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#include "Interpreter.h"
15#include "llvm/ADT/APInt.h"
16#include "llvm/ADT/Statistic.h"
17#include "llvm/CodeGen/IntrinsicLowering.h"
18#include "llvm/IR/Constants.h"
19#include "llvm/IR/DerivedTypes.h"
20#include "llvm/IR/GetElementPtrTypeIterator.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/MathExtras.h"
26#include <algorithm>
27#include <cmath>
28using namespace llvm;
29
30#define DEBUG_TYPE "interpreter"
31
32STATISTIC(NumDynamicInsts, "Number of dynamic instructions executed");
33
34static 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
41static void SetValue(Value *V, GenericValue Val, ExecutionContext &SF) {
42  SF.Values[V] = Val;
43}
44
45//===----------------------------------------------------------------------===//
46//                    Binary Instruction Implementations
47//===----------------------------------------------------------------------===//
48
49#define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
50   case Type::TY##TyID: \
51     Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; \
52     break
53
54static void executeFAddInst(GenericValue &Dest, GenericValue Src1,
55                            GenericValue Src2, Type *Ty) {
56  switch (Ty->getTypeID()) {
57    IMPLEMENT_BINARY_OPERATOR(+, Float);
58    IMPLEMENT_BINARY_OPERATOR(+, Double);
59  default:
60    dbgs() << "Unhandled type for FAdd instruction: " << *Ty << "\n";
61    llvm_unreachable(nullptr);
62  }
63}
64
65static void executeFSubInst(GenericValue &Dest, GenericValue Src1,
66                            GenericValue Src2, Type *Ty) {
67  switch (Ty->getTypeID()) {
68    IMPLEMENT_BINARY_OPERATOR(-, Float);
69    IMPLEMENT_BINARY_OPERATOR(-, Double);
70  default:
71    dbgs() << "Unhandled type for FSub instruction: " << *Ty << "\n";
72    llvm_unreachable(nullptr);
73  }
74}
75
76static void executeFMulInst(GenericValue &Dest, GenericValue Src1,
77                            GenericValue Src2, Type *Ty) {
78  switch (Ty->getTypeID()) {
79    IMPLEMENT_BINARY_OPERATOR(*, Float);
80    IMPLEMENT_BINARY_OPERATOR(*, Double);
81  default:
82    dbgs() << "Unhandled type for FMul instruction: " << *Ty << "\n";
83    llvm_unreachable(nullptr);
84  }
85}
86
87static void executeFDivInst(GenericValue &Dest, GenericValue Src1,
88                            GenericValue Src2, Type *Ty) {
89  switch (Ty->getTypeID()) {
90    IMPLEMENT_BINARY_OPERATOR(/, Float);
91    IMPLEMENT_BINARY_OPERATOR(/, Double);
92  default:
93    dbgs() << "Unhandled type for FDiv instruction: " << *Ty << "\n";
94    llvm_unreachable(nullptr);
95  }
96}
97
98static void executeFRemInst(GenericValue &Dest, GenericValue Src1,
99                            GenericValue Src2, Type *Ty) {
100  switch (Ty->getTypeID()) {
101  case Type::FloatTyID:
102    Dest.FloatVal = fmod(Src1.FloatVal, Src2.FloatVal);
103    break;
104  case Type::DoubleTyID:
105    Dest.DoubleVal = fmod(Src1.DoubleVal, Src2.DoubleVal);
106    break;
107  default:
108    dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
109    llvm_unreachable(nullptr);
110  }
111}
112
113#define IMPLEMENT_INTEGER_ICMP(OP, TY) \
114   case Type::IntegerTyID:  \
115      Dest.IntVal = APInt(1,Src1.IntVal.OP(Src2.IntVal)); \
116      break;
117
118#define IMPLEMENT_VECTOR_INTEGER_ICMP(OP, TY)                        \
119  case Type::VectorTyID: {                                           \
120    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());    \
121    Dest.AggregateVal.resize( Src1.AggregateVal.size() );            \
122    for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)             \
123      Dest.AggregateVal[_i].IntVal = APInt(1,                        \
124      Src1.AggregateVal[_i].IntVal.OP(Src2.AggregateVal[_i].IntVal));\
125  } break;
126
127// Handle pointers specially because they must be compared with only as much
128// width as the host has.  We _do not_ want to be comparing 64 bit values when
129// running on a 32-bit target, otherwise the upper 32 bits might mess up
130// comparisons if they contain garbage.
131#define IMPLEMENT_POINTER_ICMP(OP) \
132   case Type::PointerTyID: \
133      Dest.IntVal = APInt(1,(void*)(intptr_t)Src1.PointerVal OP \
134                            (void*)(intptr_t)Src2.PointerVal); \
135      break;
136
137static GenericValue executeICMP_EQ(GenericValue Src1, GenericValue Src2,
138                                   Type *Ty) {
139  GenericValue Dest;
140  switch (Ty->getTypeID()) {
141    IMPLEMENT_INTEGER_ICMP(eq,Ty);
142    IMPLEMENT_VECTOR_INTEGER_ICMP(eq,Ty);
143    IMPLEMENT_POINTER_ICMP(==);
144  default:
145    dbgs() << "Unhandled type for ICMP_EQ predicate: " << *Ty << "\n";
146    llvm_unreachable(nullptr);
147  }
148  return Dest;
149}
150
151static GenericValue executeICMP_NE(GenericValue Src1, GenericValue Src2,
152                                   Type *Ty) {
153  GenericValue Dest;
154  switch (Ty->getTypeID()) {
155    IMPLEMENT_INTEGER_ICMP(ne,Ty);
156    IMPLEMENT_VECTOR_INTEGER_ICMP(ne,Ty);
157    IMPLEMENT_POINTER_ICMP(!=);
158  default:
159    dbgs() << "Unhandled type for ICMP_NE predicate: " << *Ty << "\n";
160    llvm_unreachable(nullptr);
161  }
162  return Dest;
163}
164
165static GenericValue executeICMP_ULT(GenericValue Src1, GenericValue Src2,
166                                    Type *Ty) {
167  GenericValue Dest;
168  switch (Ty->getTypeID()) {
169    IMPLEMENT_INTEGER_ICMP(ult,Ty);
170    IMPLEMENT_VECTOR_INTEGER_ICMP(ult,Ty);
171    IMPLEMENT_POINTER_ICMP(<);
172  default:
173    dbgs() << "Unhandled type for ICMP_ULT predicate: " << *Ty << "\n";
174    llvm_unreachable(nullptr);
175  }
176  return Dest;
177}
178
179static GenericValue executeICMP_SLT(GenericValue Src1, GenericValue Src2,
180                                    Type *Ty) {
181  GenericValue Dest;
182  switch (Ty->getTypeID()) {
183    IMPLEMENT_INTEGER_ICMP(slt,Ty);
184    IMPLEMENT_VECTOR_INTEGER_ICMP(slt,Ty);
185    IMPLEMENT_POINTER_ICMP(<);
186  default:
187    dbgs() << "Unhandled type for ICMP_SLT predicate: " << *Ty << "\n";
188    llvm_unreachable(nullptr);
189  }
190  return Dest;
191}
192
193static GenericValue executeICMP_UGT(GenericValue Src1, GenericValue Src2,
194                                    Type *Ty) {
195  GenericValue Dest;
196  switch (Ty->getTypeID()) {
197    IMPLEMENT_INTEGER_ICMP(ugt,Ty);
198    IMPLEMENT_VECTOR_INTEGER_ICMP(ugt,Ty);
199    IMPLEMENT_POINTER_ICMP(>);
200  default:
201    dbgs() << "Unhandled type for ICMP_UGT predicate: " << *Ty << "\n";
202    llvm_unreachable(nullptr);
203  }
204  return Dest;
205}
206
207static GenericValue executeICMP_SGT(GenericValue Src1, GenericValue Src2,
208                                    Type *Ty) {
209  GenericValue Dest;
210  switch (Ty->getTypeID()) {
211    IMPLEMENT_INTEGER_ICMP(sgt,Ty);
212    IMPLEMENT_VECTOR_INTEGER_ICMP(sgt,Ty);
213    IMPLEMENT_POINTER_ICMP(>);
214  default:
215    dbgs() << "Unhandled type for ICMP_SGT predicate: " << *Ty << "\n";
216    llvm_unreachable(nullptr);
217  }
218  return Dest;
219}
220
221static GenericValue executeICMP_ULE(GenericValue Src1, GenericValue Src2,
222                                    Type *Ty) {
223  GenericValue Dest;
224  switch (Ty->getTypeID()) {
225    IMPLEMENT_INTEGER_ICMP(ule,Ty);
226    IMPLEMENT_VECTOR_INTEGER_ICMP(ule,Ty);
227    IMPLEMENT_POINTER_ICMP(<=);
228  default:
229    dbgs() << "Unhandled type for ICMP_ULE predicate: " << *Ty << "\n";
230    llvm_unreachable(nullptr);
231  }
232  return Dest;
233}
234
235static GenericValue executeICMP_SLE(GenericValue Src1, GenericValue Src2,
236                                    Type *Ty) {
237  GenericValue Dest;
238  switch (Ty->getTypeID()) {
239    IMPLEMENT_INTEGER_ICMP(sle,Ty);
240    IMPLEMENT_VECTOR_INTEGER_ICMP(sle,Ty);
241    IMPLEMENT_POINTER_ICMP(<=);
242  default:
243    dbgs() << "Unhandled type for ICMP_SLE predicate: " << *Ty << "\n";
244    llvm_unreachable(nullptr);
245  }
246  return Dest;
247}
248
249static GenericValue executeICMP_UGE(GenericValue Src1, GenericValue Src2,
250                                    Type *Ty) {
251  GenericValue Dest;
252  switch (Ty->getTypeID()) {
253    IMPLEMENT_INTEGER_ICMP(uge,Ty);
254    IMPLEMENT_VECTOR_INTEGER_ICMP(uge,Ty);
255    IMPLEMENT_POINTER_ICMP(>=);
256  default:
257    dbgs() << "Unhandled type for ICMP_UGE predicate: " << *Ty << "\n";
258    llvm_unreachable(nullptr);
259  }
260  return Dest;
261}
262
263static GenericValue executeICMP_SGE(GenericValue Src1, GenericValue Src2,
264                                    Type *Ty) {
265  GenericValue Dest;
266  switch (Ty->getTypeID()) {
267    IMPLEMENT_INTEGER_ICMP(sge,Ty);
268    IMPLEMENT_VECTOR_INTEGER_ICMP(sge,Ty);
269    IMPLEMENT_POINTER_ICMP(>=);
270  default:
271    dbgs() << "Unhandled type for ICMP_SGE predicate: " << *Ty << "\n";
272    llvm_unreachable(nullptr);
273  }
274  return Dest;
275}
276
277void Interpreter::visitICmpInst(ICmpInst &I) {
278  ExecutionContext &SF = ECStack.back();
279  Type *Ty    = I.getOperand(0)->getType();
280  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
281  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
282  GenericValue R;   // Result
283
284  switch (I.getPredicate()) {
285  case ICmpInst::ICMP_EQ:  R = executeICMP_EQ(Src1,  Src2, Ty); break;
286  case ICmpInst::ICMP_NE:  R = executeICMP_NE(Src1,  Src2, Ty); break;
287  case ICmpInst::ICMP_ULT: R = executeICMP_ULT(Src1, Src2, Ty); break;
288  case ICmpInst::ICMP_SLT: R = executeICMP_SLT(Src1, Src2, Ty); break;
289  case ICmpInst::ICMP_UGT: R = executeICMP_UGT(Src1, Src2, Ty); break;
290  case ICmpInst::ICMP_SGT: R = executeICMP_SGT(Src1, Src2, Ty); break;
291  case ICmpInst::ICMP_ULE: R = executeICMP_ULE(Src1, Src2, Ty); break;
292  case ICmpInst::ICMP_SLE: R = executeICMP_SLE(Src1, Src2, Ty); break;
293  case ICmpInst::ICMP_UGE: R = executeICMP_UGE(Src1, Src2, Ty); break;
294  case ICmpInst::ICMP_SGE: R = executeICMP_SGE(Src1, Src2, Ty); break;
295  default:
296    dbgs() << "Don't know how to handle this ICmp predicate!\n-->" << I;
297    llvm_unreachable(nullptr);
298  }
299
300  SetValue(&I, R, SF);
301}
302
303#define IMPLEMENT_FCMP(OP, TY) \
304   case Type::TY##TyID: \
305     Dest.IntVal = APInt(1,Src1.TY##Val OP Src2.TY##Val); \
306     break
307
308#define IMPLEMENT_VECTOR_FCMP_T(OP, TY)                             \
309  assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());     \
310  Dest.AggregateVal.resize( Src1.AggregateVal.size() );             \
311  for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)              \
312    Dest.AggregateVal[_i].IntVal = APInt(1,                         \
313    Src1.AggregateVal[_i].TY##Val OP Src2.AggregateVal[_i].TY##Val);\
314  break;
315
316#define IMPLEMENT_VECTOR_FCMP(OP)                                   \
317  case Type::VectorTyID:                                            \
318    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {   \
319      IMPLEMENT_VECTOR_FCMP_T(OP, Float);                           \
320    } else {                                                        \
321        IMPLEMENT_VECTOR_FCMP_T(OP, Double);                        \
322    }
323
324static GenericValue executeFCMP_OEQ(GenericValue Src1, GenericValue Src2,
325                                   Type *Ty) {
326  GenericValue Dest;
327  switch (Ty->getTypeID()) {
328    IMPLEMENT_FCMP(==, Float);
329    IMPLEMENT_FCMP(==, Double);
330    IMPLEMENT_VECTOR_FCMP(==);
331  default:
332    dbgs() << "Unhandled type for FCmp EQ instruction: " << *Ty << "\n";
333    llvm_unreachable(nullptr);
334  }
335  return Dest;
336}
337
338#define IMPLEMENT_SCALAR_NANS(TY, X,Y)                                      \
339  if (TY->isFloatTy()) {                                                    \
340    if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {             \
341      Dest.IntVal = APInt(1,false);                                         \
342      return Dest;                                                          \
343    }                                                                       \
344  } else {                                                                  \
345    if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) {         \
346      Dest.IntVal = APInt(1,false);                                         \
347      return Dest;                                                          \
348    }                                                                       \
349  }
350
351#define MASK_VECTOR_NANS_T(X,Y, TZ, FLAG)                                   \
352  assert(X.AggregateVal.size() == Y.AggregateVal.size());                   \
353  Dest.AggregateVal.resize( X.AggregateVal.size() );                        \
354  for( uint32_t _i=0;_i<X.AggregateVal.size();_i++) {                       \
355    if (X.AggregateVal[_i].TZ##Val != X.AggregateVal[_i].TZ##Val ||         \
356        Y.AggregateVal[_i].TZ##Val != Y.AggregateVal[_i].TZ##Val)           \
357      Dest.AggregateVal[_i].IntVal = APInt(1,FLAG);                         \
358    else  {                                                                 \
359      Dest.AggregateVal[_i].IntVal = APInt(1,!FLAG);                        \
360    }                                                                       \
361  }
362
363#define MASK_VECTOR_NANS(TY, X,Y, FLAG)                                     \
364  if (TY->isVectorTy()) {                                                   \
365    if (dyn_cast<VectorType>(TY)->getElementType()->isFloatTy()) {          \
366      MASK_VECTOR_NANS_T(X, Y, Float, FLAG)                                 \
367    } else {                                                                \
368      MASK_VECTOR_NANS_T(X, Y, Double, FLAG)                                \
369    }                                                                       \
370  }                                                                         \
371
372
373
374static GenericValue executeFCMP_ONE(GenericValue Src1, GenericValue Src2,
375                                    Type *Ty)
376{
377  GenericValue Dest;
378  // if input is scalar value and Src1 or Src2 is NaN return false
379  IMPLEMENT_SCALAR_NANS(Ty, Src1, Src2)
380  // if vector input detect NaNs and fill mask
381  MASK_VECTOR_NANS(Ty, Src1, Src2, false)
382  GenericValue DestMask = Dest;
383  switch (Ty->getTypeID()) {
384    IMPLEMENT_FCMP(!=, Float);
385    IMPLEMENT_FCMP(!=, Double);
386    IMPLEMENT_VECTOR_FCMP(!=);
387    default:
388      dbgs() << "Unhandled type for FCmp NE instruction: " << *Ty << "\n";
389      llvm_unreachable(nullptr);
390  }
391  // in vector case mask out NaN elements
392  if (Ty->isVectorTy())
393    for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
394      if (DestMask.AggregateVal[_i].IntVal == false)
395        Dest.AggregateVal[_i].IntVal = APInt(1,false);
396
397  return Dest;
398}
399
400static GenericValue executeFCMP_OLE(GenericValue Src1, GenericValue Src2,
401                                   Type *Ty) {
402  GenericValue Dest;
403  switch (Ty->getTypeID()) {
404    IMPLEMENT_FCMP(<=, Float);
405    IMPLEMENT_FCMP(<=, Double);
406    IMPLEMENT_VECTOR_FCMP(<=);
407  default:
408    dbgs() << "Unhandled type for FCmp LE instruction: " << *Ty << "\n";
409    llvm_unreachable(nullptr);
410  }
411  return Dest;
412}
413
414static GenericValue executeFCMP_OGE(GenericValue Src1, GenericValue Src2,
415                                   Type *Ty) {
416  GenericValue Dest;
417  switch (Ty->getTypeID()) {
418    IMPLEMENT_FCMP(>=, Float);
419    IMPLEMENT_FCMP(>=, Double);
420    IMPLEMENT_VECTOR_FCMP(>=);
421  default:
422    dbgs() << "Unhandled type for FCmp GE instruction: " << *Ty << "\n";
423    llvm_unreachable(nullptr);
424  }
425  return Dest;
426}
427
428static GenericValue executeFCMP_OLT(GenericValue Src1, GenericValue Src2,
429                                   Type *Ty) {
430  GenericValue Dest;
431  switch (Ty->getTypeID()) {
432    IMPLEMENT_FCMP(<, Float);
433    IMPLEMENT_FCMP(<, Double);
434    IMPLEMENT_VECTOR_FCMP(<);
435  default:
436    dbgs() << "Unhandled type for FCmp LT instruction: " << *Ty << "\n";
437    llvm_unreachable(nullptr);
438  }
439  return Dest;
440}
441
442static GenericValue executeFCMP_OGT(GenericValue Src1, GenericValue Src2,
443                                     Type *Ty) {
444  GenericValue Dest;
445  switch (Ty->getTypeID()) {
446    IMPLEMENT_FCMP(>, Float);
447    IMPLEMENT_FCMP(>, Double);
448    IMPLEMENT_VECTOR_FCMP(>);
449  default:
450    dbgs() << "Unhandled type for FCmp GT instruction: " << *Ty << "\n";
451    llvm_unreachable(nullptr);
452  }
453  return Dest;
454}
455
456#define IMPLEMENT_UNORDERED(TY, X,Y)                                     \
457  if (TY->isFloatTy()) {                                                 \
458    if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {          \
459      Dest.IntVal = APInt(1,true);                                       \
460      return Dest;                                                       \
461    }                                                                    \
462  } else if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) { \
463    Dest.IntVal = APInt(1,true);                                         \
464    return Dest;                                                         \
465  }
466
467#define IMPLEMENT_VECTOR_UNORDERED(TY, X,Y, _FUNC)                       \
468  if (TY->isVectorTy()) {                                                \
469    GenericValue DestMask = Dest;                                        \
470    Dest = _FUNC(Src1, Src2, Ty);                                        \
471      for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)               \
472        if (DestMask.AggregateVal[_i].IntVal == true)                    \
473          Dest.AggregateVal[_i].IntVal = APInt(1,true);                  \
474      return Dest;                                                       \
475  }
476
477static GenericValue executeFCMP_UEQ(GenericValue Src1, GenericValue Src2,
478                                   Type *Ty) {
479  GenericValue Dest;
480  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
481  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
482  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OEQ)
483  return executeFCMP_OEQ(Src1, Src2, Ty);
484
485}
486
487static GenericValue executeFCMP_UNE(GenericValue Src1, GenericValue Src2,
488                                   Type *Ty) {
489  GenericValue Dest;
490  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
491  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
492  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_ONE)
493  return executeFCMP_ONE(Src1, Src2, Ty);
494}
495
496static GenericValue executeFCMP_ULE(GenericValue Src1, GenericValue Src2,
497                                   Type *Ty) {
498  GenericValue Dest;
499  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
500  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
501  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLE)
502  return executeFCMP_OLE(Src1, Src2, Ty);
503}
504
505static GenericValue executeFCMP_UGE(GenericValue Src1, GenericValue Src2,
506                                   Type *Ty) {
507  GenericValue Dest;
508  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
509  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
510  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGE)
511  return executeFCMP_OGE(Src1, Src2, Ty);
512}
513
514static GenericValue executeFCMP_ULT(GenericValue Src1, GenericValue Src2,
515                                   Type *Ty) {
516  GenericValue Dest;
517  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
518  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
519  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLT)
520  return executeFCMP_OLT(Src1, Src2, Ty);
521}
522
523static GenericValue executeFCMP_UGT(GenericValue Src1, GenericValue Src2,
524                                     Type *Ty) {
525  GenericValue Dest;
526  IMPLEMENT_UNORDERED(Ty, Src1, Src2)
527  MASK_VECTOR_NANS(Ty, Src1, Src2, true)
528  IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGT)
529  return executeFCMP_OGT(Src1, Src2, Ty);
530}
531
532static GenericValue executeFCMP_ORD(GenericValue Src1, GenericValue Src2,
533                                     Type *Ty) {
534  GenericValue Dest;
535  if(Ty->isVectorTy()) {
536    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
537    Dest.AggregateVal.resize( Src1.AggregateVal.size() );
538    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
539      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
540        Dest.AggregateVal[_i].IntVal = APInt(1,
541        ( (Src1.AggregateVal[_i].FloatVal ==
542        Src1.AggregateVal[_i].FloatVal) &&
543        (Src2.AggregateVal[_i].FloatVal ==
544        Src2.AggregateVal[_i].FloatVal)));
545    } else {
546      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
547        Dest.AggregateVal[_i].IntVal = APInt(1,
548        ( (Src1.AggregateVal[_i].DoubleVal ==
549        Src1.AggregateVal[_i].DoubleVal) &&
550        (Src2.AggregateVal[_i].DoubleVal ==
551        Src2.AggregateVal[_i].DoubleVal)));
552    }
553  } else if (Ty->isFloatTy())
554    Dest.IntVal = APInt(1,(Src1.FloatVal == Src1.FloatVal &&
555                           Src2.FloatVal == Src2.FloatVal));
556  else {
557    Dest.IntVal = APInt(1,(Src1.DoubleVal == Src1.DoubleVal &&
558                           Src2.DoubleVal == Src2.DoubleVal));
559  }
560  return Dest;
561}
562
563static GenericValue executeFCMP_UNO(GenericValue Src1, GenericValue Src2,
564                                     Type *Ty) {
565  GenericValue Dest;
566  if(Ty->isVectorTy()) {
567    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
568    Dest.AggregateVal.resize( Src1.AggregateVal.size() );
569    if(dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
570      for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
571        Dest.AggregateVal[_i].IntVal = APInt(1,
572        ( (Src1.AggregateVal[_i].FloatVal !=
573           Src1.AggregateVal[_i].FloatVal) ||
574          (Src2.AggregateVal[_i].FloatVal !=
575           Src2.AggregateVal[_i].FloatVal)));
576      } else {
577        for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
578          Dest.AggregateVal[_i].IntVal = APInt(1,
579          ( (Src1.AggregateVal[_i].DoubleVal !=
580             Src1.AggregateVal[_i].DoubleVal) ||
581            (Src2.AggregateVal[_i].DoubleVal !=
582             Src2.AggregateVal[_i].DoubleVal)));
583      }
584  } else if (Ty->isFloatTy())
585    Dest.IntVal = APInt(1,(Src1.FloatVal != Src1.FloatVal ||
586                           Src2.FloatVal != Src2.FloatVal));
587  else {
588    Dest.IntVal = APInt(1,(Src1.DoubleVal != Src1.DoubleVal ||
589                           Src2.DoubleVal != Src2.DoubleVal));
590  }
591  return Dest;
592}
593
594static GenericValue executeFCMP_BOOL(GenericValue Src1, GenericValue Src2,
595                                    const Type *Ty, const bool val) {
596  GenericValue Dest;
597    if(Ty->isVectorTy()) {
598      assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
599      Dest.AggregateVal.resize( Src1.AggregateVal.size() );
600      for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
601        Dest.AggregateVal[_i].IntVal = APInt(1,val);
602    } else {
603      Dest.IntVal = APInt(1, val);
604    }
605
606    return Dest;
607}
608
609void Interpreter::visitFCmpInst(FCmpInst &I) {
610  ExecutionContext &SF = ECStack.back();
611  Type *Ty    = I.getOperand(0)->getType();
612  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
613  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
614  GenericValue R;   // Result
615
616  switch (I.getPredicate()) {
617  default:
618    dbgs() << "Don't know how to handle this FCmp predicate!\n-->" << I;
619    llvm_unreachable(nullptr);
620  break;
621  case FCmpInst::FCMP_FALSE: R = executeFCMP_BOOL(Src1, Src2, Ty, false);
622  break;
623  case FCmpInst::FCMP_TRUE:  R = executeFCMP_BOOL(Src1, Src2, Ty, true);
624  break;
625  case FCmpInst::FCMP_ORD:   R = executeFCMP_ORD(Src1, Src2, Ty); break;
626  case FCmpInst::FCMP_UNO:   R = executeFCMP_UNO(Src1, Src2, Ty); break;
627  case FCmpInst::FCMP_UEQ:   R = executeFCMP_UEQ(Src1, Src2, Ty); break;
628  case FCmpInst::FCMP_OEQ:   R = executeFCMP_OEQ(Src1, Src2, Ty); break;
629  case FCmpInst::FCMP_UNE:   R = executeFCMP_UNE(Src1, Src2, Ty); break;
630  case FCmpInst::FCMP_ONE:   R = executeFCMP_ONE(Src1, Src2, Ty); break;
631  case FCmpInst::FCMP_ULT:   R = executeFCMP_ULT(Src1, Src2, Ty); break;
632  case FCmpInst::FCMP_OLT:   R = executeFCMP_OLT(Src1, Src2, Ty); break;
633  case FCmpInst::FCMP_UGT:   R = executeFCMP_UGT(Src1, Src2, Ty); break;
634  case FCmpInst::FCMP_OGT:   R = executeFCMP_OGT(Src1, Src2, Ty); break;
635  case FCmpInst::FCMP_ULE:   R = executeFCMP_ULE(Src1, Src2, Ty); break;
636  case FCmpInst::FCMP_OLE:   R = executeFCMP_OLE(Src1, Src2, Ty); break;
637  case FCmpInst::FCMP_UGE:   R = executeFCMP_UGE(Src1, Src2, Ty); break;
638  case FCmpInst::FCMP_OGE:   R = executeFCMP_OGE(Src1, Src2, Ty); break;
639  }
640
641  SetValue(&I, R, SF);
642}
643
644static GenericValue executeCmpInst(unsigned predicate, GenericValue Src1,
645                                   GenericValue Src2, Type *Ty) {
646  GenericValue Result;
647  switch (predicate) {
648  case ICmpInst::ICMP_EQ:    return executeICMP_EQ(Src1, Src2, Ty);
649  case ICmpInst::ICMP_NE:    return executeICMP_NE(Src1, Src2, Ty);
650  case ICmpInst::ICMP_UGT:   return executeICMP_UGT(Src1, Src2, Ty);
651  case ICmpInst::ICMP_SGT:   return executeICMP_SGT(Src1, Src2, Ty);
652  case ICmpInst::ICMP_ULT:   return executeICMP_ULT(Src1, Src2, Ty);
653  case ICmpInst::ICMP_SLT:   return executeICMP_SLT(Src1, Src2, Ty);
654  case ICmpInst::ICMP_UGE:   return executeICMP_UGE(Src1, Src2, Ty);
655  case ICmpInst::ICMP_SGE:   return executeICMP_SGE(Src1, Src2, Ty);
656  case ICmpInst::ICMP_ULE:   return executeICMP_ULE(Src1, Src2, Ty);
657  case ICmpInst::ICMP_SLE:   return executeICMP_SLE(Src1, Src2, Ty);
658  case FCmpInst::FCMP_ORD:   return executeFCMP_ORD(Src1, Src2, Ty);
659  case FCmpInst::FCMP_UNO:   return executeFCMP_UNO(Src1, Src2, Ty);
660  case FCmpInst::FCMP_OEQ:   return executeFCMP_OEQ(Src1, Src2, Ty);
661  case FCmpInst::FCMP_UEQ:   return executeFCMP_UEQ(Src1, Src2, Ty);
662  case FCmpInst::FCMP_ONE:   return executeFCMP_ONE(Src1, Src2, Ty);
663  case FCmpInst::FCMP_UNE:   return executeFCMP_UNE(Src1, Src2, Ty);
664  case FCmpInst::FCMP_OLT:   return executeFCMP_OLT(Src1, Src2, Ty);
665  case FCmpInst::FCMP_ULT:   return executeFCMP_ULT(Src1, Src2, Ty);
666  case FCmpInst::FCMP_OGT:   return executeFCMP_OGT(Src1, Src2, Ty);
667  case FCmpInst::FCMP_UGT:   return executeFCMP_UGT(Src1, Src2, Ty);
668  case FCmpInst::FCMP_OLE:   return executeFCMP_OLE(Src1, Src2, Ty);
669  case FCmpInst::FCMP_ULE:   return executeFCMP_ULE(Src1, Src2, Ty);
670  case FCmpInst::FCMP_OGE:   return executeFCMP_OGE(Src1, Src2, Ty);
671  case FCmpInst::FCMP_UGE:   return executeFCMP_UGE(Src1, Src2, Ty);
672  case FCmpInst::FCMP_FALSE: return executeFCMP_BOOL(Src1, Src2, Ty, false);
673  case FCmpInst::FCMP_TRUE:  return executeFCMP_BOOL(Src1, Src2, Ty, true);
674  default:
675    dbgs() << "Unhandled Cmp predicate\n";
676    llvm_unreachable(nullptr);
677  }
678}
679
680void Interpreter::visitBinaryOperator(BinaryOperator &I) {
681  ExecutionContext &SF = ECStack.back();
682  Type *Ty    = I.getOperand(0)->getType();
683  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
684  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
685  GenericValue R;   // Result
686
687  // First process vector operation
688  if (Ty->isVectorTy()) {
689    assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
690    R.AggregateVal.resize(Src1.AggregateVal.size());
691
692    // Macros to execute binary operation 'OP' over integer vectors
693#define INTEGER_VECTOR_OPERATION(OP)                               \
694    for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
695      R.AggregateVal[i].IntVal =                                   \
696      Src1.AggregateVal[i].IntVal OP Src2.AggregateVal[i].IntVal;
697
698    // Additional macros to execute binary operations udiv/sdiv/urem/srem since
699    // they have different notation.
700#define INTEGER_VECTOR_FUNCTION(OP)                                \
701    for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
702      R.AggregateVal[i].IntVal =                                   \
703      Src1.AggregateVal[i].IntVal.OP(Src2.AggregateVal[i].IntVal);
704
705    // Macros to execute binary operation 'OP' over floating point type TY
706    // (float or double) vectors
707#define FLOAT_VECTOR_FUNCTION(OP, TY)                               \
708      for (unsigned i = 0; i < R.AggregateVal.size(); ++i)          \
709        R.AggregateVal[i].TY =                                      \
710        Src1.AggregateVal[i].TY OP Src2.AggregateVal[i].TY;
711
712    // Macros to choose appropriate TY: float or double and run operation
713    // execution
714#define FLOAT_VECTOR_OP(OP) {                                         \
715  if (dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy())        \
716    FLOAT_VECTOR_FUNCTION(OP, FloatVal)                               \
717  else {                                                              \
718    if (dyn_cast<VectorType>(Ty)->getElementType()->isDoubleTy())     \
719      FLOAT_VECTOR_FUNCTION(OP, DoubleVal)                            \
720    else {                                                            \
721      dbgs() << "Unhandled type for OP instruction: " << *Ty << "\n"; \
722      llvm_unreachable(0);                                            \
723    }                                                                 \
724  }                                                                   \
725}
726
727    switch(I.getOpcode()){
728    default:
729      dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
730      llvm_unreachable(nullptr);
731      break;
732    case Instruction::Add:   INTEGER_VECTOR_OPERATION(+) break;
733    case Instruction::Sub:   INTEGER_VECTOR_OPERATION(-) break;
734    case Instruction::Mul:   INTEGER_VECTOR_OPERATION(*) break;
735    case Instruction::UDiv:  INTEGER_VECTOR_FUNCTION(udiv) break;
736    case Instruction::SDiv:  INTEGER_VECTOR_FUNCTION(sdiv) break;
737    case Instruction::URem:  INTEGER_VECTOR_FUNCTION(urem) break;
738    case Instruction::SRem:  INTEGER_VECTOR_FUNCTION(srem) break;
739    case Instruction::And:   INTEGER_VECTOR_OPERATION(&) break;
740    case Instruction::Or:    INTEGER_VECTOR_OPERATION(|) break;
741    case Instruction::Xor:   INTEGER_VECTOR_OPERATION(^) break;
742    case Instruction::FAdd:  FLOAT_VECTOR_OP(+) break;
743    case Instruction::FSub:  FLOAT_VECTOR_OP(-) break;
744    case Instruction::FMul:  FLOAT_VECTOR_OP(*) break;
745    case Instruction::FDiv:  FLOAT_VECTOR_OP(/) break;
746    case Instruction::FRem:
747      if (dyn_cast<VectorType>(Ty)->getElementType()->isFloatTy())
748        for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
749          R.AggregateVal[i].FloatVal =
750          fmod(Src1.AggregateVal[i].FloatVal, Src2.AggregateVal[i].FloatVal);
751      else {
752        if (dyn_cast<VectorType>(Ty)->getElementType()->isDoubleTy())
753          for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
754            R.AggregateVal[i].DoubleVal =
755            fmod(Src1.AggregateVal[i].DoubleVal, Src2.AggregateVal[i].DoubleVal);
756        else {
757          dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
758          llvm_unreachable(nullptr);
759        }
760      }
761      break;
762    }
763  } else {
764    switch (I.getOpcode()) {
765    default:
766      dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
767      llvm_unreachable(nullptr);
768      break;
769    case Instruction::Add:   R.IntVal = Src1.IntVal + Src2.IntVal; break;
770    case Instruction::Sub:   R.IntVal = Src1.IntVal - Src2.IntVal; break;
771    case Instruction::Mul:   R.IntVal = Src1.IntVal * Src2.IntVal; break;
772    case Instruction::FAdd:  executeFAddInst(R, Src1, Src2, Ty); break;
773    case Instruction::FSub:  executeFSubInst(R, Src1, Src2, Ty); break;
774    case Instruction::FMul:  executeFMulInst(R, Src1, Src2, Ty); break;
775    case Instruction::FDiv:  executeFDivInst(R, Src1, Src2, Ty); break;
776    case Instruction::FRem:  executeFRemInst(R, Src1, Src2, Ty); break;
777    case Instruction::UDiv:  R.IntVal = Src1.IntVal.udiv(Src2.IntVal); break;
778    case Instruction::SDiv:  R.IntVal = Src1.IntVal.sdiv(Src2.IntVal); break;
779    case Instruction::URem:  R.IntVal = Src1.IntVal.urem(Src2.IntVal); break;
780    case Instruction::SRem:  R.IntVal = Src1.IntVal.srem(Src2.IntVal); break;
781    case Instruction::And:   R.IntVal = Src1.IntVal & Src2.IntVal; break;
782    case Instruction::Or:    R.IntVal = Src1.IntVal | Src2.IntVal; break;
783    case Instruction::Xor:   R.IntVal = Src1.IntVal ^ Src2.IntVal; break;
784    }
785  }
786  SetValue(&I, R, SF);
787}
788
789static GenericValue executeSelectInst(GenericValue Src1, GenericValue Src2,
790                                      GenericValue Src3, const Type *Ty) {
791    GenericValue Dest;
792    if(Ty->isVectorTy()) {
793      assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
794      assert(Src2.AggregateVal.size() == Src3.AggregateVal.size());
795      Dest.AggregateVal.resize( Src1.AggregateVal.size() );
796      for (size_t i = 0; i < Src1.AggregateVal.size(); ++i)
797        Dest.AggregateVal[i] = (Src1.AggregateVal[i].IntVal == 0) ?
798          Src3.AggregateVal[i] : Src2.AggregateVal[i];
799    } else {
800      Dest = (Src1.IntVal == 0) ? Src3 : Src2;
801    }
802    return Dest;
803}
804
805void Interpreter::visitSelectInst(SelectInst &I) {
806  ExecutionContext &SF = ECStack.back();
807  const Type * Ty = I.getOperand(0)->getType();
808  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
809  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
810  GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
811  GenericValue R = executeSelectInst(Src1, Src2, Src3, Ty);
812  SetValue(&I, R, SF);
813}
814
815//===----------------------------------------------------------------------===//
816//                     Terminator Instruction Implementations
817//===----------------------------------------------------------------------===//
818
819void Interpreter::exitCalled(GenericValue GV) {
820  // runAtExitHandlers() assumes there are no stack frames, but
821  // if exit() was called, then it had a stack frame. Blow away
822  // the stack before interpreting atexit handlers.
823  ECStack.clear();
824  runAtExitHandlers();
825  exit(GV.IntVal.zextOrTrunc(32).getZExtValue());
826}
827
828/// Pop the last stack frame off of ECStack and then copy the result
829/// back into the result variable if we are not returning void. The
830/// result variable may be the ExitValue, or the Value of the calling
831/// CallInst if there was a previous stack frame. This method may
832/// invalidate any ECStack iterators you have. This method also takes
833/// care of switching to the normal destination BB, if we are returning
834/// from an invoke.
835///
836void Interpreter::popStackAndReturnValueToCaller(Type *RetTy,
837                                                 GenericValue Result) {
838  // Pop the current stack frame.
839  ECStack.pop_back();
840
841  if (ECStack.empty()) {  // Finished main.  Put result into exit code...
842    if (RetTy && !RetTy->isVoidTy()) {          // Nonvoid return type?
843      ExitValue = Result;   // Capture the exit value of the program
844    } else {
845      memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
846    }
847  } else {
848    // If we have a previous stack frame, and we have a previous call,
849    // fill in the return value...
850    ExecutionContext &CallingSF = ECStack.back();
851    if (Instruction *I = CallingSF.Caller.getInstruction()) {
852      // Save result...
853      if (!CallingSF.Caller.getType()->isVoidTy())
854        SetValue(I, Result, CallingSF);
855      if (InvokeInst *II = dyn_cast<InvokeInst> (I))
856        SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
857      CallingSF.Caller = CallSite();          // We returned from the call...
858    }
859  }
860}
861
862void Interpreter::visitReturnInst(ReturnInst &I) {
863  ExecutionContext &SF = ECStack.back();
864  Type *RetTy = Type::getVoidTy(I.getContext());
865  GenericValue Result;
866
867  // Save away the return value... (if we are not 'ret void')
868  if (I.getNumOperands()) {
869    RetTy  = I.getReturnValue()->getType();
870    Result = getOperandValue(I.getReturnValue(), SF);
871  }
872
873  popStackAndReturnValueToCaller(RetTy, Result);
874}
875
876void Interpreter::visitUnreachableInst(UnreachableInst &I) {
877  report_fatal_error("Program executed an 'unreachable' instruction!");
878}
879
880void Interpreter::visitBranchInst(BranchInst &I) {
881  ExecutionContext &SF = ECStack.back();
882  BasicBlock *Dest;
883
884  Dest = I.getSuccessor(0);          // Uncond branches have a fixed dest...
885  if (!I.isUnconditional()) {
886    Value *Cond = I.getCondition();
887    if (getOperandValue(Cond, SF).IntVal == 0) // If false cond...
888      Dest = I.getSuccessor(1);
889  }
890  SwitchToNewBasicBlock(Dest, SF);
891}
892
893void Interpreter::visitSwitchInst(SwitchInst &I) {
894  ExecutionContext &SF = ECStack.back();
895  Value* Cond = I.getCondition();
896  Type *ElTy = Cond->getType();
897  GenericValue CondVal = getOperandValue(Cond, SF);
898
899  // Check to see if any of the cases match...
900  BasicBlock *Dest = nullptr;
901  for (SwitchInst::CaseIt i = I.case_begin(), e = I.case_end(); i != e; ++i) {
902    GenericValue CaseVal = getOperandValue(i.getCaseValue(), SF);
903    if (executeICMP_EQ(CondVal, CaseVal, ElTy).IntVal != 0) {
904      Dest = cast<BasicBlock>(i.getCaseSuccessor());
905      break;
906    }
907  }
908  if (!Dest) Dest = I.getDefaultDest();   // No cases matched: use default
909  SwitchToNewBasicBlock(Dest, SF);
910}
911
912void Interpreter::visitIndirectBrInst(IndirectBrInst &I) {
913  ExecutionContext &SF = ECStack.back();
914  void *Dest = GVTOP(getOperandValue(I.getAddress(), SF));
915  SwitchToNewBasicBlock((BasicBlock*)Dest, SF);
916}
917
918
919// SwitchToNewBasicBlock - This method is used to jump to a new basic block.
920// This function handles the actual updating of block and instruction iterators
921// as well as execution of all of the PHI nodes in the destination block.
922//
923// This method does this because all of the PHI nodes must be executed
924// atomically, reading their inputs before any of the results are updated.  Not
925// doing this can cause problems if the PHI nodes depend on other PHI nodes for
926// their inputs.  If the input PHI node is updated before it is read, incorrect
927// results can happen.  Thus we use a two phase approach.
928//
929void Interpreter::SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF){
930  BasicBlock *PrevBB = SF.CurBB;      // Remember where we came from...
931  SF.CurBB   = Dest;                  // Update CurBB to branch destination
932  SF.CurInst = SF.CurBB->begin();     // Update new instruction ptr...
933
934  if (!isa<PHINode>(SF.CurInst)) return;  // Nothing fancy to do
935
936  // Loop over all of the PHI nodes in the current block, reading their inputs.
937  std::vector<GenericValue> ResultValues;
938
939  for (; PHINode *PN = dyn_cast<PHINode>(SF.CurInst); ++SF.CurInst) {
940    // Search for the value corresponding to this previous bb...
941    int i = PN->getBasicBlockIndex(PrevBB);
942    assert(i != -1 && "PHINode doesn't contain entry for predecessor??");
943    Value *IncomingValue = PN->getIncomingValue(i);
944
945    // Save the incoming value for this PHI node...
946    ResultValues.push_back(getOperandValue(IncomingValue, SF));
947  }
948
949  // Now loop over all of the PHI nodes setting their values...
950  SF.CurInst = SF.CurBB->begin();
951  for (unsigned i = 0; isa<PHINode>(SF.CurInst); ++SF.CurInst, ++i) {
952    PHINode *PN = cast<PHINode>(SF.CurInst);
953    SetValue(PN, ResultValues[i], SF);
954  }
955}
956
957//===----------------------------------------------------------------------===//
958//                     Memory Instruction Implementations
959//===----------------------------------------------------------------------===//
960
961void Interpreter::visitAllocaInst(AllocaInst &I) {
962  ExecutionContext &SF = ECStack.back();
963
964  Type *Ty = I.getType()->getElementType();  // Type to be allocated
965
966  // Get the number of elements being allocated by the array...
967  unsigned NumElements =
968    getOperandValue(I.getOperand(0), SF).IntVal.getZExtValue();
969
970  unsigned TypeSize = (size_t)TD.getTypeAllocSize(Ty);
971
972  // Avoid malloc-ing zero bytes, use max()...
973  unsigned MemToAlloc = std::max(1U, NumElements * TypeSize);
974
975  // Allocate enough memory to hold the type...
976  void *Memory = malloc(MemToAlloc);
977
978  DEBUG(dbgs() << "Allocated Type: " << *Ty << " (" << TypeSize << " bytes) x "
979               << NumElements << " (Total: " << MemToAlloc << ") at "
980               << uintptr_t(Memory) << '\n');
981
982  GenericValue Result = PTOGV(Memory);
983  assert(Result.PointerVal && "Null pointer returned by malloc!");
984  SetValue(&I, Result, SF);
985
986  if (I.getOpcode() == Instruction::Alloca)
987    ECStack.back().Allocas.add(Memory);
988}
989
990// getElementOffset - The workhorse for getelementptr.
991//
992GenericValue Interpreter::executeGEPOperation(Value *Ptr, gep_type_iterator I,
993                                              gep_type_iterator E,
994                                              ExecutionContext &SF) {
995  assert(Ptr->getType()->isPointerTy() &&
996         "Cannot getElementOffset of a nonpointer type!");
997
998  uint64_t Total = 0;
999
1000  for (; I != E; ++I) {
1001    if (StructType *STy = dyn_cast<StructType>(*I)) {
1002      const StructLayout *SLO = TD.getStructLayout(STy);
1003
1004      const ConstantInt *CPU = cast<ConstantInt>(I.getOperand());
1005      unsigned Index = unsigned(CPU->getZExtValue());
1006
1007      Total += SLO->getElementOffset(Index);
1008    } else {
1009      SequentialType *ST = cast<SequentialType>(*I);
1010      // Get the index number for the array... which must be long type...
1011      GenericValue IdxGV = getOperandValue(I.getOperand(), SF);
1012
1013      int64_t Idx;
1014      unsigned BitWidth =
1015        cast<IntegerType>(I.getOperand()->getType())->getBitWidth();
1016      if (BitWidth == 32)
1017        Idx = (int64_t)(int32_t)IdxGV.IntVal.getZExtValue();
1018      else {
1019        assert(BitWidth == 64 && "Invalid index type for getelementptr");
1020        Idx = (int64_t)IdxGV.IntVal.getZExtValue();
1021      }
1022      Total += TD.getTypeAllocSize(ST->getElementType())*Idx;
1023    }
1024  }
1025
1026  GenericValue Result;
1027  Result.PointerVal = ((char*)getOperandValue(Ptr, SF).PointerVal) + Total;
1028  DEBUG(dbgs() << "GEP Index " << Total << " bytes.\n");
1029  return Result;
1030}
1031
1032void Interpreter::visitGetElementPtrInst(GetElementPtrInst &I) {
1033  ExecutionContext &SF = ECStack.back();
1034  SetValue(&I, executeGEPOperation(I.getPointerOperand(),
1035                                   gep_type_begin(I), gep_type_end(I), SF), SF);
1036}
1037
1038void Interpreter::visitLoadInst(LoadInst &I) {
1039  ExecutionContext &SF = ECStack.back();
1040  GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1041  GenericValue *Ptr = (GenericValue*)GVTOP(SRC);
1042  GenericValue Result;
1043  LoadValueFromMemory(Result, Ptr, I.getType());
1044  SetValue(&I, Result, SF);
1045  if (I.isVolatile() && PrintVolatile)
1046    dbgs() << "Volatile load " << I;
1047}
1048
1049void Interpreter::visitStoreInst(StoreInst &I) {
1050  ExecutionContext &SF = ECStack.back();
1051  GenericValue Val = getOperandValue(I.getOperand(0), SF);
1052  GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1053  StoreValueToMemory(Val, (GenericValue *)GVTOP(SRC),
1054                     I.getOperand(0)->getType());
1055  if (I.isVolatile() && PrintVolatile)
1056    dbgs() << "Volatile store: " << I;
1057}
1058
1059//===----------------------------------------------------------------------===//
1060//                 Miscellaneous Instruction Implementations
1061//===----------------------------------------------------------------------===//
1062
1063void Interpreter::visitCallSite(CallSite CS) {
1064  ExecutionContext &SF = ECStack.back();
1065
1066  // Check to see if this is an intrinsic function call...
1067  Function *F = CS.getCalledFunction();
1068  if (F && F->isDeclaration())
1069    switch (F->getIntrinsicID()) {
1070    case Intrinsic::not_intrinsic:
1071      break;
1072    case Intrinsic::vastart: { // va_start
1073      GenericValue ArgIndex;
1074      ArgIndex.UIntPairVal.first = ECStack.size() - 1;
1075      ArgIndex.UIntPairVal.second = 0;
1076      SetValue(CS.getInstruction(), ArgIndex, SF);
1077      return;
1078    }
1079    case Intrinsic::vaend:    // va_end is a noop for the interpreter
1080      return;
1081    case Intrinsic::vacopy:   // va_copy: dest = src
1082      SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
1083      return;
1084    default:
1085      // If it is an unknown intrinsic function, use the intrinsic lowering
1086      // class to transform it into hopefully tasty LLVM code.
1087      //
1088      BasicBlock::iterator me(CS.getInstruction());
1089      BasicBlock *Parent = CS.getInstruction()->getParent();
1090      bool atBegin(Parent->begin() == me);
1091      if (!atBegin)
1092        --me;
1093      IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
1094
1095      // Restore the CurInst pointer to the first instruction newly inserted, if
1096      // any.
1097      if (atBegin) {
1098        SF.CurInst = Parent->begin();
1099      } else {
1100        SF.CurInst = me;
1101        ++SF.CurInst;
1102      }
1103      return;
1104    }
1105
1106
1107  SF.Caller = CS;
1108  std::vector<GenericValue> ArgVals;
1109  const unsigned NumArgs = SF.Caller.arg_size();
1110  ArgVals.reserve(NumArgs);
1111  uint16_t pNum = 1;
1112  for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
1113         e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
1114    Value *V = *i;
1115    ArgVals.push_back(getOperandValue(V, SF));
1116  }
1117
1118  // To handle indirect calls, we must get the pointer value from the argument
1119  // and treat it as a function pointer.
1120  GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
1121  callFunction((Function*)GVTOP(SRC), ArgVals);
1122}
1123
1124// auxiliary function for shift operations
1125static unsigned getShiftAmount(uint64_t orgShiftAmount,
1126                               llvm::APInt valueToShift) {
1127  unsigned valueWidth = valueToShift.getBitWidth();
1128  if (orgShiftAmount < (uint64_t)valueWidth)
1129    return orgShiftAmount;
1130  // according to the llvm documentation, if orgShiftAmount > valueWidth,
1131  // the result is undfeined. but we do shift by this rule:
1132  return (NextPowerOf2(valueWidth-1) - 1) & orgShiftAmount;
1133}
1134
1135
1136void Interpreter::visitShl(BinaryOperator &I) {
1137  ExecutionContext &SF = ECStack.back();
1138  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1139  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1140  GenericValue Dest;
1141  const Type *Ty = I.getType();
1142
1143  if (Ty->isVectorTy()) {
1144    uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1145    assert(src1Size == Src2.AggregateVal.size());
1146    for (unsigned i = 0; i < src1Size; i++) {
1147      GenericValue Result;
1148      uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1149      llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1150      Result.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1151      Dest.AggregateVal.push_back(Result);
1152    }
1153  } else {
1154    // scalar
1155    uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1156    llvm::APInt valueToShift = Src1.IntVal;
1157    Dest.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1158  }
1159
1160  SetValue(&I, Dest, SF);
1161}
1162
1163void Interpreter::visitLShr(BinaryOperator &I) {
1164  ExecutionContext &SF = ECStack.back();
1165  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1166  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1167  GenericValue Dest;
1168  const Type *Ty = I.getType();
1169
1170  if (Ty->isVectorTy()) {
1171    uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1172    assert(src1Size == Src2.AggregateVal.size());
1173    for (unsigned i = 0; i < src1Size; i++) {
1174      GenericValue Result;
1175      uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1176      llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1177      Result.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1178      Dest.AggregateVal.push_back(Result);
1179    }
1180  } else {
1181    // scalar
1182    uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1183    llvm::APInt valueToShift = Src1.IntVal;
1184    Dest.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1185  }
1186
1187  SetValue(&I, Dest, SF);
1188}
1189
1190void Interpreter::visitAShr(BinaryOperator &I) {
1191  ExecutionContext &SF = ECStack.back();
1192  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1193  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1194  GenericValue Dest;
1195  const Type *Ty = I.getType();
1196
1197  if (Ty->isVectorTy()) {
1198    size_t src1Size = Src1.AggregateVal.size();
1199    assert(src1Size == Src2.AggregateVal.size());
1200    for (unsigned i = 0; i < src1Size; i++) {
1201      GenericValue Result;
1202      uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1203      llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1204      Result.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1205      Dest.AggregateVal.push_back(Result);
1206    }
1207  } else {
1208    // scalar
1209    uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1210    llvm::APInt valueToShift = Src1.IntVal;
1211    Dest.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1212  }
1213
1214  SetValue(&I, Dest, SF);
1215}
1216
1217GenericValue Interpreter::executeTruncInst(Value *SrcVal, Type *DstTy,
1218                                           ExecutionContext &SF) {
1219  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1220  Type *SrcTy = SrcVal->getType();
1221  if (SrcTy->isVectorTy()) {
1222    Type *DstVecTy = DstTy->getScalarType();
1223    unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1224    unsigned NumElts = Src.AggregateVal.size();
1225    // the sizes of src and dst vectors must be equal
1226    Dest.AggregateVal.resize(NumElts);
1227    for (unsigned i = 0; i < NumElts; i++)
1228      Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.trunc(DBitWidth);
1229  } else {
1230    IntegerType *DITy = cast<IntegerType>(DstTy);
1231    unsigned DBitWidth = DITy->getBitWidth();
1232    Dest.IntVal = Src.IntVal.trunc(DBitWidth);
1233  }
1234  return Dest;
1235}
1236
1237GenericValue Interpreter::executeSExtInst(Value *SrcVal, Type *DstTy,
1238                                          ExecutionContext &SF) {
1239  const Type *SrcTy = SrcVal->getType();
1240  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1241  if (SrcTy->isVectorTy()) {
1242    const Type *DstVecTy = DstTy->getScalarType();
1243    unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1244    unsigned size = Src.AggregateVal.size();
1245    // the sizes of src and dst vectors must be equal.
1246    Dest.AggregateVal.resize(size);
1247    for (unsigned i = 0; i < size; i++)
1248      Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.sext(DBitWidth);
1249  } else {
1250    const IntegerType *DITy = cast<IntegerType>(DstTy);
1251    unsigned DBitWidth = DITy->getBitWidth();
1252    Dest.IntVal = Src.IntVal.sext(DBitWidth);
1253  }
1254  return Dest;
1255}
1256
1257GenericValue Interpreter::executeZExtInst(Value *SrcVal, Type *DstTy,
1258                                          ExecutionContext &SF) {
1259  const Type *SrcTy = SrcVal->getType();
1260  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1261  if (SrcTy->isVectorTy()) {
1262    const Type *DstVecTy = DstTy->getScalarType();
1263    unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1264
1265    unsigned size = Src.AggregateVal.size();
1266    // the sizes of src and dst vectors must be equal.
1267    Dest.AggregateVal.resize(size);
1268    for (unsigned i = 0; i < size; i++)
1269      Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.zext(DBitWidth);
1270  } else {
1271    const IntegerType *DITy = cast<IntegerType>(DstTy);
1272    unsigned DBitWidth = DITy->getBitWidth();
1273    Dest.IntVal = Src.IntVal.zext(DBitWidth);
1274  }
1275  return Dest;
1276}
1277
1278GenericValue Interpreter::executeFPTruncInst(Value *SrcVal, Type *DstTy,
1279                                             ExecutionContext &SF) {
1280  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1281
1282  if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1283    assert(SrcVal->getType()->getScalarType()->isDoubleTy() &&
1284           DstTy->getScalarType()->isFloatTy() &&
1285           "Invalid FPTrunc instruction");
1286
1287    unsigned size = Src.AggregateVal.size();
1288    // the sizes of src and dst vectors must be equal.
1289    Dest.AggregateVal.resize(size);
1290    for (unsigned i = 0; i < size; i++)
1291      Dest.AggregateVal[i].FloatVal = (float)Src.AggregateVal[i].DoubleVal;
1292  } else {
1293    assert(SrcVal->getType()->isDoubleTy() && DstTy->isFloatTy() &&
1294           "Invalid FPTrunc instruction");
1295    Dest.FloatVal = (float)Src.DoubleVal;
1296  }
1297
1298  return Dest;
1299}
1300
1301GenericValue Interpreter::executeFPExtInst(Value *SrcVal, Type *DstTy,
1302                                           ExecutionContext &SF) {
1303  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1304
1305  if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1306    assert(SrcVal->getType()->getScalarType()->isFloatTy() &&
1307           DstTy->getScalarType()->isDoubleTy() && "Invalid FPExt instruction");
1308
1309    unsigned size = Src.AggregateVal.size();
1310    // the sizes of src and dst vectors must be equal.
1311    Dest.AggregateVal.resize(size);
1312    for (unsigned i = 0; i < size; i++)
1313      Dest.AggregateVal[i].DoubleVal = (double)Src.AggregateVal[i].FloatVal;
1314  } else {
1315    assert(SrcVal->getType()->isFloatTy() && DstTy->isDoubleTy() &&
1316           "Invalid FPExt instruction");
1317    Dest.DoubleVal = (double)Src.FloatVal;
1318  }
1319
1320  return Dest;
1321}
1322
1323GenericValue Interpreter::executeFPToUIInst(Value *SrcVal, Type *DstTy,
1324                                            ExecutionContext &SF) {
1325  Type *SrcTy = SrcVal->getType();
1326  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1327
1328  if (SrcTy->getTypeID() == Type::VectorTyID) {
1329    const Type *DstVecTy = DstTy->getScalarType();
1330    const Type *SrcVecTy = SrcTy->getScalarType();
1331    uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1332    unsigned size = Src.AggregateVal.size();
1333    // the sizes of src and dst vectors must be equal.
1334    Dest.AggregateVal.resize(size);
1335
1336    if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1337      assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1338      for (unsigned i = 0; i < size; i++)
1339        Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1340            Src.AggregateVal[i].FloatVal, DBitWidth);
1341    } else {
1342      for (unsigned i = 0; i < size; i++)
1343        Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1344            Src.AggregateVal[i].DoubleVal, DBitWidth);
1345    }
1346  } else {
1347    // scalar
1348    uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1349    assert(SrcTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1350
1351    if (SrcTy->getTypeID() == Type::FloatTyID)
1352      Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1353    else {
1354      Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1355    }
1356  }
1357
1358  return Dest;
1359}
1360
1361GenericValue Interpreter::executeFPToSIInst(Value *SrcVal, Type *DstTy,
1362                                            ExecutionContext &SF) {
1363  Type *SrcTy = SrcVal->getType();
1364  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1365
1366  if (SrcTy->getTypeID() == Type::VectorTyID) {
1367    const Type *DstVecTy = DstTy->getScalarType();
1368    const Type *SrcVecTy = SrcTy->getScalarType();
1369    uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1370    unsigned size = Src.AggregateVal.size();
1371    // the sizes of src and dst vectors must be equal
1372    Dest.AggregateVal.resize(size);
1373
1374    if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1375      assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1376      for (unsigned i = 0; i < size; i++)
1377        Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1378            Src.AggregateVal[i].FloatVal, DBitWidth);
1379    } else {
1380      for (unsigned i = 0; i < size; i++)
1381        Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1382            Src.AggregateVal[i].DoubleVal, DBitWidth);
1383    }
1384  } else {
1385    // scalar
1386    unsigned DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1387    assert(SrcTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1388
1389    if (SrcTy->getTypeID() == Type::FloatTyID)
1390      Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1391    else {
1392      Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1393    }
1394  }
1395  return Dest;
1396}
1397
1398GenericValue Interpreter::executeUIToFPInst(Value *SrcVal, Type *DstTy,
1399                                            ExecutionContext &SF) {
1400  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1401
1402  if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1403    const Type *DstVecTy = DstTy->getScalarType();
1404    unsigned size = Src.AggregateVal.size();
1405    // the sizes of src and dst vectors must be equal
1406    Dest.AggregateVal.resize(size);
1407
1408    if (DstVecTy->getTypeID() == Type::FloatTyID) {
1409      assert(DstVecTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1410      for (unsigned i = 0; i < size; i++)
1411        Dest.AggregateVal[i].FloatVal =
1412            APIntOps::RoundAPIntToFloat(Src.AggregateVal[i].IntVal);
1413    } else {
1414      for (unsigned i = 0; i < size; i++)
1415        Dest.AggregateVal[i].DoubleVal =
1416            APIntOps::RoundAPIntToDouble(Src.AggregateVal[i].IntVal);
1417    }
1418  } else {
1419    // scalar
1420    assert(DstTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1421    if (DstTy->getTypeID() == Type::FloatTyID)
1422      Dest.FloatVal = APIntOps::RoundAPIntToFloat(Src.IntVal);
1423    else {
1424      Dest.DoubleVal = APIntOps::RoundAPIntToDouble(Src.IntVal);
1425    }
1426  }
1427  return Dest;
1428}
1429
1430GenericValue Interpreter::executeSIToFPInst(Value *SrcVal, Type *DstTy,
1431                                            ExecutionContext &SF) {
1432  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1433
1434  if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1435    const Type *DstVecTy = DstTy->getScalarType();
1436    unsigned size = Src.AggregateVal.size();
1437    // the sizes of src and dst vectors must be equal
1438    Dest.AggregateVal.resize(size);
1439
1440    if (DstVecTy->getTypeID() == Type::FloatTyID) {
1441      assert(DstVecTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1442      for (unsigned i = 0; i < size; i++)
1443        Dest.AggregateVal[i].FloatVal =
1444            APIntOps::RoundSignedAPIntToFloat(Src.AggregateVal[i].IntVal);
1445    } else {
1446      for (unsigned i = 0; i < size; i++)
1447        Dest.AggregateVal[i].DoubleVal =
1448            APIntOps::RoundSignedAPIntToDouble(Src.AggregateVal[i].IntVal);
1449    }
1450  } else {
1451    // scalar
1452    assert(DstTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1453
1454    if (DstTy->getTypeID() == Type::FloatTyID)
1455      Dest.FloatVal = APIntOps::RoundSignedAPIntToFloat(Src.IntVal);
1456    else {
1457      Dest.DoubleVal = APIntOps::RoundSignedAPIntToDouble(Src.IntVal);
1458    }
1459  }
1460
1461  return Dest;
1462}
1463
1464GenericValue Interpreter::executePtrToIntInst(Value *SrcVal, Type *DstTy,
1465                                              ExecutionContext &SF) {
1466  uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1467  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1468  assert(SrcVal->getType()->isPointerTy() && "Invalid PtrToInt instruction");
1469
1470  Dest.IntVal = APInt(DBitWidth, (intptr_t) Src.PointerVal);
1471  return Dest;
1472}
1473
1474GenericValue Interpreter::executeIntToPtrInst(Value *SrcVal, Type *DstTy,
1475                                              ExecutionContext &SF) {
1476  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1477  assert(DstTy->isPointerTy() && "Invalid PtrToInt instruction");
1478
1479  uint32_t PtrSize = TD.getPointerSizeInBits();
1480  if (PtrSize != Src.IntVal.getBitWidth())
1481    Src.IntVal = Src.IntVal.zextOrTrunc(PtrSize);
1482
1483  Dest.PointerVal = PointerTy(intptr_t(Src.IntVal.getZExtValue()));
1484  return Dest;
1485}
1486
1487GenericValue Interpreter::executeBitCastInst(Value *SrcVal, Type *DstTy,
1488                                             ExecutionContext &SF) {
1489
1490  // This instruction supports bitwise conversion of vectors to integers and
1491  // to vectors of other types (as long as they have the same size)
1492  Type *SrcTy = SrcVal->getType();
1493  GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1494
1495  if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1496      (DstTy->getTypeID() == Type::VectorTyID)) {
1497    // vector src bitcast to vector dst or vector src bitcast to scalar dst or
1498    // scalar src bitcast to vector dst
1499    bool isLittleEndian = TD.isLittleEndian();
1500    GenericValue TempDst, TempSrc, SrcVec;
1501    const Type *SrcElemTy;
1502    const Type *DstElemTy;
1503    unsigned SrcBitSize;
1504    unsigned DstBitSize;
1505    unsigned SrcNum;
1506    unsigned DstNum;
1507
1508    if (SrcTy->getTypeID() == Type::VectorTyID) {
1509      SrcElemTy = SrcTy->getScalarType();
1510      SrcBitSize = SrcTy->getScalarSizeInBits();
1511      SrcNum = Src.AggregateVal.size();
1512      SrcVec = Src;
1513    } else {
1514      // if src is scalar value, make it vector <1 x type>
1515      SrcElemTy = SrcTy;
1516      SrcBitSize = SrcTy->getPrimitiveSizeInBits();
1517      SrcNum = 1;
1518      SrcVec.AggregateVal.push_back(Src);
1519    }
1520
1521    if (DstTy->getTypeID() == Type::VectorTyID) {
1522      DstElemTy = DstTy->getScalarType();
1523      DstBitSize = DstTy->getScalarSizeInBits();
1524      DstNum = (SrcNum * SrcBitSize) / DstBitSize;
1525    } else {
1526      DstElemTy = DstTy;
1527      DstBitSize = DstTy->getPrimitiveSizeInBits();
1528      DstNum = 1;
1529    }
1530
1531    if (SrcNum * SrcBitSize != DstNum * DstBitSize)
1532      llvm_unreachable("Invalid BitCast");
1533
1534    // If src is floating point, cast to integer first.
1535    TempSrc.AggregateVal.resize(SrcNum);
1536    if (SrcElemTy->isFloatTy()) {
1537      for (unsigned i = 0; i < SrcNum; i++)
1538        TempSrc.AggregateVal[i].IntVal =
1539            APInt::floatToBits(SrcVec.AggregateVal[i].FloatVal);
1540
1541    } else if (SrcElemTy->isDoubleTy()) {
1542      for (unsigned i = 0; i < SrcNum; i++)
1543        TempSrc.AggregateVal[i].IntVal =
1544            APInt::doubleToBits(SrcVec.AggregateVal[i].DoubleVal);
1545    } else if (SrcElemTy->isIntegerTy()) {
1546      for (unsigned i = 0; i < SrcNum; i++)
1547        TempSrc.AggregateVal[i].IntVal = SrcVec.AggregateVal[i].IntVal;
1548    } else {
1549      // Pointers are not allowed as the element type of vector.
1550      llvm_unreachable("Invalid Bitcast");
1551    }
1552
1553    // now TempSrc is integer type vector
1554    if (DstNum < SrcNum) {
1555      // Example: bitcast <4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>
1556      unsigned Ratio = SrcNum / DstNum;
1557      unsigned SrcElt = 0;
1558      for (unsigned i = 0; i < DstNum; i++) {
1559        GenericValue Elt;
1560        Elt.IntVal = 0;
1561        Elt.IntVal = Elt.IntVal.zext(DstBitSize);
1562        unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize * (Ratio - 1);
1563        for (unsigned j = 0; j < Ratio; j++) {
1564          APInt Tmp;
1565          Tmp = Tmp.zext(SrcBitSize);
1566          Tmp = TempSrc.AggregateVal[SrcElt++].IntVal;
1567          Tmp = Tmp.zext(DstBitSize);
1568          Tmp = Tmp.shl(ShiftAmt);
1569          ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
1570          Elt.IntVal |= Tmp;
1571        }
1572        TempDst.AggregateVal.push_back(Elt);
1573      }
1574    } else {
1575      // Example: bitcast <2 x i64> <i64 0, i64 1> to <4 x i32>
1576      unsigned Ratio = DstNum / SrcNum;
1577      for (unsigned i = 0; i < SrcNum; i++) {
1578        unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize * (Ratio - 1);
1579        for (unsigned j = 0; j < Ratio; j++) {
1580          GenericValue Elt;
1581          Elt.IntVal = Elt.IntVal.zext(SrcBitSize);
1582          Elt.IntVal = TempSrc.AggregateVal[i].IntVal;
1583          Elt.IntVal = Elt.IntVal.lshr(ShiftAmt);
1584          // it could be DstBitSize == SrcBitSize, so check it
1585          if (DstBitSize < SrcBitSize)
1586            Elt.IntVal = Elt.IntVal.trunc(DstBitSize);
1587          ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
1588          TempDst.AggregateVal.push_back(Elt);
1589        }
1590      }
1591    }
1592
1593    // convert result from integer to specified type
1594    if (DstTy->getTypeID() == Type::VectorTyID) {
1595      if (DstElemTy->isDoubleTy()) {
1596        Dest.AggregateVal.resize(DstNum);
1597        for (unsigned i = 0; i < DstNum; i++)
1598          Dest.AggregateVal[i].DoubleVal =
1599              TempDst.AggregateVal[i].IntVal.bitsToDouble();
1600      } else if (DstElemTy->isFloatTy()) {
1601        Dest.AggregateVal.resize(DstNum);
1602        for (unsigned i = 0; i < DstNum; i++)
1603          Dest.AggregateVal[i].FloatVal =
1604              TempDst.AggregateVal[i].IntVal.bitsToFloat();
1605      } else {
1606        Dest = TempDst;
1607      }
1608    } else {
1609      if (DstElemTy->isDoubleTy())
1610        Dest.DoubleVal = TempDst.AggregateVal[0].IntVal.bitsToDouble();
1611      else if (DstElemTy->isFloatTy()) {
1612        Dest.FloatVal = TempDst.AggregateVal[0].IntVal.bitsToFloat();
1613      } else {
1614        Dest.IntVal = TempDst.AggregateVal[0].IntVal;
1615      }
1616    }
1617  } else { //  if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1618           //     (DstTy->getTypeID() == Type::VectorTyID))
1619
1620    // scalar src bitcast to scalar dst
1621    if (DstTy->isPointerTy()) {
1622      assert(SrcTy->isPointerTy() && "Invalid BitCast");
1623      Dest.PointerVal = Src.PointerVal;
1624    } else if (DstTy->isIntegerTy()) {
1625      if (SrcTy->isFloatTy())
1626        Dest.IntVal = APInt::floatToBits(Src.FloatVal);
1627      else if (SrcTy->isDoubleTy()) {
1628        Dest.IntVal = APInt::doubleToBits(Src.DoubleVal);
1629      } else if (SrcTy->isIntegerTy()) {
1630        Dest.IntVal = Src.IntVal;
1631      } else {
1632        llvm_unreachable("Invalid BitCast");
1633      }
1634    } else if (DstTy->isFloatTy()) {
1635      if (SrcTy->isIntegerTy())
1636        Dest.FloatVal = Src.IntVal.bitsToFloat();
1637      else {
1638        Dest.FloatVal = Src.FloatVal;
1639      }
1640    } else if (DstTy->isDoubleTy()) {
1641      if (SrcTy->isIntegerTy())
1642        Dest.DoubleVal = Src.IntVal.bitsToDouble();
1643      else {
1644        Dest.DoubleVal = Src.DoubleVal;
1645      }
1646    } else {
1647      llvm_unreachable("Invalid Bitcast");
1648    }
1649  }
1650
1651  return Dest;
1652}
1653
1654void Interpreter::visitTruncInst(TruncInst &I) {
1655  ExecutionContext &SF = ECStack.back();
1656  SetValue(&I, executeTruncInst(I.getOperand(0), I.getType(), SF), SF);
1657}
1658
1659void Interpreter::visitSExtInst(SExtInst &I) {
1660  ExecutionContext &SF = ECStack.back();
1661  SetValue(&I, executeSExtInst(I.getOperand(0), I.getType(), SF), SF);
1662}
1663
1664void Interpreter::visitZExtInst(ZExtInst &I) {
1665  ExecutionContext &SF = ECStack.back();
1666  SetValue(&I, executeZExtInst(I.getOperand(0), I.getType(), SF), SF);
1667}
1668
1669void Interpreter::visitFPTruncInst(FPTruncInst &I) {
1670  ExecutionContext &SF = ECStack.back();
1671  SetValue(&I, executeFPTruncInst(I.getOperand(0), I.getType(), SF), SF);
1672}
1673
1674void Interpreter::visitFPExtInst(FPExtInst &I) {
1675  ExecutionContext &SF = ECStack.back();
1676  SetValue(&I, executeFPExtInst(I.getOperand(0), I.getType(), SF), SF);
1677}
1678
1679void Interpreter::visitUIToFPInst(UIToFPInst &I) {
1680  ExecutionContext &SF = ECStack.back();
1681  SetValue(&I, executeUIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1682}
1683
1684void Interpreter::visitSIToFPInst(SIToFPInst &I) {
1685  ExecutionContext &SF = ECStack.back();
1686  SetValue(&I, executeSIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1687}
1688
1689void Interpreter::visitFPToUIInst(FPToUIInst &I) {
1690  ExecutionContext &SF = ECStack.back();
1691  SetValue(&I, executeFPToUIInst(I.getOperand(0), I.getType(), SF), SF);
1692}
1693
1694void Interpreter::visitFPToSIInst(FPToSIInst &I) {
1695  ExecutionContext &SF = ECStack.back();
1696  SetValue(&I, executeFPToSIInst(I.getOperand(0), I.getType(), SF), SF);
1697}
1698
1699void Interpreter::visitPtrToIntInst(PtrToIntInst &I) {
1700  ExecutionContext &SF = ECStack.back();
1701  SetValue(&I, executePtrToIntInst(I.getOperand(0), I.getType(), SF), SF);
1702}
1703
1704void Interpreter::visitIntToPtrInst(IntToPtrInst &I) {
1705  ExecutionContext &SF = ECStack.back();
1706  SetValue(&I, executeIntToPtrInst(I.getOperand(0), I.getType(), SF), SF);
1707}
1708
1709void Interpreter::visitBitCastInst(BitCastInst &I) {
1710  ExecutionContext &SF = ECStack.back();
1711  SetValue(&I, executeBitCastInst(I.getOperand(0), I.getType(), SF), SF);
1712}
1713
1714#define IMPLEMENT_VAARG(TY) \
1715   case Type::TY##TyID: Dest.TY##Val = Src.TY##Val; break
1716
1717void Interpreter::visitVAArgInst(VAArgInst &I) {
1718  ExecutionContext &SF = ECStack.back();
1719
1720  // Get the incoming valist parameter.  LLI treats the valist as a
1721  // (ec-stack-depth var-arg-index) pair.
1722  GenericValue VAList = getOperandValue(I.getOperand(0), SF);
1723  GenericValue Dest;
1724  GenericValue Src = ECStack[VAList.UIntPairVal.first]
1725                      .VarArgs[VAList.UIntPairVal.second];
1726  Type *Ty = I.getType();
1727  switch (Ty->getTypeID()) {
1728  case Type::IntegerTyID:
1729    Dest.IntVal = Src.IntVal;
1730    break;
1731  IMPLEMENT_VAARG(Pointer);
1732  IMPLEMENT_VAARG(Float);
1733  IMPLEMENT_VAARG(Double);
1734  default:
1735    dbgs() << "Unhandled dest type for vaarg instruction: " << *Ty << "\n";
1736    llvm_unreachable(nullptr);
1737  }
1738
1739  // Set the Value of this Instruction.
1740  SetValue(&I, Dest, SF);
1741
1742  // Move the pointer to the next vararg.
1743  ++VAList.UIntPairVal.second;
1744}
1745
1746void Interpreter::visitExtractElementInst(ExtractElementInst &I) {
1747  ExecutionContext &SF = ECStack.back();
1748  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1749  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1750  GenericValue Dest;
1751
1752  Type *Ty = I.getType();
1753  const unsigned indx = unsigned(Src2.IntVal.getZExtValue());
1754
1755  if(Src1.AggregateVal.size() > indx) {
1756    switch (Ty->getTypeID()) {
1757    default:
1758      dbgs() << "Unhandled destination type for extractelement instruction: "
1759      << *Ty << "\n";
1760      llvm_unreachable(nullptr);
1761      break;
1762    case Type::IntegerTyID:
1763      Dest.IntVal = Src1.AggregateVal[indx].IntVal;
1764      break;
1765    case Type::FloatTyID:
1766      Dest.FloatVal = Src1.AggregateVal[indx].FloatVal;
1767      break;
1768    case Type::DoubleTyID:
1769      Dest.DoubleVal = Src1.AggregateVal[indx].DoubleVal;
1770      break;
1771    }
1772  } else {
1773    dbgs() << "Invalid index in extractelement instruction\n";
1774  }
1775
1776  SetValue(&I, Dest, SF);
1777}
1778
1779void Interpreter::visitInsertElementInst(InsertElementInst &I) {
1780  ExecutionContext &SF = ECStack.back();
1781  Type *Ty = I.getType();
1782
1783  if(!(Ty->isVectorTy()) )
1784    llvm_unreachable("Unhandled dest type for insertelement instruction");
1785
1786  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1787  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1788  GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1789  GenericValue Dest;
1790
1791  Type *TyContained = Ty->getContainedType(0);
1792
1793  const unsigned indx = unsigned(Src3.IntVal.getZExtValue());
1794  Dest.AggregateVal = Src1.AggregateVal;
1795
1796  if(Src1.AggregateVal.size() <= indx)
1797      llvm_unreachable("Invalid index in insertelement instruction");
1798  switch (TyContained->getTypeID()) {
1799    default:
1800      llvm_unreachable("Unhandled dest type for insertelement instruction");
1801    case Type::IntegerTyID:
1802      Dest.AggregateVal[indx].IntVal = Src2.IntVal;
1803      break;
1804    case Type::FloatTyID:
1805      Dest.AggregateVal[indx].FloatVal = Src2.FloatVal;
1806      break;
1807    case Type::DoubleTyID:
1808      Dest.AggregateVal[indx].DoubleVal = Src2.DoubleVal;
1809      break;
1810  }
1811  SetValue(&I, Dest, SF);
1812}
1813
1814void Interpreter::visitShuffleVectorInst(ShuffleVectorInst &I){
1815  ExecutionContext &SF = ECStack.back();
1816
1817  Type *Ty = I.getType();
1818  if(!(Ty->isVectorTy()))
1819    llvm_unreachable("Unhandled dest type for shufflevector instruction");
1820
1821  GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1822  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1823  GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1824  GenericValue Dest;
1825
1826  // There is no need to check types of src1 and src2, because the compiled
1827  // bytecode can't contain different types for src1 and src2 for a
1828  // shufflevector instruction.
1829
1830  Type *TyContained = Ty->getContainedType(0);
1831  unsigned src1Size = (unsigned)Src1.AggregateVal.size();
1832  unsigned src2Size = (unsigned)Src2.AggregateVal.size();
1833  unsigned src3Size = (unsigned)Src3.AggregateVal.size();
1834
1835  Dest.AggregateVal.resize(src3Size);
1836
1837  switch (TyContained->getTypeID()) {
1838    default:
1839      llvm_unreachable("Unhandled dest type for insertelement instruction");
1840      break;
1841    case Type::IntegerTyID:
1842      for( unsigned i=0; i<src3Size; i++) {
1843        unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1844        if(j < src1Size)
1845          Dest.AggregateVal[i].IntVal = Src1.AggregateVal[j].IntVal;
1846        else if(j < src1Size + src2Size)
1847          Dest.AggregateVal[i].IntVal = Src2.AggregateVal[j-src1Size].IntVal;
1848        else
1849          // The selector may not be greater than sum of lengths of first and
1850          // second operands and llasm should not allow situation like
1851          // %tmp = shufflevector <2 x i32> <i32 3, i32 4>, <2 x i32> undef,
1852          //                      <2 x i32> < i32 0, i32 5 >,
1853          // where i32 5 is invalid, but let it be additional check here:
1854          llvm_unreachable("Invalid mask in shufflevector instruction");
1855      }
1856      break;
1857    case Type::FloatTyID:
1858      for( unsigned i=0; i<src3Size; i++) {
1859        unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1860        if(j < src1Size)
1861          Dest.AggregateVal[i].FloatVal = Src1.AggregateVal[j].FloatVal;
1862        else if(j < src1Size + src2Size)
1863          Dest.AggregateVal[i].FloatVal = Src2.AggregateVal[j-src1Size].FloatVal;
1864        else
1865          llvm_unreachable("Invalid mask in shufflevector instruction");
1866        }
1867      break;
1868    case Type::DoubleTyID:
1869      for( unsigned i=0; i<src3Size; i++) {
1870        unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1871        if(j < src1Size)
1872          Dest.AggregateVal[i].DoubleVal = Src1.AggregateVal[j].DoubleVal;
1873        else if(j < src1Size + src2Size)
1874          Dest.AggregateVal[i].DoubleVal =
1875            Src2.AggregateVal[j-src1Size].DoubleVal;
1876        else
1877          llvm_unreachable("Invalid mask in shufflevector instruction");
1878      }
1879      break;
1880  }
1881  SetValue(&I, Dest, SF);
1882}
1883
1884void Interpreter::visitExtractValueInst(ExtractValueInst &I) {
1885  ExecutionContext &SF = ECStack.back();
1886  Value *Agg = I.getAggregateOperand();
1887  GenericValue Dest;
1888  GenericValue Src = getOperandValue(Agg, SF);
1889
1890  ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1891  unsigned Num = I.getNumIndices();
1892  GenericValue *pSrc = &Src;
1893
1894  for (unsigned i = 0 ; i < Num; ++i) {
1895    pSrc = &pSrc->AggregateVal[*IdxBegin];
1896    ++IdxBegin;
1897  }
1898
1899  Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1900  switch (IndexedType->getTypeID()) {
1901    default:
1902      llvm_unreachable("Unhandled dest type for extractelement instruction");
1903    break;
1904    case Type::IntegerTyID:
1905      Dest.IntVal = pSrc->IntVal;
1906    break;
1907    case Type::FloatTyID:
1908      Dest.FloatVal = pSrc->FloatVal;
1909    break;
1910    case Type::DoubleTyID:
1911      Dest.DoubleVal = pSrc->DoubleVal;
1912    break;
1913    case Type::ArrayTyID:
1914    case Type::StructTyID:
1915    case Type::VectorTyID:
1916      Dest.AggregateVal = pSrc->AggregateVal;
1917    break;
1918    case Type::PointerTyID:
1919      Dest.PointerVal = pSrc->PointerVal;
1920    break;
1921  }
1922
1923  SetValue(&I, Dest, SF);
1924}
1925
1926void Interpreter::visitInsertValueInst(InsertValueInst &I) {
1927
1928  ExecutionContext &SF = ECStack.back();
1929  Value *Agg = I.getAggregateOperand();
1930
1931  GenericValue Src1 = getOperandValue(Agg, SF);
1932  GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1933  GenericValue Dest = Src1; // Dest is a slightly changed Src1
1934
1935  ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1936  unsigned Num = I.getNumIndices();
1937
1938  GenericValue *pDest = &Dest;
1939  for (unsigned i = 0 ; i < Num; ++i) {
1940    pDest = &pDest->AggregateVal[*IdxBegin];
1941    ++IdxBegin;
1942  }
1943  // pDest points to the target value in the Dest now
1944
1945  Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1946
1947  switch (IndexedType->getTypeID()) {
1948    default:
1949      llvm_unreachable("Unhandled dest type for insertelement instruction");
1950    break;
1951    case Type::IntegerTyID:
1952      pDest->IntVal = Src2.IntVal;
1953    break;
1954    case Type::FloatTyID:
1955      pDest->FloatVal = Src2.FloatVal;
1956    break;
1957    case Type::DoubleTyID:
1958      pDest->DoubleVal = Src2.DoubleVal;
1959    break;
1960    case Type::ArrayTyID:
1961    case Type::StructTyID:
1962    case Type::VectorTyID:
1963      pDest->AggregateVal = Src2.AggregateVal;
1964    break;
1965    case Type::PointerTyID:
1966      pDest->PointerVal = Src2.PointerVal;
1967    break;
1968  }
1969
1970  SetValue(&I, Dest, SF);
1971}
1972
1973GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
1974                                                ExecutionContext &SF) {
1975  switch (CE->getOpcode()) {
1976  case Instruction::Trunc:
1977      return executeTruncInst(CE->getOperand(0), CE->getType(), SF);
1978  case Instruction::ZExt:
1979      return executeZExtInst(CE->getOperand(0), CE->getType(), SF);
1980  case Instruction::SExt:
1981      return executeSExtInst(CE->getOperand(0), CE->getType(), SF);
1982  case Instruction::FPTrunc:
1983      return executeFPTruncInst(CE->getOperand(0), CE->getType(), SF);
1984  case Instruction::FPExt:
1985      return executeFPExtInst(CE->getOperand(0), CE->getType(), SF);
1986  case Instruction::UIToFP:
1987      return executeUIToFPInst(CE->getOperand(0), CE->getType(), SF);
1988  case Instruction::SIToFP:
1989      return executeSIToFPInst(CE->getOperand(0), CE->getType(), SF);
1990  case Instruction::FPToUI:
1991      return executeFPToUIInst(CE->getOperand(0), CE->getType(), SF);
1992  case Instruction::FPToSI:
1993      return executeFPToSIInst(CE->getOperand(0), CE->getType(), SF);
1994  case Instruction::PtrToInt:
1995      return executePtrToIntInst(CE->getOperand(0), CE->getType(), SF);
1996  case Instruction::IntToPtr:
1997      return executeIntToPtrInst(CE->getOperand(0), CE->getType(), SF);
1998  case Instruction::BitCast:
1999      return executeBitCastInst(CE->getOperand(0), CE->getType(), SF);
2000  case Instruction::GetElementPtr:
2001    return executeGEPOperation(CE->getOperand(0), gep_type_begin(CE),
2002                               gep_type_end(CE), SF);
2003  case Instruction::FCmp:
2004  case Instruction::ICmp:
2005    return executeCmpInst(CE->getPredicate(),
2006                          getOperandValue(CE->getOperand(0), SF),
2007                          getOperandValue(CE->getOperand(1), SF),
2008                          CE->getOperand(0)->getType());
2009  case Instruction::Select:
2010    return executeSelectInst(getOperandValue(CE->getOperand(0), SF),
2011                             getOperandValue(CE->getOperand(1), SF),
2012                             getOperandValue(CE->getOperand(2), SF),
2013                             CE->getOperand(0)->getType());
2014  default :
2015    break;
2016  }
2017
2018  // The cases below here require a GenericValue parameter for the result
2019  // so we initialize one, compute it and then return it.
2020  GenericValue Op0 = getOperandValue(CE->getOperand(0), SF);
2021  GenericValue Op1 = getOperandValue(CE->getOperand(1), SF);
2022  GenericValue Dest;
2023  Type * Ty = CE->getOperand(0)->getType();
2024  switch (CE->getOpcode()) {
2025  case Instruction::Add:  Dest.IntVal = Op0.IntVal + Op1.IntVal; break;
2026  case Instruction::Sub:  Dest.IntVal = Op0.IntVal - Op1.IntVal; break;
2027  case Instruction::Mul:  Dest.IntVal = Op0.IntVal * Op1.IntVal; break;
2028  case Instruction::FAdd: executeFAddInst(Dest, Op0, Op1, Ty); break;
2029  case Instruction::FSub: executeFSubInst(Dest, Op0, Op1, Ty); break;
2030  case Instruction::FMul: executeFMulInst(Dest, Op0, Op1, Ty); break;
2031  case Instruction::FDiv: executeFDivInst(Dest, Op0, Op1, Ty); break;
2032  case Instruction::FRem: executeFRemInst(Dest, Op0, Op1, Ty); break;
2033  case Instruction::SDiv: Dest.IntVal = Op0.IntVal.sdiv(Op1.IntVal); break;
2034  case Instruction::UDiv: Dest.IntVal = Op0.IntVal.udiv(Op1.IntVal); break;
2035  case Instruction::URem: Dest.IntVal = Op0.IntVal.urem(Op1.IntVal); break;
2036  case Instruction::SRem: Dest.IntVal = Op0.IntVal.srem(Op1.IntVal); break;
2037  case Instruction::And:  Dest.IntVal = Op0.IntVal & Op1.IntVal; break;
2038  case Instruction::Or:   Dest.IntVal = Op0.IntVal | Op1.IntVal; break;
2039  case Instruction::Xor:  Dest.IntVal = Op0.IntVal ^ Op1.IntVal; break;
2040  case Instruction::Shl:
2041    Dest.IntVal = Op0.IntVal.shl(Op1.IntVal.getZExtValue());
2042    break;
2043  case Instruction::LShr:
2044    Dest.IntVal = Op0.IntVal.lshr(Op1.IntVal.getZExtValue());
2045    break;
2046  case Instruction::AShr:
2047    Dest.IntVal = Op0.IntVal.ashr(Op1.IntVal.getZExtValue());
2048    break;
2049  default:
2050    dbgs() << "Unhandled ConstantExpr: " << *CE << "\n";
2051    llvm_unreachable("Unhandled ConstantExpr");
2052  }
2053  return Dest;
2054}
2055
2056GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
2057  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
2058    return getConstantExprValue(CE, SF);
2059  } else if (Constant *CPV = dyn_cast<Constant>(V)) {
2060    return getConstantValue(CPV);
2061  } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
2062    return PTOGV(getPointerToGlobal(GV));
2063  } else {
2064    return SF.Values[V];
2065  }
2066}
2067
2068//===----------------------------------------------------------------------===//
2069//                        Dispatch and Execution Code
2070//===----------------------------------------------------------------------===//
2071
2072//===----------------------------------------------------------------------===//
2073// callFunction - Execute the specified function...
2074//
2075void Interpreter::callFunction(Function *F,
2076                               const std::vector<GenericValue> &ArgVals) {
2077  assert((ECStack.empty() || !ECStack.back().Caller.getInstruction() ||
2078          ECStack.back().Caller.arg_size() == ArgVals.size()) &&
2079         "Incorrect number of arguments passed into function call!");
2080  // Make a new stack frame... and fill it in.
2081  ECStack.push_back(ExecutionContext());
2082  ExecutionContext &StackFrame = ECStack.back();
2083  StackFrame.CurFunction = F;
2084
2085  // Special handling for external functions.
2086  if (F->isDeclaration()) {
2087    GenericValue Result = callExternalFunction (F, ArgVals);
2088    // Simulate a 'ret' instruction of the appropriate type.
2089    popStackAndReturnValueToCaller (F->getReturnType (), Result);
2090    return;
2091  }
2092
2093  // Get pointers to first LLVM BB & Instruction in function.
2094  StackFrame.CurBB     = F->begin();
2095  StackFrame.CurInst   = StackFrame.CurBB->begin();
2096
2097  // Run through the function arguments and initialize their values...
2098  assert((ArgVals.size() == F->arg_size() ||
2099         (ArgVals.size() > F->arg_size() && F->getFunctionType()->isVarArg()))&&
2100         "Invalid number of values passed to function invocation!");
2101
2102  // Handle non-varargs arguments...
2103  unsigned i = 0;
2104  for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
2105       AI != E; ++AI, ++i)
2106    SetValue(AI, ArgVals[i], StackFrame);
2107
2108  // Handle varargs arguments...
2109  StackFrame.VarArgs.assign(ArgVals.begin()+i, ArgVals.end());
2110}
2111
2112
2113void Interpreter::run() {
2114  while (!ECStack.empty()) {
2115    // Interpret a single instruction & increment the "PC".
2116    ExecutionContext &SF = ECStack.back();  // Current stack frame
2117    Instruction &I = *SF.CurInst++;         // Increment before execute
2118
2119    // Track the number of dynamic instructions executed.
2120    ++NumDynamicInsts;
2121
2122    DEBUG(dbgs() << "About to interpret: " << I);
2123    visit(I);   // Dispatch to one of the visit* methods...
2124#if 0
2125    // This is not safe, as visiting the instruction could lower it and free I.
2126DEBUG(
2127    if (!isa<CallInst>(I) && !isa<InvokeInst>(I) &&
2128        I.getType() != Type::VoidTy) {
2129      dbgs() << "  --> ";
2130      const GenericValue &Val = SF.Values[&I];
2131      switch (I.getType()->getTypeID()) {
2132      default: llvm_unreachable("Invalid GenericValue Type");
2133      case Type::VoidTyID:    dbgs() << "void"; break;
2134      case Type::FloatTyID:   dbgs() << "float " << Val.FloatVal; break;
2135      case Type::DoubleTyID:  dbgs() << "double " << Val.DoubleVal; break;
2136      case Type::PointerTyID: dbgs() << "void* " << intptr_t(Val.PointerVal);
2137        break;
2138      case Type::IntegerTyID:
2139        dbgs() << "i" << Val.IntVal.getBitWidth() << " "
2140               << Val.IntVal.toStringUnsigned(10)
2141               << " (0x" << Val.IntVal.toStringUnsigned(16) << ")\n";
2142        break;
2143      }
2144    });
2145#endif
2146  }
2147}
2148