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 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 Fence: return "fence";
131 case GetElementPtr: return "getelementptr";
133 // Convert instructions...
134 case Trunc: return "trunc";
135 case ZExt: return "zext";
136 case SExt: return "sext";
137 case FPTrunc: return "fptrunc";
138 case FPExt: return "fpext";
139 case FPToUI: return "fptoui";
140 case FPToSI: return "fptosi";
141 case UIToFP: return "uitofp";
142 case SIToFP: return "sitofp";
143 case IntToPtr: return "inttoptr";
144 case PtrToInt: return "ptrtoint";
145 case BitCast: return "bitcast";
147 // Other instructions...
148 case ICmp: return "icmp";
149 case FCmp: return "fcmp";
150 case PHI: return "phi";
151 case Select: return "select";
152 case Call: return "call";
153 case Shl: return "shl";
154 case LShr: return "lshr";
155 case AShr: return "ashr";
156 case VAArg: return "va_arg";
157 case ExtractElement: return "extractelement";
158 case InsertElement: return "insertelement";
159 case ShuffleVector: return "shufflevector";
160 case ExtractValue: return "extractvalue";
161 case InsertValue: return "insertvalue";
163 default: return "<Invalid operator> ";
169 /// isIdenticalTo - Return true if the specified instruction is exactly
170 /// identical to the current one. This means that all operands match and any
171 /// extra information (e.g. load is volatile) agree.
172 bool Instruction::isIdenticalTo(const Instruction *I) const {
173 return isIdenticalToWhenDefined(I) &&
174 SubclassOptionalData == I->SubclassOptionalData;
177 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
178 /// ignores the SubclassOptionalData flags, which specify conditions
179 /// under which the instruction's result is undefined.
180 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
181 if (getOpcode() != I->getOpcode() ||
182 getNumOperands() != I->getNumOperands() ||
183 getType() != I->getType())
186 // We have two instructions of identical opcode and #operands. Check to see
187 // if all operands are the same.
188 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
189 if (getOperand(i) != I->getOperand(i))
192 // Check special state that is a part of some instructions.
193 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
194 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
195 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
196 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
197 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
198 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
199 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
200 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
201 if (const CallInst *CI = dyn_cast<CallInst>(this))
202 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
203 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
204 CI->getAttributes() == cast<CallInst>(I)->getAttributes();
205 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
206 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
207 CI->getAttributes() == cast<InvokeInst>(I)->getAttributes();
208 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this))
209 return IVI->getIndices() == cast<InsertValueInst>(I)->getIndices();
210 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this))
211 return EVI->getIndices() == cast<ExtractValueInst>(I)->getIndices();
212 if (const FenceInst *FI = dyn_cast<FenceInst>(this))
213 return FI->getOrdering() == cast<FenceInst>(FI)->getOrdering() &&
214 FI->getSynchScope() == cast<FenceInst>(FI)->getSynchScope();
220 // This should be kept in sync with isEquivalentOperation in
221 // lib/Transforms/IPO/MergeFunctions.cpp.
222 bool Instruction::isSameOperationAs(const Instruction *I) const {
223 if (getOpcode() != I->getOpcode() ||
224 getNumOperands() != I->getNumOperands() ||
225 getType() != I->getType())
228 // We have two instructions of identical opcode and #operands. Check to see
229 // if all operands are the same type
230 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
231 if (getOperand(i)->getType() != I->getOperand(i)->getType())
234 // Check special state that is a part of some instructions.
235 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
236 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
237 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
238 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
239 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
240 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
241 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
242 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
243 if (const CallInst *CI = dyn_cast<CallInst>(this))
244 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
245 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
246 CI->getAttributes() == cast<CallInst>(I)->getAttributes();
247 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
248 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
249 CI->getAttributes() ==
250 cast<InvokeInst>(I)->getAttributes();
251 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this))
252 return IVI->getIndices() == cast<InsertValueInst>(I)->getIndices();
253 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this))
254 return EVI->getIndices() == cast<ExtractValueInst>(I)->getIndices();
255 if (const FenceInst *FI = dyn_cast<FenceInst>(this))
256 return FI->getOrdering() == cast<FenceInst>(FI)->getOrdering() &&
257 FI->getSynchScope() == cast<FenceInst>(FI)->getSynchScope();
262 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
263 /// specified block. Note that PHI nodes are considered to evaluate their
264 /// operands in the corresponding predecessor block.
265 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
266 for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
267 // PHI nodes uses values in the corresponding predecessor block. For other
268 // instructions, just check to see whether the parent of the use matches up.
270 const PHINode *PN = dyn_cast<PHINode>(U);
272 if (cast<Instruction>(U)->getParent() != BB)
277 if (PN->getIncomingBlock(UI) != BB)
283 /// mayReadFromMemory - Return true if this instruction may read memory.
285 bool Instruction::mayReadFromMemory() const {
286 switch (getOpcode()) {
287 default: return false;
288 case Instruction::VAArg:
289 case Instruction::Load:
290 case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
292 case Instruction::Call:
293 return !cast<CallInst>(this)->doesNotAccessMemory();
294 case Instruction::Invoke:
295 return !cast<InvokeInst>(this)->doesNotAccessMemory();
296 case Instruction::Store:
297 return cast<StoreInst>(this)->isVolatile();
301 /// mayWriteToMemory - Return true if this instruction may modify memory.
303 bool Instruction::mayWriteToMemory() const {
304 switch (getOpcode()) {
305 default: return false;
306 case Instruction::Fence: // FIXME: refine definition of mayWriteToMemory
307 case Instruction::Store:
308 case Instruction::VAArg:
310 case Instruction::Call:
311 return !cast<CallInst>(this)->onlyReadsMemory();
312 case Instruction::Invoke:
313 return !cast<InvokeInst>(this)->onlyReadsMemory();
314 case Instruction::Load:
315 return cast<LoadInst>(this)->isVolatile();
319 /// mayThrow - Return true if this instruction may throw an exception.
321 bool Instruction::mayThrow() const {
322 if (const CallInst *CI = dyn_cast<CallInst>(this))
323 return !CI->doesNotThrow();
327 /// isAssociative - Return true if the instruction is associative:
329 /// Associative operators satisfy: x op (y op z) === (x op y) op z
331 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
333 bool Instruction::isAssociative(unsigned Opcode) {
334 return Opcode == And || Opcode == Or || Opcode == Xor ||
335 Opcode == Add || Opcode == Mul;
338 /// isCommutative - Return true if the instruction is commutative:
340 /// Commutative operators satisfy: (x op y) === (y op x)
342 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
343 /// applied to any type.
345 bool Instruction::isCommutative(unsigned op) {
360 bool Instruction::isSafeToSpeculativelyExecute() const {
361 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
362 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
366 switch (getOpcode()) {
371 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
372 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
373 return Op && !Op->isNullValue();
377 // x / y is undefined if y == 0, and might be undefined if y == -1,
378 // but calcuations like x / 3 are safe.
379 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
380 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
383 const LoadInst *LI = cast<LoadInst>(this);
384 if (LI->isVolatile())
386 return LI->getPointerOperand()->isDereferenceablePointer();
389 return false; // The called function could have undefined behavior or
391 // FIXME: We should special-case some intrinsics (bswap,
392 // overflow-checking arithmetic, etc.)
405 return false; // Misc instructions which have effects
409 Instruction *Instruction::clone() const {
410 Instruction *New = clone_impl();
411 New->SubclassOptionalData = SubclassOptionalData;
415 // Otherwise, enumerate and copy over metadata from the old instruction to the
417 SmallVector<std::pair<unsigned, MDNode*>, 4> TheMDs;
418 getAllMetadataOtherThanDebugLoc(TheMDs);
419 for (unsigned i = 0, e = TheMDs.size(); i != e; ++i)
420 New->setMetadata(TheMDs[i].first, TheMDs[i].second);
422 New->setDebugLoc(getDebugLoc());