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 Alloca: return "alloca";
131 case Load: return "load";
132 case Store: return "store";
133 case GetElementPtr: return "getelementptr";
135 // Convert instructions...
136 case Trunc: return "trunc";
137 case ZExt: return "zext";
138 case SExt: return "sext";
139 case FPTrunc: return "fptrunc";
140 case FPExt: return "fpext";
141 case FPToUI: return "fptoui";
142 case FPToSI: return "fptosi";
143 case UIToFP: return "uitofp";
144 case SIToFP: return "sitofp";
145 case IntToPtr: return "inttoptr";
146 case PtrToInt: return "ptrtoint";
147 case BitCast: return "bitcast";
149 // Other instructions...
150 case ICmp: return "icmp";
151 case FCmp: return "fcmp";
152 case PHI: return "phi";
153 case Select: return "select";
154 case Call: return "call";
155 case Shl: return "shl";
156 case LShr: return "lshr";
157 case AShr: return "ashr";
158 case VAArg: return "va_arg";
159 case ExtractElement: return "extractelement";
160 case InsertElement: return "insertelement";
161 case ShuffleVector: return "shufflevector";
162 case ExtractValue: return "extractvalue";
163 case InsertValue: return "insertvalue";
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().getRawPointer() ==
207 cast<CallInst>(I)->getAttributes().getRawPointer();
208 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
209 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
210 CI->getAttributes().getRawPointer() ==
211 cast<InvokeInst>(I)->getAttributes().getRawPointer();
212 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
213 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
215 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
216 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
220 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
221 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
223 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
224 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
233 // This should be kept in sync with isEquivalentOperation in
234 // lib/Transforms/IPO/MergeFunctions.cpp.
235 bool Instruction::isSameOperationAs(const Instruction *I) const {
236 if (getOpcode() != I->getOpcode() ||
237 getNumOperands() != I->getNumOperands() ||
238 getType() != I->getType())
241 // We have two instructions of identical opcode and #operands. Check to see
242 // if all operands are the same type
243 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
244 if (getOperand(i)->getType() != I->getOperand(i)->getType())
247 // Check special state that is a part of some instructions.
248 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
249 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
250 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
251 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
252 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
253 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
254 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
255 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
256 if (const CallInst *CI = dyn_cast<CallInst>(this))
257 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
258 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
259 CI->getAttributes().getRawPointer() ==
260 cast<CallInst>(I)->getAttributes().getRawPointer();
261 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
262 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
263 CI->getAttributes().getRawPointer() ==
264 cast<InvokeInst>(I)->getAttributes().getRawPointer();
265 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
266 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
268 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
269 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
273 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
274 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
276 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
277 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
285 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
286 /// specified block. Note that PHI nodes are considered to evaluate their
287 /// operands in the corresponding predecessor block.
288 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
289 for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
290 // PHI nodes uses values in the corresponding predecessor block. For other
291 // instructions, just check to see whether the parent of the use matches up.
292 const PHINode *PN = dyn_cast<PHINode>(*UI);
294 if (cast<Instruction>(*UI)->getParent() != BB)
299 if (PN->getIncomingBlock(UI) != BB)
305 // Code here matches isFreeCall from MallocHelper, which is not in VMCore.
306 static bool isFreeCall(const Value* I) {
307 const CallInst *CI = dyn_cast<CallInst>(I);
311 const Module* M = CI->getParent()->getParent()->getParent();
312 Function *FreeFunc = M->getFunction("free");
314 if (CI->getOperand(0) != FreeFunc)
317 // Check free prototype.
318 // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
319 // attribute will exist.
320 const FunctionType *FTy = FreeFunc->getFunctionType();
321 if (FTy->getReturnType() != Type::getVoidTy(M->getContext()))
323 if (FTy->getNumParams() != 1)
325 if (FTy->param_begin()->get() != Type::getInt8PtrTy(M->getContext()))
331 /// mayReadFromMemory - Return true if this instruction may read memory.
333 bool Instruction::mayReadFromMemory() const {
334 switch (getOpcode()) {
335 default: return false;
336 case Instruction::VAArg:
337 case Instruction::Load:
339 case Instruction::Call:
340 if (isFreeCall(this))
342 return !cast<CallInst>(this)->doesNotAccessMemory();
343 case Instruction::Invoke:
344 return !cast<InvokeInst>(this)->doesNotAccessMemory();
345 case Instruction::Store:
346 return cast<StoreInst>(this)->isVolatile();
350 /// mayWriteToMemory - Return true if this instruction may modify memory.
352 bool Instruction::mayWriteToMemory() const {
353 switch (getOpcode()) {
354 default: return false;
355 case Instruction::Store:
356 case Instruction::VAArg:
358 case Instruction::Call:
359 if (isFreeCall(this))
361 return !cast<CallInst>(this)->onlyReadsMemory();
362 case Instruction::Invoke:
363 return !cast<InvokeInst>(this)->onlyReadsMemory();
364 case Instruction::Load:
365 return cast<LoadInst>(this)->isVolatile();
369 /// mayThrow - Return true if this instruction may throw an exception.
371 bool Instruction::mayThrow() const {
372 if (const CallInst *CI = dyn_cast<CallInst>(this))
373 return !CI->doesNotThrow();
377 /// isAssociative - Return true if the instruction is associative:
379 /// Associative operators satisfy: x op (y op z) === (x op y) op z
381 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
383 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
384 return Opcode == And || Opcode == Or || Opcode == Xor ||
385 Opcode == Add || Opcode == Mul;
388 /// isCommutative - Return true if the instruction is commutative:
390 /// Commutative operators satisfy: (x op y) === (y op x)
392 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
393 /// applied to any type.
395 bool Instruction::isCommutative(unsigned op) {
410 // Code here matches isMalloc from MallocHelper, which is not in VMCore.
411 static bool isMalloc(const Value* I) {
412 const CallInst *CI = dyn_cast<CallInst>(I);
414 const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
415 if (!BCI) return false;
417 CI = dyn_cast<CallInst>(BCI->getOperand(0));
420 if (!CI) return false;
422 const Module* M = CI->getParent()->getParent()->getParent();
423 Constant *MallocFunc = M->getFunction("malloc");
425 if (CI->getOperand(0) != MallocFunc)
428 // Check malloc prototype.
429 // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
430 // attribute will exist.
431 const FunctionType *FTy = cast<Function>(MallocFunc)->getFunctionType();
432 if (FTy->getNumParams() != 1)
434 if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
435 if (ITy->getBitWidth() != 32 && ITy->getBitWidth() != 64)
443 bool Instruction::isSafeToSpeculativelyExecute() const {
444 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
445 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
449 switch (getOpcode()) {
454 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
455 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
456 return Op && !Op->isNullValue();
460 // x / y is undefined if y == 0, and might be undefined if y == -1,
461 // but calcuations like x / 3 are safe.
462 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
463 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
466 if (cast<LoadInst>(this)->isVolatile())
468 if (isa<AllocaInst>(getOperand(0)) || isMalloc(getOperand(0)))
470 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
471 return !GV->hasExternalWeakLinkage();
472 // FIXME: Handle cases involving GEPs. We have to be careful because
473 // a load of a out-of-bounds GEP has undefined behavior.
477 return false; // The called function could have undefined behavior or
479 // FIXME: We should special-case some intrinsics (bswap,
480 // overflow-checking arithmetic, etc.)
491 return false; // Misc instructions which have effects