizeInBytes);
}
bool User::isDroppable() const {
return isa<AssumeInst>(this) || isa<PseudoProbeInst>(this);
}
//===----------------------------------------------------------------------===//
// User operator new Implementations
//===----------------------------------------------------------------------===//
void *User::allocateFixedOperandUser(size_t Size, unsigned Us,
unsigned DescBytes) {
assert(Us < (1u << NumUserOperandsBits) && "Too many operands");
static_assert(sizeof(DescriptorInfo) % sizeof(void *) == 0, "Required below");
unsigned DescBytesToAllocate =
DescBytes == 0 ? 0 : (DescBytes + sizeof(DescriptorInfo));
assert(DescBytesToAllocate % sizeof(void *) == 0 &&
"We need this to satisfy alignment constraints for Uses");
uint8_t *Storage = static_cast<uint8_t *>(
::operator new(Size + sizeof(Use) * Us + DescBytesToAllocate));
Use *Start = reinterpret_cast<Use *>(Storage + DescBytesToAllocate);
Use *End = Start + Us;
User *Obj = reinterpret_cast<User*>(End);
Obj->NumUserOperands = Us;
Obj->HasHungOffUses = false;
Obj->HasDescriptor = DescBytes != 0;
for (; Start != End; Start++)
new (Start) Use(Obj);
if (DescBytes != 0) {
auto *DescInfo = reinterpret_cast<DescriptorInfo *>(Storage + DescBytes);
DescInfo->SizeInBytes = DescBytes;
}
return Obj;
}
void *User::operator new(size_t Size, unsigned Us) {
return allocateFixedOperandUser(Size, Us, 0);
}
void *User::operator new(size_t Size, unsigned Us, unsigned DescBytes) {
return allocateFixedOperandUser(Size, Us, DescBytes);
}
void *User::operator new(size_t Size) {
// Allocate space for a single Use*
void *Storage = ::operator new(Size + sizeof(Use *));
Use **HungOffOperandList = static_cast<Use **>(Storage);
User *Obj = reinterpret_cast<User *>(HungOffOperandList + 1);
Obj->NumUserOperands = 0;
Obj->HasHungOffUses = true;
Obj->HasDescriptor = false;
*HungOffOperandList = nullptr;
return Obj;
}
//===----------------------------------------------------------------------===//
// User operator delete Implementation
//===----------------------------------------------------------------------===//
// Repress memory sanitization, due to use-after-destroy by operator
// delete. Bug report 24578 identifies this issue.
LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE void User::operator delete(void *Usr) {
// Hung off uses use a single Use* before the User, while other subclasses
// use a Use[] allocated prior to the user.
User *Obj = static_cast<User *>(Usr);
if (Obj->HasHungOffUses) {
assert(!Obj->HasDescriptor && "not supported!");
Use **HungOffOperandList = static_cast<Use **>(Usr) - 1;
// drop the hung off uses.
Use::zap(*HungOffOperandList, *HungOffOperandList + Obj->NumUserOperands,
/* Delete */ true);
::operator delete(HungOffOperandList);
} else if (Obj->HasDescriptor) {
Use *UseBegin = static_cast<Use *>(Usr) - Obj->NumUserOperands;
Use::zap(UseBegin, UseBegin + Obj->NumUserOperands, /* Delete */ false);
auto *DI = reinterpret_cast<DescriptorInfo *>(UseBegin) - 1;
uint8_t *Storage = reinterpret_cast<uint8_t *>(DI) - DI->SizeInBytes;
::operator delete(Storage);
} else {
Use *Storage = static_cast<Use *>(Usr) - Obj->NumUserOperands;
Use::zap(Storage, Storage + Obj->NumUserOperands,
/* Delete */ false);
::operator delete(Storage);
}
}
} // namespace llvm
|
