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 Malloc: return "malloc";
131 case Free: return "free";
132 case Alloca: return "alloca";
133 case Load: return "load";
134 case Store: return "store";
135 case GetElementPtr: return "getelementptr";
137 // Convert instructions...
138 case Trunc: return "trunc";
139 case ZExt: return "zext";
140 case SExt: return "sext";
141 case FPTrunc: return "fptrunc";
142 case FPExt: return "fpext";
143 case FPToUI: return "fptoui";
144 case FPToSI: return "fptosi";
145 case UIToFP: return "uitofp";
146 case SIToFP: return "sitofp";
147 case IntToPtr: return "inttoptr";
148 case PtrToInt: return "ptrtoint";
149 case BitCast: return "bitcast";
151 // Other instructions...
152 case ICmp: return "icmp";
153 case FCmp: return "fcmp";
154 case PHI: return "phi";
155 case Select: return "select";
156 case Call: return "call";
157 case Shl: return "shl";
158 case LShr: return "lshr";
159 case AShr: return "ashr";
160 case VAArg: return "va_arg";
161 case ExtractElement: return "extractelement";
162 case InsertElement: return "insertelement";
163 case ShuffleVector: return "shufflevector";
164 case ExtractValue: return "extractvalue";
165 case InsertValue: return "insertvalue";
167 default: return "<Invalid operator> ";
173 /// isIdenticalTo - Return true if the specified instruction is exactly
174 /// identical to the current one. This means that all operands match and any
175 /// extra information (e.g. load is volatile) agree.
176 bool Instruction::isIdenticalTo(const Instruction *I) const {
177 return isIdenticalToWhenDefined(I) &&
178 SubclassOptionalData == I->SubclassOptionalData;
181 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
182 /// ignores the SubclassOptionalData flags, which specify conditions
183 /// under which the instruction's result is undefined.
184 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
185 if (getOpcode() != I->getOpcode() ||
186 getNumOperands() != I->getNumOperands() ||
187 getType() != I->getType())
190 // We have two instructions of identical opcode and #operands. Check to see
191 // if all operands are the same.
192 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
193 if (getOperand(i) != I->getOperand(i))
196 // Check special state that is a part of some instructions.
197 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
198 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
199 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
200 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
201 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
202 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
203 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
204 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
205 if (const CallInst *CI = dyn_cast<CallInst>(this))
206 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
207 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
208 CI->getAttributes().getRawPointer() ==
209 cast<CallInst>(I)->getAttributes().getRawPointer();
210 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
211 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
212 CI->getAttributes().getRawPointer() ==
213 cast<InvokeInst>(I)->getAttributes().getRawPointer();
214 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
215 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
217 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
218 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
222 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
223 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
225 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
226 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
235 // This should be kept in sync with isEquivalentOperation in
236 // lib/Transforms/IPO/MergeFunctions.cpp.
237 bool Instruction::isSameOperationAs(const Instruction *I) const {
238 if (getOpcode() != I->getOpcode() ||
239 getNumOperands() != I->getNumOperands() ||
240 getType() != I->getType())
243 // We have two instructions of identical opcode and #operands. Check to see
244 // if all operands are the same type
245 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
246 if (getOperand(i)->getType() != I->getOperand(i)->getType())
249 // Check special state that is a part of some instructions.
250 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
251 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
252 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
253 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
254 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
255 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
256 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
257 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
258 if (const CallInst *CI = dyn_cast<CallInst>(this))
259 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
260 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
261 CI->getAttributes().getRawPointer() ==
262 cast<CallInst>(I)->getAttributes().getRawPointer();
263 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
264 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
265 CI->getAttributes().getRawPointer() ==
266 cast<InvokeInst>(I)->getAttributes().getRawPointer();
267 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
268 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
270 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
271 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
275 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
276 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
278 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
279 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
287 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
288 /// specified block. Note that PHI nodes are considered to evaluate their
289 /// operands in the corresponding predecessor block.
290 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
291 for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
292 // PHI nodes uses values in the corresponding predecessor block. For other
293 // instructions, just check to see whether the parent of the use matches up.
294 const PHINode *PN = dyn_cast<PHINode>(*UI);
296 if (cast<Instruction>(*UI)->getParent() != BB)
301 if (PN->getIncomingBlock(UI) != BB)
307 /// mayReadFromMemory - Return true if this instruction may read memory.
309 bool Instruction::mayReadFromMemory() const {
310 switch (getOpcode()) {
311 default: return false;
312 case Instruction::Free:
313 case Instruction::VAArg:
314 case Instruction::Load:
316 case Instruction::Call:
317 return !cast<CallInst>(this)->doesNotAccessMemory();
318 case Instruction::Invoke:
319 return !cast<InvokeInst>(this)->doesNotAccessMemory();
320 case Instruction::Store:
321 return cast<StoreInst>(this)->isVolatile();
325 /// mayWriteToMemory - Return true if this instruction may modify memory.
327 bool Instruction::mayWriteToMemory() const {
328 switch (getOpcode()) {
329 default: return false;
330 case Instruction::Free:
331 case Instruction::Store:
332 case Instruction::VAArg:
334 case Instruction::Call:
335 return !cast<CallInst>(this)->onlyReadsMemory();
336 case Instruction::Invoke:
337 return !cast<InvokeInst>(this)->onlyReadsMemory();
338 case Instruction::Load:
339 return cast<LoadInst>(this)->isVolatile();
343 /// mayThrow - Return true if this instruction may throw an exception.
345 bool Instruction::mayThrow() const {
346 if (const CallInst *CI = dyn_cast<CallInst>(this))
347 return !CI->doesNotThrow();
351 /// isAssociative - Return true if the instruction is associative:
353 /// Associative operators satisfy: x op (y op z) === (x op y) op z
355 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
357 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
358 return Opcode == And || Opcode == Or || Opcode == Xor ||
359 Opcode == Add || Opcode == Mul;
362 /// isCommutative - Return true if the instruction is commutative:
364 /// Commutative operators satisfy: (x op y) === (y op x)
366 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
367 /// applied to any type.
369 bool Instruction::isCommutative(unsigned op) {
384 // Code here matches isMalloc from MallocHelper, which is not in VMCore.
385 static bool isMalloc(const Value* I) {
386 const CallInst *CI = dyn_cast<CallInst>(I);
388 const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
389 if (!BCI) return false;
391 CI = dyn_cast<CallInst>(BCI->getOperand(0));
394 if (!CI) return false;
396 const Module* M = CI->getParent()->getParent()->getParent();
397 Constant *MallocFunc = M->getFunction("malloc");
399 if (CI->getOperand(0) != MallocFunc)
405 bool Instruction::isSafeToSpeculativelyExecute() const {
406 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
407 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
411 switch (getOpcode()) {
416 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
417 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
418 return Op && !Op->isNullValue();
422 // x / y is undefined if y == 0, and might be undefined if y == -1,
423 // but calcuations like x / 3 are safe.
424 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
425 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
428 if (cast<LoadInst>(this)->isVolatile())
430 if (isa<AllocationInst>(getOperand(0)) || isMalloc(getOperand(0)))
432 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
433 return !GV->hasExternalWeakLinkage();
434 // FIXME: Handle cases involving GEPs. We have to be careful because
435 // a load of a out-of-bounds GEP has undefined behavior.
439 return false; // The called function could have undefined behavior or
441 // FIXME: We should special-case some intrinsics (bswap,
442 // overflow-checking arithmetic, etc.)
455 return false; // Misc instructions which have effects