lib/VMCore/Instruction.cpp

   1 //===-- Instruction.cpp - Implement the Instruction class -----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the Instruction class for the VMCore library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Type.h"
  15 #include "llvm/Instructions.h"
  16 #include "llvm/Function.h"
  17 #include "llvm/Support/CallSite.h"
  18 #include "llvm/Support/LeakDetector.h"
  19 using namespace llvm;
  20
  21 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
  22                          Instruction *InsertBefore)
  23   : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
  24   // Make sure that we get added to a basicblock
  25   LeakDetector::addGarbageObject(this);
  26
  27   // If requested, insert this instruction into a basic block...
  28   if (InsertBefore) {
  29     assert(InsertBefore->getParent() &&
  30            "Instruction to insert before is not in a basic block!");
  31     InsertBefore->getParent()->getInstList().insert(InsertBefore, this);
  32   }
  33 }
  34
  35 Instruction::Instruction(const Type *ty, unsigned it, Use *Ops, unsigned NumOps,
  36                          BasicBlock *InsertAtEnd)
  37   : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(0) {
  38   // Make sure that we get added to a basicblock
  39   LeakDetector::addGarbageObject(this);
  40
  41   // append this instruction into the basic block
  42   assert(InsertAtEnd && "Basic block to append to may not be NULL!");
  43   InsertAtEnd->getInstList().push_back(this);
  44 }
  45
  46
  47 // Out of line virtual method, so the vtable, etc has a home.
  48 Instruction::~Instruction() {
  49   assert(Parent == 0 && "Instruction still linked in the program!");
  50 }
  51
  52
  53 void Instruction::setParent(BasicBlock *P) {
  54   if (getParent()) {
  55     if (!P) LeakDetector::addGarbageObject(this);
  56   } else {
  57     if (P) LeakDetector::removeGarbageObject(this);
  58   }
  59
  60   Parent = P;
  61 }
  62
  63 void Instruction::removeFromParent() {
  64   getParent()->getInstList().remove(this);
  65 }
  66
  67 void Instruction::eraseFromParent() {
  68   getParent()->getInstList().erase(this);
  69 }
  70
  71 /// insertBefore - Insert an unlinked instructions into a basic block
  72 /// immediately before the specified instruction.
  73 void Instruction::insertBefore(Instruction *InsertPos) {
  74   InsertPos->getParent()->getInstList().insert(InsertPos, this);
  75 }
  76
  77 /// insertAfter - Insert an unlinked instructions into a basic block
  78 /// immediately after the specified instruction.
  79 void Instruction::insertAfter(Instruction *InsertPos) {
  80   InsertPos->getParent()->getInstList().insertAfter(InsertPos, this);
  81 }
  82
  83 /// moveBefore - Unlink this instruction from its current basic block and
  84 /// insert it into the basic block that MovePos lives in, right before
  85 /// MovePos.
  86 void Instruction::moveBefore(Instruction *MovePos) {
  87   MovePos->getParent()->getInstList().splice(MovePos,getParent()->getInstList(),
  88                                              this);
  89 }
  90
  91
  92 const char *Instruction::getOpcodeName(unsigned OpCode) {
  93   switch (OpCode) {
  94   // Terminators
  95   case Ret:    return "ret";
  96   case Br:     return "br";
  97   case Switch: return "switch";
  98   case Invoke: return "invoke";
  99   case Unwind: return "unwind";
 100   case Unreachable: return "unreachable";
 101
 102   // Standard binary operators...
 103   case Add: return "add";
 104   case Sub: return "sub";
 105   case Mul: return "mul";
 106   case UDiv: return "udiv";
 107   case SDiv: return "sdiv";
 108   case FDiv: return "fdiv";
 109   case URem: return "urem";
 110   case SRem: return "srem";
 111   case FRem: return "frem";
 112
 113   // Logical operators...
 114   case And: return "and";
 115   case Or : return "or";
 116   case Xor: return "xor";
 117
 118   // Memory instructions...
 119   case Malloc:        return "malloc";
 120   case Free:          return "free";
 121   case Alloca:        return "alloca";
 122   case Load:          return "load";
 123   case Store:         return "store";
 124   case GetElementPtr: return "getelementptr";
 125
 126   // Convert instructions...
 127   case Trunc:     return "trunc";
 128   case ZExt:      return "zext";
 129   case SExt:      return "sext";
 130   case FPTrunc:   return "fptrunc";
 131   case FPExt:     return "fpext";
 132   case FPToUI:    return "fptoui";
 133   case FPToSI:    return "fptosi";
 134   case UIToFP:    return "uitofp";
 135   case SIToFP:    return "sitofp";
 136   case IntToPtr:  return "inttoptr";
 137   case PtrToInt:  return "ptrtoint";
 138   case BitCast:   return "bitcast";
 139
 140   // Other instructions...
 141   case ICmp:           return "icmp";
 142   case FCmp:           return "fcmp";
 143   case VICmp:          return "vicmp";
 144   case VFCmp:          return "vfcmp";
 145   case PHI:            return "phi";
 146   case Select:         return "select";
 147   case Call:           return "call";
 148   case Shl:            return "shl";
 149   case LShr:           return "lshr";
 150   case AShr:           return "ashr";
 151   case VAArg:          return "va_arg";
 152   case ExtractElement: return "extractelement";
 153   case InsertElement:  return "insertelement";
 154   case ShuffleVector:  return "shufflevector";
 155   case ExtractValue:   return "extractvalue";
 156   case InsertValue:    return "insertvalue";
 157
 158   default: return "<Invalid operator> ";
 159   }
 160
 161   return 0;
 162 }
 163
 164 /// isIdenticalTo - Return true if the specified instruction is exactly
 165 /// identical to the current one.  This means that all operands match and any
 166 /// extra information (e.g. load is volatile) agree.
 167 bool Instruction::isIdenticalTo(const Instruction *I) const {
 168   if (getOpcode() != I->getOpcode() ||
 169       getNumOperands() != I->getNumOperands() ||
 170       getType() != I->getType())
 171     return false;
 172
 173   // We have two instructions of identical opcode and #operands.  Check to see
 174   // if all operands are the same.
 175   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 176     if (getOperand(i) != I->getOperand(i))
 177       return false;
 178
 179   // Check special state that is a part of some instructions.
 180   if (const LoadInst *LI = dyn_cast<LoadInst>(this))
 181     return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
 182            LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
 183   if (const StoreInst *SI = dyn_cast<StoreInst>(this))
 184     return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
 185            SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
 186   if (const CmpInst *CI = dyn_cast<CmpInst>(this))
 187     return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
 188   if (const CallInst *CI = dyn_cast<CallInst>(this))
 189     return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
 190            CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
 191            CI->getAttributes().getRawPointer() ==
 192              cast<CallInst>(I)->getAttributes().getRawPointer();
 193   if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
 194     return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
 195            CI->getAttributes().getRawPointer() ==
 196              cast<InvokeInst>(I)->getAttributes().getRawPointer();
 197   if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
 198     if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
 199       return false;
 200     for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
 201       if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
 202         return false;
 203     return true;
 204   }
 205   if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
 206     if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
 207       return false;
 208     for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
 209       if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
 210         return false;
 211     return true;
 212   }
 213
 214   return true;
 215 }
 216
 217 // isSameOperationAs
 218 bool Instruction::isSameOperationAs(const Instruction *I) const {
 219   if (getOpcode() != I->getOpcode() || getType() != I->getType() ||
 220       getNumOperands() != I->getNumOperands())
 221     return false;
 222
 223   // We have two instructions of identical opcode and #operands.  Check to see
 224   // if all operands are the same type
 225   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
 226     if (getOperand(i)->getType() != I->getOperand(i)->getType())
 227       return false;
 228
 229   // Check special state that is a part of some instructions.
 230   if (const LoadInst *LI = dyn_cast<LoadInst>(this))
 231     return LI->isVolatile() == cast<LoadInst>(I)->isVolatile() &&
 232            LI->getAlignment() == cast<LoadInst>(I)->getAlignment();
 233   if (const StoreInst *SI = dyn_cast<StoreInst>(this))
 234     return SI->isVolatile() == cast<StoreInst>(I)->isVolatile() &&
 235            SI->getAlignment() == cast<StoreInst>(I)->getAlignment();
 236   if (const CmpInst *CI = dyn_cast<CmpInst>(this))
 237     return CI->getPredicate() == cast<CmpInst>(I)->getPredicate();
 238   if (const CallInst *CI = dyn_cast<CallInst>(this))
 239     return CI->isTailCall() == cast<CallInst>(I)->isTailCall() &&
 240            CI->getCallingConv() == cast<CallInst>(I)->getCallingConv() &&
 241            CI->getAttributes().getRawPointer() ==
 242              cast<CallInst>(I)->getAttributes().getRawPointer();
 243   if (const InvokeInst *CI = dyn_cast<InvokeInst>(this))
 244     return CI->getCallingConv() == cast<InvokeInst>(I)->getCallingConv() &&
 245            CI->getAttributes().getRawPointer() ==
 246              cast<InvokeInst>(I)->getAttributes().getRawPointer();
 247   if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(this)) {
 248     if (IVI->getNumIndices() != cast<InsertValueInst>(I)->getNumIndices())
 249       return false;
 250     for (unsigned i = 0, e = IVI->getNumIndices(); i != e; ++i)
 251       if (IVI->idx_begin()[i] != cast<InsertValueInst>(I)->idx_begin()[i])
 252         return false;
 253     return true;
 254   }
 255   if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(this)) {
 256     if (EVI->getNumIndices() != cast<ExtractValueInst>(I)->getNumIndices())
 257       return false;
 258     for (unsigned i = 0, e = EVI->getNumIndices(); i != e; ++i)
 259       if (EVI->idx_begin()[i] != cast<ExtractValueInst>(I)->idx_begin()[i])
 260         return false;
 261     return true;
 262   }
 263
 264   return true;
 265 }
 266
 267 /// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
 268 /// specified block.  Note that PHI nodes are considered to evaluate their
 269 /// operands in the corresponding predecessor block.
 270 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
 271   for (use_const_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
 272     // PHI nodes uses values in the corresponding predecessor block.  For other
 273     // instructions, just check to see whether the parent of the use matches up.
 274     const PHINode *PN = dyn_cast<PHINode>(*UI);
 275     if (PN == 0) {
 276       if (cast<Instruction>(*UI)->getParent() != BB)
 277         return true;
 278       continue;
 279     }
 280
 281     if (PN->getIncomingBlock(UI) != BB)
 282       return true;
 283   }
 284   return false;
 285 }
 286
 287 /// mayReadFromMemory - Return true if this instruction may read memory.
 288 ///
 289 bool Instruction::mayReadFromMemory() const {
 290   switch (getOpcode()) {
 291   default: return false;
 292   case Instruction::Free:
 293   case Instruction::VAArg:
 294   case Instruction::Load:
 295     return true;
 296   case Instruction::Call:
 297     return !cast<CallInst>(this)->doesNotAccessMemory();
 298   case Instruction::Invoke:
 299     return !cast<InvokeInst>(this)->doesNotAccessMemory();
 300   case Instruction::Store:
 301     return cast<StoreInst>(this)->isVolatile();
 302   }
 303 }
 304
 305 /// mayWriteToMemory - Return true if this instruction may modify memory.
 306 ///
 307 bool Instruction::mayWriteToMemory() const {
 308   switch (getOpcode()) {
 309   default: return false;
 310   case Instruction::Free:
 311   case Instruction::Store:
 312   case Instruction::VAArg:
 313     return true;
 314   case Instruction::Call:
 315     return !cast<CallInst>(this)->onlyReadsMemory();
 316   case Instruction::Invoke:
 317     return !cast<InvokeInst>(this)->onlyReadsMemory();
 318   case Instruction::Load:
 319     return cast<LoadInst>(this)->isVolatile();
 320   }
 321 }
 322
 323 /// isAssociative - Return true if the instruction is associative:
 324 ///
 325 ///   Associative operators satisfy:  x op (y op z) === (x op y) op z)
 326 ///
 327 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative, when not
 328 /// applied to floating point types.
 329 ///
 330 bool Instruction::isAssociative(unsigned Opcode, const Type *Ty) {
 331   if (Opcode == And || Opcode == Or || Opcode == Xor)
 332     return true;
 333
 334   // Add/Mul reassociate unless they are FP or FP vectors.
 335   if (Opcode == Add || Opcode == Mul)
 336     return !Ty->isFPOrFPVector();
 337   return 0;
 338 }
 339
 340 /// isCommutative - Return true if the instruction is commutative:
 341 ///
 342 ///   Commutative operators satisfy: (x op y) === (y op x)
 343 ///
 344 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
 345 /// applied to any type.
 346 ///
 347 bool Instruction::isCommutative(unsigned op) {
 348   switch (op) {
 349   case Add:
 350   case Mul:
 351   case And:
 352   case Or:
 353   case Xor:
 354     return true;
 355   default:
 356     return false;
 357   }
 358 }
 359
 360 /// isTrapping - Return true if the instruction may trap.
 361 ///
 362 bool Instruction::isTrapping(unsigned op) {
 363   switch(op) {
 364   case UDiv:
 365   case SDiv:
 366   case FDiv:
 367   case URem:
 368   case SRem:
 369   case FRem:
 370   case Load:
 371   case Store:
 372   case Call:
 373   case Invoke:
 374   case VAArg:
 375     return true;
 376   default:
 377     return false;
 378   }
 379 }