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(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(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 Resume: return "resume";
105 case Unwind: return "unwind";
106 case Unreachable: return "unreachable";
108 // Standard binary operators...
109 case Add: return "add";
110 case FAdd: return "fadd";
111 case Sub: return "sub";
112 case FSub: return "fsub";
113 case Mul: return "mul";
114 case FMul: return "fmul";
115 case UDiv: return "udiv";
116 case SDiv: return "sdiv";
117 case FDiv: return "fdiv";
118 case URem: return "urem";
119 case SRem: return "srem";
120 case FRem: return "frem";
122 // Logical operators...
123 case And: return "and";
124 case Or : return "or";
125 case Xor: return "xor";
127 // Memory instructions...
128 case Alloca: return "alloca";
129 case Load: return "load";
130 case Store: return "store";
131 case Fence: return "fence";
132 case GetElementPtr: return "getelementptr";
134 // Convert instructions...
135 case Trunc: return "trunc";
136 case ZExt: return "zext";
137 case SExt: return "sext";
138 case FPTrunc: return "fptrunc";
139 case FPExt: return "fpext";
140 case FPToUI: return "fptoui";
141 case FPToSI: return "fptosi";
142 case UIToFP: return "uitofp";
143 case SIToFP: return "sitofp";
144 case IntToPtr: return "inttoptr";
145 case PtrToInt: return "ptrtoint";
146 case BitCast: return "bitcast";
148 // Other instructions...
149 case ICmp: return "icmp";
150 case FCmp: return "fcmp";
151 case PHI: return "phi";
152 case Select: return "select";
153 case Call: return "call";
154 case Shl: return "shl";
155 case LShr: return "lshr";
156 case AShr: return "ashr";
157 case VAArg: return "va_arg";
158 case ExtractElement: return "extractelement";
159 case InsertElement: return "insertelement";
160 case ShuffleVector: return "shufflevector";
161 case ExtractValue: return "extractvalue";
162 case InsertValue: return "insertvalue";
163 case LandingPad: return "landingpad";
165 default: return "<Invalid operator> ";
171 /// isIdenticalTo - Return true if the specified instruction is exactly
172 /// identical to the current one. This means that all operands match and any
173 /// extra information (e.g. load is volatile) agree.
174 bool Instruction::isIdenticalTo(const Instruction *I) const {
175 return isIdenticalToWhenDefined(I) &&
176 SubclassOptionalData == I->SubclassOptionalData;
179 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
180 /// ignores the SubclassOptionalData flags, which specify conditions
181 /// under which the instruction's result is undefined.
182 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
183 if (getOpcode() != I->getOpcode() ||
184 getNumOperands() != I->getNumOperands() ||
185 getType() != I->getType())
188 // We have two instructions of identical opcode and #operands. Check to see
189 // if all operands are the same.
190 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
191 if (getOperand(i) != I->getOperand(i))
194 // Check special state that is a part of some instructions.
195 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
196 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
197 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
198 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
199 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
200 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
201 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
202 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
203 if (const CallInst *CI = dyn_cast<CallInst>(this))
204 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
205 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
206 CI->getAttributes() == cast<CallInst>(I)->getAttributes();
207 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
208 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
209 CI->getAttributes() == cast<InvokeInst>(I)->getAttributes();
210 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this))
211 return IVI->getIndices() == cast<InsertValueInst>(I)->getIndices();
212 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this))
213 return EVI->getIndices() == cast<ExtractValueInst>(I)->getIndices();
214 if (const FenceInst *FI = dyn_cast<FenceInst>(this))
215 return FI->getOrdering() == cast<FenceInst>(FI)->getOrdering() &&
216 FI->getSynchScope() == cast<FenceInst>(FI)->getSynchScope();
222 // This should be kept in sync with isEquivalentOperation in
223 // lib/Transforms/IPO/MergeFunctions.cpp.
224 bool Instruction::isSameOperationAs(const Instruction *I) const {
225 if (getOpcode() != I->getOpcode() ||
226 getNumOperands() != I->getNumOperands() ||
227 getType() != I->getType())
230 // We have two instructions of identical opcode and #operands. Check to see
231 // if all operands are the same type
232 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
233 if (getOperand(i)->getType() != I->getOperand(i)->getType())
236 // Check special state that is a part of some instructions.
237 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
238 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
239 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
240 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
241 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
242 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
243 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
244 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
245 if (const CallInst *CI = dyn_cast<CallInst>(this))
246 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
247 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
248 CI->getAttributes() == cast<CallInst>(I)->getAttributes();
249 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
250 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
251 CI->getAttributes() ==
252 cast<InvokeInst>(I)->getAttributes();
253 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this))
254 return IVI->getIndices() == cast<InsertValueInst>(I)->getIndices();
255 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this))
256 return EVI->getIndices() == cast<ExtractValueInst>(I)->getIndices();
257 if (const FenceInst *FI = dyn_cast<FenceInst>(this))
258 return FI->getOrdering() == cast<FenceInst>(FI)->getOrdering() &&
259 FI->getSynchScope() == cast<FenceInst>(FI)->getSynchScope();
264 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
265 /// specified block. Note that PHI nodes are considered to evaluate their
266 /// operands in the corresponding predecessor block.
267 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
268 for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
269 // PHI nodes uses values in the corresponding predecessor block. For other
270 // instructions, just check to see whether the parent of the use matches up.
272 const PHINode *PN = dyn_cast<PHINode>(U);
274 if (cast<Instruction>(U)->getParent() != BB)
279 if (PN->getIncomingBlock(UI) != BB)
285 /// mayReadFromMemory - Return true if this instruction may read memory.
287 bool Instruction::mayReadFromMemory() const {
288 switch (getOpcode()) {
289 default: return false;
290 case Instruction::VAArg:
291 case Instruction::Load:
292 case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
294 case Instruction::Call:
295 return !cast<CallInst>(this)->doesNotAccessMemory();
296 case Instruction::Invoke:
297 return !cast<InvokeInst>(this)->doesNotAccessMemory();
298 case Instruction::Store:
299 return cast<StoreInst>(this)->isVolatile();
303 /// mayWriteToMemory - Return true if this instruction may modify memory.
305 bool Instruction::mayWriteToMemory() const {
306 switch (getOpcode()) {
307 default: return false;
308 case Instruction::Fence: // FIXME: refine definition of mayWriteToMemory
309 case Instruction::Store:
310 case Instruction::VAArg:
312 case Instruction::Call:
313 return !cast<CallInst>(this)->onlyReadsMemory();
314 case Instruction::Invoke:
315 return !cast<InvokeInst>(this)->onlyReadsMemory();
316 case Instruction::Load:
317 return cast<LoadInst>(this)->isVolatile();
321 /// mayThrow - Return true if this instruction may throw an exception.
323 bool Instruction::mayThrow() const {
324 if (const CallInst *CI = dyn_cast<CallInst>(this))
325 return !CI->doesNotThrow();
329 /// isAssociative - Return true if the instruction is associative:
331 /// Associative operators satisfy: x op (y op z) === (x op y) op z
333 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
335 bool Instruction::isAssociative(unsigned Opcode) {
336 return Opcode == And || Opcode == Or || Opcode == Xor ||
337 Opcode == Add || Opcode == Mul;
340 /// isCommutative - Return true if the instruction is commutative:
342 /// Commutative operators satisfy: (x op y) === (y op x)
344 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
345 /// applied to any type.
347 bool Instruction::isCommutative(unsigned op) {
362 bool Instruction::isSafeToSpeculativelyExecute() const {
363 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
364 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
368 switch (getOpcode()) {
373 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
374 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
375 return Op && !Op->isNullValue();
379 // x / y is undefined if y == 0, and might be undefined if y == -1,
380 // but calcuations like x / 3 are safe.
381 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
382 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
385 const LoadInst *LI = cast<LoadInst>(this);
386 if (LI->isVolatile())
388 return LI->getPointerOperand()->isDereferenceablePointer();
391 return false; // The called function could have undefined behavior or
393 // FIXME: We should special-case some intrinsics (bswap,
394 // overflow-checking arithmetic, etc.)
407 return false; // Misc instructions which have effects
411 Instruction *Instruction::clone() const {
412 Instruction *New = clone_impl();
413 New->SubclassOptionalData = SubclassOptionalData;
417 // Otherwise, enumerate and copy over metadata from the old instruction to the
419 SmallVector<std::pair<unsigned, MDNode*>, 4> TheMDs;
420 getAllMetadataOtherThanDebugLoc(TheMDs);
421 for (unsigned i = 0, e = TheMDs.size(); i != e; ++i)
422 New->setMetadata(TheMDs[i].first, TheMDs[i].second);
424 New->setDebugLoc(getDebugLoc());