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 "LLVMContextImpl.h"
15 #include "llvm/Type.h"
16 #include "llvm/Instructions.h"
17 #include "llvm/Function.h"
18 #include "llvm/Constants.h"
19 #include "llvm/GlobalVariable.h"
20 #include "llvm/Module.h"
21 #include "llvm/Support/CallSite.h"
22 #include "llvm/Support/LeakDetector.h"
25 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
26 Instruction *InsertBefore)
27 : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
28 // Make sure that we get added to a basicblock
29 LeakDetector::addGarbageObject(this);
31 // If requested, insert this instruction into a basic block...
33 assert(InsertBefore->getParent() &&
34 "Instruction to insert before is not in a basic block!");
35 InsertBefore->getParent()->getInstList().insert(InsertBefore, this);
39 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
40 BasicBlock *InsertAtEnd)
41 : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
42 // Make sure that we get added to a basicblock
43 LeakDetector::addGarbageObject(this);
45 // append this instruction into the basic block
46 assert(InsertAtEnd && "Basic block to append to may not be NULL!");
47 InsertAtEnd->getInstList().push_back(this);
51 // Out of line virtual method, so the vtable, etc has a home.
52 Instruction::~Instruction() {
53 assert(Parent == 0 && "Instruction still linked in the program!");
55 LLVMContext &Context = getContext();
56 Context.pImpl->TheMetadata.ValueIsDeleted(this);
61 void Instruction::setParent(BasicBlock *P) {
63 if (!P) LeakDetector::addGarbageObject(this);
65 if (P) LeakDetector::removeGarbageObject(this);
71 void Instruction::removeFromParent() {
72 getParent()->getInstList().remove(this);
75 void Instruction::eraseFromParent() {
76 getParent()->getInstList().erase(this);
79 /// insertBefore - Insert an unlinked instructions into a basic block
80 /// immediately before the specified instruction.
81 void Instruction::insertBefore(Instruction *InsertPos) {
82 InsertPos->getParent()->getInstList().insert(InsertPos, this);
85 /// insertAfter - Insert an unlinked instructions into a basic block
86 /// immediately after the specified instruction.
87 void Instruction::insertAfter(Instruction *InsertPos) {
88 InsertPos->getParent()->getInstList().insertAfter(InsertPos, this);
91 /// moveBefore - Unlink this instruction from its current basic block and
92 /// insert it into the basic block that MovePos lives in, right before
94 void Instruction::moveBefore(Instruction *MovePos) {
95 MovePos->getParent()->getInstList().splice(MovePos,getParent()->getInstList(),
100 const char *Instruction::getOpcodeName(unsigned OpCode) {
103 case Ret: return "ret";
104 case Br: return "br";
105 case Switch: return "switch";
106 case Invoke: return "invoke";
107 case Unwind: return "unwind";
108 case Unreachable: return "unreachable";
110 // Standard binary operators...
111 case Add: return "add";
112 case FAdd: return "fadd";
113 case Sub: return "sub";
114 case FSub: return "fsub";
115 case Mul: return "mul";
116 case FMul: return "fmul";
117 case UDiv: return "udiv";
118 case SDiv: return "sdiv";
119 case FDiv: return "fdiv";
120 case URem: return "urem";
121 case SRem: return "srem";
122 case FRem: return "frem";
124 // Logical operators...
125 case And: return "and";
126 case Or : return "or";
127 case Xor: return "xor";
129 // Memory instructions...
130 case Free: return "free";
131 case Alloca: return "alloca";
132 case Load: return "load";
133 case Store: return "store";
134 case GetElementPtr: return "getelementptr";
136 // Convert instructions...
137 case Trunc: return "trunc";
138 case ZExt: return "zext";
139 case SExt: return "sext";
140 case FPTrunc: return "fptrunc";
141 case FPExt: return "fpext";
142 case FPToUI: return "fptoui";
143 case FPToSI: return "fptosi";
144 case UIToFP: return "uitofp";
145 case SIToFP: return "sitofp";
146 case IntToPtr: return "inttoptr";
147 case PtrToInt: return "ptrtoint";
148 case BitCast: return "bitcast";
150 // Other instructions...
151 case ICmp: return "icmp";
152 case FCmp: return "fcmp";
153 case PHI: return "phi";
154 case Select: return "select";
155 case Call: return "call";
156 case Shl: return "shl";
157 case LShr: return "lshr";
158 case AShr: return "ashr";
159 case VAArg: return "va_arg";
160 case ExtractElement: return "extractelement";
161 case InsertElement: return "insertelement";
162 case ShuffleVector: return "shufflevector";
163 case ExtractValue: return "extractvalue";
164 case InsertValue: return "insertvalue";
166 default: return "<Invalid operator> ";
172 /// isIdenticalTo - Return true if the specified instruction is exactly
173 /// identical to the current one. This means that all operands match and any
174 /// extra information (e.g. load is volatile) agree.
175 bool Instruction::isIdenticalTo(const Instruction *I) const {
176 return isIdenticalToWhenDefined(I) &&
177 SubclassOptionalData == I->SubclassOptionalData;
180 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
181 /// ignores the SubclassOptionalData flags, which specify conditions
182 /// under which the instruction's result is undefined.
183 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
184 if (getOpcode() != I->getOpcode() ||
185 getNumOperands() != I->getNumOperands() ||
186 getType() != I->getType())
189 // We have two instructions of identical opcode and #operands. Check to see
190 // if all operands are the same.
191 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
192 if (getOperand(i) != I->getOperand(i))
195 // Check special state that is a part of some instructions.
196 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
197 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
198 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
199 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
200 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
201 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
202 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
203 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
204 if (const CallInst *CI = dyn_cast<CallInst>(this))
205 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
206 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
207 CI->getAttributes().getRawPointer() ==
208 cast<CallInst>(I)->getAttributes().getRawPointer();
209 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
210 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
211 CI->getAttributes().getRawPointer() ==
212 cast<InvokeInst>(I)->getAttributes().getRawPointer();
213 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
214 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
216 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
217 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
221 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
222 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
224 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
225 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
234 // This should be kept in sync with isEquivalentOperation in
235 // lib/Transforms/IPO/MergeFunctions.cpp.
236 bool Instruction::isSameOperationAs(const Instruction *I) const {
237 if (getOpcode() != I->getOpcode() ||
238 getNumOperands() != I->getNumOperands() ||
239 getType() != I->getType())
242 // We have two instructions of identical opcode and #operands. Check to see
243 // if all operands are the same type
244 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
245 if (getOperand(i)->getType() != I->getOperand(i)->getType())
248 // Check special state that is a part of some instructions.
249 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
250 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
251 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
252 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
253 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
254 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
255 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
256 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
257 if (const CallInst *CI = dyn_cast<CallInst>(this))
258 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
259 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
260 CI->getAttributes().getRawPointer() ==
261 cast<CallInst>(I)->getAttributes().getRawPointer();
262 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
263 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
264 CI->getAttributes().getRawPointer() ==
265 cast<InvokeInst>(I)->getAttributes().getRawPointer();
266 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
267 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
269 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
270 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
274 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
275 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
277 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
278 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
286 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
287 /// specified block. Note that PHI nodes are considered to evaluate their
288 /// operands in the corresponding predecessor block.
289 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
290 for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
291 // PHI nodes uses values in the corresponding predecessor block. For other
292 // instructions, just check to see whether the parent of the use matches up.
293 const PHINode *PN = dyn_cast<PHINode>(*UI);
295 if (cast<Instruction>(*UI)->getParent() != BB)
300 if (PN->getIncomingBlock(UI) != BB)
306 /// mayReadFromMemory - Return true if this instruction may read memory.
308 bool Instruction::mayReadFromMemory() const {
309 switch (getOpcode()) {
310 default: return false;
311 case Instruction::Free:
312 case Instruction::VAArg:
313 case Instruction::Load:
315 case Instruction::Call:
316 return !cast<CallInst>(this)->doesNotAccessMemory();
317 case Instruction::Invoke:
318 return !cast<InvokeInst>(this)->doesNotAccessMemory();
319 case Instruction::Store:
320 return cast<StoreInst>(this)->isVolatile();
324 /// mayWriteToMemory - Return true if this instruction may modify memory.
326 bool Instruction::mayWriteToMemory() const {
327 switch (getOpcode()) {
328 default: return false;
329 case Instruction::Free:
330 case Instruction::Store:
331 case Instruction::VAArg:
333 case Instruction::Call:
334 return !cast<CallInst>(this)->onlyReadsMemory();
335 case Instruction::Invoke:
336 return !cast<InvokeInst>(this)->onlyReadsMemory();
337 case Instruction::Load:
338 return cast<LoadInst>(this)->isVolatile();
342 /// mayThrow - Return true if this instruction may throw an exception.
344 bool Instruction::mayThrow() const {
345 if (const CallInst *CI = dyn_cast<CallInst>(this))
346 return !CI->doesNotThrow();
350 /// isAssociative - Return true if the instruction is associative:
352 /// Associative operators satisfy: x op (y op z) === (x op y) op z
354 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
356 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
357 return Opcode == And || Opcode == Or || Opcode == Xor ||
358 Opcode == Add || Opcode == Mul;
361 /// isCommutative - Return true if the instruction is commutative:
363 /// Commutative operators satisfy: (x op y) === (y op x)
365 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
366 /// applied to any type.
368 bool Instruction::isCommutative(unsigned op) {
383 // Code here matches isMalloc from MallocHelper, which is not in VMCore.
384 static bool isMalloc(const Value* I) {
385 const CallInst *CI = dyn_cast<CallInst>(I);
387 const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
388 if (!BCI) return false;
390 CI = dyn_cast<CallInst>(BCI->getOperand(0));
393 if (!CI) return false;
395 const Module* M = CI->getParent()->getParent()->getParent();
396 Constant *MallocFunc = M->getFunction("malloc");
398 if (CI->getOperand(0) != MallocFunc)
404 bool Instruction::isSafeToSpeculativelyExecute() const {
405 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
406 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
410 switch (getOpcode()) {
415 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
416 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
417 return Op && !Op->isNullValue();
421 // x / y is undefined if y == 0, and might be undefined if y == -1,
422 // but calcuations like x / 3 are safe.
423 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
424 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
427 if (cast<LoadInst>(this)->isVolatile())
429 if (isa<AllocaInst>(getOperand(0)) || isMalloc(getOperand(0)))
431 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
432 return !GV->hasExternalWeakLinkage();
433 // FIXME: Handle cases involving GEPs. We have to be careful because
434 // a load of a out-of-bounds GEP has undefined behavior.
438 return false; // The called function could have undefined behavior or
440 // FIXME: We should special-case some intrinsics (bswap,
441 // overflow-checking arithmetic, etc.)
453 return false; // Misc instructions which have effects