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 IndirectBr: return "indirectbr";
107 case Invoke: return "invoke";
108 case Unwind: return "unwind";
109 case Unreachable: return "unreachable";
111 // Standard binary operators...
112 case Add: return "add";
113 case FAdd: return "fadd";
114 case Sub: return "sub";
115 case FSub: return "fsub";
116 case Mul: return "mul";
117 case FMul: return "fmul";
118 case UDiv: return "udiv";
119 case SDiv: return "sdiv";
120 case FDiv: return "fdiv";
121 case URem: return "urem";
122 case SRem: return "srem";
123 case FRem: return "frem";
125 // Logical operators...
126 case And: return "and";
127 case Or : return "or";
128 case Xor: return "xor";
130 // Memory instructions...
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 // Code here matches isFreeCall from MemoryBuiltins, which is not in VMCore.
307 static bool isFreeCall(const Value* I) {
308 const CallInst *CI = dyn_cast<CallInst>(I);
312 const Module* M = CI->getParent()->getParent()->getParent();
313 Function *FreeFunc = M->getFunction("free");
315 if (CI->getOperand(0) != FreeFunc)
318 // Check free prototype.
319 // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
320 // attribute will exist.
321 const FunctionType *FTy = FreeFunc->getFunctionType();
322 if (FTy->getReturnType() != Type::getVoidTy(M->getContext()))
324 if (FTy->getNumParams() != 1)
326 if (FTy->param_begin()->get() != Type::getInt8PtrTy(M->getContext()))
332 /// mayReadFromMemory - Return true if this instruction may read memory.
334 bool Instruction::mayReadFromMemory() const {
335 switch (getOpcode()) {
336 default: return false;
337 case Instruction::VAArg:
338 case Instruction::Load:
340 case Instruction::Call:
341 if (isFreeCall(this))
343 return !cast<CallInst>(this)->doesNotAccessMemory();
344 case Instruction::Invoke:
345 return !cast<InvokeInst>(this)->doesNotAccessMemory();
346 case Instruction::Store:
347 return cast<StoreInst>(this)->isVolatile();
351 /// mayWriteToMemory - Return true if this instruction may modify memory.
353 bool Instruction::mayWriteToMemory() const {
354 switch (getOpcode()) {
355 default: return false;
356 case Instruction::Store:
357 case Instruction::VAArg:
359 case Instruction::Call:
360 if (isFreeCall(this))
362 return !cast<CallInst>(this)->onlyReadsMemory();
363 case Instruction::Invoke:
364 return !cast<InvokeInst>(this)->onlyReadsMemory();
365 case Instruction::Load:
366 return cast<LoadInst>(this)->isVolatile();
370 /// mayThrow - Return true if this instruction may throw an exception.
372 bool Instruction::mayThrow() const {
373 if (const CallInst *CI = dyn_cast<CallInst>(this))
374 return !CI->doesNotThrow();
378 /// isAssociative - Return true if the instruction is associative:
380 /// Associative operators satisfy: x op (y op z) === (x op y) op z
382 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
384 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
385 return Opcode == And || Opcode == Or || Opcode == Xor ||
386 Opcode == Add || Opcode == Mul;
389 /// isCommutative - Return true if the instruction is commutative:
391 /// Commutative operators satisfy: (x op y) === (y op x)
393 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
394 /// applied to any type.
396 bool Instruction::isCommutative(unsigned op) {
411 // Code here matches isMalloc from MemoryBuiltins, which is not in VMCore.
412 static bool isMalloc(const Value* I) {
413 const CallInst *CI = dyn_cast<CallInst>(I);
415 const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
416 if (!BCI) return false;
418 CI = dyn_cast<CallInst>(BCI->getOperand(0));
421 if (!CI) return false;
423 const Module* M = CI->getParent()->getParent()->getParent();
424 Constant *MallocFunc = M->getFunction("malloc");
426 if (CI->getOperand(0) != MallocFunc)
429 // Check malloc prototype.
430 // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
431 // attribute will exist.
432 const FunctionType *FTy = cast<Function>(MallocFunc)->getFunctionType();
433 if (FTy->getNumParams() != 1)
435 if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
436 if (ITy->getBitWidth() != 32 && ITy->getBitWidth() != 64)
444 bool Instruction::isSafeToSpeculativelyExecute() const {
445 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
446 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
450 switch (getOpcode()) {
455 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
456 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
457 return Op && !Op->isNullValue();
461 // x / y is undefined if y == 0, and might be undefined if y == -1,
462 // but calcuations like x / 3 are safe.
463 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
464 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
467 if (cast<LoadInst>(this)->isVolatile())
469 if (isa<AllocaInst>(getOperand(0)) || isMalloc(getOperand(0)))
471 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
472 return !GV->hasExternalWeakLinkage();
473 // FIXME: Handle cases involving GEPs. We have to be careful because
474 // a load of a out-of-bounds GEP has undefined behavior.
478 return false; // The called function could have undefined behavior or
480 // FIXME: We should special-case some intrinsics (bswap,
481 // overflow-checking arithmetic, etc.)
492 return false; // Misc instructions which have effects
496 Instruction *Instruction::clone() const {
497 Instruction *New = clone_impl();
498 New->SubclassOptionalData = SubclassOptionalData;
500 getContext().pImpl->TheMetadata.ValueIsCloned(this, New);