1 //===-- Instruction.cpp - Implement the Instruction class -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Instruction class for the VMCore library.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Instruction.h"
15 #include "llvm/Type.h"
16 #include "llvm/Instructions.h"
17 #include "llvm/Constants.h"
18 #include "llvm/Module.h"
19 #include "llvm/Support/CallSite.h"
20 #include "llvm/Support/LeakDetector.h"
23 Instruction::Instruction(const Type
*ty
, unsigned it
, Use
*Ops
, unsigned NumOps
,
24 Instruction
*InsertBefore
)
25 : User(ty
, Value::InstructionVal
+ it
, Ops
, NumOps
), Parent(0) {
26 // Make sure that we get added to a basicblock
27 LeakDetector::addGarbageObject(this);
29 // If requested, insert this instruction into a basic block...
31 assert(InsertBefore
->getParent() &&
32 "Instruction to insert before is not in a basic block!");
33 InsertBefore
->getParent()->getInstList().insert(InsertBefore
, this);
37 Instruction::Instruction(const Type
*ty
, unsigned it
, Use
*Ops
, unsigned NumOps
,
38 BasicBlock
*InsertAtEnd
)
39 : User(ty
, Value::InstructionVal
+ it
, Ops
, NumOps
), Parent(0) {
40 // Make sure that we get added to a basicblock
41 LeakDetector::addGarbageObject(this);
43 // append this instruction into the basic block
44 assert(InsertAtEnd
&& "Basic block to append to may not be NULL!");
45 InsertAtEnd
->getInstList().push_back(this);
49 // Out of line virtual method, so the vtable, etc has a home.
50 Instruction::~Instruction() {
51 assert(Parent
== 0 && "Instruction still linked in the program!");
52 if (hasMetadataHashEntry())
53 clearMetadataHashEntries();
57 void Instruction::setParent(BasicBlock
*P
) {
59 if (!P
) LeakDetector::addGarbageObject(this);
61 if (P
) LeakDetector::removeGarbageObject(this);
67 void Instruction::removeFromParent() {
68 getParent()->getInstList().remove(this);
71 void Instruction::eraseFromParent() {
72 getParent()->getInstList().erase(this);
75 /// insertBefore - Insert an unlinked instructions into a basic block
76 /// immediately before the specified instruction.
77 void Instruction::insertBefore(Instruction
*InsertPos
) {
78 InsertPos
->getParent()->getInstList().insert(InsertPos
, this);
81 /// insertAfter - Insert an unlinked instructions into a basic block
82 /// immediately after the specified instruction.
83 void Instruction::insertAfter(Instruction
*InsertPos
) {
84 InsertPos
->getParent()->getInstList().insertAfter(InsertPos
, this);
87 /// moveBefore - Unlink this instruction from its current basic block and
88 /// insert it into the basic block that MovePos lives in, right before
90 void Instruction::moveBefore(Instruction
*MovePos
) {
91 MovePos
->getParent()->getInstList().splice(MovePos
,getParent()->getInstList(),
96 const char *Instruction::getOpcodeName(unsigned OpCode
) {
99 case Ret
: return "ret";
100 case Br
: return "br";
101 case Switch
: return "switch";
102 case IndirectBr
: return "indirectbr";
103 case Invoke
: return "invoke";
104 case Unwind
: return "unwind";
105 case Unreachable
: return "unreachable";
107 // Standard binary operators...
108 case Add
: return "add";
109 case FAdd
: return "fadd";
110 case Sub
: return "sub";
111 case FSub
: return "fsub";
112 case Mul
: return "mul";
113 case FMul
: return "fmul";
114 case UDiv
: return "udiv";
115 case SDiv
: return "sdiv";
116 case FDiv
: return "fdiv";
117 case URem
: return "urem";
118 case SRem
: return "srem";
119 case FRem
: return "frem";
121 // Logical operators...
122 case And
: return "and";
123 case Or
: return "or";
124 case Xor
: return "xor";
126 // Memory instructions...
127 case Alloca
: return "alloca";
128 case Load
: return "load";
129 case Store
: return "store";
130 case GetElementPtr
: return "getelementptr";
132 // Convert instructions...
133 case Trunc
: return "trunc";
134 case ZExt
: return "zext";
135 case SExt
: return "sext";
136 case FPTrunc
: return "fptrunc";
137 case FPExt
: return "fpext";
138 case FPToUI
: return "fptoui";
139 case FPToSI
: return "fptosi";
140 case UIToFP
: return "uitofp";
141 case SIToFP
: return "sitofp";
142 case IntToPtr
: return "inttoptr";
143 case PtrToInt
: return "ptrtoint";
144 case BitCast
: return "bitcast";
146 // Other instructions...
147 case ICmp
: return "icmp";
148 case FCmp
: return "fcmp";
149 case PHI
: return "phi";
150 case Select
: return "select";
151 case Call
: return "call";
152 case Shl
: return "shl";
153 case LShr
: return "lshr";
154 case AShr
: return "ashr";
155 case VAArg
: return "va_arg";
156 case ExtractElement
: return "extractelement";
157 case InsertElement
: return "insertelement";
158 case ShuffleVector
: return "shufflevector";
159 case ExtractValue
: return "extractvalue";
160 case InsertValue
: return "insertvalue";
162 default: return "<Invalid operator> ";
168 /// isIdenticalTo - Return true if the specified instruction is exactly
169 /// identical to the current one. This means that all operands match and any
170 /// extra information (e.g. load is volatile) agree.
171 bool Instruction::isIdenticalTo(const Instruction
*I
) const {
172 return isIdenticalToWhenDefined(I
) &&
173 SubclassOptionalData
== I
->SubclassOptionalData
;
176 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
177 /// ignores the SubclassOptionalData flags, which specify conditions
178 /// under which the instruction's result is undefined.
179 bool Instruction::isIdenticalToWhenDefined(const Instruction
*I
) const {
180 if (getOpcode() != I
->getOpcode() ||
181 getNumOperands() != I
->getNumOperands() ||
182 getType() != I
->getType())
185 // We have two instructions of identical opcode and #operands. Check to see
186 // if all operands are the same.
187 for (unsigned i
= 0, e
= getNumOperands(); i
!= e
; ++i
)
188 if (getOperand(i
) != I
->getOperand(i
))
191 // Check special state that is a part of some instructions.
192 if (const LoadInst
*LI
= dyn_cast
<LoadInst
>(this))
193 return LI
->isVolatile() == cast
<LoadInst
>(I
)->isVolatile() &&
194 LI
->getAlignment() == cast
<LoadInst
>(I
)->getAlignment();
195 if (const StoreInst
*SI
= dyn_cast
<StoreInst
>(this))
196 return SI
->isVolatile() == cast
<StoreInst
>(I
)->isVolatile() &&
197 SI
->getAlignment() == cast
<StoreInst
>(I
)->getAlignment();
198 if (const CmpInst
*CI
= dyn_cast
<CmpInst
>(this))
199 return CI
->getPredicate() == cast
<CmpInst
>(I
)->getPredicate();
200 if (const CallInst
*CI
= dyn_cast
<CallInst
>(this))
201 return CI
->isTailCall() == cast
<CallInst
>(I
)->isTailCall() &&
202 CI
->getCallingConv() == cast
<CallInst
>(I
)->getCallingConv() &&
203 CI
->getAttributes().getRawPointer() ==
204 cast
<CallInst
>(I
)->getAttributes().getRawPointer();
205 if (const InvokeInst
*CI
= dyn_cast
<InvokeInst
>(this))
206 return CI
->getCallingConv() == cast
<InvokeInst
>(I
)->getCallingConv() &&
207 CI
->getAttributes().getRawPointer() ==
208 cast
<InvokeInst
>(I
)->getAttributes().getRawPointer();
209 if (const InsertValueInst
*IVI
= dyn_cast
<InsertValueInst
>(this)) {
210 if (IVI
->getNumIndices() != cast
<InsertValueInst
>(I
)->getNumIndices())
212 for (unsigned i
= 0, e
= IVI
->getNumIndices(); i
!= e
; ++i
)
213 if (IVI
->idx_begin()[i
] != cast
<InsertValueInst
>(I
)->idx_begin()[i
])
217 if (const ExtractValueInst
*EVI
= dyn_cast
<ExtractValueInst
>(this)) {
218 if (EVI
->getNumIndices() != cast
<ExtractValueInst
>(I
)->getNumIndices())
220 for (unsigned i
= 0, e
= EVI
->getNumIndices(); i
!= e
; ++i
)
221 if (EVI
->idx_begin()[i
] != cast
<ExtractValueInst
>(I
)->idx_begin()[i
])
230 // This should be kept in sync with isEquivalentOperation in
231 // lib/Transforms/IPO/MergeFunctions.cpp.
232 bool Instruction::isSameOperationAs(const Instruction
*I
) const {
233 if (getOpcode() != I
->getOpcode() ||
234 getNumOperands() != I
->getNumOperands() ||
235 getType() != I
->getType())
238 // We have two instructions of identical opcode and #operands. Check to see
239 // if all operands are the same type
240 for (unsigned i
= 0, e
= getNumOperands(); i
!= e
; ++i
)
241 if (getOperand(i
)->getType() != I
->getOperand(i
)->getType())
244 // Check special state that is a part of some instructions.
245 if (const LoadInst
*LI
= dyn_cast
<LoadInst
>(this))
246 return LI
->isVolatile() == cast
<LoadInst
>(I
)->isVolatile() &&
247 LI
->getAlignment() == cast
<LoadInst
>(I
)->getAlignment();
248 if (const StoreInst
*SI
= dyn_cast
<StoreInst
>(this))
249 return SI
->isVolatile() == cast
<StoreInst
>(I
)->isVolatile() &&
250 SI
->getAlignment() == cast
<StoreInst
>(I
)->getAlignment();
251 if (const CmpInst
*CI
= dyn_cast
<CmpInst
>(this))
252 return CI
->getPredicate() == cast
<CmpInst
>(I
)->getPredicate();
253 if (const CallInst
*CI
= dyn_cast
<CallInst
>(this))
254 return CI
->isTailCall() == cast
<CallInst
>(I
)->isTailCall() &&
255 CI
->getCallingConv() == cast
<CallInst
>(I
)->getCallingConv() &&
256 CI
->getAttributes().getRawPointer() ==
257 cast
<CallInst
>(I
)->getAttributes().getRawPointer();
258 if (const InvokeInst
*CI
= dyn_cast
<InvokeInst
>(this))
259 return CI
->getCallingConv() == cast
<InvokeInst
>(I
)->getCallingConv() &&
260 CI
->getAttributes().getRawPointer() ==
261 cast
<InvokeInst
>(I
)->getAttributes().getRawPointer();
262 if (const InsertValueInst
*IVI
= dyn_cast
<InsertValueInst
>(this)) {
263 if (IVI
->getNumIndices() != cast
<InsertValueInst
>(I
)->getNumIndices())
265 for (unsigned i
= 0, e
= IVI
->getNumIndices(); i
!= e
; ++i
)
266 if (IVI
->idx_begin()[i
] != cast
<InsertValueInst
>(I
)->idx_begin()[i
])
270 if (const ExtractValueInst
*EVI
= dyn_cast
<ExtractValueInst
>(this)) {
271 if (EVI
->getNumIndices() != cast
<ExtractValueInst
>(I
)->getNumIndices())
273 for (unsigned i
= 0, e
= EVI
->getNumIndices(); i
!= e
; ++i
)
274 if (EVI
->idx_begin()[i
] != cast
<ExtractValueInst
>(I
)->idx_begin()[i
])
282 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
283 /// specified block. Note that PHI nodes are considered to evaluate their
284 /// operands in the corresponding predecessor block.
285 bool Instruction::isUsedOutsideOfBlock(const BasicBlock
*BB
) const {
286 for (const_use_iterator UI
= use_begin(), E
= use_end(); UI
!= E
; ++UI
) {
287 // PHI nodes uses values in the corresponding predecessor block. For other
288 // instructions, just check to see whether the parent of the use matches up.
290 const PHINode
*PN
= dyn_cast
<PHINode
>(U
);
292 if (cast
<Instruction
>(U
)->getParent() != BB
)
297 if (PN
->getIncomingBlock(UI
) != BB
)
303 /// mayReadFromMemory - Return true if this instruction may read memory.
305 bool Instruction::mayReadFromMemory() const {
306 switch (getOpcode()) {
307 default: return false;
308 case Instruction::VAArg
:
309 case Instruction::Load
:
311 case Instruction::Call
:
312 return !cast
<CallInst
>(this)->doesNotAccessMemory();
313 case Instruction::Invoke
:
314 return !cast
<InvokeInst
>(this)->doesNotAccessMemory();
315 case Instruction::Store
:
316 return cast
<StoreInst
>(this)->isVolatile();
320 /// mayWriteToMemory - Return true if this instruction may modify memory.
322 bool Instruction::mayWriteToMemory() const {
323 switch (getOpcode()) {
324 default: return false;
325 case Instruction::Store
:
326 case Instruction::VAArg
:
328 case Instruction::Call
:
329 return !cast
<CallInst
>(this)->onlyReadsMemory();
330 case Instruction::Invoke
:
331 return !cast
<InvokeInst
>(this)->onlyReadsMemory();
332 case Instruction::Load
:
333 return cast
<LoadInst
>(this)->isVolatile();
337 /// mayThrow - Return true if this instruction may throw an exception.
339 bool Instruction::mayThrow() const {
340 if (const CallInst
*CI
= dyn_cast
<CallInst
>(this))
341 return !CI
->doesNotThrow();
345 /// isAssociative - Return true if the instruction is associative:
347 /// Associative operators satisfy: x op (y op z) === (x op y) op z
349 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
351 bool Instruction::isAssociative(unsigned Opcode
, const Type
*Ty
) {
352 return Opcode
== And
|| Opcode
== Or
|| Opcode
== Xor
||
353 Opcode
== Add
|| Opcode
== Mul
;
356 /// isCommutative - Return true if the instruction is commutative:
358 /// Commutative operators satisfy: (x op y) === (y op x)
360 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
361 /// applied to any type.
363 bool Instruction::isCommutative(unsigned op
) {
378 bool Instruction::isSafeToSpeculativelyExecute() const {
379 for (unsigned i
= 0, e
= getNumOperands(); i
!= e
; ++i
)
380 if (Constant
*C
= dyn_cast
<Constant
>(getOperand(i
)))
384 switch (getOpcode()) {
389 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
390 ConstantInt
*Op
= dyn_cast
<ConstantInt
>(getOperand(1));
391 return Op
&& !Op
->isNullValue();
395 // x / y is undefined if y == 0, and might be undefined if y == -1,
396 // but calcuations like x / 3 are safe.
397 ConstantInt
*Op
= dyn_cast
<ConstantInt
>(getOperand(1));
398 return Op
&& !Op
->isNullValue() && !Op
->isAllOnesValue();
401 if (cast
<LoadInst
>(this)->isVolatile())
403 // Note that it is not safe to speculate into a malloc'd region because
404 // malloc may return null.
405 // It's also not safe to follow a bitcast, for example:
406 // bitcast i8* (alloca i8) to i32*
407 // would result in a 4-byte load from a 1-byte alloca.
408 Value
*Op0
= getOperand(0);
409 if (GEPOperator
*GEP
= dyn_cast
<GEPOperator
>(Op0
)) {
410 // TODO: it's safe to do this for any GEP with constant indices that
411 // compute inside the allocated type, but not for any inbounds gep.
412 if (GEP
->hasAllZeroIndices())
413 Op0
= GEP
->getPointerOperand();
415 if (isa
<AllocaInst
>(Op0
))
417 if (GlobalVariable
*GV
= dyn_cast
<GlobalVariable
>(getOperand(0)))
418 return !GV
->hasExternalWeakLinkage();
422 return false; // The called function could have undefined behavior or
424 // FIXME: We should special-case some intrinsics (bswap,
425 // overflow-checking arithmetic, etc.)
437 return false; // Misc instructions which have effects
441 Instruction
*Instruction::clone() const {
442 Instruction
*New
= clone_impl();
443 New
->SubclassOptionalData
= SubclassOptionalData
;
447 // Otherwise, enumerate and copy over metadata from the old instruction to the
449 SmallVector
<std::pair
<unsigned, MDNode
*>, 4> TheMDs
;
450 getAllMetadata(TheMDs
);
451 for (unsigned i
= 0, e
= TheMDs
.size(); i
!= e
; ++i
)
452 New
->setMetadata(TheMDs
[i
].first
, TheMDs
[i
].second
);