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/Type.h"
15 #include "llvm/Instructions.h"
16 #include "llvm/Function.h"
17 #include "llvm/Constants.h"
18 #include "llvm/GlobalVariable.h"
19 #include "llvm/Module.h"
20 #include "llvm/Support/CallSite.h"
21 #include "llvm/Support/LeakDetector.h"
24 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
25 Instruction *InsertBefore)
26 : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
27 // Make sure that we get added to a basicblock
28 LeakDetector::addGarbageObject(this);
30 // If requested, insert this instruction into a basic block...
32 assert(InsertBefore->getParent() &&
33 "Instruction to insert before is not in a basic block!");
34 InsertBefore->getParent()->getInstList().insert(InsertBefore, this);
38 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
39 BasicBlock *InsertAtEnd)
40 : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
41 // Make sure that we get added to a basicblock
42 LeakDetector::addGarbageObject(this);
44 // append this instruction into the basic block
45 assert(InsertAtEnd && "Basic block to append to may not be NULL!");
46 InsertAtEnd->getInstList().push_back(this);
50 // Out of line virtual method, so the vtable, etc has a home.
51 Instruction::~Instruction() {
52 assert(Parent == 0 && "Instruction still linked in the program!");
56 void Instruction::setParent(BasicBlock *P) {
58 if (!P) LeakDetector::addGarbageObject(this);
60 if (P) LeakDetector::removeGarbageObject(this);
66 void Instruction::removeFromParent() {
67 getParent()->getInstList().remove(this);
70 void Instruction::eraseFromParent() {
71 getParent()->getInstList().erase(this);
74 /// insertBefore - Insert an unlinked instructions into a basic block
75 /// immediately before the specified instruction.
76 void Instruction::insertBefore(Instruction *InsertPos) {
77 InsertPos->getParent()->getInstList().insert(InsertPos, this);
80 /// insertAfter - Insert an unlinked instructions into a basic block
81 /// immediately after the specified instruction.
82 void Instruction::insertAfter(Instruction *InsertPos) {
83 InsertPos->getParent()->getInstList().insertAfter(InsertPos, this);
86 /// moveBefore - Unlink this instruction from its current basic block and
87 /// insert it into the basic block that MovePos lives in, right before
89 void Instruction::moveBefore(Instruction *MovePos) {
90 MovePos->getParent()->getInstList().splice(MovePos,getParent()->getInstList(),
95 const char *Instruction::getOpcodeName(unsigned OpCode) {
98 case Ret: return "ret";
100 case Switch: return "switch";
101 case Invoke: return "invoke";
102 case Unwind: return "unwind";
103 case Unreachable: return "unreachable";
105 // Standard binary operators...
106 case Add: return "add";
107 case FAdd: return "fadd";
108 case Sub: return "sub";
109 case FSub: return "fsub";
110 case Mul: return "mul";
111 case FMul: return "fmul";
112 case UDiv: return "udiv";
113 case SDiv: return "sdiv";
114 case FDiv: return "fdiv";
115 case URem: return "urem";
116 case SRem: return "srem";
117 case FRem: return "frem";
119 // Logical operators...
120 case And: return "and";
121 case Or : return "or";
122 case Xor: return "xor";
124 // Memory instructions...
125 case Malloc: return "malloc";
126 case Free: return "free";
127 case Alloca: return "alloca";
128 case Load: return "load";
129 case Store: return "store";
130 case GetElementPtr: return "getelementptr";
132 // Convert instructions...
133 case Trunc: return "trunc";
134 case ZExt: return "zext";
135 case SExt: return "sext";
136 case FPTrunc: return "fptrunc";
137 case FPExt: return "fpext";
138 case FPToUI: return "fptoui";
139 case FPToSI: return "fptosi";
140 case UIToFP: return "uitofp";
141 case SIToFP: return "sitofp";
142 case IntToPtr: return "inttoptr";
143 case PtrToInt: return "ptrtoint";
144 case BitCast: return "bitcast";
146 // Other instructions...
147 case ICmp: return "icmp";
148 case FCmp: return "fcmp";
149 case PHI: return "phi";
150 case Select: return "select";
151 case Call: return "call";
152 case Shl: return "shl";
153 case LShr: return "lshr";
154 case AShr: return "ashr";
155 case VAArg: return "va_arg";
156 case ExtractElement: return "extractelement";
157 case InsertElement: return "insertelement";
158 case ShuffleVector: return "shufflevector";
159 case ExtractValue: return "extractvalue";
160 case InsertValue: return "insertvalue";
162 default: return "<Invalid operator> ";
168 /// isIdenticalTo - Return true if the specified instruction is exactly
169 /// identical to the current one. This means that all operands match and any
170 /// extra information (e.g. load is volatile) agree.
171 bool Instruction::isIdenticalTo(const Instruction *I) const {
172 return isIdenticalToWhenDefined(I) &&
173 SubclassOptionalData == I->SubclassOptionalData;
176 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
177 /// ignores the SubclassOptionalData flags, which specify conditions
178 /// under which the instruction's result is undefined.
179 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
180 if (getOpcode() != I->getOpcode() ||
181 getNumOperands() != I->getNumOperands() ||
182 getType() != I->getType())
185 // We have two instructions of identical opcode and #operands. Check to see
186 // if all operands are the same.
187 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
188 if (getOperand(i) != I->getOperand(i))
191 // Check special state that is a part of some instructions.
192 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
193 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
194 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
195 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
196 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
197 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
198 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
199 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
200 if (const CallInst *CI = dyn_cast<CallInst>(this))
201 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
202 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
203 CI->getAttributes().getRawPointer() ==
204 cast<CallInst>(I)->getAttributes().getRawPointer();
205 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
206 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
207 CI->getAttributes().getRawPointer() ==
208 cast<InvokeInst>(I)->getAttributes().getRawPointer();
209 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
210 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
212 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
213 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
217 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
218 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
220 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
221 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
230 // This should be kept in sync with isEquivalentOperation in
231 // lib/Transforms/IPO/MergeFunctions.cpp.
232 bool Instruction::isSameOperationAs(const Instruction *I) const {
233 if (getOpcode() != I->getOpcode() ||
234 getNumOperands() != I->getNumOperands() ||
235 getType() != I->getType())
238 // We have two instructions of identical opcode and #operands. Check to see
239 // if all operands are the same type
240 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
241 if (getOperand(i)->getType() != I->getOperand(i)->getType())
244 // Check special state that is a part of some instructions.
245 if (const LoadInst *LI = dyn_cast<LoadInst>(this))
246 return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
247 LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
248 if (const StoreInst *SI = dyn_cast<StoreInst>(this))
249 return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
250 SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
251 if (const CmpInst *CI = dyn_cast<CmpInst>(this))
252 return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
253 if (const CallInst *CI = dyn_cast<CallInst>(this))
254 return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
255 CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
256 CI->getAttributes().getRawPointer() ==
257 cast<CallInst>(I)->getAttributes().getRawPointer();
258 if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
259 return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
260 CI->getAttributes().getRawPointer() ==
261 cast<InvokeInst>(I)->getAttributes().getRawPointer();
262 if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
263 if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
265 for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
266 if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
270 if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
271 if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
273 for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
274 if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
282 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
283 /// specified block. Note that PHI nodes are considered to evaluate their
284 /// operands in the corresponding predecessor block.
285 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
286 for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
287 // PHI nodes uses values in the corresponding predecessor block. For other
288 // instructions, just check to see whether the parent of the use matches up.
289 const PHINode *PN = dyn_cast<PHINode>(*UI);
291 if (cast<Instruction>(*UI)->getParent() != BB)
296 if (PN->getIncomingBlock(UI) != BB)
302 /// mayReadFromMemory - Return true if this instruction may read memory.
304 bool Instruction::mayReadFromMemory() const {
305 switch (getOpcode()) {
306 default: return false;
307 case Instruction::Free:
308 case Instruction::VAArg:
309 case Instruction::Load:
311 case Instruction::Call:
312 return !cast<CallInst>(this)->doesNotAccessMemory();
313 case Instruction::Invoke:
314 return !cast<InvokeInst>(this)->doesNotAccessMemory();
315 case Instruction::Store:
316 return cast<StoreInst>(this)->isVolatile();
320 /// mayWriteToMemory - Return true if this instruction may modify memory.
322 bool Instruction::mayWriteToMemory() const {
323 switch (getOpcode()) {
324 default: return false;
325 case Instruction::Free:
326 case Instruction::Store:
327 case Instruction::VAArg:
329 case Instruction::Call:
330 return !cast<CallInst>(this)->onlyReadsMemory();
331 case Instruction::Invoke:
332 return !cast<InvokeInst>(this)->onlyReadsMemory();
333 case Instruction::Load:
334 return cast<LoadInst>(this)->isVolatile();
338 /// mayThrow - Return true if this instruction may throw an exception.
340 bool Instruction::mayThrow() const {
341 if (const CallInst *CI = dyn_cast<CallInst>(this))
342 return !CI->doesNotThrow();
346 /// isAssociative - Return true if the instruction is associative:
348 /// Associative operators satisfy: x op (y op z) === (x op y) op z
350 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
352 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
353 return Opcode == And || Opcode == Or || Opcode == Xor ||
354 Opcode == Add || Opcode == Mul;
357 /// isCommutative - Return true if the instruction is commutative:
359 /// Commutative operators satisfy: (x op y) === (y op x)
361 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
362 /// applied to any type.
364 bool Instruction::isCommutative(unsigned op) {
379 // Code here matches isMalloc from MallocHelper, which is not in VMCore.
380 static bool isMalloc(const Value* I) {
381 const CallInst *CI = dyn_cast<CallInst>(I);
383 const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
384 if (!BCI) return false;
386 CI = dyn_cast<CallInst>(BCI->getOperand(0));
389 if (!CI) return false;
391 const Module* M = CI->getParent()->getParent()->getParent();
392 Constant *MallocFunc = M->getFunction("malloc");
394 if (CI->getOperand(0) != MallocFunc)
400 bool Instruction::isSafeToSpeculativelyExecute() const {
401 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
402 if (Constant *C = dyn_cast<Constant>(getOperand(i)))
406 switch (getOpcode()) {
411 // x / y is undefined if y == 0, but calcuations like x / 3 are safe.
412 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
413 return Op && !Op->isNullValue();
417 // x / y is undefined if y == 0, and might be undefined if y == -1,
418 // but calcuations like x / 3 are safe.
419 ConstantInt *Op = dyn_cast<ConstantInt>(getOperand(1));
420 return Op && !Op->isNullValue() && !Op->isAllOnesValue();
423 if (cast<LoadInst>(this)->isVolatile())
425 if (isa<AllocationInst>(getOperand(0)) || isMalloc(getOperand(0)))
427 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(getOperand(0)))
428 return !GV->hasExternalWeakLinkage();
429 // FIXME: Handle cases involving GEPs. We have to be careful because
430 // a load of a out-of-bounds GEP has undefined behavior.
434 return false; // The called function could have undefined behavior or
436 // FIXME: We should special-case some intrinsics (bswap,
437 // overflow-checking arithmetic, etc.)
450 return false; // Misc instructions which have effects