lib/ExecutionEngine/Interpreter/Execution.cpp

   1 //===-- Execution.cpp - Implement code to simulate the program ------------===//
   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 contains the actual instruction interpreter.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #define DEBUG_TYPE "interpreter"
  15 #include "Interpreter.h"
  16 #include "llvm/Constants.h"
  17 #include "llvm/DerivedTypes.h"
  18 #include "llvm/Instructions.h"
  19 #include "llvm/CodeGen/IntrinsicLowering.h"
  20 #include "llvm/Support/GetElementPtrTypeIterator.h"
  21 #include "llvm/ADT/APInt.h"
  22 #include "llvm/ADT/Statistic.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/Debug.h"
  25 #include "llvm/Support/MathExtras.h"
  26 #include <algorithm>
  27 #include <cmath>
  28 #include <cstring>
  29 using namespace llvm;
  30
  31 STATISTIC(NumDynamicInsts, "Number of dynamic instructions executed");
  32 static Interpreter *TheEE = 0;
  33
  34 static cl::opt<bool> PrintVolatile("interpreter-print-volatile", cl::Hidden,
  35           cl::desc("make the interpreter print every volatile load and store"));
  36
  37 //===----------------------------------------------------------------------===//
  38 //                     Various Helper Functions
  39 //===----------------------------------------------------------------------===//
  40
  41 static inline uint64_t doSignExtension(uint64_t Val, const IntegerType* ITy) {
  42   // Determine if the value is signed or not
  43   bool isSigned = (Val & (1 << (ITy->getBitWidth()-1))) != 0;
  44   // If its signed, extend the sign bits
  45   if (isSigned)
  46     Val |= ~ITy->getBitMask();
  47   return Val;
  48 }
  49
  50 static void SetValue(Value *V, GenericValue Val, ExecutionContext &SF) {
  51   SF.Values[V] = Val;
  52 }
  53
  54 void Interpreter::initializeExecutionEngine() {
  55   TheEE = this;
  56 }
  57
  58 //===----------------------------------------------------------------------===//
  59 //                    Binary Instruction Implementations
  60 //===----------------------------------------------------------------------===//
  61
  62 #define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
  63    case Type::TY##TyID: \
  64      Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; \
  65      break
  66
  67 #define IMPLEMENT_INTEGER_BINOP1(OP, TY) \
  68    case Type::IntegerTyID: { \
  69      Dest.IntVal = Src1.IntVal OP Src2.IntVal; \
  70      break; \
  71    }
  72
  73
  74 static void executeAddInst(GenericValue &Dest, GenericValue Src1,
  75                            GenericValue Src2, const Type *Ty) {
  76   switch (Ty->getTypeID()) {
  77     IMPLEMENT_INTEGER_BINOP1(+, Ty);
  78     IMPLEMENT_BINARY_OPERATOR(+, Float);
  79     IMPLEMENT_BINARY_OPERATOR(+, Double);
  80   default:
  81     cerr << "Unhandled type for Add instruction: " << *Ty << "\n";
  82     abort();
  83   }
  84 }
  85
  86 static void executeSubInst(GenericValue &Dest, GenericValue Src1,
  87                            GenericValue Src2, const Type *Ty) {
  88   switch (Ty->getTypeID()) {
  89     IMPLEMENT_INTEGER_BINOP1(-, Ty);
  90     IMPLEMENT_BINARY_OPERATOR(-, Float);
  91     IMPLEMENT_BINARY_OPERATOR(-, Double);
  92   default:
  93     cerr << "Unhandled type for Sub instruction: " << *Ty << "\n";
  94     abort();
  95   }
  96 }
  97
  98 static void executeMulInst(GenericValue &Dest, GenericValue Src1,
  99                            GenericValue Src2, const Type *Ty) {
 100   switch (Ty->getTypeID()) {
 101     IMPLEMENT_INTEGER_BINOP1(*, Ty);
 102     IMPLEMENT_BINARY_OPERATOR(*, Float);
 103     IMPLEMENT_BINARY_OPERATOR(*, Double);
 104   default:
 105     cerr << "Unhandled type for Mul instruction: " << *Ty << "\n";
 106     abort();
 107   }
 108 }
 109
 110 static void executeFDivInst(GenericValue &Dest, GenericValue Src1,
 111                             GenericValue Src2, const Type *Ty) {
 112   switch (Ty->getTypeID()) {
 113     IMPLEMENT_BINARY_OPERATOR(/, Float);
 114     IMPLEMENT_BINARY_OPERATOR(/, Double);
 115   default:
 116     cerr << "Unhandled type for FDiv instruction: " << *Ty << "\n";
 117     abort();
 118   }
 119 }
 120
 121 static void executeFRemInst(GenericValue &Dest, GenericValue Src1,
 122                             GenericValue Src2, const Type *Ty) {
 123   switch (Ty->getTypeID()) {
 124   case Type::FloatTyID:
 125     Dest.FloatVal = fmod(Src1.FloatVal, Src2.FloatVal);
 126     break;
 127   case Type::DoubleTyID:
 128     Dest.DoubleVal = fmod(Src1.DoubleVal, Src2.DoubleVal);
 129     break;
 130   default:
 131     cerr << "Unhandled type for Rem instruction: " << *Ty << "\n";
 132     abort();
 133   }
 134 }
 135
 136 #define IMPLEMENT_INTEGER_ICMP(OP, TY) \
 137    case Type::IntegerTyID:  \
 138       Dest.IntVal = APInt(1,Src1.IntVal.OP(Src2.IntVal)); \
 139       break;
 140
 141 // Handle pointers specially because they must be compared with only as much
 142 // width as the host has.  We _do not_ want to be comparing 64 bit values when
 143 // running on a 32-bit target, otherwise the upper 32 bits might mess up
 144 // comparisons if they contain garbage.
 145 #define IMPLEMENT_POINTER_ICMP(OP) \
 146    case Type::PointerTyID: \
 147       Dest.IntVal = APInt(1,(void*)(intptr_t)Src1.PointerVal OP \
 148                             (void*)(intptr_t)Src2.PointerVal); \
 149       break;
 150
 151 static GenericValue executeICMP_EQ(GenericValue Src1, GenericValue Src2,
 152                                    const Type *Ty) {
 153   GenericValue Dest;
 154   switch (Ty->getTypeID()) {
 155     IMPLEMENT_INTEGER_ICMP(eq,Ty);
 156     IMPLEMENT_POINTER_ICMP(==);
 157   default:
 158     cerr << "Unhandled type for ICMP_EQ predicate: " << *Ty << "\n";
 159     abort();
 160   }
 161   return Dest;
 162 }
 163
 164 static GenericValue executeICMP_NE(GenericValue Src1, GenericValue Src2,
 165                                    const Type *Ty) {
 166   GenericValue Dest;
 167   switch (Ty->getTypeID()) {
 168     IMPLEMENT_INTEGER_ICMP(ne,Ty);
 169     IMPLEMENT_POINTER_ICMP(!=);
 170   default:
 171     cerr << "Unhandled type for ICMP_NE predicate: " << *Ty << "\n";
 172     abort();
 173   }
 174   return Dest;
 175 }
 176
 177 static GenericValue executeICMP_ULT(GenericValue Src1, GenericValue Src2,
 178                                     const Type *Ty) {
 179   GenericValue Dest;
 180   switch (Ty->getTypeID()) {
 181     IMPLEMENT_INTEGER_ICMP(ult,Ty);
 182     IMPLEMENT_POINTER_ICMP(<);
 183   default:
 184     cerr << "Unhandled type for ICMP_ULT predicate: " << *Ty << "\n";
 185     abort();
 186   }
 187   return Dest;
 188 }
 189
 190 static GenericValue executeICMP_SLT(GenericValue Src1, GenericValue Src2,
 191                                     const Type *Ty) {
 192   GenericValue Dest;
 193   switch (Ty->getTypeID()) {
 194     IMPLEMENT_INTEGER_ICMP(slt,Ty);
 195     IMPLEMENT_POINTER_ICMP(<);
 196   default:
 197     cerr << "Unhandled type for ICMP_SLT predicate: " << *Ty << "\n";
 198     abort();
 199   }
 200   return Dest;
 201 }
 202
 203 static GenericValue executeICMP_UGT(GenericValue Src1, GenericValue Src2,
 204                                     const Type *Ty) {
 205   GenericValue Dest;
 206   switch (Ty->getTypeID()) {
 207     IMPLEMENT_INTEGER_ICMP(ugt,Ty);
 208     IMPLEMENT_POINTER_ICMP(>);
 209   default:
 210     cerr << "Unhandled type for ICMP_UGT predicate: " << *Ty << "\n";
 211     abort();
 212   }
 213   return Dest;
 214 }
 215
 216 static GenericValue executeICMP_SGT(GenericValue Src1, GenericValue Src2,
 217                                     const Type *Ty) {
 218   GenericValue Dest;
 219   switch (Ty->getTypeID()) {
 220     IMPLEMENT_INTEGER_ICMP(sgt,Ty);
 221     IMPLEMENT_POINTER_ICMP(>);
 222   default:
 223     cerr << "Unhandled type for ICMP_SGT predicate: " << *Ty << "\n";
 224     abort();
 225   }
 226   return Dest;
 227 }
 228
 229 static GenericValue executeICMP_ULE(GenericValue Src1, GenericValue Src2,
 230                                     const Type *Ty) {
 231   GenericValue Dest;
 232   switch (Ty->getTypeID()) {
 233     IMPLEMENT_INTEGER_ICMP(ule,Ty);
 234     IMPLEMENT_POINTER_ICMP(<=);
 235   default:
 236     cerr << "Unhandled type for ICMP_ULE predicate: " << *Ty << "\n";
 237     abort();
 238   }
 239   return Dest;
 240 }
 241
 242 static GenericValue executeICMP_SLE(GenericValue Src1, GenericValue Src2,
 243                                     const Type *Ty) {
 244   GenericValue Dest;
 245   switch (Ty->getTypeID()) {
 246     IMPLEMENT_INTEGER_ICMP(sle,Ty);
 247     IMPLEMENT_POINTER_ICMP(<=);
 248   default:
 249     cerr << "Unhandled type for ICMP_SLE predicate: " << *Ty << "\n";
 250     abort();
 251   }
 252   return Dest;
 253 }
 254
 255 static GenericValue executeICMP_UGE(GenericValue Src1, GenericValue Src2,
 256                                     const Type *Ty) {
 257   GenericValue Dest;
 258   switch (Ty->getTypeID()) {
 259     IMPLEMENT_INTEGER_ICMP(uge,Ty);
 260     IMPLEMENT_POINTER_ICMP(>=);
 261   default:
 262     cerr << "Unhandled type for ICMP_UGE predicate: " << *Ty << "\n";
 263     abort();
 264   }
 265   return Dest;
 266 }
 267
 268 static GenericValue executeICMP_SGE(GenericValue Src1, GenericValue Src2,
 269                                     const Type *Ty) {
 270   GenericValue Dest;
 271   switch (Ty->getTypeID()) {
 272     IMPLEMENT_INTEGER_ICMP(sge,Ty);
 273     IMPLEMENT_POINTER_ICMP(>=);
 274   default:
 275     cerr << "Unhandled type for ICMP_SGE predicate: " << *Ty << "\n";
 276     abort();
 277   }
 278   return Dest;
 279 }
 280
 281 void Interpreter::visitICmpInst(ICmpInst &I) {
 282   ExecutionContext &SF = ECStack.back();
 283   const Type *Ty    = I.getOperand(0)->getType();
 284   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 285   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 286   GenericValue R;   // Result
 287
 288   switch (I.getPredicate()) {
 289   case ICmpInst::ICMP_EQ:  R = executeICMP_EQ(Src1,  Src2, Ty); break;
 290   case ICmpInst::ICMP_NE:  R = executeICMP_NE(Src1,  Src2, Ty); break;
 291   case ICmpInst::ICMP_ULT: R = executeICMP_ULT(Src1, Src2, Ty); break;
 292   case ICmpInst::ICMP_SLT: R = executeICMP_SLT(Src1, Src2, Ty); break;
 293   case ICmpInst::ICMP_UGT: R = executeICMP_UGT(Src1, Src2, Ty); break;
 294   case ICmpInst::ICMP_SGT: R = executeICMP_SGT(Src1, Src2, Ty); break;
 295   case ICmpInst::ICMP_ULE: R = executeICMP_ULE(Src1, Src2, Ty); break;
 296   case ICmpInst::ICMP_SLE: R = executeICMP_SLE(Src1, Src2, Ty); break;
 297   case ICmpInst::ICMP_UGE: R = executeICMP_UGE(Src1, Src2, Ty); break;
 298   case ICmpInst::ICMP_SGE: R = executeICMP_SGE(Src1, Src2, Ty); break;
 299   default:
 300     cerr << "Don't know how to handle this ICmp predicate!\n-->" << I;
 301     abort();
 302   }
 303
 304   SetValue(&I, R, SF);
 305 }
 306
 307 #define IMPLEMENT_FCMP(OP, TY) \
 308    case Type::TY##TyID: \
 309      Dest.IntVal = APInt(1,Src1.TY##Val OP Src2.TY##Val); \
 310      break
 311
 312 static GenericValue executeFCMP_OEQ(GenericValue Src1, GenericValue Src2,
 313                                    const Type *Ty) {
 314   GenericValue Dest;
 315   switch (Ty->getTypeID()) {
 316     IMPLEMENT_FCMP(==, Float);
 317     IMPLEMENT_FCMP(==, Double);
 318   default:
 319     cerr << "Unhandled type for FCmp EQ instruction: " << *Ty << "\n";
 320     abort();
 321   }
 322   return Dest;
 323 }
 324
 325 static GenericValue executeFCMP_ONE(GenericValue Src1, GenericValue Src2,
 326                                    const Type *Ty) {
 327   GenericValue Dest;
 328   switch (Ty->getTypeID()) {
 329     IMPLEMENT_FCMP(!=, Float);
 330     IMPLEMENT_FCMP(!=, Double);
 331
 332   default:
 333     cerr << "Unhandled type for FCmp NE instruction: " << *Ty << "\n";
 334     abort();
 335   }
 336   return Dest;
 337 }
 338
 339 static GenericValue executeFCMP_OLE(GenericValue Src1, GenericValue Src2,
 340                                    const Type *Ty) {
 341   GenericValue Dest;
 342   switch (Ty->getTypeID()) {
 343     IMPLEMENT_FCMP(<=, Float);
 344     IMPLEMENT_FCMP(<=, Double);
 345   default:
 346     cerr << "Unhandled type for FCmp LE instruction: " << *Ty << "\n";
 347     abort();
 348   }
 349   return Dest;
 350 }
 351
 352 static GenericValue executeFCMP_OGE(GenericValue Src1, GenericValue Src2,
 353                                    const Type *Ty) {
 354   GenericValue Dest;
 355   switch (Ty->getTypeID()) {
 356     IMPLEMENT_FCMP(>=, Float);
 357     IMPLEMENT_FCMP(>=, Double);
 358   default:
 359     cerr << "Unhandled type for FCmp GE instruction: " << *Ty << "\n";
 360     abort();
 361   }
 362   return Dest;
 363 }
 364
 365 static GenericValue executeFCMP_OLT(GenericValue Src1, GenericValue Src2,
 366                                    const Type *Ty) {
 367   GenericValue Dest;
 368   switch (Ty->getTypeID()) {
 369     IMPLEMENT_FCMP(<, Float);
 370     IMPLEMENT_FCMP(<, Double);
 371   default:
 372     cerr << "Unhandled type for FCmp LT instruction: " << *Ty << "\n";
 373     abort();
 374   }
 375   return Dest;
 376 }
 377
 378 static GenericValue executeFCMP_OGT(GenericValue Src1, GenericValue Src2,
 379                                      const Type *Ty) {
 380   GenericValue Dest;
 381   switch (Ty->getTypeID()) {
 382     IMPLEMENT_FCMP(>, Float);
 383     IMPLEMENT_FCMP(>, Double);
 384   default:
 385     cerr << "Unhandled type for FCmp GT instruction: " << *Ty << "\n";
 386     abort();
 387   }
 388   return Dest;
 389 }
 390
 391 #define IMPLEMENT_UNORDERED(TY, X,Y)                                     \
 392   if (TY == Type::FloatTy) {                                             \
 393     if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {          \
 394       Dest.IntVal = APInt(1,true);                                       \
 395       return Dest;                                                       \
 396     }                                                                    \
 397   } else if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) { \
 398     Dest.IntVal = APInt(1,true);                                         \
 399     return Dest;                                                         \
 400   }
 401
 402
 403 static GenericValue executeFCMP_UEQ(GenericValue Src1, GenericValue Src2,
 404                                    const Type *Ty) {
 405   GenericValue Dest;
 406   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 407   return executeFCMP_OEQ(Src1, Src2, Ty);
 408 }
 409
 410 static GenericValue executeFCMP_UNE(GenericValue Src1, GenericValue Src2,
 411                                    const Type *Ty) {
 412   GenericValue Dest;
 413   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 414   return executeFCMP_ONE(Src1, Src2, Ty);
 415 }
 416
 417 static GenericValue executeFCMP_ULE(GenericValue Src1, GenericValue Src2,
 418                                    const Type *Ty) {
 419   GenericValue Dest;
 420   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 421   return executeFCMP_OLE(Src1, Src2, Ty);
 422 }
 423
 424 static GenericValue executeFCMP_UGE(GenericValue Src1, GenericValue Src2,
 425                                    const Type *Ty) {
 426   GenericValue Dest;
 427   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 428   return executeFCMP_OGE(Src1, Src2, Ty);
 429 }
 430
 431 static GenericValue executeFCMP_ULT(GenericValue Src1, GenericValue Src2,
 432                                    const Type *Ty) {
 433   GenericValue Dest;
 434   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 435   return executeFCMP_OLT(Src1, Src2, Ty);
 436 }
 437
 438 static GenericValue executeFCMP_UGT(GenericValue Src1, GenericValue Src2,
 439                                      const Type *Ty) {
 440   GenericValue Dest;
 441   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
 442   return executeFCMP_OGT(Src1, Src2, Ty);
 443 }
 444
 445 static GenericValue executeFCMP_ORD(GenericValue Src1, GenericValue Src2,
 446                                      const Type *Ty) {
 447   GenericValue Dest;
 448   if (Ty == Type::FloatTy)
 449     Dest.IntVal = APInt(1,(Src1.FloatVal == Src1.FloatVal &&
 450                            Src2.FloatVal == Src2.FloatVal));
 451   else
 452     Dest.IntVal = APInt(1,(Src1.DoubleVal == Src1.DoubleVal &&
 453                            Src2.DoubleVal == Src2.DoubleVal));
 454   return Dest;
 455 }
 456
 457 static GenericValue executeFCMP_UNO(GenericValue Src1, GenericValue Src2,
 458                                      const Type *Ty) {
 459   GenericValue Dest;
 460   if (Ty == Type::FloatTy)
 461     Dest.IntVal = APInt(1,(Src1.FloatVal != Src1.FloatVal ||
 462                            Src2.FloatVal != Src2.FloatVal));
 463   else
 464     Dest.IntVal = APInt(1,(Src1.DoubleVal != Src1.DoubleVal ||
 465                            Src2.DoubleVal != Src2.DoubleVal));
 466   return Dest;
 467 }
 468
 469 void Interpreter::visitFCmpInst(FCmpInst &I) {
 470   ExecutionContext &SF = ECStack.back();
 471   const Type *Ty    = I.getOperand(0)->getType();
 472   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 473   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 474   GenericValue R;   // Result
 475
 476   switch (I.getPredicate()) {
 477   case FCmpInst::FCMP_FALSE: R.IntVal = APInt(1,false); break;
 478   case FCmpInst::FCMP_TRUE:  R.IntVal = APInt(1,true); break;
 479   case FCmpInst::FCMP_ORD:   R = executeFCMP_ORD(Src1, Src2, Ty); break;
 480   case FCmpInst::FCMP_UNO:   R = executeFCMP_UNO(Src1, Src2, Ty); break;
 481   case FCmpInst::FCMP_UEQ:   R = executeFCMP_UEQ(Src1, Src2, Ty); break;
 482   case FCmpInst::FCMP_OEQ:   R = executeFCMP_OEQ(Src1, Src2, Ty); break;
 483   case FCmpInst::FCMP_UNE:   R = executeFCMP_UNE(Src1, Src2, Ty); break;
 484   case FCmpInst::FCMP_ONE:   R = executeFCMP_ONE(Src1, Src2, Ty); break;
 485   case FCmpInst::FCMP_ULT:   R = executeFCMP_ULT(Src1, Src2, Ty); break;
 486   case FCmpInst::FCMP_OLT:   R = executeFCMP_OLT(Src1, Src2, Ty); break;
 487   case FCmpInst::FCMP_UGT:   R = executeFCMP_UGT(Src1, Src2, Ty); break;
 488   case FCmpInst::FCMP_OGT:   R = executeFCMP_OGT(Src1, Src2, Ty); break;
 489   case FCmpInst::FCMP_ULE:   R = executeFCMP_ULE(Src1, Src2, Ty); break;
 490   case FCmpInst::FCMP_OLE:   R = executeFCMP_OLE(Src1, Src2, Ty); break;
 491   case FCmpInst::FCMP_UGE:   R = executeFCMP_UGE(Src1, Src2, Ty); break;
 492   case FCmpInst::FCMP_OGE:   R = executeFCMP_OGE(Src1, Src2, Ty); break;
 493   default:
 494     cerr << "Don't know how to handle this FCmp predicate!\n-->" << I;
 495     abort();
 496   }
 497
 498   SetValue(&I, R, SF);
 499 }
 500
 501 static GenericValue executeCmpInst(unsigned predicate, GenericValue Src1,
 502                                    GenericValue Src2, const Type *Ty) {
 503   GenericValue Result;
 504   switch (predicate) {
 505   case ICmpInst::ICMP_EQ:    return executeICMP_EQ(Src1, Src2, Ty);
 506   case ICmpInst::ICMP_NE:    return executeICMP_NE(Src1, Src2, Ty);
 507   case ICmpInst::ICMP_UGT:   return executeICMP_UGT(Src1, Src2, Ty);
 508   case ICmpInst::ICMP_SGT:   return executeICMP_SGT(Src1, Src2, Ty);
 509   case ICmpInst::ICMP_ULT:   return executeICMP_ULT(Src1, Src2, Ty);
 510   case ICmpInst::ICMP_SLT:   return executeICMP_SLT(Src1, Src2, Ty);
 511   case ICmpInst::ICMP_UGE:   return executeICMP_UGE(Src1, Src2, Ty);
 512   case ICmpInst::ICMP_SGE:   return executeICMP_SGE(Src1, Src2, Ty);
 513   case ICmpInst::ICMP_ULE:   return executeICMP_ULE(Src1, Src2, Ty);
 514   case ICmpInst::ICMP_SLE:   return executeICMP_SLE(Src1, Src2, Ty);
 515   case FCmpInst::FCMP_ORD:   return executeFCMP_ORD(Src1, Src2, Ty);
 516   case FCmpInst::FCMP_UNO:   return executeFCMP_UNO(Src1, Src2, Ty);
 517   case FCmpInst::FCMP_OEQ:   return executeFCMP_OEQ(Src1, Src2, Ty);
 518   case FCmpInst::FCMP_UEQ:   return executeFCMP_UEQ(Src1, Src2, Ty);
 519   case FCmpInst::FCMP_ONE:   return executeFCMP_ONE(Src1, Src2, Ty);
 520   case FCmpInst::FCMP_UNE:   return executeFCMP_UNE(Src1, Src2, Ty);
 521   case FCmpInst::FCMP_OLT:   return executeFCMP_OLT(Src1, Src2, Ty);
 522   case FCmpInst::FCMP_ULT:   return executeFCMP_ULT(Src1, Src2, Ty);
 523   case FCmpInst::FCMP_OGT:   return executeFCMP_OGT(Src1, Src2, Ty);
 524   case FCmpInst::FCMP_UGT:   return executeFCMP_UGT(Src1, Src2, Ty);
 525   case FCmpInst::FCMP_OLE:   return executeFCMP_OLE(Src1, Src2, Ty);
 526   case FCmpInst::FCMP_ULE:   return executeFCMP_ULE(Src1, Src2, Ty);
 527   case FCmpInst::FCMP_OGE:   return executeFCMP_OGE(Src1, Src2, Ty);
 528   case FCmpInst::FCMP_UGE:   return executeFCMP_UGE(Src1, Src2, Ty);
 529   case FCmpInst::FCMP_FALSE: {
 530     GenericValue Result;
 531     Result.IntVal = APInt(1, false);
 532     return Result;
 533   }
 534   case FCmpInst::FCMP_TRUE: {
 535     GenericValue Result;
 536     Result.IntVal = APInt(1, true);
 537     return Result;
 538   }
 539   default:
 540     cerr << "Unhandled Cmp predicate\n";
 541     abort();
 542   }
 543 }
 544
 545 void Interpreter::visitBinaryOperator(BinaryOperator &I) {
 546   ExecutionContext &SF = ECStack.back();
 547   const Type *Ty    = I.getOperand(0)->getType();
 548   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 549   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 550   GenericValue R;   // Result
 551
 552   switch (I.getOpcode()) {
 553   case Instruction::Add:   executeAddInst  (R, Src1, Src2, Ty); break;
 554   case Instruction::Sub:   executeSubInst  (R, Src1, Src2, Ty); break;
 555   case Instruction::Mul:   executeMulInst  (R, Src1, Src2, Ty); break;
 556   case Instruction::FDiv:  executeFDivInst (R, Src1, Src2, Ty); break;
 557   case Instruction::FRem:  executeFRemInst (R, Src1, Src2, Ty); break;
 558   case Instruction::UDiv:  R.IntVal = Src1.IntVal.udiv(Src2.IntVal); break;
 559   case Instruction::SDiv:  R.IntVal = Src1.IntVal.sdiv(Src2.IntVal); break;
 560   case Instruction::URem:  R.IntVal = Src1.IntVal.urem(Src2.IntVal); break;
 561   case Instruction::SRem:  R.IntVal = Src1.IntVal.srem(Src2.IntVal); break;
 562   case Instruction::And:   R.IntVal = Src1.IntVal & Src2.IntVal; break;
 563   case Instruction::Or:    R.IntVal = Src1.IntVal | Src2.IntVal; break;
 564   case Instruction::Xor:   R.IntVal = Src1.IntVal ^ Src2.IntVal; break;
 565   default:
 566     cerr << "Don't know how to handle this binary operator!\n-->" << I;
 567     abort();
 568   }
 569
 570   SetValue(&I, R, SF);
 571 }
 572
 573 static GenericValue executeSelectInst(GenericValue Src1, GenericValue Src2,
 574                                       GenericValue Src3) {
 575   return Src1.IntVal == 0 ? Src3 : Src2;
 576 }
 577
 578 void Interpreter::visitSelectInst(SelectInst &I) {
 579   ExecutionContext &SF = ECStack.back();
 580   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 581   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 582   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
 583   GenericValue R = executeSelectInst(Src1, Src2, Src3);
 584   SetValue(&I, R, SF);
 585 }
 586
 587
 588 //===----------------------------------------------------------------------===//
 589 //                     Terminator Instruction Implementations
 590 //===----------------------------------------------------------------------===//
 591
 592 void Interpreter::exitCalled(GenericValue GV) {
 593   // runAtExitHandlers() assumes there are no stack frames, but
 594   // if exit() was called, then it had a stack frame. Blow away
 595   // the stack before interpreting atexit handlers.
 596   ECStack.clear ();
 597   runAtExitHandlers ();
 598   exit (GV.IntVal.zextOrTrunc(32).getZExtValue());
 599 }
 600
 601 /// Pop the last stack frame off of ECStack and then copy the result
 602 /// back into the result variable if we are not returning void. The
 603 /// result variable may be the ExitValue, or the Value of the calling
 604 /// CallInst if there was a previous stack frame. This method may
 605 /// invalidate any ECStack iterators you have. This method also takes
 606 /// care of switching to the normal destination BB, if we are returning
 607 /// from an invoke.
 608 ///
 609 void Interpreter::popStackAndReturnValueToCaller (const Type *RetTy,
 610                                                   GenericValue Result) {
 611   // Pop the current stack frame.
 612   ECStack.pop_back();
 613
 614   if (ECStack.empty()) {  // Finished main.  Put result into exit code...
 615     if (RetTy && RetTy->isInteger()) {          // Nonvoid return type?
 616       ExitValue = Result;   // Capture the exit value of the program
 617     } else {
 618       memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
 619     }
 620   } else {
 621     // If we have a previous stack frame, and we have a previous call,
 622     // fill in the return value...
 623     ExecutionContext &CallingSF = ECStack.back();
 624     if (Instruction *I = CallingSF.Caller.getInstruction()) {
 625       if (CallingSF.Caller.getType() != Type::VoidTy)      // Save result...
 626         SetValue(I, Result, CallingSF);
 627       if (InvokeInst *II = dyn_cast<InvokeInst> (I))
 628         SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
 629       CallingSF.Caller = CallSite();          // We returned from the call...
 630     }
 631   }
 632 }
 633
 634 void Interpreter::visitReturnInst(ReturnInst &I) {
 635   ExecutionContext &SF = ECStack.back();
 636   const Type *RetTy = Type::VoidTy;
 637   GenericValue Result;
 638
 639   // Save away the return value... (if we are not 'ret void')
 640   if (I.getNumOperands()) {
 641     RetTy  = I.getReturnValue()->getType();
 642     Result = getOperandValue(I.getReturnValue(), SF);
 643   }
 644
 645   popStackAndReturnValueToCaller(RetTy, Result);
 646 }
 647
 648 void Interpreter::visitUnwindInst(UnwindInst &I) {
 649   // Unwind stack
 650   Instruction *Inst;
 651   do {
 652     ECStack.pop_back ();
 653     if (ECStack.empty ())
 654       abort ();
 655     Inst = ECStack.back ().Caller.getInstruction ();
 656   } while (!(Inst && isa<InvokeInst> (Inst)));
 657
 658   // Return from invoke
 659   ExecutionContext &InvokingSF = ECStack.back ();
 660   InvokingSF.Caller = CallSite ();
 661
 662   // Go to exceptional destination BB of invoke instruction
 663   SwitchToNewBasicBlock(cast<InvokeInst>(Inst)->getUnwindDest(), InvokingSF);
 664 }
 665
 666 void Interpreter::visitUnreachableInst(UnreachableInst &I) {
 667   cerr << "ERROR: Program executed an 'unreachable' instruction!\n";
 668   abort();
 669 }
 670
 671 void Interpreter::visitBranchInst(BranchInst &I) {
 672   ExecutionContext &SF = ECStack.back();
 673   BasicBlock *Dest;
 674
 675   Dest = I.getSuccessor(0);          // Uncond branches have a fixed dest...
 676   if (!I.isUnconditional()) {
 677     Value *Cond = I.getCondition();
 678     if (getOperandValue(Cond, SF).IntVal == 0) // If false cond...
 679       Dest = I.getSuccessor(1);
 680   }
 681   SwitchToNewBasicBlock(Dest, SF);
 682 }
 683
 684 void Interpreter::visitSwitchInst(SwitchInst &I) {
 685   ExecutionContext &SF = ECStack.back();
 686   GenericValue CondVal = getOperandValue(I.getOperand(0), SF);
 687   const Type *ElTy = I.getOperand(0)->getType();
 688
 689   // Check to see if any of the cases match...
 690   BasicBlock *Dest = 0;
 691   for (unsigned i = 2, e = I.getNumOperands(); i != e; i += 2)
 692     if (executeICMP_EQ(CondVal, getOperandValue(I.getOperand(i), SF), ElTy)
 693         .IntVal != 0) {
 694       Dest = cast<BasicBlock>(I.getOperand(i+1));
 695       break;
 696     }
 697
 698   if (!Dest) Dest = I.getDefaultDest();   // No cases matched: use default
 699   SwitchToNewBasicBlock(Dest, SF);
 700 }
 701
 702 // SwitchToNewBasicBlock - This method is used to jump to a new basic block.
 703 // This function handles the actual updating of block and instruction iterators
 704 // as well as execution of all of the PHI nodes in the destination block.
 705 //
 706 // This method does this because all of the PHI nodes must be executed
 707 // atomically, reading their inputs before any of the results are updated.  Not
 708 // doing this can cause problems if the PHI nodes depend on other PHI nodes for
 709 // their inputs.  If the input PHI node is updated before it is read, incorrect
 710 // results can happen.  Thus we use a two phase approach.
 711 //
 712 void Interpreter::SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF){
 713   BasicBlock *PrevBB = SF.CurBB;      // Remember where we came from...
 714   SF.CurBB   = Dest;                  // Update CurBB to branch destination
 715   SF.CurInst = SF.CurBB->begin();     // Update new instruction ptr...
 716
 717   if (!isa<PHINode>(SF.CurInst)) return;  // Nothing fancy to do
 718
 719   // Loop over all of the PHI nodes in the current block, reading their inputs.
 720   std::vector<GenericValue> ResultValues;
 721
 722   for (; PHINode *PN = dyn_cast<PHINode>(SF.CurInst); ++SF.CurInst) {
 723     // Search for the value corresponding to this previous bb...
 724     int i = PN->getBasicBlockIndex(PrevBB);
 725     assert(i != -1 && "PHINode doesn't contain entry for predecessor??");
 726     Value *IncomingValue = PN->getIncomingValue(i);
 727
 728     // Save the incoming value for this PHI node...
 729     ResultValues.push_back(getOperandValue(IncomingValue, SF));
 730   }
 731
 732   // Now loop over all of the PHI nodes setting their values...
 733   SF.CurInst = SF.CurBB->begin();
 734   for (unsigned i = 0; isa<PHINode>(SF.CurInst); ++SF.CurInst, ++i) {
 735     PHINode *PN = cast<PHINode>(SF.CurInst);
 736     SetValue(PN, ResultValues[i], SF);
 737   }
 738 }
 739
 740 //===----------------------------------------------------------------------===//
 741 //                     Memory Instruction Implementations
 742 //===----------------------------------------------------------------------===//
 743
 744 void Interpreter::visitAllocationInst(AllocationInst &I) {
 745   ExecutionContext &SF = ECStack.back();
 746
 747   const Type *Ty = I.getType()->getElementType();  // Type to be allocated
 748
 749   // Get the number of elements being allocated by the array...
 750   unsigned NumElements =
 751     getOperandValue(I.getOperand(0), SF).IntVal.getZExtValue();
 752
 753   unsigned TypeSize = (size_t)TD.getTypeAllocSize(Ty);
 754
 755   // Avoid malloc-ing zero bytes, use max()...
 756   unsigned MemToAlloc = std::max(1U, NumElements * TypeSize);
 757
 758   // Allocate enough memory to hold the type...
 759   void *Memory = malloc(MemToAlloc);
 760
 761   DOUT << "Allocated Type: " << *Ty << " (" << TypeSize << " bytes) x "
 762        << NumElements << " (Total: " << MemToAlloc << ") at "
 763        << uintptr_t(Memory) << '\n';
 764
 765   GenericValue Result = PTOGV(Memory);
 766   assert(Result.PointerVal != 0 && "Null pointer returned by malloc!");
 767   SetValue(&I, Result, SF);
 768
 769   if (I.getOpcode() == Instruction::Alloca)
 770     ECStack.back().Allocas.add(Memory);
 771 }
 772
 773 void Interpreter::visitFreeInst(FreeInst &I) {
 774   ExecutionContext &SF = ECStack.back();
 775   assert(isa<PointerType>(I.getOperand(0)->getType()) && "Freeing nonptr?");
 776   GenericValue Value = getOperandValue(I.getOperand(0), SF);
 777   // TODO: Check to make sure memory is allocated
 778   free(GVTOP(Value));   // Free memory
 779 }
 780
 781 // getElementOffset - The workhorse for getelementptr.
 782 //
 783 GenericValue Interpreter::executeGEPOperation(Value *Ptr, gep_type_iterator I,
 784                                               gep_type_iterator E,
 785                                               ExecutionContext &SF) {
 786   assert(isa<PointerType>(Ptr->getType()) &&
 787          "Cannot getElementOffset of a nonpointer type!");
 788
 789   uint64_t Total = 0;
 790
 791   for (; I != E; ++I) {
 792     if (const StructType *STy = dyn_cast<StructType>(*I)) {
 793       const StructLayout *SLO = TD.getStructLayout(STy);
 794
 795       const ConstantInt *CPU = cast<ConstantInt>(I.getOperand());
 796       unsigned Index = unsigned(CPU->getZExtValue());
 797
 798       Total += SLO->getElementOffset(Index);
 799     } else {
 800       const SequentialType *ST = cast<SequentialType>(*I);
 801       // Get the index number for the array... which must be long type...
 802       GenericValue IdxGV = getOperandValue(I.getOperand(), SF);
 803
 804       int64_t Idx;
 805       unsigned BitWidth =
 806         cast<IntegerType>(I.getOperand()->getType())->getBitWidth();
 807       if (BitWidth == 32)
 808         Idx = (int64_t)(int32_t)IdxGV.IntVal.getZExtValue();
 809       else {
 810         assert(BitWidth == 64 && "Invalid index type for getelementptr");
 811         Idx = (int64_t)IdxGV.IntVal.getZExtValue();
 812       }
 813       Total += TD.getTypeAllocSize(ST->getElementType())*Idx;
 814     }
 815   }
 816
 817   GenericValue Result;
 818   Result.PointerVal = ((char*)getOperandValue(Ptr, SF).PointerVal) + Total;
 819   DOUT << "GEP Index " << Total << " bytes.\n";
 820   return Result;
 821 }
 822
 823 void Interpreter::visitGetElementPtrInst(GetElementPtrInst &I) {
 824   ExecutionContext &SF = ECStack.back();
 825   SetValue(&I, TheEE->executeGEPOperation(I.getPointerOperand(),
 826                                    gep_type_begin(I), gep_type_end(I), SF), SF);
 827 }
 828
 829 void Interpreter::visitLoadInst(LoadInst &I) {
 830   ExecutionContext &SF = ECStack.back();
 831   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
 832   GenericValue *Ptr = (GenericValue*)GVTOP(SRC);
 833   GenericValue Result;
 834   LoadValueFromMemory(Result, Ptr, I.getType());
 835   SetValue(&I, Result, SF);
 836   if (I.isVolatile() && PrintVolatile)
 837     cerr << "Volatile load " << I;
 838 }
 839
 840 void Interpreter::visitStoreInst(StoreInst &I) {
 841   ExecutionContext &SF = ECStack.back();
 842   GenericValue Val = getOperandValue(I.getOperand(0), SF);
 843   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
 844   StoreValueToMemory(Val, (GenericValue *)GVTOP(SRC),
 845                      I.getOperand(0)->getType());
 846   if (I.isVolatile() && PrintVolatile)
 847     cerr << "Volatile store: " << I;
 848 }
 849
 850 //===----------------------------------------------------------------------===//
 851 //                 Miscellaneous Instruction Implementations
 852 //===----------------------------------------------------------------------===//
 853
 854 void Interpreter::visitCallSite(CallSite CS) {
 855   ExecutionContext &SF = ECStack.back();
 856
 857   // Check to see if this is an intrinsic function call...
 858   Function *F = CS.getCalledFunction();
 859   if (F && F->isDeclaration ())
 860     switch (F->getIntrinsicID()) {
 861     case Intrinsic::not_intrinsic:
 862       break;
 863     case Intrinsic::vastart: { // va_start
 864       GenericValue ArgIndex;
 865       ArgIndex.UIntPairVal.first = ECStack.size() - 1;
 866       ArgIndex.UIntPairVal.second = 0;
 867       SetValue(CS.getInstruction(), ArgIndex, SF);
 868       return;
 869     }
 870     case Intrinsic::vaend:    // va_end is a noop for the interpreter
 871       return;
 872     case Intrinsic::vacopy:   // va_copy: dest = src
 873       SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
 874       return;
 875     default:
 876       // If it is an unknown intrinsic function, use the intrinsic lowering
 877       // class to transform it into hopefully tasty LLVM code.
 878       //
 879       BasicBlock::iterator me(CS.getInstruction());
 880       BasicBlock *Parent = CS.getInstruction()->getParent();
 881       bool atBegin(Parent->begin() == me);
 882       if (!atBegin)
 883         --me;
 884       IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
 885
 886       // Restore the CurInst pointer to the first instruction newly inserted, if
 887       // any.
 888       if (atBegin) {
 889         SF.CurInst = Parent->begin();
 890       } else {
 891         SF.CurInst = me;
 892         ++SF.CurInst;
 893       }
 894       return;
 895     }
 896
 897
 898   SF.Caller = CS;
 899   std::vector<GenericValue> ArgVals;
 900   const unsigned NumArgs = SF.Caller.arg_size();
 901   ArgVals.reserve(NumArgs);
 902   uint16_t pNum = 1;
 903   for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
 904          e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
 905     Value *V = *i;
 906     ArgVals.push_back(getOperandValue(V, SF));
 907     // Promote all integral types whose size is < sizeof(i32) into i32.
 908     // We do this by zero or sign extending the value as appropriate
 909     // according to the parameter attributes
 910     const Type *Ty = V->getType();
 911     if (Ty->isInteger() && (ArgVals.back().IntVal.getBitWidth() < 32)) {
 912       if (CS.paramHasAttr(pNum, Attribute::ZExt))
 913         ArgVals.back().IntVal = ArgVals.back().IntVal.zext(32);
 914       else if (CS.paramHasAttr(pNum, Attribute::SExt))
 915         ArgVals.back().IntVal = ArgVals.back().IntVal.sext(32);
 916     }
 917   }
 918
 919   // To handle indirect calls, we must get the pointer value from the argument
 920   // and treat it as a function pointer.
 921   GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
 922   callFunction((Function*)GVTOP(SRC), ArgVals);
 923 }
 924
 925 void Interpreter::visitShl(BinaryOperator &I) {
 926   ExecutionContext &SF = ECStack.back();
 927   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 928   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 929   GenericValue Dest;
 930   if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
 931     Dest.IntVal = Src1.IntVal.shl(Src2.IntVal.getZExtValue());
 932   else
 933     Dest.IntVal = Src1.IntVal;
 934
 935   SetValue(&I, Dest, SF);
 936 }
 937
 938 void Interpreter::visitLShr(BinaryOperator &I) {
 939   ExecutionContext &SF = ECStack.back();
 940   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 941   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 942   GenericValue Dest;
 943   if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
 944     Dest.IntVal = Src1.IntVal.lshr(Src2.IntVal.getZExtValue());
 945   else
 946     Dest.IntVal = Src1.IntVal;
 947
 948   SetValue(&I, Dest, SF);
 949 }
 950
 951 void Interpreter::visitAShr(BinaryOperator &I) {
 952   ExecutionContext &SF = ECStack.back();
 953   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
 954   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
 955   GenericValue Dest;
 956   if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
 957     Dest.IntVal = Src1.IntVal.ashr(Src2.IntVal.getZExtValue());
 958   else
 959     Dest.IntVal = Src1.IntVal;
 960
 961   SetValue(&I, Dest, SF);
 962 }
 963
 964 GenericValue Interpreter::executeTruncInst(Value *SrcVal, const Type *DstTy,
 965                                            ExecutionContext &SF) {
 966   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
 967   const IntegerType *DITy = cast<IntegerType>(DstTy);
 968   unsigned DBitWidth = DITy->getBitWidth();
 969   Dest.IntVal = Src.IntVal.trunc(DBitWidth);
 970   return Dest;
 971 }
 972
 973 GenericValue Interpreter::executeSExtInst(Value *SrcVal, const Type *DstTy,
 974                                           ExecutionContext &SF) {
 975   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
 976   const IntegerType *DITy = cast<IntegerType>(DstTy);
 977   unsigned DBitWidth = DITy->getBitWidth();
 978   Dest.IntVal = Src.IntVal.sext(DBitWidth);
 979   return Dest;
 980 }
 981
 982 GenericValue Interpreter::executeZExtInst(Value *SrcVal, const Type *DstTy,
 983                                           ExecutionContext &SF) {
 984   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
 985   const IntegerType *DITy = cast<IntegerType>(DstTy);
 986   unsigned DBitWidth = DITy->getBitWidth();
 987   Dest.IntVal = Src.IntVal.zext(DBitWidth);
 988   return Dest;
 989 }
 990
 991 GenericValue Interpreter::executeFPTruncInst(Value *SrcVal, const Type *DstTy,
 992                                              ExecutionContext &SF) {
 993   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
 994   assert(SrcVal->getType() == Type::DoubleTy && DstTy == Type::FloatTy &&
 995          "Invalid FPTrunc instruction");
 996   Dest.FloatVal = (float) Src.DoubleVal;
 997   return Dest;
 998 }
 999
1000 GenericValue Interpreter::executeFPExtInst(Value *SrcVal, const Type *DstTy,
1001                                            ExecutionContext &SF) {
1002   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1003   assert(SrcVal->getType() == Type::FloatTy && DstTy == Type::DoubleTy &&
1004          "Invalid FPTrunc instruction");
1005   Dest.DoubleVal = (double) Src.FloatVal;
1006   return Dest;
1007 }
1008
1009 GenericValue Interpreter::executeFPToUIInst(Value *SrcVal, const Type *DstTy,
1010                                             ExecutionContext &SF) {
1011   const Type *SrcTy = SrcVal->getType();
1012   uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1013   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1014   assert(SrcTy->isFloatingPoint() && "Invalid FPToUI instruction");
1015
1016   if (SrcTy->getTypeID() == Type::FloatTyID)
1017     Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1018   else
1019     Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1020   return Dest;
1021 }
1022
1023 GenericValue Interpreter::executeFPToSIInst(Value *SrcVal, const Type *DstTy,
1024                                             ExecutionContext &SF) {
1025   const Type *SrcTy = SrcVal->getType();
1026   uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1027   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1028   assert(SrcTy->isFloatingPoint() && "Invalid FPToSI instruction");
1029
1030   if (SrcTy->getTypeID() == Type::FloatTyID)
1031     Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1032   else
1033     Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1034   return Dest;
1035 }
1036
1037 GenericValue Interpreter::executeUIToFPInst(Value *SrcVal, const Type *DstTy,
1038                                             ExecutionContext &SF) {
1039   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1040   assert(DstTy->isFloatingPoint() && "Invalid UIToFP instruction");
1041
1042   if (DstTy->getTypeID() == Type::FloatTyID)
1043     Dest.FloatVal = APIntOps::RoundAPIntToFloat(Src.IntVal);
1044   else
1045     Dest.DoubleVal = APIntOps::RoundAPIntToDouble(Src.IntVal);
1046   return Dest;
1047 }
1048
1049 GenericValue Interpreter::executeSIToFPInst(Value *SrcVal, const Type *DstTy,
1050                                             ExecutionContext &SF) {
1051   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1052   assert(DstTy->isFloatingPoint() && "Invalid SIToFP instruction");
1053
1054   if (DstTy->getTypeID() == Type::FloatTyID)
1055     Dest.FloatVal = APIntOps::RoundSignedAPIntToFloat(Src.IntVal);
1056   else
1057     Dest.DoubleVal = APIntOps::RoundSignedAPIntToDouble(Src.IntVal);
1058   return Dest;
1059
1060 }
1061
1062 GenericValue Interpreter::executePtrToIntInst(Value *SrcVal, const Type *DstTy,
1063                                               ExecutionContext &SF) {
1064   uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1065   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1066   assert(isa<PointerType>(SrcVal->getType()) && "Invalid PtrToInt instruction");
1067
1068   Dest.IntVal = APInt(DBitWidth, (intptr_t) Src.PointerVal);
1069   return Dest;
1070 }
1071
1072 GenericValue Interpreter::executeIntToPtrInst(Value *SrcVal, const Type *DstTy,
1073                                               ExecutionContext &SF) {
1074   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1075   assert(isa<PointerType>(DstTy) && "Invalid PtrToInt instruction");
1076
1077   uint32_t PtrSize = TD.getPointerSizeInBits();
1078   if (PtrSize != Src.IntVal.getBitWidth())
1079     Src.IntVal = Src.IntVal.zextOrTrunc(PtrSize);
1080
1081   Dest.PointerVal = PointerTy(intptr_t(Src.IntVal.getZExtValue()));
1082   return Dest;
1083 }
1084
1085 GenericValue Interpreter::executeBitCastInst(Value *SrcVal, const Type *DstTy,
1086                                              ExecutionContext &SF) {
1087
1088   const Type *SrcTy = SrcVal->getType();
1089   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1090   if (isa<PointerType>(DstTy)) {
1091     assert(isa<PointerType>(SrcTy) && "Invalid BitCast");
1092     Dest.PointerVal = Src.PointerVal;
1093   } else if (DstTy->isInteger()) {
1094     if (SrcTy == Type::FloatTy) {
1095       Dest.IntVal.zext(sizeof(Src.FloatVal) * CHAR_BIT);
1096       Dest.IntVal.floatToBits(Src.FloatVal);
1097     } else if (SrcTy == Type::DoubleTy) {
1098       Dest.IntVal.zext(sizeof(Src.DoubleVal) * CHAR_BIT);
1099       Dest.IntVal.doubleToBits(Src.DoubleVal);
1100     } else if (SrcTy->isInteger()) {
1101       Dest.IntVal = Src.IntVal;
1102     } else
1103       assert(0 && "Invalid BitCast");
1104   } else if (DstTy == Type::FloatTy) {
1105     if (SrcTy->isInteger())
1106       Dest.FloatVal = Src.IntVal.bitsToFloat();
1107     else
1108       Dest.FloatVal = Src.FloatVal;
1109   } else if (DstTy == Type::DoubleTy) {
1110     if (SrcTy->isInteger())
1111       Dest.DoubleVal = Src.IntVal.bitsToDouble();
1112     else
1113       Dest.DoubleVal = Src.DoubleVal;
1114   } else
1115     assert(0 && "Invalid Bitcast");
1116
1117   return Dest;
1118 }
1119
1120 void Interpreter::visitTruncInst(TruncInst &I) {
1121   ExecutionContext &SF = ECStack.back();
1122   SetValue(&I, executeTruncInst(I.getOperand(0), I.getType(), SF), SF);
1123 }
1124
1125 void Interpreter::visitSExtInst(SExtInst &I) {
1126   ExecutionContext &SF = ECStack.back();
1127   SetValue(&I, executeSExtInst(I.getOperand(0), I.getType(), SF), SF);
1128 }
1129
1130 void Interpreter::visitZExtInst(ZExtInst &I) {
1131   ExecutionContext &SF = ECStack.back();
1132   SetValue(&I, executeZExtInst(I.getOperand(0), I.getType(), SF), SF);
1133 }
1134
1135 void Interpreter::visitFPTruncInst(FPTruncInst &I) {
1136   ExecutionContext &SF = ECStack.back();
1137   SetValue(&I, executeFPTruncInst(I.getOperand(0), I.getType(), SF), SF);
1138 }
1139
1140 void Interpreter::visitFPExtInst(FPExtInst &I) {
1141   ExecutionContext &SF = ECStack.back();
1142   SetValue(&I, executeFPExtInst(I.getOperand(0), I.getType(), SF), SF);
1143 }
1144
1145 void Interpreter::visitUIToFPInst(UIToFPInst &I) {
1146   ExecutionContext &SF = ECStack.back();
1147   SetValue(&I, executeUIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1148 }
1149
1150 void Interpreter::visitSIToFPInst(SIToFPInst &I) {
1151   ExecutionContext &SF = ECStack.back();
1152   SetValue(&I, executeSIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1153 }
1154
1155 void Interpreter::visitFPToUIInst(FPToUIInst &I) {
1156   ExecutionContext &SF = ECStack.back();
1157   SetValue(&I, executeFPToUIInst(I.getOperand(0), I.getType(), SF), SF);
1158 }
1159
1160 void Interpreter::visitFPToSIInst(FPToSIInst &I) {
1161   ExecutionContext &SF = ECStack.back();
1162   SetValue(&I, executeFPToSIInst(I.getOperand(0), I.getType(), SF), SF);
1163 }
1164
1165 void Interpreter::visitPtrToIntInst(PtrToIntInst &I) {
1166   ExecutionContext &SF = ECStack.back();
1167   SetValue(&I, executePtrToIntInst(I.getOperand(0), I.getType(), SF), SF);
1168 }
1169
1170 void Interpreter::visitIntToPtrInst(IntToPtrInst &I) {
1171   ExecutionContext &SF = ECStack.back();
1172   SetValue(&I, executeIntToPtrInst(I.getOperand(0), I.getType(), SF), SF);
1173 }
1174
1175 void Interpreter::visitBitCastInst(BitCastInst &I) {
1176   ExecutionContext &SF = ECStack.back();
1177   SetValue(&I, executeBitCastInst(I.getOperand(0), I.getType(), SF), SF);
1178 }
1179
1180 #define IMPLEMENT_VAARG(TY) \
1181    case Type::TY##TyID: Dest.TY##Val = Src.TY##Val; break
1182
1183 void Interpreter::visitVAArgInst(VAArgInst &I) {
1184   ExecutionContext &SF = ECStack.back();
1185
1186   // Get the incoming valist parameter.  LLI treats the valist as a
1187   // (ec-stack-depth var-arg-index) pair.
1188   GenericValue VAList = getOperandValue(I.getOperand(0), SF);
1189   GenericValue Dest;
1190   GenericValue Src = ECStack[VAList.UIntPairVal.first]
1191                       .VarArgs[VAList.UIntPairVal.second];
1192   const Type *Ty = I.getType();
1193   switch (Ty->getTypeID()) {
1194     case Type::IntegerTyID: Dest.IntVal = Src.IntVal;
1195     IMPLEMENT_VAARG(Pointer);
1196     IMPLEMENT_VAARG(Float);
1197     IMPLEMENT_VAARG(Double);
1198   default:
1199     cerr << "Unhandled dest type for vaarg instruction: " << *Ty << "\n";
1200     abort();
1201   }
1202
1203   // Set the Value of this Instruction.
1204   SetValue(&I, Dest, SF);
1205
1206   // Move the pointer to the next vararg.
1207   ++VAList.UIntPairVal.second;
1208 }
1209
1210 GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
1211                                                 ExecutionContext &SF) {
1212   switch (CE->getOpcode()) {
1213   case Instruction::Trunc:
1214       return executeTruncInst(CE->getOperand(0), CE->getType(), SF);
1215   case Instruction::ZExt:
1216       return executeZExtInst(CE->getOperand(0), CE->getType(), SF);
1217   case Instruction::SExt:
1218       return executeSExtInst(CE->getOperand(0), CE->getType(), SF);
1219   case Instruction::FPTrunc:
1220       return executeFPTruncInst(CE->getOperand(0), CE->getType(), SF);
1221   case Instruction::FPExt:
1222       return executeFPExtInst(CE->getOperand(0), CE->getType(), SF);
1223   case Instruction::UIToFP:
1224       return executeUIToFPInst(CE->getOperand(0), CE->getType(), SF);
1225   case Instruction::SIToFP:
1226       return executeSIToFPInst(CE->getOperand(0), CE->getType(), SF);
1227   case Instruction::FPToUI:
1228       return executeFPToUIInst(CE->getOperand(0), CE->getType(), SF);
1229   case Instruction::FPToSI:
1230       return executeFPToSIInst(CE->getOperand(0), CE->getType(), SF);
1231   case Instruction::PtrToInt:
1232       return executePtrToIntInst(CE->getOperand(0), CE->getType(), SF);
1233   case Instruction::IntToPtr:
1234       return executeIntToPtrInst(CE->getOperand(0), CE->getType(), SF);
1235   case Instruction::BitCast:
1236       return executeBitCastInst(CE->getOperand(0), CE->getType(), SF);
1237   case Instruction::GetElementPtr:
1238     return executeGEPOperation(CE->getOperand(0), gep_type_begin(CE),
1239                                gep_type_end(CE), SF);
1240   case Instruction::FCmp:
1241   case Instruction::ICmp:
1242     return executeCmpInst(CE->getPredicate(),
1243                           getOperandValue(CE->getOperand(0), SF),
1244                           getOperandValue(CE->getOperand(1), SF),
1245                           CE->getOperand(0)->getType());
1246   case Instruction::Select:
1247     return executeSelectInst(getOperandValue(CE->getOperand(0), SF),
1248                              getOperandValue(CE->getOperand(1), SF),
1249                              getOperandValue(CE->getOperand(2), SF));
1250   default :
1251     break;
1252   }
1253
1254   // The cases below here require a GenericValue parameter for the result
1255   // so we initialize one, compute it and then return it.
1256   GenericValue Op0 = getOperandValue(CE->getOperand(0), SF);
1257   GenericValue Op1 = getOperandValue(CE->getOperand(1), SF);
1258   GenericValue Dest;
1259   const Type * Ty = CE->getOperand(0)->getType();
1260   switch (CE->getOpcode()) {
1261   case Instruction::Add:  executeAddInst (Dest, Op0, Op1, Ty); break;
1262   case Instruction::Sub:  executeSubInst (Dest, Op0, Op1, Ty); break;
1263   case Instruction::Mul:  executeMulInst (Dest, Op0, Op1, Ty); break;
1264   case Instruction::FDiv: executeFDivInst(Dest, Op0, Op1, Ty); break;
1265   case Instruction::FRem: executeFRemInst(Dest, Op0, Op1, Ty); break;
1266   case Instruction::SDiv: Dest.IntVal = Op0.IntVal.sdiv(Op1.IntVal); break;
1267   case Instruction::UDiv: Dest.IntVal = Op0.IntVal.udiv(Op1.IntVal); break;
1268   case Instruction::URem: Dest.IntVal = Op0.IntVal.urem(Op1.IntVal); break;
1269   case Instruction::SRem: Dest.IntVal = Op0.IntVal.srem(Op1.IntVal); break;
1270   case Instruction::And:  Dest.IntVal = Op0.IntVal.And(Op1.IntVal); break;
1271   case Instruction::Or:   Dest.IntVal = Op0.IntVal.Or(Op1.IntVal); break;
1272   case Instruction::Xor:  Dest.IntVal = Op0.IntVal.Xor(Op1.IntVal); break;
1273   case Instruction::Shl:
1274     Dest.IntVal = Op0.IntVal.shl(Op1.IntVal.getZExtValue());
1275     break;
1276   case Instruction::LShr:
1277     Dest.IntVal = Op0.IntVal.lshr(Op1.IntVal.getZExtValue());
1278     break;
1279   case Instruction::AShr:
1280     Dest.IntVal = Op0.IntVal.ashr(Op1.IntVal.getZExtValue());
1281     break;
1282   default:
1283     cerr << "Unhandled ConstantExpr: " << *CE << "\n";
1284     abort();
1285     return GenericValue();
1286   }
1287   return Dest;
1288 }
1289
1290 GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
1291   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
1292     return getConstantExprValue(CE, SF);
1293   } else if (Constant *CPV = dyn_cast<Constant>(V)) {
1294     return getConstantValue(CPV);
1295   } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
1296     return PTOGV(getPointerToGlobal(GV));
1297   } else {
1298     return SF.Values[V];
1299   }
1300 }
1301
1302 //===----------------------------------------------------------------------===//
1303 //                        Dispatch and Execution Code
1304 //===----------------------------------------------------------------------===//
1305
1306 //===----------------------------------------------------------------------===//
1307 // callFunction - Execute the specified function...
1308 //
1309 void Interpreter::callFunction(Function *F,
1310                                const std::vector<GenericValue> &ArgVals) {
1311   assert((ECStack.empty() || ECStack.back().Caller.getInstruction() == 0 ||
1312           ECStack.back().Caller.arg_size() == ArgVals.size()) &&
1313          "Incorrect number of arguments passed into function call!");
1314   // Make a new stack frame... and fill it in.
1315   ECStack.push_back(ExecutionContext());
1316   ExecutionContext &StackFrame = ECStack.back();
1317   StackFrame.CurFunction = F;
1318
1319   // Special handling for external functions.
1320   if (F->isDeclaration()) {
1321     GenericValue Result = callExternalFunction (F, ArgVals);
1322     // Simulate a 'ret' instruction of the appropriate type.
1323     popStackAndReturnValueToCaller (F->getReturnType (), Result);
1324     return;
1325   }
1326
1327   // Get pointers to first LLVM BB & Instruction in function.
1328   StackFrame.CurBB     = F->begin();
1329   StackFrame.CurInst   = StackFrame.CurBB->begin();
1330
1331   // Run through the function arguments and initialize their values...
1332   assert((ArgVals.size() == F->arg_size() ||
1333          (ArgVals.size() > F->arg_size() && F->getFunctionType()->isVarArg()))&&
1334          "Invalid number of values passed to function invocation!");
1335
1336   // Handle non-varargs arguments...
1337   unsigned i = 0;
1338   for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
1339        AI != E; ++AI, ++i)
1340     SetValue(AI, ArgVals[i], StackFrame);
1341
1342   // Handle varargs arguments...
1343   StackFrame.VarArgs.assign(ArgVals.begin()+i, ArgVals.end());
1344 }
1345
1346
1347 void Interpreter::run() {
1348   while (!ECStack.empty()) {
1349     // Interpret a single instruction & increment the "PC".
1350     ExecutionContext &SF = ECStack.back();  // Current stack frame
1351     Instruction &I = *SF.CurInst++;         // Increment before execute
1352
1353     // Track the number of dynamic instructions executed.
1354     ++NumDynamicInsts;
1355
1356     DOUT << "About to interpret: " << I;
1357     visit(I);   // Dispatch to one of the visit* methods...
1358 #if 0
1359     // This is not safe, as visiting the instruction could lower it and free I.
1360 #ifndef NDEBUG
1361     if (!isa<CallInst>(I) && !isa<InvokeInst>(I) &&
1362         I.getType() != Type::VoidTy) {
1363       DOUT << "  --> ";
1364       const GenericValue &Val = SF.Values[&I];
1365       switch (I.getType()->getTypeID()) {
1366       default: assert(0 && "Invalid GenericValue Type");
1367       case Type::VoidTyID:    DOUT << "void"; break;
1368       case Type::FloatTyID:   DOUT << "float " << Val.FloatVal; break;
1369       case Type::DoubleTyID:  DOUT << "double " << Val.DoubleVal; break;
1370       case Type::PointerTyID: DOUT << "void* " << intptr_t(Val.PointerVal);
1371         break;
1372       case Type::IntegerTyID:
1373         DOUT << "i" << Val.IntVal.getBitWidth() << " "
1374         << Val.IntVal.toStringUnsigned(10)
1375         << " (0x" << Val.IntVal.toStringUnsigned(16) << ")\n";
1376         break;
1377       }
1378     }
1379 #endif
1380 #endif
1381   }
1382 }