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/ADT/APInt.h"
17#include "llvm/ADT/Statistic.h"
18#include "llvm/CodeGen/IntrinsicLowering.h"
19#include "llvm/IR/Constants.h"
20#include "llvm/IR/DerivedTypes.h"
21#include "llvm/IR/Instructions.h"
22#include "llvm/Support/CommandLine.h"
23#include "llvm/Support/Debug.h"
24#include "llvm/Support/ErrorHandling.h"
25#include "llvm/Support/GetElementPtrTypeIterator.h"
26#include "llvm/Support/MathExtras.h"
27#include <algorithm>
28#include <cmath>
29using namespace llvm;
30
31STATISTIC(NumDynamicInsts, "Number of dynamic instructions executed");
32
33static cl::opt<bool> PrintVolatile("interpreter-print-volatile", cl::Hidden,
34          cl::desc("make the interpreter print every volatile load and store"));
35
36//===----------------------------------------------------------------------===//
37//                     Various Helper Functions
38//===----------------------------------------------------------------------===//
39
40static void SetValue(Value *V, GenericValue Val, ExecutionContext &SF) {
41  SF.Values[V] = Val;
42}
43
44//===----------------------------------------------------------------------===//
45//                    Binary Instruction Implementations
46//===----------------------------------------------------------------------===//
47
48#define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
49   case Type::TY##TyID: \
50     Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; \
51     break
52
53static void executeFAddInst(GenericValue &Dest, GenericValue Src1,
54                            GenericValue Src2, Type *Ty) {
55  switch (Ty->getTypeID()) {
56    IMPLEMENT_BINARY_OPERATOR(+, Float);
57    IMPLEMENT_BINARY_OPERATOR(+, Double);
58  default:
59    dbgs() << "Unhandled type for FAdd instruction: " << *Ty << "\n";
60    llvm_unreachable(0);
61  }
62}
63
64static void executeFSubInst(GenericValue &Dest, GenericValue Src1,
65                            GenericValue Src2, Type *Ty) {
66  switch (Ty->getTypeID()) {
67    IMPLEMENT_BINARY_OPERATOR(-, Float);
68    IMPLEMENT_BINARY_OPERATOR(-, Double);
69  default:
70    dbgs() << "Unhandled type for FSub instruction: " << *Ty << "\n";
71    llvm_unreachable(0);
72  }
73}
74
75static void executeFMulInst(GenericValue &Dest, GenericValue Src1,
76                            GenericValue Src2, Type *Ty) {
77  switch (Ty->getTypeID()) {
78    IMPLEMENT_BINARY_OPERATOR(*, Float);
79    IMPLEMENT_BINARY_OPERATOR(*, Double);
80  default:
81    dbgs() << "Unhandled type for FMul instruction: " << *Ty << "\n";
82    llvm_unreachable(0);
83  }
84}
85
86static void executeFDivInst(GenericValue &Dest, GenericValue Src1,
87                            GenericValue Src2, Type *Ty) {
88  switch (Ty->getTypeID()) {
89    IMPLEMENT_BINARY_OPERATOR(/, Float);
90    IMPLEMENT_BINARY_OPERATOR(/, Double);
91  default:
92    dbgs() << "Unhandled type for FDiv instruction: " << *Ty << "\n";
93    llvm_unreachable(0);
94  }
95}
96
97static void executeFRemInst(GenericValue &Dest, GenericValue Src1,
98                            GenericValue Src2, Type *Ty) {
99  switch (Ty->getTypeID()) {
100  case Type::FloatTyID:
101    Dest.FloatVal = fmod(Src1.FloatVal, Src2.FloatVal);
102    break;
103  case Type::DoubleTyID:
104    Dest.DoubleVal = fmod(Src1.DoubleVal, Src2.DoubleVal);
105    break;
106  default:
107    dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
108    llvm_unreachable(0);
109  }
110}
111
112#define IMPLEMENT_INTEGER_ICMP(OP, TY) \
113   case Type::IntegerTyID:  \
114      Dest.IntVal = APInt(1,Src1.IntVal.OP(Src2.IntVal)); \
115      break;
116
117#define IMPLEMENT_VECTOR_INTEGER_ICMP(OP, TY)                        \
118  case Type::VectorTyID: {                                           \
119    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());    \
120    Dest.AggregateVal.resize( Src1.AggregateVal.size() );            \
121    for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)             \
122      Dest.AggregateVal[_i].IntVal = APInt(1,                        \
123      Src1.AggregateVal[_i].IntVal.OP(Src2.AggregateVal[_i].IntVal));\
124  } break;
125
126// Handle pointers specially because they must be compared with only as much
127// width as the host has.  We _do not_ want to be comparing 64 bit values when
128// running on a 32-bit target, otherwise the upper 32 bits might mess up
129// comparisons if they contain garbage.
130#define IMPLEMENT_POINTER_ICMP(OP) \
131   case Type::PointerTyID: \
132      Dest.IntVal = APInt(1,(void*)(intptr_t)Src1.PointerVal OP \
133                            (void*)(intptr_t)Src2.PointerVal); \
134      break;
135
136static GenericValue executeICMP_EQ(GenericValue Src1, GenericValue Src2,
137                                   Type *Ty) {
138  GenericValue Dest;
139  switch (Ty->getTypeID()) {
140    IMPLEMENT_INTEGER_ICMP(eq,Ty);
141    IMPLEMENT_VECTOR_INTEGER_ICMP(eq,Ty);
142    IMPLEMENT_POINTER_ICMP(==);
143  default:
144    dbgs() << "Unhandled type for ICMP_EQ predicate: " << *Ty << "\n";
145    llvm_unreachable(0);
146  }
147  return Dest;
148}
149
150static GenericValue executeICMP_NE(GenericValue Src1, GenericValue Src2,
151                                   Type *Ty) {
152  GenericValue Dest;
153  switch (Ty->getTypeID()) {
154    IMPLEMENT_INTEGER_ICMP(ne,Ty);
155    IMPLEMENT_VECTOR_INTEGER_ICMP(ne,Ty);
156    IMPLEMENT_POINTER_ICMP(!=);
157  default:
158    dbgs() << "Unhandled type for ICMP_NE predicate: " << *Ty << "\n";
159    llvm_unreachable(0);
160  }
161  return Dest;
162}
163
164static GenericValue executeICMP_ULT(GenericValue Src1, GenericValue Src2,
165                                    Type *Ty) {
166  GenericValue Dest;
167  switch (Ty->getTypeID()) {
168    IMPLEMENT_INTEGER_ICMP(ult,Ty);
169    IMPLEMENT_VECTOR_INTEGER_ICMP(ult,Ty);
170    IMPLEMENT_POINTER_ICMP(<);
171  default:
172    dbgs() << "Unhandled type for ICMP_ULT predicate: " << *Ty << "\n";
173    llvm_unreachable(0);
174  }
175  return Dest;
176}
177
178static GenericValue executeICMP_SLT(GenericValue Src1, GenericValue Src2,
179                                    Type *Ty) {
180  GenericValue Dest;
181  switch (Ty->getTypeID()) {
182    IMPLEMENT_INTEGER_ICMP(slt,Ty);
183    IMPLEMENT_VECTOR_INTEGER_ICMP(slt,Ty);
184    IMPLEMENT_POINTER_ICMP(<);
185  default:
186    dbgs() << "Unhandled type for ICMP_SLT predicate: " << *Ty << "\n";
187    llvm_unreachable(0);
188  }
189  return Dest;
190}
191
192static GenericValue executeICMP_UGT(GenericValue Src1, GenericValue Src2,
193                                    Type *Ty) {
194  GenericValue Dest;
195  switch (Ty->getTypeID()) {
196    IMPLEMENT_INTEGER_ICMP(ugt,Ty);
197    IMPLEMENT_VECTOR_INTEGER_ICMP(ugt,Ty);
198    IMPLEMENT_POINTER_ICMP(>);
199  default:
200    dbgs() << "Unhandled type for ICMP_UGT predicate: " << *Ty << "\n";
201    llvm_unreachable(0);
202  }
203  return Dest;
204}
205
206static GenericValue executeICMP_SGT(GenericValue Src1, GenericValue Src2,
207                                    Type *Ty) {
208  GenericValue Dest;
209  switch (Ty->getTypeID()) {
210    IMPLEMENT_INTEGER_ICMP(sgt,Ty);
211    IMPLEMENT_VECTOR_INTEGER_ICMP(sgt,Ty);
212    IMPLEMENT_POINTER_ICMP(>);
213  default:
214    dbgs() << "Unhandled type for ICMP_SGT predicate: " << *Ty << "\n";
215    llvm_unreachable(0);
216  }
217  return Dest;
218}
219
220static GenericValue executeICMP_ULE(GenericValue Src1, GenericValue Src2,
221                                    Type *Ty) {
222  GenericValue Dest;
223  switch (Ty->getTypeID()) {
224    IMPLEMENT_INTEGER_ICMP(ule,Ty);
225    IMPLEMENT_VECTOR_INTEGER_ICMP(ule,Ty);
226    IMPLEMENT_POINTER_ICMP(<=);
227  default:
228    dbgs() << "Unhandled type for ICMP_ULE predicate: " << *Ty << "\n";
229    llvm_unreachable(0);
230  }
231  return Dest;
232}
233
234static GenericValue executeICMP_SLE(GenericValue Src1, GenericValue Src2,
235                                    Type *Ty) {
236  GenericValue Dest;
237  switch (Ty->getTypeID()) {
238    IMPLEMENT_INTEGER_ICMP(sle,Ty);
239    IMPLEMENT_VECTOR_INTEGER_ICMP(sle,Ty);
240    IMPLEMENT_POINTER_ICMP(<=);
241  default:
242    dbgs() << "Unhandled type for ICMP_SLE predicate: " << *Ty << "\n";
243    llvm_unreachable(0);
244  }
245  return Dest;
246}
247
248static GenericValue executeICMP_UGE(GenericValue Src1, GenericValue Src2,
249                                    Type *Ty) {
250  GenericValue Dest;
251  switch (Ty->getTypeID()) {
252    IMPLEMENT_INTEGER_ICMP(uge,Ty);
253    IMPLEMENT_VECTOR_INTEGER_ICMP(uge,Ty);
254    IMPLEMENT_POINTER_ICMP(>=);
255  default:
256    dbgs() << "Unhandled type for ICMP_UGE predicate: " << *Ty << "\n";
257    llvm_unreachable(0);
258  }
259  return Dest;
260}
261
262static GenericValue executeICMP_SGE(GenericValue Src1, GenericValue Src2,
263                                    Type *Ty) {
264  GenericValue Dest;
265  switch (Ty->getTypeID()) {
266    IMPLEMENT_INTEGER_ICMP(sge,Ty);
267    IMPLEMENT_VECTOR_INTEGER_ICMP(sge,Ty);
268    IMPLEMENT_POINTER_ICMP(>=);
269  default:
270    dbgs() << "Unhandled type for ICMP_SGE predicate: " << *Ty << "\n";
271    llvm_unreachable(0);
272  }
273  return Dest;
274}
275
276void Interpreter::visitICmpInst(ICmpInst &I) {
277  ExecutionContext &SF = ECStack.back();
278  Type *Ty    = I.getOperand(0)->getType();
279  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
280  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
281  GenericValue R;   // Result
282
283  switch (I.getPredicate()) {
284  case ICmpInst::ICMP_EQ:  R = executeICMP_EQ(Src1,  Src2, Ty); break;
285  case ICmpInst::ICMP_NE:  R = executeICMP_NE(Src1,  Src2, Ty); break;
286  case ICmpInst::ICMP_ULT: R = executeICMP_ULT(Src1, Src2, Ty); break;
287  case ICmpInst::ICMP_SLT: R = executeICMP_SLT(Src1, Src2, Ty); break;
288  case ICmpInst::ICMP_UGT: R = executeICMP_UGT(Src1, Src2, Ty); break;
289  case ICmpInst::ICMP_SGT: R = executeICMP_SGT(Src1, Src2, Ty); break;
290  case ICmpInst::ICMP_ULE: R = executeICMP_ULE(Src1, Src2, Ty); break;
291  case ICmpInst::ICMP_SLE: R = executeICMP_SLE(Src1, Src2, Ty); break;
292  case ICmpInst::ICMP_UGE: R = executeICMP_UGE(Src1, Src2, Ty); break;
293  case ICmpInst::ICMP_SGE: R = executeICMP_SGE(Src1, Src2, Ty); break;
294  default:
295    dbgs() << "Don't know how to handle this ICmp predicate!\n-->" << I;
296    llvm_unreachable(0);
297  }
298
299  SetValue(&I, R, SF);
300}
301
302#define IMPLEMENT_FCMP(OP, TY) \
303   case Type::TY##TyID: \
304     Dest.IntVal = APInt(1,Src1.TY##Val OP Src2.TY##Val); \
305     break
306
307#define IMPLEMENT_VECTOR_FCMP_T(OP, TY)                             \
308  assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());     \
309  Dest.AggregateVal.resize( Src1.AggregateVal.size() );             \
310  for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)              \
311    Dest.AggregateVal[_i].IntVal = APInt(1,                         \
312    Src1.AggregateVal[_i].TY##Val OP Src2.AggregateVal[_i].TY##Val);\
313  break;
314
315#define IMPLEMENT_VECTOR_FCMP(OP)                                   \
316  case Type::VectorTyID:                                            \
317    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {   \
318      IMPLEMENT_VECTOR_FCMP_T(OP, Float);                           \
319    } else {                                                        \
320        IMPLEMENT_VECTOR_FCMP_T(OP, Double);                        \
321    }
322
323static GenericValue executeFCMP_OEQ(GenericValue Src1, GenericValue Src2,
324                                   Type *Ty) {
325  GenericValue Dest;
326  switch (Ty->getTypeID()) {
327    IMPLEMENT_FCMP(==, Float);
328    IMPLEMENT_FCMP(==, Double);
329    IMPLEMENT_VECTOR_FCMP(==);
330  default:
331    dbgs() << "Unhandled type for FCmp EQ instruction: " << *Ty << "\n";
332    llvm_unreachable(0);
333  }
334  return Dest;
335}
336
337#define IMPLEMENT_SCALAR_NANS(TY, X,Y)                                      \
338  if (TY->isFloatTy()) {                                                    \
339    if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {             \
340      Dest.IntVal = APInt(1,false);                                         \
341      return Dest;                                                          \
342    }                                                                       \
343  } else {                                                                  \
344    if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) {         \
345      Dest.IntVal = APInt(1,false);                                         \
346      return Dest;                                                          \
347    }                                                                       \
348  }
349
350#define MASK_VECTOR_NANS_T(X,Y, TZ, FLAG)                                   \
351  assert(X.AggregateVal.size() == Y.AggregateVal.size());                   \
352  Dest.AggregateVal.resize( X.AggregateVal.size() );                        \
353  for( uint32_t _i=0;_i<X.AggregateVal.size();_i++) {                       \
354    if (X.AggregateVal[_i].TZ##Val != X.AggregateVal[_i].TZ##Val ||         \
355        Y.AggregateVal[_i].TZ##Val != Y.AggregateVal[_i].TZ##Val)           \
356      Dest.AggregateVal[_i].IntVal = APInt(1,FLAG);                         \
357    else  {                                                                 \
358      Dest.AggregateVal[_i].IntVal = APInt(1,!FLAG);                        \
359    }                                                                       \
360  }
361
362#define MASK_VECTOR_NANS(TY, X,Y, FLAG)                                     \
363  if (TY->isVectorTy()) {                                                   \
364    if (dyn_cast<VectorType>(TY)->getElementType()->isFloatTy()) {          \
365      MASK_VECTOR_NANS_T(X, Y, Float, FLAG)                                 \
366    } else {                                                                \
367      MASK_VECTOR_NANS_T(X, Y, Double, FLAG)                                \
368    }                                                                       \
369  }                                                                         \
370
371
372
373static GenericValue executeFCMP_ONE(GenericValue Src1, GenericValue Src2,
374                                    Type *Ty)
375{
376  GenericValue Dest;
377  // if input is scalar value and Src1 or Src2 is NaN return false
378  IMPLEMENT_SCALAR_NANS(Ty, Src1, Src2)
379  // if vector input detect NaNs and fill mask
380  MASK_VECTOR_NANS(Ty, Src1, Src2, false)
381  GenericValue DestMask = Dest;
382  switch (Ty->getTypeID()) {
383    IMPLEMENT_FCMP(!=, Float);
384    IMPLEMENT_FCMP(!=, Double);
385    IMPLEMENT_VECTOR_FCMP(!=);
386    default:
387      dbgs() << "Unhandled type for FCmp NE instruction: " << *Ty << "\n";
388      llvm_unreachable(0);
389  }
390  // in vector case mask out NaN elements
391  if (Ty->isVectorTy())
392    for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
393      if (DestMask.AggregateVal[_i].IntVal == false)
394        Dest.AggregateVal[_i].IntVal = APInt(1,false);
395
396  return Dest;
397}
398
399static GenericValue executeFCMP_OLE(GenericValue Src1, GenericValue Src2,
400                                   Type *Ty) {
401  GenericValue Dest;
402  switch (Ty->getTypeID()) {
403    IMPLEMENT_FCMP(<=, Float);
404    IMPLEMENT_FCMP(<=, Double);
405    IMPLEMENT_VECTOR_FCMP(<=);
406  default:
407    dbgs() << "Unhandled type for FCmp LE instruction: " << *Ty << "\n";
408    llvm_unreachable(0);
409  }
410  return Dest;
411}
412
413static GenericValue executeFCMP_OGE(GenericValue Src1, GenericValue Src2,
414                                   Type *Ty) {
415  GenericValue Dest;
416  switch (Ty->getTypeID()) {
417    IMPLEMENT_FCMP(>=, Float);
418    IMPLEMENT_FCMP(>=, Double);
419    IMPLEMENT_VECTOR_FCMP(>=);
420  default:
421    dbgs() << "Unhandled type for FCmp GE instruction: " << *Ty << "\n";
422    llvm_unreachable(0);
423  }
424  return Dest;
425}
426
427static GenericValue executeFCMP_OLT(GenericValue Src1, GenericValue Src2,
428                                   Type *Ty) {
429  GenericValue Dest;
430  switch (Ty->getTypeID()) {
431    IMPLEMENT_FCMP(<, Float);
432    IMPLEMENT_FCMP(<, Double);
433    IMPLEMENT_VECTOR_FCMP(<);
434  default:
435    dbgs() << "Unhandled type for FCmp LT instruction: " << *Ty << "\n";
436    llvm_unreachable(0);
437  }
438  return Dest;
439}
440
441static GenericValue executeFCMP_OGT(GenericValue Src1, GenericValue Src2,
442                                     Type *Ty) {
443  GenericValue Dest;
444  switch (Ty->getTypeID()) {
445    IMPLEMENT_FCMP(>, Float);
446    IMPLEMENT_FCMP(>, Double);
447    IMPLEMENT_VECTOR_FCMP(>);
448  default:
449    dbgs() << "Unhandled type for FCmp GT instruction: " << *Ty << "\n";
450    llvm_unreachable(0);
451  }
452  return Dest;
453}
454
455#define IMPLEMENT_UNORDERED(TY, X,Y)                                     \
456  if (TY->isFloatTy()) {                                                 \
457    if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {          \
458      Dest.IntVal = APInt(1,true);                                       \
459      return Dest;                                                       \
460    }                                                                    \
461  } else if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) { \
462    Dest.IntVal = APInt(1,true);                                         \
463    return Dest;                                                         \
464  }
465
466#define IMPLEMENT_VECTOR_UNORDERED(TY, X,Y, _FUNC)                       \
467  if (TY->isVectorTy()) {                                                \
468    GenericValue DestMask = Dest;                                        \
469    Dest = _FUNC(Src1, Src2, Ty);                                        \
470      for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)               \
471        if (DestMask.AggregateVal[_i].IntVal == true)                    \
472          Dest.AggregateVal[_i].IntVal = APInt(1,true);                  \
473      return Dest;                                                       \
474  }
475
476static GenericValue executeFCMP_UEQ(GenericValue Src1, GenericValue Src2,
477                                   Type *Ty) {
478  GenericValue Dest;
479  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
480  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
481  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OEQ)
482  return executeFCMP_OEQ(Src1, Src2, Ty);
483
484}
485
486static GenericValue executeFCMP_UNE(GenericValue Src1, GenericValue Src2,
487                                   Type *Ty) {
488  GenericValue Dest;
489  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
490  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
491  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_ONE)
492  return executeFCMP_ONE(Src1, Src2, Ty);
493}
494
495static GenericValue executeFCMP_ULE(GenericValue Src1, GenericValue Src2,
496                                   Type *Ty) {
497  GenericValue Dest;
498  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
499  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
500  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLE)
501  return executeFCMP_OLE(Src1, Src2, Ty);
502}
503
504static GenericValue executeFCMP_UGE(GenericValue Src1, GenericValue Src2,
505                                   Type *Ty) {
506  GenericValue Dest;
507  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
508  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
509  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGE)
510  return executeFCMP_OGE(Src1, Src2, Ty);
511}
512
513static GenericValue executeFCMP_ULT(GenericValue Src1, GenericValue Src2,
514                                   Type *Ty) {
515  GenericValue Dest;
516  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
517  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
518  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLT)
519  return executeFCMP_OLT(Src1, Src2, Ty);
520}
521
522static GenericValue executeFCMP_UGT(GenericValue Src1, GenericValue Src2,
523                                     Type *Ty) {
524  GenericValue Dest;
525  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
526  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
527  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGT)
528  return executeFCMP_OGT(Src1, Src2, Ty);
529}
530
531static GenericValue executeFCMP_ORD(GenericValue Src1, GenericValue Src2,
532                                     Type *Ty) {
533  GenericValue Dest;
534  if(Ty->isVectorTy()) {
535    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
536    Dest.AggregateVal.resize( Src1.AggregateVal.size() );
537    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
538      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
539        Dest.AggregateVal[_i].IntVal = APInt(1,
540        ( (Src1.AggregateVal[_i].FloatVal ==
541        Src1.AggregateVal[_i].FloatVal) &&
542        (Src2.AggregateVal[_i].FloatVal ==
543        Src2.AggregateVal[_i].FloatVal)));
544    } else {
545      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
546        Dest.AggregateVal[_i].IntVal = APInt(1,
547        ( (Src1.AggregateVal[_i].DoubleVal ==
548        Src1.AggregateVal[_i].DoubleVal) &&
549        (Src2.AggregateVal[_i].DoubleVal ==
550        Src2.AggregateVal[_i].DoubleVal)));
551    }
552  } else if (Ty->isFloatTy())
553    Dest.IntVal = APInt(1,(Src1.FloatVal == Src1.FloatVal &&
554                           Src2.FloatVal == Src2.FloatVal));
555  else {
556    Dest.IntVal = APInt(1,(Src1.DoubleVal == Src1.DoubleVal &&
557                           Src2.DoubleVal == Src2.DoubleVal));
558  }
559  return Dest;
560}
561
562static GenericValue executeFCMP_UNO(GenericValue Src1, GenericValue Src2,
563                                     Type *Ty) {
564  GenericValue Dest;
565  if(Ty->isVectorTy()) {
566    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
567    Dest.AggregateVal.resize( Src1.AggregateVal.size() );
568    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
569      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
570        Dest.AggregateVal[_i].IntVal = APInt(1,
571        ( (Src1.AggregateVal[_i].FloatVal !=
572           Src1.AggregateVal[_i].FloatVal) ||
573          (Src2.AggregateVal[_i].FloatVal !=
574           Src2.AggregateVal[_i].FloatVal)));
575      } else {
576        for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
577          Dest.AggregateVal[_i].IntVal = APInt(1,
578          ( (Src1.AggregateVal[_i].DoubleVal !=
579             Src1.AggregateVal[_i].DoubleVal) ||
580            (Src2.AggregateVal[_i].DoubleVal !=
581             Src2.AggregateVal[_i].DoubleVal)));
582      }
583  } else if (Ty->isFloatTy())
584    Dest.IntVal = APInt(1,(Src1.FloatVal != Src1.FloatVal ||
585                           Src2.FloatVal != Src2.FloatVal));
586  else {
587    Dest.IntVal = APInt(1,(Src1.DoubleVal != Src1.DoubleVal ||
588                           Src2.DoubleVal != Src2.DoubleVal));
589  }
590  return Dest;
591}
592
593static GenericValue executeFCMP_BOOL(GenericValue Src1, GenericValue Src2,
594                                    const Type *Ty, const bool val) {
595  GenericValue Dest;
596    if(Ty->isVectorTy()) {
597      assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
598      Dest.AggregateVal.resize( Src1.AggregateVal.size() );
599      for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
600        Dest.AggregateVal[_i].IntVal = APInt(1,val);
601    } else {
602      Dest.IntVal = APInt(1, val);
603    }
604
605    return Dest;
606}
607
608void Interpreter::visitFCmpInst(FCmpInst &I) {
609  ExecutionContext &SF = ECStack.back();
610  Type *Ty    = I.getOperand(0)->getType();
611  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
612  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
613  GenericValue R;   // Result
614
615  switch (I.getPredicate()) {
616  default:
617    dbgs() << "Don't know how to handle this FCmp predicate!\n-->" << I;
618    llvm_unreachable(0);
619  break;
620  case FCmpInst::FCMP_FALSE: R = executeFCMP_BOOL(Src1, Src2, Ty, false);
621  break;
622  case FCmpInst::FCMP_TRUE:  R = executeFCMP_BOOL(Src1, Src2, Ty, true);
623  break;
624  case FCmpInst::FCMP_ORD:   R = executeFCMP_ORD(Src1, Src2, Ty); break;
625  case FCmpInst::FCMP_UNO:   R = executeFCMP_UNO(Src1, Src2, Ty); break;
626  case FCmpInst::FCMP_UEQ:   R = executeFCMP_UEQ(Src1, Src2, Ty); break;
627  case FCmpInst::FCMP_OEQ:   R = executeFCMP_OEQ(Src1, Src2, Ty); break;
628  case FCmpInst::FCMP_UNE:   R = executeFCMP_UNE(Src1, Src2, Ty); break;
629  case FCmpInst::FCMP_ONE:   R = executeFCMP_ONE(Src1, Src2, Ty); break;
630  case FCmpInst::FCMP_ULT:   R = executeFCMP_ULT(Src1, Src2, Ty); break;
631  case FCmpInst::FCMP_OLT:   R = executeFCMP_OLT(Src1, Src2, Ty); break;
632  case FCmpInst::FCMP_UGT:   R = executeFCMP_UGT(Src1, Src2, Ty); break;
633  case FCmpInst::FCMP_OGT:   R = executeFCMP_OGT(Src1, Src2, Ty); break;
634  case FCmpInst::FCMP_ULE:   R = executeFCMP_ULE(Src1, Src2, Ty); break;
635  case FCmpInst::FCMP_OLE:   R = executeFCMP_OLE(Src1, Src2, Ty); break;
636  case FCmpInst::FCMP_UGE:   R = executeFCMP_UGE(Src1, Src2, Ty); break;
637  case FCmpInst::FCMP_OGE:   R = executeFCMP_OGE(Src1, Src2, Ty); break;
638  }
639
640  SetValue(&I, R, SF);
641}
642
643static GenericValue executeCmpInst(unsigned predicate, GenericValue Src1,
644                                   GenericValue Src2, Type *Ty) {
645  GenericValue Result;
646  switch (predicate) {
647  case ICmpInst::ICMP_EQ:    return executeICMP_EQ(Src1, Src2, Ty);
648  case ICmpInst::ICMP_NE:    return executeICMP_NE(Src1, Src2, Ty);
649  case ICmpInst::ICMP_UGT:   return executeICMP_UGT(Src1, Src2, Ty);
650  case ICmpInst::ICMP_SGT:   return executeICMP_SGT(Src1, Src2, Ty);
651  case ICmpInst::ICMP_ULT:   return executeICMP_ULT(Src1, Src2, Ty);
652  case ICmpInst::ICMP_SLT:   return executeICMP_SLT(Src1, Src2, Ty);
653  case ICmpInst::ICMP_UGE:   return executeICMP_UGE(Src1, Src2, Ty);
654  case ICmpInst::ICMP_SGE:   return executeICMP_SGE(Src1, Src2, Ty);
655  case ICmpInst::ICMP_ULE:   return executeICMP_ULE(Src1, Src2, Ty);
656  case ICmpInst::ICMP_SLE:   return executeICMP_SLE(Src1, Src2, Ty);
657  case FCmpInst::FCMP_ORD:   return executeFCMP_ORD(Src1, Src2, Ty);
658  case FCmpInst::FCMP_UNO:   return executeFCMP_UNO(Src1, Src2, Ty);
659  case FCmpInst::FCMP_OEQ:   return executeFCMP_OEQ(Src1, Src2, Ty);
660  case FCmpInst::FCMP_UEQ:   return executeFCMP_UEQ(Src1, Src2, Ty);
661  case FCmpInst::FCMP_ONE:   return executeFCMP_ONE(Src1, Src2, Ty);
662  case FCmpInst::FCMP_UNE:   return executeFCMP_UNE(Src1, Src2, Ty);
663  case FCmpInst::FCMP_OLT:   return executeFCMP_OLT(Src1, Src2, Ty);
664  case FCmpInst::FCMP_ULT:   return executeFCMP_ULT(Src1, Src2, Ty);
665  case FCmpInst::FCMP_OGT:   return executeFCMP_OGT(Src1, Src2, Ty);
666  case FCmpInst::FCMP_UGT:   return executeFCMP_UGT(Src1, Src2, Ty);
667  case FCmpInst::FCMP_OLE:   return executeFCMP_OLE(Src1, Src2, Ty);
668  case FCmpInst::FCMP_ULE:   return executeFCMP_ULE(Src1, Src2, Ty);
669  case FCmpInst::FCMP_OGE:   return executeFCMP_OGE(Src1, Src2, Ty);
670  case FCmpInst::FCMP_UGE:   return executeFCMP_UGE(Src1, Src2, Ty);
671  case FCmpInst::FCMP_FALSE: return executeFCMP_BOOL(Src1, Src2, Ty, false);
672  case FCmpInst::FCMP_TRUE:  return executeFCMP_BOOL(Src1, Src2, Ty, true);
673  default:
674    dbgs() << "Unhandled Cmp predicate\n";
675    llvm_unreachable(0);
676  }
677}
678
679void Interpreter::visitBinaryOperator(BinaryOperator &I) {
680  ExecutionContext &SF = ECStack.back();
681  Type *Ty    = I.getOperand(0)->getType();
682  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
683  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
684  GenericValue R;   // Result
685
686  // First process vector operation
687  if (Ty->isVectorTy()) {
688    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
689    R.AggregateVal.resize(Src1.AggregateVal.size());
690
691    // Macros to execute binary operation 'OP' over integer vectors
692#define INTEGER_VECTOR_OPERATION(OP)                               \
693    for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
694      R.AggregateVal[i].IntVal =                                   \
695      Src1.AggregateVal[i].IntVal OP Src2.AggregateVal[i].IntVal;
696
697    // Additional macros to execute binary operations udiv/sdiv/urem/srem since
698    // they have different notation.
699#define INTEGER_VECTOR_FUNCTION(OP)                                \
700    for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
701      R.AggregateVal[i].IntVal =                                   \
702      Src1.AggregateVal[i].IntVal.OP(Src2.AggregateVal[i].IntVal);
703
704    // Macros to execute binary operation 'OP' over floating point type TY
705    // (float or double) vectors
706#define FLOAT_VECTOR_FUNCTION(OP, TY)                               \
707      for (unsigned i = 0; i < R.AggregateVal.size(); ++i)          \
708        R.AggregateVal[i].TY =                                      \
709        Src1.AggregateVal[i].TY OP Src2.AggregateVal[i].TY;
710
711    // Macros to choose appropriate TY: float or double and run operation
712    // execution
713#define FLOAT_VECTOR_OP(OP) {                                         \
714  if (dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy())        \
715    FLOAT_VECTOR_FUNCTION(OP, FloatVal)                               \
716  else {                                                              \
717    if (dyn_cast<VectorType>(Ty)->getElementType()->isDoubleTy())     \
718      FLOAT_VECTOR_FUNCTION(OP, DoubleVal)                            \
719    else {                                                            \
720      dbgs() << "Unhandled type for OP instruction: " << *Ty << "\n"; \
721      llvm_unreachable(0);                                            \
722    }                                                                 \
723  }                                                                   \
724}
725
726    switch(I.getOpcode()){
727    default:
728      dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
729      llvm_unreachable(0);
730      break;
731    case Instruction::Add:   INTEGER_VECTOR_OPERATION(+) break;
732    case Instruction::Sub:   INTEGER_VECTOR_OPERATION(-) break;
733    case Instruction::Mul:   INTEGER_VECTOR_OPERATION(*) break;
734    case Instruction::UDiv:  INTEGER_VECTOR_FUNCTION(udiv) break;
735    case Instruction::SDiv:  INTEGER_VECTOR_FUNCTION(sdiv) break;
736    case Instruction::URem:  INTEGER_VECTOR_FUNCTION(urem) break;
737    case Instruction::SRem:  INTEGER_VECTOR_FUNCTION(srem) break;
738    case Instruction::And:   INTEGER_VECTOR_OPERATION(&) break;
739    case Instruction::Or:    INTEGER_VECTOR_OPERATION(|) break;
740    case Instruction::Xor:   INTEGER_VECTOR_OPERATION(^) break;
741    case Instruction::FAdd:  FLOAT_VECTOR_OP(+) break;
742    case Instruction::FSub:  FLOAT_VECTOR_OP(-) break;
743    case Instruction::FMul:  FLOAT_VECTOR_OP(*) break;
744    case Instruction::FDiv:  FLOAT_VECTOR_OP(/) break;
745    case Instruction::FRem:
746      if (dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy())
747        for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
748          R.AggregateVal[i].FloatVal =
749          fmod(Src1.AggregateVal[i].FloatVal, Src2.AggregateVal[i].FloatVal);
750      else {
751        if (dyn_cast<VectorType>(Ty)->getElementType()->isDoubleTy())
752          for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
753            R.AggregateVal[i].DoubleVal =
754            fmod(Src1.AggregateVal[i].DoubleVal, Src2.AggregateVal[i].DoubleVal);
755        else {
756          dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
757          llvm_unreachable(0);
758        }
759      }
760      break;
761    }
762  } else {
763    switch (I.getOpcode()) {
764    default:
765      dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
766      llvm_unreachable(0);
767      break;
768    case Instruction::Add:   R.IntVal = Src1.IntVal + Src2.IntVal; break;
769    case Instruction::Sub:   R.IntVal = Src1.IntVal - Src2.IntVal; break;
770    case Instruction::Mul:   R.IntVal = Src1.IntVal * Src2.IntVal; break;
771    case Instruction::FAdd:  executeFAddInst(R, Src1, Src2, Ty); break;
772    case Instruction::FSub:  executeFSubInst(R, Src1, Src2, Ty); break;
773    case Instruction::FMul:  executeFMulInst(R, Src1, Src2, Ty); break;
774    case Instruction::FDiv:  executeFDivInst(R, Src1, Src2, Ty); break;
775    case Instruction::FRem:  executeFRemInst(R, Src1, Src2, Ty); break;
776    case Instruction::UDiv:  R.IntVal = Src1.IntVal.udiv(Src2.IntVal); break;
777    case Instruction::SDiv:  R.IntVal = Src1.IntVal.sdiv(Src2.IntVal); break;
778    case Instruction::URem:  R.IntVal = Src1.IntVal.urem(Src2.IntVal); break;
779    case Instruction::SRem:  R.IntVal = Src1.IntVal.srem(Src2.IntVal); break;
780    case Instruction::And:   R.IntVal = Src1.IntVal & Src2.IntVal; break;
781    case Instruction::Or:    R.IntVal = Src1.IntVal | Src2.IntVal; break;
782    case Instruction::Xor:   R.IntVal = Src1.IntVal ^ Src2.IntVal; break;
783    }
784  }
785  SetValue(&I, R, SF);
786}
787
788static GenericValue executeSelectInst(GenericValue Src1, GenericValue Src2,
789                                      GenericValue Src3) {
790  return Src1.IntVal == 0 ? Src3 : Src2;
791}
792
793void Interpreter::visitSelectInst(SelectInst &I) {
794  ExecutionContext &SF = ECStack.back();
795  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
796  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
797  GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
798  GenericValue R = executeSelectInst(Src1, Src2, Src3);
799  SetValue(&I, R, SF);
800}
801
802
803//===----------------------------------------------------------------------===//
804//                     Terminator Instruction Implementations
805//===----------------------------------------------------------------------===//
806
807void Interpreter::exitCalled(GenericValue GV) {
808  // runAtExitHandlers() assumes there are no stack frames, but
809  // if exit() was called, then it had a stack frame. Blow away
810  // the stack before interpreting atexit handlers.
811  ECStack.clear();
812  runAtExitHandlers();
813  exit(GV.IntVal.zextOrTrunc(32).getZExtValue());
814}
815
816/// Pop the last stack frame off of ECStack and then copy the result
817/// back into the result variable if we are not returning void. The
818/// result variable may be the ExitValue, or the Value of the calling
819/// CallInst if there was a previous stack frame. This method may
820/// invalidate any ECStack iterators you have. This method also takes
821/// care of switching to the normal destination BB, if we are returning
822/// from an invoke.
823///
824void Interpreter::popStackAndReturnValueToCaller(Type *RetTy,
825                                                 GenericValue Result) {
826  // Pop the current stack frame.
827  ECStack.pop_back();
828
829  if (ECStack.empty()) {  // Finished main.  Put result into exit code...
830    if (RetTy && !RetTy->isVoidTy()) {          // Nonvoid return type?
831      ExitValue = Result;   // Capture the exit value of the program
832    } else {
833      memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
834    }
835  } else {
836    // If we have a previous stack frame, and we have a previous call,
837    // fill in the return value...
838    ExecutionContext &CallingSF = ECStack.back();
839    if (Instruction *I = CallingSF.Caller.getInstruction()) {
840      // Save result...
841      if (!CallingSF.Caller.getType()->isVoidTy())
842        SetValue(I, Result, CallingSF);
843      if (InvokeInst *II = dyn_cast<InvokeInst> (I))
844        SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
845      CallingSF.Caller = CallSite();          // We returned from the call...
846    }
847  }
848}
849
850void Interpreter::visitReturnInst(ReturnInst &I) {
851  ExecutionContext &SF = ECStack.back();
852  Type *RetTy = Type::getVoidTy(I.getContext());
853  GenericValue Result;
854
855  // Save away the return value... (if we are not 'ret void')
856  if (I.getNumOperands()) {
857    RetTy  = I.getReturnValue()->getType();
858    Result = getOperandValue(I.getReturnValue(), SF);
859  }
860
861  popStackAndReturnValueToCaller(RetTy, Result);
862}
863
864void Interpreter::visitUnreachableInst(UnreachableInst &I) {
865  report_fatal_error("Program executed an 'unreachable' instruction!");
866}
867
868void Interpreter::visitBranchInst(BranchInst &I) {
869  ExecutionContext &SF = ECStack.back();
870  BasicBlock *Dest;
871
872  Dest = I.getSuccessor(0);          // Uncond branches have a fixed dest...
873  if (!I.isUnconditional()) {
874    Value *Cond = I.getCondition();
875    if (getOperandValue(Cond, SF).IntVal == 0) // If false cond...
876      Dest = I.getSuccessor(1);
877  }
878  SwitchToNewBasicBlock(Dest, SF);
879}
880
881void Interpreter::visitSwitchInst(SwitchInst &I) {
882  ExecutionContext &SF = ECStack.back();
883  Value* Cond = I.getCondition();
884  Type *ElTy = Cond->getType();
885  GenericValue CondVal = getOperandValue(Cond, SF);
886
887  // Check to see if any of the cases match...
888  BasicBlock *Dest = 0;
889  for (SwitchInst::CaseIt i = I.case_begin(), e = I.case_end(); i != e; ++i) {
890    IntegersSubset& Case = i.getCaseValueEx();
891    if (Case.isSingleNumber()) {
892      // FIXME: Currently work with ConstantInt based numbers.
893      const ConstantInt *CI = Case.getSingleNumber(0).toConstantInt();
894      GenericValue Val = getOperandValue(const_cast<ConstantInt*>(CI), SF);
895      if (executeICMP_EQ(Val, CondVal, ElTy).IntVal != 0) {
896        Dest = cast<BasicBlock>(i.getCaseSuccessor());
897        break;
898      }
899    }
900    if (Case.isSingleNumbersOnly()) {
901      for (unsigned n = 0, en = Case.getNumItems(); n != en; ++n) {
902        // FIXME: Currently work with ConstantInt based numbers.
903        const ConstantInt *CI = Case.getSingleNumber(n).toConstantInt();
904        GenericValue Val = getOperandValue(const_cast<ConstantInt*>(CI), SF);
905        if (executeICMP_EQ(Val, CondVal, ElTy).IntVal != 0) {
906          Dest = cast<BasicBlock>(i.getCaseSuccessor());
907          break;
908        }
909      }
910    } else
911      for (unsigned n = 0, en = Case.getNumItems(); n != en; ++n) {
912        IntegersSubset::Range r = Case.getItem(n);
913        // FIXME: Currently work with ConstantInt based numbers.
914        const ConstantInt *LowCI = r.getLow().toConstantInt();
915        const ConstantInt *HighCI = r.getHigh().toConstantInt();
916        GenericValue Low = getOperandValue(const_cast<ConstantInt*>(LowCI), SF);
917        GenericValue High = getOperandValue(const_cast<ConstantInt*>(HighCI), SF);
918        if (executeICMP_ULE(Low, CondVal, ElTy).IntVal != 0 &&
919            executeICMP_ULE(CondVal, High, ElTy).IntVal != 0) {
920          Dest = cast<BasicBlock>(i.getCaseSuccessor());
921          break;
922        }
923      }
924  }
925  if (!Dest) Dest = I.getDefaultDest();   // No cases matched: use default
926  SwitchToNewBasicBlock(Dest, SF);
927}
928
929void Interpreter::visitIndirectBrInst(IndirectBrInst &I) {
930  ExecutionContext &SF = ECStack.back();
931  void *Dest = GVTOP(getOperandValue(I.getAddress(), SF));
932  SwitchToNewBasicBlock((BasicBlock*)Dest, SF);
933}
934
935
936// SwitchToNewBasicBlock - This method is used to jump to a new basic block.
937// This function handles the actual updating of block and instruction iterators
938// as well as execution of all of the PHI nodes in the destination block.
939//
940// This method does this because all of the PHI nodes must be executed
941// atomically, reading their inputs before any of the results are updated.  Not
942// doing this can cause problems if the PHI nodes depend on other PHI nodes for
943// their inputs.  If the input PHI node is updated before it is read, incorrect
944// results can happen.  Thus we use a two phase approach.
945//
946void Interpreter::SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF){
947  BasicBlock *PrevBB = SF.CurBB;      // Remember where we came from...
948  SF.CurBB   = Dest;                  // Update CurBB to branch destination
949  SF.CurInst = SF.CurBB->begin();     // Update new instruction ptr...
950
951  if (!isa<PHINode>(SF.CurInst)) return;  // Nothing fancy to do
952
953  // Loop over all of the PHI nodes in the current block, reading their inputs.
954  std::vector<GenericValue> ResultValues;
955
956  for (; PHINode *PN = dyn_cast<PHINode>(SF.CurInst); ++SF.CurInst) {
957    // Search for the value corresponding to this previous bb...
958    int i = PN->getBasicBlockIndex(PrevBB);
959    assert(i != -1 && "PHINode doesn't contain entry for predecessor??");
960    Value *IncomingValue = PN->getIncomingValue(i);
961
962    // Save the incoming value for this PHI node...
963    ResultValues.push_back(getOperandValue(IncomingValue, SF));
964  }
965
966  // Now loop over all of the PHI nodes setting their values...
967  SF.CurInst = SF.CurBB->begin();
968  for (unsigned i = 0; isa<PHINode>(SF.CurInst); ++SF.CurInst, ++i) {
969    PHINode *PN = cast<PHINode>(SF.CurInst);
970    SetValue(PN, ResultValues[i], SF);
971  }
972}
973
974//===----------------------------------------------------------------------===//
975//                     Memory Instruction Implementations
976//===----------------------------------------------------------------------===//
977
978void Interpreter::visitAllocaInst(AllocaInst &I) {
979  ExecutionContext &SF = ECStack.back();
980
981  Type *Ty = I.getType()->getElementType();  // Type to be allocated
982
983  // Get the number of elements being allocated by the array...
984  unsigned NumElements =
985    getOperandValue(I.getOperand(0), SF).IntVal.getZExtValue();
986
987  unsigned TypeSize = (size_t)TD.getTypeAllocSize(Ty);
988
989  // Avoid malloc-ing zero bytes, use max()...
990  unsigned MemToAlloc = std::max(1U, NumElements * TypeSize);
991
992  // Allocate enough memory to hold the type...
993  void *Memory = malloc(MemToAlloc);
994
995  DEBUG(dbgs() << "Allocated Type: " << *Ty << " (" << TypeSize << " bytes) x "
996               << NumElements << " (Total: " << MemToAlloc << ") at "
997               << uintptr_t(Memory) << '\n');
998
999  GenericValue Result = PTOGV(Memory);
1000  assert(Result.PointerVal != 0 && "Null pointer returned by malloc!");
1001  SetValue(&I, Result, SF);
1002
1003  if (I.getOpcode() == Instruction::Alloca)
1004    ECStack.back().Allocas.add(Memory);
1005}
1006
1007// getElementOffset - The workhorse for getelementptr.
1008//
1009GenericValue Interpreter::executeGEPOperation(Value *Ptr, gep_type_iterator I,
1010                                              gep_type_iterator E,
1011                                              ExecutionContext &SF) {
1012  assert(Ptr->getType()->isPointerTy() &&
1013         "Cannot getElementOffset of a nonpointer type!");
1014
1015  uint64_t Total = 0;
1016
1017  for (; I != E; ++I) {
1018    if (StructType *STy = dyn_cast<StructType>(*I)) {
1019      const StructLayout *SLO = TD.getStructLayout(STy);
1020
1021      const ConstantInt *CPU = cast<ConstantInt>(I.getOperand());
1022      unsigned Index = unsigned(CPU->getZExtValue());
1023
1024      Total += SLO->getElementOffset(Index);
1025    } else {
1026      SequentialType *ST = cast<SequentialType>(*I);
1027      // Get the index number for the array... which must be long type...
1028      GenericValue IdxGV = getOperandValue(I.getOperand(), SF);
1029
1030      int64_t Idx;
1031      unsigned BitWidth =
1032        cast<IntegerType>(I.getOperand()->getType())->getBitWidth();
1033      if (BitWidth == 32)
1034        Idx = (int64_t)(int32_t)IdxGV.IntVal.getZExtValue();
1035      else {
1036        assert(BitWidth == 64 && "Invalid index type for getelementptr");
1037        Idx = (int64_t)IdxGV.IntVal.getZExtValue();
1038      }
1039      Total += TD.getTypeAllocSize(ST->getElementType())*Idx;
1040    }
1041  }
1042
1043  GenericValue Result;
1044  Result.PointerVal = ((char*)getOperandValue(Ptr, SF).PointerVal) + Total;
1045  DEBUG(dbgs() << "GEP Index " << Total << " bytes.\n");
1046  return Result;
1047}
1048
1049void Interpreter::visitGetElementPtrInst(GetElementPtrInst &I) {
1050  ExecutionContext &SF = ECStack.back();
1051  SetValue(&I, executeGEPOperation(I.getPointerOperand(),
1052                                   gep_type_begin(I), gep_type_end(I), SF), SF);
1053}
1054
1055void Interpreter::visitLoadInst(LoadInst &I) {
1056  ExecutionContext &SF = ECStack.back();
1057  GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1058  GenericValue *Ptr = (GenericValue*)GVTOP(SRC);
1059  GenericValue Result;
1060  LoadValueFromMemory(Result, Ptr, I.getType());
1061  SetValue(&I, Result, SF);
1062  if (I.isVolatile() && PrintVolatile)
1063    dbgs() << "Volatile load " << I;
1064}
1065
1066void Interpreter::visitStoreInst(StoreInst &I) {
1067  ExecutionContext &SF = ECStack.back();
1068  GenericValue Val = getOperandValue(I.getOperand(0), SF);
1069  GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1070  StoreValueToMemory(Val, (GenericValue *)GVTOP(SRC),
1071                     I.getOperand(0)->getType());
1072  if (I.isVolatile() && PrintVolatile)
1073    dbgs() << "Volatile store: " << I;
1074}
1075
1076//===----------------------------------------------------------------------===//
1077//                 Miscellaneous Instruction Implementations
1078//===----------------------------------------------------------------------===//
1079
1080void Interpreter::visitCallSite(CallSite CS) {
1081  ExecutionContext &SF = ECStack.back();
1082
1083  // Check to see if this is an intrinsic function call...
1084  Function *F = CS.getCalledFunction();
1085  if (F && F->isDeclaration())
1086    switch (F->getIntrinsicID()) {
1087    case Intrinsic::not_intrinsic:
1088      break;
1089    case Intrinsic::vastart: { // va_start
1090      GenericValue ArgIndex;
1091      ArgIndex.UIntPairVal.first = ECStack.size() - 1;
1092      ArgIndex.UIntPairVal.second = 0;
1093      SetValue(CS.getInstruction(), ArgIndex, SF);
1094      return;
1095    }
1096    case Intrinsic::vaend:    // va_end is a noop for the interpreter
1097      return;
1098    case Intrinsic::vacopy:   // va_copy: dest = src
1099      SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
1100      return;
1101    default:
1102      // If it is an unknown intrinsic function, use the intrinsic lowering
1103      // class to transform it into hopefully tasty LLVM code.
1104      //
1105      BasicBlock::iterator me(CS.getInstruction());
1106      BasicBlock *Parent = CS.getInstruction()->getParent();
1107      bool atBegin(Parent->begin() == me);
1108      if (!atBegin)
1109        --me;
1110      IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
1111
1112      // Restore the CurInst pointer to the first instruction newly inserted, if
1113      // any.
1114      if (atBegin) {
1115        SF.CurInst = Parent->begin();
1116      } else {
1117        SF.CurInst = me;
1118        ++SF.CurInst;
1119      }
1120      return;
1121    }
1122
1123
1124  SF.Caller = CS;
1125  std::vector<GenericValue> ArgVals;
1126  const unsigned NumArgs = SF.Caller.arg_size();
1127  ArgVals.reserve(NumArgs);
1128  uint16_t pNum = 1;
1129  for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
1130         e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
1131    Value *V = *i;
1132    ArgVals.push_back(getOperandValue(V, SF));
1133  }
1134
1135  // To handle indirect calls, we must get the pointer value from the argument
1136  // and treat it as a function pointer.
1137  GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
1138  callFunction((Function*)GVTOP(SRC), ArgVals);
1139}
1140
1141void Interpreter::visitShl(BinaryOperator &I) {
1142  ExecutionContext &SF = ECStack.back();
1143  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1144  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1145  GenericValue Dest;
1146  if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
1147    Dest.IntVal = Src1.IntVal.shl(Src2.IntVal.getZExtValue());
1148  else
1149    Dest.IntVal = Src1.IntVal;
1150
1151  SetValue(&I, Dest, SF);
1152}
1153
1154void Interpreter::visitLShr(BinaryOperator &I) {
1155  ExecutionContext &SF = ECStack.back();
1156  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1157  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1158  GenericValue Dest;
1159  if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
1160    Dest.IntVal = Src1.IntVal.lshr(Src2.IntVal.getZExtValue());
1161  else
1162    Dest.IntVal = Src1.IntVal;
1163
1164  SetValue(&I, Dest, SF);
1165}
1166
1167void Interpreter::visitAShr(BinaryOperator &I) {
1168  ExecutionContext &SF = ECStack.back();
1169  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1170  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1171  GenericValue Dest;
1172  if (Src2.IntVal.getZExtValue() < Src1.IntVal.getBitWidth())
1173    Dest.IntVal = Src1.IntVal.ashr(Src2.IntVal.getZExtValue());
1174  else
1175    Dest.IntVal = Src1.IntVal;
1176
1177  SetValue(&I, Dest, SF);
1178}
1179
1180GenericValue Interpreter::executeTruncInst(Value *SrcVal, Type *DstTy,
1181                                           ExecutionContext &SF) {
1182  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1183  IntegerType *DITy = cast<IntegerType>(DstTy);
1184  unsigned DBitWidth = DITy->getBitWidth();
1185  Dest.IntVal = Src.IntVal.trunc(DBitWidth);
1186  return Dest;
1187}
1188
1189GenericValue Interpreter::executeSExtInst(Value *SrcVal, Type *DstTy,
1190                                          ExecutionContext &SF) {
1191  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1192  IntegerType *DITy = cast<IntegerType>(DstTy);
1193  unsigned DBitWidth = DITy->getBitWidth();
1194  Dest.IntVal = Src.IntVal.sext(DBitWidth);
1195  return Dest;
1196}
1197
1198GenericValue Interpreter::executeZExtInst(Value *SrcVal, Type *DstTy,
1199                                          ExecutionContext &SF) {
1200  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1201  IntegerType *DITy = cast<IntegerType>(DstTy);
1202  unsigned DBitWidth = DITy->getBitWidth();
1203  Dest.IntVal = Src.IntVal.zext(DBitWidth);
1204  return Dest;
1205}
1206
1207GenericValue Interpreter::executeFPTruncInst(Value *SrcVal, Type *DstTy,
1208                                             ExecutionContext &SF) {
1209  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1210  assert(SrcVal->getType()->isDoubleTy() && DstTy->isFloatTy() &&
1211         "Invalid FPTrunc instruction");
1212  Dest.FloatVal = (float) Src.DoubleVal;
1213  return Dest;
1214}
1215
1216GenericValue Interpreter::executeFPExtInst(Value *SrcVal, Type *DstTy,
1217                                           ExecutionContext &SF) {
1218  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1219  assert(SrcVal->getType()->isFloatTy() && DstTy->isDoubleTy() &&
1220         "Invalid FPTrunc instruction");
1221  Dest.DoubleVal = (double) Src.FloatVal;
1222  return Dest;
1223}
1224
1225GenericValue Interpreter::executeFPToUIInst(Value *SrcVal, Type *DstTy,
1226                                            ExecutionContext &SF) {
1227  Type *SrcTy = SrcVal->getType();
1228  uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1229  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1230  assert(SrcTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1231
1232  if (SrcTy->getTypeID() == Type::FloatTyID)
1233    Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1234  else
1235    Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1236  return Dest;
1237}
1238
1239GenericValue Interpreter::executeFPToSIInst(Value *SrcVal, Type *DstTy,
1240                                            ExecutionContext &SF) {
1241  Type *SrcTy = SrcVal->getType();
1242  uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1243  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1244  assert(SrcTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1245
1246  if (SrcTy->getTypeID() == Type::FloatTyID)
1247    Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1248  else
1249    Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1250  return Dest;
1251}
1252
1253GenericValue Interpreter::executeUIToFPInst(Value *SrcVal, Type *DstTy,
1254                                            ExecutionContext &SF) {
1255  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1256  assert(DstTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1257
1258  if (DstTy->getTypeID() == Type::FloatTyID)
1259    Dest.FloatVal = APIntOps::RoundAPIntToFloat(Src.IntVal);
1260  else
1261    Dest.DoubleVal = APIntOps::RoundAPIntToDouble(Src.IntVal);
1262  return Dest;
1263}
1264
1265GenericValue Interpreter::executeSIToFPInst(Value *SrcVal, Type *DstTy,
1266                                            ExecutionContext &SF) {
1267  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1268  assert(DstTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1269
1270  if (DstTy->getTypeID() == Type::FloatTyID)
1271    Dest.FloatVal = APIntOps::RoundSignedAPIntToFloat(Src.IntVal);
1272  else
1273    Dest.DoubleVal = APIntOps::RoundSignedAPIntToDouble(Src.IntVal);
1274  return Dest;
1275
1276}
1277
1278GenericValue Interpreter::executePtrToIntInst(Value *SrcVal, Type *DstTy,
1279                                              ExecutionContext &SF) {
1280  uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1281  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1282  assert(SrcVal->getType()->isPointerTy() && "Invalid PtrToInt instruction");
1283
1284  Dest.IntVal = APInt(DBitWidth, (intptr_t) Src.PointerVal);
1285  return Dest;
1286}
1287
1288GenericValue Interpreter::executeIntToPtrInst(Value *SrcVal, Type *DstTy,
1289                                              ExecutionContext &SF) {
1290  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1291  assert(DstTy->isPointerTy() && "Invalid PtrToInt instruction");
1292
1293  uint32_t PtrSize = TD.getPointerSizeInBits();
1294  if (PtrSize != Src.IntVal.getBitWidth())
1295    Src.IntVal = Src.IntVal.zextOrTrunc(PtrSize);
1296
1297  Dest.PointerVal = PointerTy(intptr_t(Src.IntVal.getZExtValue()));
1298  return Dest;
1299}
1300
1301GenericValue Interpreter::executeBitCastInst(Value *SrcVal, Type *DstTy,
1302                                             ExecutionContext &SF) {
1303
1304  Type *SrcTy = SrcVal->getType();
1305  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1306  if (DstTy->isPointerTy()) {
1307    assert(SrcTy->isPointerTy() && "Invalid BitCast");
1308    Dest.PointerVal = Src.PointerVal;
1309  } else if (DstTy->isIntegerTy()) {
1310    if (SrcTy->isFloatTy()) {
1311      Dest.IntVal = APInt::floatToBits(Src.FloatVal);
1312    } else if (SrcTy->isDoubleTy()) {
1313      Dest.IntVal = APInt::doubleToBits(Src.DoubleVal);
1314    } else if (SrcTy->isIntegerTy()) {
1315      Dest.IntVal = Src.IntVal;
1316    } else
1317      llvm_unreachable("Invalid BitCast");
1318  } else if (DstTy->isFloatTy()) {
1319    if (SrcTy->isIntegerTy())
1320      Dest.FloatVal = Src.IntVal.bitsToFloat();
1321    else
1322      Dest.FloatVal = Src.FloatVal;
1323  } else if (DstTy->isDoubleTy()) {
1324    if (SrcTy->isIntegerTy())
1325      Dest.DoubleVal = Src.IntVal.bitsToDouble();
1326    else
1327      Dest.DoubleVal = Src.DoubleVal;
1328  } else
1329    llvm_unreachable("Invalid Bitcast");
1330
1331  return Dest;
1332}
1333
1334void Interpreter::visitTruncInst(TruncInst &I) {
1335  ExecutionContext &SF = ECStack.back();
1336  SetValue(&I, executeTruncInst(I.getOperand(0), I.getType(), SF), SF);
1337}
1338
1339void Interpreter::visitSExtInst(SExtInst &I) {
1340  ExecutionContext &SF = ECStack.back();
1341  SetValue(&I, executeSExtInst(I.getOperand(0), I.getType(), SF), SF);
1342}
1343
1344void Interpreter::visitZExtInst(ZExtInst &I) {
1345  ExecutionContext &SF = ECStack.back();
1346  SetValue(&I, executeZExtInst(I.getOperand(0), I.getType(), SF), SF);
1347}
1348
1349void Interpreter::visitFPTruncInst(FPTruncInst &I) {
1350  ExecutionContext &SF = ECStack.back();
1351  SetValue(&I, executeFPTruncInst(I.getOperand(0), I.getType(), SF), SF);
1352}
1353
1354void Interpreter::visitFPExtInst(FPExtInst &I) {
1355  ExecutionContext &SF = ECStack.back();
1356  SetValue(&I, executeFPExtInst(I.getOperand(0), I.getType(), SF), SF);
1357}
1358
1359void Interpreter::visitUIToFPInst(UIToFPInst &I) {
1360  ExecutionContext &SF = ECStack.back();
1361  SetValue(&I, executeUIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1362}
1363
1364void Interpreter::visitSIToFPInst(SIToFPInst &I) {
1365  ExecutionContext &SF = ECStack.back();
1366  SetValue(&I, executeSIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1367}
1368
1369void Interpreter::visitFPToUIInst(FPToUIInst &I) {
1370  ExecutionContext &SF = ECStack.back();
1371  SetValue(&I, executeFPToUIInst(I.getOperand(0), I.getType(), SF), SF);
1372}
1373
1374void Interpreter::visitFPToSIInst(FPToSIInst &I) {
1375  ExecutionContext &SF = ECStack.back();
1376  SetValue(&I, executeFPToSIInst(I.getOperand(0), I.getType(), SF), SF);
1377}
1378
1379void Interpreter::visitPtrToIntInst(PtrToIntInst &I) {
1380  ExecutionContext &SF = ECStack.back();
1381  SetValue(&I, executePtrToIntInst(I.getOperand(0), I.getType(), SF), SF);
1382}
1383
1384void Interpreter::visitIntToPtrInst(IntToPtrInst &I) {
1385  ExecutionContext &SF = ECStack.back();
1386  SetValue(&I, executeIntToPtrInst(I.getOperand(0), I.getType(), SF), SF);
1387}
1388
1389void Interpreter::visitBitCastInst(BitCastInst &I) {
1390  ExecutionContext &SF = ECStack.back();
1391  SetValue(&I, executeBitCastInst(I.getOperand(0), I.getType(), SF), SF);
1392}
1393
1394#define IMPLEMENT_VAARG(TY) \
1395   case Type::TY##TyID: Dest.TY##Val = Src.TY##Val; break
1396
1397void Interpreter::visitVAArgInst(VAArgInst &I) {
1398  ExecutionContext &SF = ECStack.back();
1399
1400  // Get the incoming valist parameter.  LLI treats the valist as a
1401  // (ec-stack-depth var-arg-index) pair.
1402  GenericValue VAList = getOperandValue(I.getOperand(0), SF);
1403  GenericValue Dest;
1404  GenericValue Src = ECStack[VAList.UIntPairVal.first]
1405                      .VarArgs[VAList.UIntPairVal.second];
1406  Type *Ty = I.getType();
1407  switch (Ty->getTypeID()) {
1408  case Type::IntegerTyID:
1409    Dest.IntVal = Src.IntVal;
1410    break;
1411  IMPLEMENT_VAARG(Pointer);
1412  IMPLEMENT_VAARG(Float);
1413  IMPLEMENT_VAARG(Double);
1414  default:
1415    dbgs() << "Unhandled dest type for vaarg instruction: " << *Ty << "\n";
1416    llvm_unreachable(0);
1417  }
1418
1419  // Set the Value of this Instruction.
1420  SetValue(&I, Dest, SF);
1421
1422  // Move the pointer to the next vararg.
1423  ++VAList.UIntPairVal.second;
1424}
1425
1426void Interpreter::visitExtractElementInst(ExtractElementInst &I) {
1427  ExecutionContext &SF = ECStack.back();
1428  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1429  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1430  GenericValue Dest;
1431
1432  Type *Ty = I.getType();
1433  const unsigned indx = unsigned(Src2.IntVal.getZExtValue());
1434
1435  if(Src1.AggregateVal.size() > indx) {
1436    switch (Ty->getTypeID()) {
1437    default:
1438      dbgs() << "Unhandled destination type for extractelement instruction: "
1439      << *Ty << "\n";
1440      llvm_unreachable(0);
1441      break;
1442    case Type::IntegerTyID:
1443      Dest.IntVal = Src1.AggregateVal[indx].IntVal;
1444      break;
1445    case Type::FloatTyID:
1446      Dest.FloatVal = Src1.AggregateVal[indx].FloatVal;
1447      break;
1448    case Type::DoubleTyID:
1449      Dest.DoubleVal = Src1.AggregateVal[indx].DoubleVal;
1450      break;
1451    }
1452  } else {
1453    dbgs() << "Invalid index in extractelement instruction\n";
1454  }
1455
1456  SetValue(&I, Dest, SF);
1457}
1458
1459GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
1460                                                ExecutionContext &SF) {
1461  switch (CE->getOpcode()) {
1462  case Instruction::Trunc:
1463      return executeTruncInst(CE->getOperand(0), CE->getType(), SF);
1464  case Instruction::ZExt:
1465      return executeZExtInst(CE->getOperand(0), CE->getType(), SF);
1466  case Instruction::SExt:
1467      return executeSExtInst(CE->getOperand(0), CE->getType(), SF);
1468  case Instruction::FPTrunc:
1469      return executeFPTruncInst(CE->getOperand(0), CE->getType(), SF);
1470  case Instruction::FPExt:
1471      return executeFPExtInst(CE->getOperand(0), CE->getType(), SF);
1472  case Instruction::UIToFP:
1473      return executeUIToFPInst(CE->getOperand(0), CE->getType(), SF);
1474  case Instruction::SIToFP:
1475      return executeSIToFPInst(CE->getOperand(0), CE->getType(), SF);
1476  case Instruction::FPToUI:
1477      return executeFPToUIInst(CE->getOperand(0), CE->getType(), SF);
1478  case Instruction::FPToSI:
1479      return executeFPToSIInst(CE->getOperand(0), CE->getType(), SF);
1480  case Instruction::PtrToInt:
1481      return executePtrToIntInst(CE->getOperand(0), CE->getType(), SF);
1482  case Instruction::IntToPtr:
1483      return executeIntToPtrInst(CE->getOperand(0), CE->getType(), SF);
1484  case Instruction::BitCast:
1485      return executeBitCastInst(CE->getOperand(0), CE->getType(), SF);
1486  case Instruction::GetElementPtr:
1487    return executeGEPOperation(CE->getOperand(0), gep_type_begin(CE),
1488                               gep_type_end(CE), SF);
1489  case Instruction::FCmp:
1490  case Instruction::ICmp:
1491    return executeCmpInst(CE->getPredicate(),
1492                          getOperandValue(CE->getOperand(0), SF),
1493                          getOperandValue(CE->getOperand(1), SF),
1494                          CE->getOperand(0)->getType());
1495  case Instruction::Select:
1496    return executeSelectInst(getOperandValue(CE->getOperand(0), SF),
1497                             getOperandValue(CE->getOperand(1), SF),
1498                             getOperandValue(CE->getOperand(2), SF));
1499  default :
1500    break;
1501  }
1502
1503  // The cases below here require a GenericValue parameter for the result
1504  // so we initialize one, compute it and then return it.
1505  GenericValue Op0 = getOperandValue(CE->getOperand(0), SF);
1506  GenericValue Op1 = getOperandValue(CE->getOperand(1), SF);
1507  GenericValue Dest;
1508  Type * Ty = CE->getOperand(0)->getType();
1509  switch (CE->getOpcode()) {
1510  case Instruction::Add:  Dest.IntVal = Op0.IntVal + Op1.IntVal; break;
1511  case Instruction::Sub:  Dest.IntVal = Op0.IntVal - Op1.IntVal; break;
1512  case Instruction::Mul:  Dest.IntVal = Op0.IntVal * Op1.IntVal; break;
1513  case Instruction::FAdd: executeFAddInst(Dest, Op0, Op1, Ty); break;
1514  case Instruction::FSub: executeFSubInst(Dest, Op0, Op1, Ty); break;
1515  case Instruction::FMul: executeFMulInst(Dest, Op0, Op1, Ty); break;
1516  case Instruction::FDiv: executeFDivInst(Dest, Op0, Op1, Ty); break;
1517  case Instruction::FRem: executeFRemInst(Dest, Op0, Op1, Ty); break;
1518  case Instruction::SDiv: Dest.IntVal = Op0.IntVal.sdiv(Op1.IntVal); break;
1519  case Instruction::UDiv: Dest.IntVal = Op0.IntVal.udiv(Op1.IntVal); break;
1520  case Instruction::URem: Dest.IntVal = Op0.IntVal.urem(Op1.IntVal); break;
1521  case Instruction::SRem: Dest.IntVal = Op0.IntVal.srem(Op1.IntVal); break;
1522  case Instruction::And:  Dest.IntVal = Op0.IntVal & Op1.IntVal; break;
1523  case Instruction::Or:   Dest.IntVal = Op0.IntVal | Op1.IntVal; break;
1524  case Instruction::Xor:  Dest.IntVal = Op0.IntVal ^ Op1.IntVal; break;
1525  case Instruction::Shl:
1526    Dest.IntVal = Op0.IntVal.shl(Op1.IntVal.getZExtValue());
1527    break;
1528  case Instruction::LShr:
1529    Dest.IntVal = Op0.IntVal.lshr(Op1.IntVal.getZExtValue());
1530    break;
1531  case Instruction::AShr:
1532    Dest.IntVal = Op0.IntVal.ashr(Op1.IntVal.getZExtValue());
1533    break;
1534  default:
1535    dbgs() << "Unhandled ConstantExpr: " << *CE << "\n";
1536    llvm_unreachable("Unhandled ConstantExpr");
1537  }
1538  return Dest;
1539}
1540
1541GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
1542  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
1543    return getConstantExprValue(CE, SF);
1544  } else if (Constant *CPV = dyn_cast<Constant>(V)) {
1545    return getConstantValue(CPV);
1546  } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
1547    return PTOGV(getPointerToGlobal(GV));
1548  } else {
1549    return SF.Values[V];
1550  }
1551}
1552
1553//===----------------------------------------------------------------------===//
1554//                        Dispatch and Execution Code
1555//===----------------------------------------------------------------------===//
1556
1557//===----------------------------------------------------------------------===//
1558// callFunction - Execute the specified function...
1559//
1560void Interpreter::callFunction(Function *F,
1561                               const std::vector<GenericValue> &ArgVals) {
1562  assert((ECStack.empty() || ECStack.back().Caller.getInstruction() == 0 ||
1563          ECStack.back().Caller.arg_size() == ArgVals.size()) &&
1564         "Incorrect number of arguments passed into function call!");
1565  // Make a new stack frame... and fill it in.
1566  ECStack.push_back(ExecutionContext());
1567  ExecutionContext &StackFrame = ECStack.back();
1568  StackFrame.CurFunction = F;
1569
1570  // Special handling for external functions.
1571  if (F->isDeclaration()) {
1572    GenericValue Result = callExternalFunction (F, ArgVals);
1573    // Simulate a 'ret' instruction of the appropriate type.
1574    popStackAndReturnValueToCaller (F->getReturnType (), Result);
1575    return;
1576  }
1577
1578  // Get pointers to first LLVM BB & Instruction in function.
1579  StackFrame.CurBB     = F->begin();
1580  StackFrame.CurInst   = StackFrame.CurBB->begin();
1581
1582  // Run through the function arguments and initialize their values...
1583  assert((ArgVals.size() == F->arg_size() ||
1584         (ArgVals.size() > F->arg_size() && F->getFunctionType()->isVarArg()))&&
1585         "Invalid number of values passed to function invocation!");
1586
1587  // Handle non-varargs arguments...
1588  unsigned i = 0;
1589  for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
1590       AI != E; ++AI, ++i)
1591    SetValue(AI, ArgVals[i], StackFrame);
1592
1593  // Handle varargs arguments...
1594  StackFrame.VarArgs.assign(ArgVals.begin()+i, ArgVals.end());
1595}
1596
1597
1598void Interpreter::run() {
1599  while (!ECStack.empty()) {
1600    // Interpret a single instruction & increment the "PC".
1601    ExecutionContext &SF = ECStack.back();  // Current stack frame
1602    Instruction &I = *SF.CurInst++;         // Increment before execute
1603
1604    // Track the number of dynamic instructions executed.
1605    ++NumDynamicInsts;
1606
1607    DEBUG(dbgs() << "About to interpret: " << I);
1608    visit(I);   // Dispatch to one of the visit* methods...
1609#if 0
1610    // This is not safe, as visiting the instruction could lower it and free I.
1611DEBUG(
1612    if (!isa<CallInst>(I) && !isa<InvokeInst>(I) &&
1613        I.getType() != Type::VoidTy) {
1614      dbgs() << "  --> ";
1615      const GenericValue &Val = SF.Values[&I];
1616      switch (I.getType()->getTypeID()) {
1617      default: llvm_unreachable("Invalid GenericValue Type");
1618      case Type::VoidTyID:    dbgs() << "void"; break;
1619      case Type::FloatTyID:   dbgs() << "float " << Val.FloatVal; break;
1620      case Type::DoubleTyID:  dbgs() << "double " << Val.DoubleVal; break;
1621      case Type::PointerTyID: dbgs() << "void* " << intptr_t(Val.PointerVal);
1622        break;
1623      case Type::IntegerTyID:
1624        dbgs() << "i" << Val.IntVal.getBitWidth() << " "
1625               << Val.IntVal.toStringUnsigned(10)
1626               << " (0x" << Val.IntVal.toStringUnsigned(16) << ")\n";
1627        break;
1628      }
1629    });
1630#endif
1631  }
1632}
1633