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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
|
//===-- Instruction.cpp - Implement the Instruction 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 Instruction class for the VMCore library.
//
//===----------------------------------------------------------------------===//
#include "llvm/Instruction.h"
#include "llvm/Type.h"
#include "llvm/Instructions.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/LeakDetector.h"
using namespace llvm;
Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
Instruction *InsertBefore)
: User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
// Make sure that we get added to a basicblock
LeakDetector::addGarbageObject(this);
// If requested, insert this instruction into a basic block...
if (InsertBefore) {
assert(InsertBefore->getParent() &&
"Instruction to insert before is not in a basic block!");
InsertBefore->getParent()->getInstList().insert(InsertBefore, this);
}
}
Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
BasicBlock *InsertAtEnd)
: User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
// Make sure that we get added to a basicblock
LeakDetector::addGarbageObject(this);
// append this instruction into the basic block
assert(InsertAtEnd && "Basic block to append to may not be NULL!");
InsertAtEnd->getInstList().push_back(this);
}
// Out of line virtual method, so the vtable, etc has a home.
Instruction::~Instruction() {
assert(Parent == 0 && "Instruction still linked in the program!");
if (hasMetadata())
removeAllMetadata();
}
void Instruction::setParent(BasicBlock *P) {
if (getParent()) {
if (!P) LeakDetector::addGarbageObject(this);
} else {
if (P) LeakDetector::removeGarbageObject(this);
}
Parent = P;
}
void Instruction::removeFromParent() {
getParent()->getInstList().remove(this);
}
void Instruction::eraseFromParent() {
getParent()->getInstList().erase(this);
}
/// insertBefore - Insert an unlinked instructions into a basic block
/// immediately before the specified instruction.
void Instruction::insertBefore(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insert(InsertPos, this);
}
/// insertAfter - Insert an unlinked instructions into a basic block
/// immediately after the specified instruction.
void Instruction::insertAfter(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insertAfter(InsertPos, this);
}
/// moveBefore - Unlink this instruction from its current basic block and
/// insert it into the basic block that MovePos lives in, right before
/// MovePos.
void Instruction::moveBefore(Instruction *MovePos) {
MovePos->getParent()->getInstList().splice(MovePos,getParent()->getInstList(),
this);
}
const char *Instruction::getOpcodeName(unsigned OpCode) {
switch (OpCode) {
// Terminators
case Ret: return "ret";
case Br: return "br";
case Switch: return "switch";
case IndirectBr: return "indirectbr";
case Invoke: return "invoke";
case Unwind: return "unwind";
case Unreachable: return "unreachable";
// Standard binary operators...
case Add: return "add";
case FAdd: return "fadd";
case Sub: return "sub";
case FSub: return "fsub";
case Mul: return "mul";
case FMul: return "fmul";
case UDiv: return "udiv";
case SDiv: return "sdiv";
case FDiv: return "fdiv";
case URem: return "urem";
case SRem: return "srem";
case FRem: return "frem";
// Logical operators...
case And: return "and";
case Or : return "or";
case Xor: return "xor";
// Memory instructions...
case Alloca: return "alloca";
case Load: return "load";
case Store: return "store";
case GetElementPtr: return "getelementptr";
// Convert instructions...
case Trunc: return "trunc";
case ZExt: return "zext";
case SExt: return "sext";
case FPTrunc: return "fptrunc";
case FPExt: return "fpext";
case FPToUI: return "fptoui";
case FPToSI: return "fptosi";
case UIToFP: return "uitofp";
case SIToFP: return "sitofp";
case IntToPtr: return "inttoptr";
case PtrToInt: return "ptrtoint";
case BitCast: return "bitcast";
// Other instructions...
case ICmp: return "icmp";
case FCmp: return "fcmp";
case PHI: return "phi";
case Select: return "select";
case Call: return "call";
case Shl: return "shl";
case LShr: return "lshr";
case AShr: return "ashr";
case VAArg: return "va_arg";
case ExtractElement: return "extractelement";
case InsertElement: return "insertelement";
case ShuffleVector: return "shufflevector";
case ExtractValue: return "extractvalue";
case InsertValue: return "insertvalue";
default: return "<Invalid operator> ";
}
return 0;
}
/// isIdenticalTo - Return true if the specified instruction is exactly
/// identical to the current one. This means that all operands match and any
/// extra information (e.g. load is volatile) agree.
bool Instruction::isIdenticalTo(const Instruction *I) const {
return isIdenticalToWhenDefined(I) &&
SubclassOptionalData == I->SubclassOptionalData;
}
/// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
/// ignores the SubclassOptionalData flags, which specify conditions
/// under which the instruction's result is undefined.
bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
if (getOpcode() != I->getOpcode() ||
getNumOperands() != I->getNumOperands() ||
getType() != I->getType())
return false;
// We have two instructions of identical opcode and #operands. Check to see
// if all operands are the same.
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (getOperand(i) != I->getOperand(i))
return false;
// Check special state that is a part of some instructions.
if (const LoadInst *LI = dyn_cast<LoadInst>(this))
return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
if (const StoreInst *SI = dyn_cast<StoreInst>(this))
return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
if (const CmpInst *CI = dyn_cast<CmpInst>(this))
return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
if (const CallInst *CI = dyn_cast<CallInst>(this))
return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
CI->getAttributes().getRawPointer() ==
cast<CallInst>(I)->getAttributes().getRawPointer();
if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
CI->getAttributes().getRawPointer() ==
cast<InvokeInst>(I)->getAttributes().getRawPointer();
if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
return false;
for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
return false;
return true;
}
if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
return false;
for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
return false;
return true;
}
return true;
}
// isSameOperationAs
// This should be kept in sync with isEquivalentOperation in
// lib/Transforms/IPO/MergeFunctions.cpp.
bool Instruction::isSameOperationAs(const Instruction *I) const {
if (getOpcode() != I->getOpcode() ||
getNumOperands() != I->getNumOperands() ||
getType() != I->getType())
return false;
// We have two instructions of identical opcode and #operands. Check to see
// if all operands are the same type
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (getOperand(i)->getType() != I->getOperand(i)->getType())
return false;
// Check special state that is a part of some instructions.
if (const LoadInst *LI = dyn_cast<LoadInst>(this))
return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
if (const StoreInst *SI = dyn_cast<StoreInst>(this))
return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
if (const CmpInst *CI = dyn_cast<CmpInst>(this))
return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
if (const CallInst *CI = dyn_cast<CallInst>(this))
return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
CI->getAttributes().getRawPointer() ==
cast<CallInst>(I)->getAttributes().getRawPointer();
if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
CI->getAttributes().getRawPointer() ==
cast<InvokeInst>(I)->getAttributes().getRawPointer();
if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
return false;
for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
return false;
return true;
}
if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
return false;
for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
return false;
return true;
}
return true;
}
/// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
/// specified block. Note that PHI nodes are considered to evaluate their
/// operands in the corresponding predecessor block.
bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
// PHI nodes uses values in the corresponding predecessor block. For other
// instructions, just check to see whether the parent of the use matches up.
const PHINode *PN = dyn_cast<PHINode>(*UI);
if (PN == 0) {
if (cast<Instruction>(*UI)->getParent() != BB)
return true;
continue;
}
if (PN->getIncomingBlock(UI) != BB)
return true;
}
return false;
}
/// mayReadFromMemory - Return true if this instruction may read memory.
///
bool Instruction::mayReadFromMemory() const {
switch (getOpcode()) {
default: return false;
case Instruction::VAArg:
case Instruction::Load:
return true;
case Instruction::Call:
return !cast<CallInst>(this)->doesNotAccessMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->doesNotAccessMemory();
case Instruction::Store:
return cast<StoreInst>(this)->isVolatile();
}
}
/// mayWriteToMemory - Return true if this instruction may modify memory.
///
bool Instruction::mayWriteToMemory() const {
switch (getOpcode()) {
default: return false;
case Instruction::Store:
case Instruction::VAArg:
return true;
case Instruction::Call:
return !cast<CallInst>(this)->onlyReadsMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->onlyReadsMemory();
case Instruction::Load:
return cast<LoadInst>(this)->isVolatile();
}
}
/// mayThrow - Return true if this instruction may throw an exception.
///
bool Instruction::mayThrow() const {
if (const CallInst *CI = dyn_cast<CallInst>(this))
return !CI->doesNotThrow();
return false;
}
/// isAssociative - Return true if the instruction is associative:
///
/// Associative operators satisfy: x op (y op z) === (x op y) op z
///
/// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
///
bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
return Opcode == And || Opcode == Or || Opcode == Xor ||
Opcode == Add || Opcode == Mul;
}
/// isCommutative - Return true if the instruction is commutative:
///
/// Commutative operators satisfy: (x op y) === (y op x)
///
/// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
/// applied to any type.
///
bool Instruction::isCommutative(unsigned op) {
switch (op) {
case Add:
case FAdd:
case Mul:
case FMul:
case And:
case Or:
case Xor:
return true;
default:
return false;
}
}
bool Instruction::isSafeToSpeculativelyExecute() const {
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (Constant *C = dyn_cast<Constant>(getOperand(i)))
if (C->canTrap())
return false;
switch (getOpcode()) {
default:
return true;
case UDiv:
case URem: {
// x / y is undefined if y == 0, but calcuations like x / 3 are safe.
ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
return Op && !Op->isNullValue();
}
case SDiv:
case SRem: {
// x / y is undefined if y == 0, and might be undefined if y == -1,
// but calcuations like x / 3 are safe.
ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
return Op && !Op->isNullValue() && !Op->isAllOnesValue();
}
case Load: {
if (cast<LoadInst>(this)->isVolatile())
return false;
// Note that it is not safe to speculate into a malloc'd region because
// malloc may return null.
if (isa<AllocaInst>(getOperand(0)))
return true;
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
return !GV->hasExternalWeakLinkage();
// FIXME: Handle cases involving GEPs. We have to be careful because
// a load of a out-of-bounds GEP has undefined behavior.
return false;
}
case Call:
return false; // The called function could have undefined behavior or
// side-effects.
// FIXME: We should special-case some intrinsics (bswap,
// overflow-checking arithmetic, etc.)
case VAArg:
case Alloca:
case Invoke:
case PHI:
case Store:
case Ret:
case Br:
case IndirectBr:
case Switch:
case Unwind:
case Unreachable:
return false; // Misc instructions which have effects
}
}
Instruction *Instruction::clone() const {
Instruction *New = clone_impl();
New->SubclassOptionalData = SubclassOptionalData;
if (!hasMetadata())
return New;
// Otherwise, enumerate and copy over metadata from the old instruction to the
// new one.
SmallVector<std::pair<unsigned, MDNode*>, 4> TheMDs;
getAllMetadata(TheMDs);
for (unsigned i = 0, e = TheMDs.size(); i != e; ++i)
New->setMetadata(TheMDs[i].first, TheMDs[i].second);
return New;
}
|