xref: /llvm-project/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp (revision ce49e2231bb6096f2a859b939243efdec85c1ca1)
1 //===-- Execution.cpp - Implement code to simulate the program ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file contains the actual instruction interpreter.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "Interpreter.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/Statistic.h"
16 #include "llvm/CodeGen/IntrinsicLowering.h"
17 #include "llvm/IR/Constants.h"
18 #include "llvm/IR/DerivedTypes.h"
19 #include "llvm/IR/GetElementPtrTypeIterator.h"
20 #include "llvm/IR/Instructions.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/Debug.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/Support/raw_ostream.h"
26 #include <algorithm>
27 #include <cmath>
28 using namespace llvm;
29 
30 #define DEBUG_TYPE "interpreter"
31 
32 STATISTIC(NumDynamicInsts, "Number of dynamic instructions executed");
33 
34 static cl::opt<bool> PrintVolatile("interpreter-print-volatile", cl::Hidden,
35           cl::desc("make the interpreter print every volatile load and store"));
36 
37 //===----------------------------------------------------------------------===//
38 //                     Various Helper Functions
39 //===----------------------------------------------------------------------===//
40 
41 static void SetValue(Value *V, GenericValue Val, ExecutionContext &SF) {
42   SF.Values[V] = Val;
43 }
44 
45 //===----------------------------------------------------------------------===//
46 //                    Unary Instruction Implementations
47 //===----------------------------------------------------------------------===//
48 
49 static void executeFNegInst(GenericValue &Dest, GenericValue Src, Type *Ty) {
50   switch (Ty->getTypeID()) {
51   case Type::FloatTyID:
52     Dest.FloatVal = -Src.FloatVal;
53   case Type::DoubleTyID:
54     Dest.DoubleVal = -Src.DoubleVal;
55   default:
56     llvm_unreachable("Unhandled type for FNeg instruction");
57   }
58 }
59 
60 void Interpreter::visitUnaryOperator(UnaryOperator &I) {
61   ExecutionContext &SF = ECStack.back();
62   Type *Ty = I.getOperand(0)->getType();
63   GenericValue Src = getOperandValue(I.getOperand(0), SF);
64   GenericValue R; // Result
65 
66   // First process vector operation
67   if (Ty->isVectorTy()) {
68     R.AggregateVal.resize(Src.AggregateVal.size());
69 
70     switch(I.getOpcode()) {
71     default:
72       llvm_unreachable("Don't know how to handle this unary operator");
73       break;
74     case Instruction::FNeg:
75       if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
76         for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
77           R.AggregateVal[i].FloatVal = -Src.AggregateVal[i].FloatVal;
78       } else if (cast<VectorType>(Ty)->getElementType()->isDoubleTy()) {
79         for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
80           R.AggregateVal[i].DoubleVal = -Src.AggregateVal[i].DoubleVal;
81       } else {
82         llvm_unreachable("Unhandled type for FNeg instruction");
83       }
84       break;
85     }
86   } else {
87     switch (I.getOpcode()) {
88     default:
89       llvm_unreachable("Don't know how to handle this unary operator");
90       break;
91     case Instruction::FNeg: executeFNegInst(R, Src, Ty); break;
92     }
93   }
94   SetValue(&I, R, SF);
95 }
96 
97 //===----------------------------------------------------------------------===//
98 //                    Binary Instruction Implementations
99 //===----------------------------------------------------------------------===//
100 
101 #define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
102    case Type::TY##TyID: \
103      Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; \
104      break
105 
106 static void executeFAddInst(GenericValue &Dest, GenericValue Src1,
107                             GenericValue Src2, Type *Ty) {
108   switch (Ty->getTypeID()) {
109     IMPLEMENT_BINARY_OPERATOR(+, Float);
110     IMPLEMENT_BINARY_OPERATOR(+, Double);
111   default:
112     dbgs() << "Unhandled type for FAdd instruction: " << *Ty << "\n";
113     llvm_unreachable(nullptr);
114   }
115 }
116 
117 static void executeFSubInst(GenericValue &Dest, GenericValue Src1,
118                             GenericValue Src2, Type *Ty) {
119   switch (Ty->getTypeID()) {
120     IMPLEMENT_BINARY_OPERATOR(-, Float);
121     IMPLEMENT_BINARY_OPERATOR(-, Double);
122   default:
123     dbgs() << "Unhandled type for FSub instruction: " << *Ty << "\n";
124     llvm_unreachable(nullptr);
125   }
126 }
127 
128 static void executeFMulInst(GenericValue &Dest, GenericValue Src1,
129                             GenericValue Src2, Type *Ty) {
130   switch (Ty->getTypeID()) {
131     IMPLEMENT_BINARY_OPERATOR(*, Float);
132     IMPLEMENT_BINARY_OPERATOR(*, Double);
133   default:
134     dbgs() << "Unhandled type for FMul instruction: " << *Ty << "\n";
135     llvm_unreachable(nullptr);
136   }
137 }
138 
139 static void executeFDivInst(GenericValue &Dest, GenericValue Src1,
140                             GenericValue Src2, Type *Ty) {
141   switch (Ty->getTypeID()) {
142     IMPLEMENT_BINARY_OPERATOR(/, Float);
143     IMPLEMENT_BINARY_OPERATOR(/, Double);
144   default:
145     dbgs() << "Unhandled type for FDiv instruction: " << *Ty << "\n";
146     llvm_unreachable(nullptr);
147   }
148 }
149 
150 static void executeFRemInst(GenericValue &Dest, GenericValue Src1,
151                             GenericValue Src2, Type *Ty) {
152   switch (Ty->getTypeID()) {
153   case Type::FloatTyID:
154     Dest.FloatVal = fmod(Src1.FloatVal, Src2.FloatVal);
155     break;
156   case Type::DoubleTyID:
157     Dest.DoubleVal = fmod(Src1.DoubleVal, Src2.DoubleVal);
158     break;
159   default:
160     dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
161     llvm_unreachable(nullptr);
162   }
163 }
164 
165 #define IMPLEMENT_INTEGER_ICMP(OP, TY) \
166    case Type::IntegerTyID:  \
167       Dest.IntVal = APInt(1,Src1.IntVal.OP(Src2.IntVal)); \
168       break;
169 
170 #define IMPLEMENT_VECTOR_INTEGER_ICMP(OP, TY)                        \
171   case Type::VectorTyID: {                                           \
172     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());    \
173     Dest.AggregateVal.resize( Src1.AggregateVal.size() );            \
174     for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)             \
175       Dest.AggregateVal[_i].IntVal = APInt(1,                        \
176       Src1.AggregateVal[_i].IntVal.OP(Src2.AggregateVal[_i].IntVal));\
177   } break;
178 
179 // Handle pointers specially because they must be compared with only as much
180 // width as the host has.  We _do not_ want to be comparing 64 bit values when
181 // running on a 32-bit target, otherwise the upper 32 bits might mess up
182 // comparisons if they contain garbage.
183 #define IMPLEMENT_POINTER_ICMP(OP) \
184    case Type::PointerTyID: \
185       Dest.IntVal = APInt(1,(void*)(intptr_t)Src1.PointerVal OP \
186                             (void*)(intptr_t)Src2.PointerVal); \
187       break;
188 
189 static GenericValue executeICMP_EQ(GenericValue Src1, GenericValue Src2,
190                                    Type *Ty) {
191   GenericValue Dest;
192   switch (Ty->getTypeID()) {
193     IMPLEMENT_INTEGER_ICMP(eq,Ty);
194     IMPLEMENT_VECTOR_INTEGER_ICMP(eq,Ty);
195     IMPLEMENT_POINTER_ICMP(==);
196   default:
197     dbgs() << "Unhandled type for ICMP_EQ predicate: " << *Ty << "\n";
198     llvm_unreachable(nullptr);
199   }
200   return Dest;
201 }
202 
203 static GenericValue executeICMP_NE(GenericValue Src1, GenericValue Src2,
204                                    Type *Ty) {
205   GenericValue Dest;
206   switch (Ty->getTypeID()) {
207     IMPLEMENT_INTEGER_ICMP(ne,Ty);
208     IMPLEMENT_VECTOR_INTEGER_ICMP(ne,Ty);
209     IMPLEMENT_POINTER_ICMP(!=);
210   default:
211     dbgs() << "Unhandled type for ICMP_NE predicate: " << *Ty << "\n";
212     llvm_unreachable(nullptr);
213   }
214   return Dest;
215 }
216 
217 static GenericValue executeICMP_ULT(GenericValue Src1, GenericValue Src2,
218                                     Type *Ty) {
219   GenericValue Dest;
220   switch (Ty->getTypeID()) {
221     IMPLEMENT_INTEGER_ICMP(ult,Ty);
222     IMPLEMENT_VECTOR_INTEGER_ICMP(ult,Ty);
223     IMPLEMENT_POINTER_ICMP(<);
224   default:
225     dbgs() << "Unhandled type for ICMP_ULT predicate: " << *Ty << "\n";
226     llvm_unreachable(nullptr);
227   }
228   return Dest;
229 }
230 
231 static GenericValue executeICMP_SLT(GenericValue Src1, GenericValue Src2,
232                                     Type *Ty) {
233   GenericValue Dest;
234   switch (Ty->getTypeID()) {
235     IMPLEMENT_INTEGER_ICMP(slt,Ty);
236     IMPLEMENT_VECTOR_INTEGER_ICMP(slt,Ty);
237     IMPLEMENT_POINTER_ICMP(<);
238   default:
239     dbgs() << "Unhandled type for ICMP_SLT predicate: " << *Ty << "\n";
240     llvm_unreachable(nullptr);
241   }
242   return Dest;
243 }
244 
245 static GenericValue executeICMP_UGT(GenericValue Src1, GenericValue Src2,
246                                     Type *Ty) {
247   GenericValue Dest;
248   switch (Ty->getTypeID()) {
249     IMPLEMENT_INTEGER_ICMP(ugt,Ty);
250     IMPLEMENT_VECTOR_INTEGER_ICMP(ugt,Ty);
251     IMPLEMENT_POINTER_ICMP(>);
252   default:
253     dbgs() << "Unhandled type for ICMP_UGT predicate: " << *Ty << "\n";
254     llvm_unreachable(nullptr);
255   }
256   return Dest;
257 }
258 
259 static GenericValue executeICMP_SGT(GenericValue Src1, GenericValue Src2,
260                                     Type *Ty) {
261   GenericValue Dest;
262   switch (Ty->getTypeID()) {
263     IMPLEMENT_INTEGER_ICMP(sgt,Ty);
264     IMPLEMENT_VECTOR_INTEGER_ICMP(sgt,Ty);
265     IMPLEMENT_POINTER_ICMP(>);
266   default:
267     dbgs() << "Unhandled type for ICMP_SGT predicate: " << *Ty << "\n";
268     llvm_unreachable(nullptr);
269   }
270   return Dest;
271 }
272 
273 static GenericValue executeICMP_ULE(GenericValue Src1, GenericValue Src2,
274                                     Type *Ty) {
275   GenericValue Dest;
276   switch (Ty->getTypeID()) {
277     IMPLEMENT_INTEGER_ICMP(ule,Ty);
278     IMPLEMENT_VECTOR_INTEGER_ICMP(ule,Ty);
279     IMPLEMENT_POINTER_ICMP(<=);
280   default:
281     dbgs() << "Unhandled type for ICMP_ULE predicate: " << *Ty << "\n";
282     llvm_unreachable(nullptr);
283   }
284   return Dest;
285 }
286 
287 static GenericValue executeICMP_SLE(GenericValue Src1, GenericValue Src2,
288                                     Type *Ty) {
289   GenericValue Dest;
290   switch (Ty->getTypeID()) {
291     IMPLEMENT_INTEGER_ICMP(sle,Ty);
292     IMPLEMENT_VECTOR_INTEGER_ICMP(sle,Ty);
293     IMPLEMENT_POINTER_ICMP(<=);
294   default:
295     dbgs() << "Unhandled type for ICMP_SLE predicate: " << *Ty << "\n";
296     llvm_unreachable(nullptr);
297   }
298   return Dest;
299 }
300 
301 static GenericValue executeICMP_UGE(GenericValue Src1, GenericValue Src2,
302                                     Type *Ty) {
303   GenericValue Dest;
304   switch (Ty->getTypeID()) {
305     IMPLEMENT_INTEGER_ICMP(uge,Ty);
306     IMPLEMENT_VECTOR_INTEGER_ICMP(uge,Ty);
307     IMPLEMENT_POINTER_ICMP(>=);
308   default:
309     dbgs() << "Unhandled type for ICMP_UGE predicate: " << *Ty << "\n";
310     llvm_unreachable(nullptr);
311   }
312   return Dest;
313 }
314 
315 static GenericValue executeICMP_SGE(GenericValue Src1, GenericValue Src2,
316                                     Type *Ty) {
317   GenericValue Dest;
318   switch (Ty->getTypeID()) {
319     IMPLEMENT_INTEGER_ICMP(sge,Ty);
320     IMPLEMENT_VECTOR_INTEGER_ICMP(sge,Ty);
321     IMPLEMENT_POINTER_ICMP(>=);
322   default:
323     dbgs() << "Unhandled type for ICMP_SGE predicate: " << *Ty << "\n";
324     llvm_unreachable(nullptr);
325   }
326   return Dest;
327 }
328 
329 void Interpreter::visitICmpInst(ICmpInst &I) {
330   ExecutionContext &SF = ECStack.back();
331   Type *Ty    = I.getOperand(0)->getType();
332   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
333   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
334   GenericValue R;   // Result
335 
336   switch (I.getPredicate()) {
337   case ICmpInst::ICMP_EQ:  R = executeICMP_EQ(Src1,  Src2, Ty); break;
338   case ICmpInst::ICMP_NE:  R = executeICMP_NE(Src1,  Src2, Ty); break;
339   case ICmpInst::ICMP_ULT: R = executeICMP_ULT(Src1, Src2, Ty); break;
340   case ICmpInst::ICMP_SLT: R = executeICMP_SLT(Src1, Src2, Ty); break;
341   case ICmpInst::ICMP_UGT: R = executeICMP_UGT(Src1, Src2, Ty); break;
342   case ICmpInst::ICMP_SGT: R = executeICMP_SGT(Src1, Src2, Ty); break;
343   case ICmpInst::ICMP_ULE: R = executeICMP_ULE(Src1, Src2, Ty); break;
344   case ICmpInst::ICMP_SLE: R = executeICMP_SLE(Src1, Src2, Ty); break;
345   case ICmpInst::ICMP_UGE: R = executeICMP_UGE(Src1, Src2, Ty); break;
346   case ICmpInst::ICMP_SGE: R = executeICMP_SGE(Src1, Src2, Ty); break;
347   default:
348     dbgs() << "Don't know how to handle this ICmp predicate!\n-->" << I;
349     llvm_unreachable(nullptr);
350   }
351 
352   SetValue(&I, R, SF);
353 }
354 
355 #define IMPLEMENT_FCMP(OP, TY) \
356    case Type::TY##TyID: \
357      Dest.IntVal = APInt(1,Src1.TY##Val OP Src2.TY##Val); \
358      break
359 
360 #define IMPLEMENT_VECTOR_FCMP_T(OP, TY)                             \
361   assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());     \
362   Dest.AggregateVal.resize( Src1.AggregateVal.size() );             \
363   for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)              \
364     Dest.AggregateVal[_i].IntVal = APInt(1,                         \
365     Src1.AggregateVal[_i].TY##Val OP Src2.AggregateVal[_i].TY##Val);\
366   break;
367 
368 #define IMPLEMENT_VECTOR_FCMP(OP)                                   \
369   case Type::VectorTyID:                                            \
370     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {      \
371       IMPLEMENT_VECTOR_FCMP_T(OP, Float);                           \
372     } else {                                                        \
373         IMPLEMENT_VECTOR_FCMP_T(OP, Double);                        \
374     }
375 
376 static GenericValue executeFCMP_OEQ(GenericValue Src1, GenericValue Src2,
377                                    Type *Ty) {
378   GenericValue Dest;
379   switch (Ty->getTypeID()) {
380     IMPLEMENT_FCMP(==, Float);
381     IMPLEMENT_FCMP(==, Double);
382     IMPLEMENT_VECTOR_FCMP(==);
383   default:
384     dbgs() << "Unhandled type for FCmp EQ instruction: " << *Ty << "\n";
385     llvm_unreachable(nullptr);
386   }
387   return Dest;
388 }
389 
390 #define IMPLEMENT_SCALAR_NANS(TY, X,Y)                                      \
391   if (TY->isFloatTy()) {                                                    \
392     if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {             \
393       Dest.IntVal = APInt(1,false);                                         \
394       return Dest;                                                          \
395     }                                                                       \
396   } else {                                                                  \
397     if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) {         \
398       Dest.IntVal = APInt(1,false);                                         \
399       return Dest;                                                          \
400     }                                                                       \
401   }
402 
403 #define MASK_VECTOR_NANS_T(X,Y, TZ, FLAG)                                   \
404   assert(X.AggregateVal.size() == Y.AggregateVal.size());                   \
405   Dest.AggregateVal.resize( X.AggregateVal.size() );                        \
406   for( uint32_t _i=0;_i<X.AggregateVal.size();_i++) {                       \
407     if (X.AggregateVal[_i].TZ##Val != X.AggregateVal[_i].TZ##Val ||         \
408         Y.AggregateVal[_i].TZ##Val != Y.AggregateVal[_i].TZ##Val)           \
409       Dest.AggregateVal[_i].IntVal = APInt(1,FLAG);                         \
410     else  {                                                                 \
411       Dest.AggregateVal[_i].IntVal = APInt(1,!FLAG);                        \
412     }                                                                       \
413   }
414 
415 #define MASK_VECTOR_NANS(TY, X,Y, FLAG)                                     \
416   if (TY->isVectorTy()) {                                                   \
417     if (cast<VectorType>(TY)->getElementType()->isFloatTy()) {              \
418       MASK_VECTOR_NANS_T(X, Y, Float, FLAG)                                 \
419     } else {                                                                \
420       MASK_VECTOR_NANS_T(X, Y, Double, FLAG)                                \
421     }                                                                       \
422   }                                                                         \
423 
424 
425 
426 static GenericValue executeFCMP_ONE(GenericValue Src1, GenericValue Src2,
427                                     Type *Ty)
428 {
429   GenericValue Dest;
430   // if input is scalar value and Src1 or Src2 is NaN return false
431   IMPLEMENT_SCALAR_NANS(Ty, Src1, Src2)
432   // if vector input detect NaNs and fill mask
433   MASK_VECTOR_NANS(Ty, Src1, Src2, false)
434   GenericValue DestMask = Dest;
435   switch (Ty->getTypeID()) {
436     IMPLEMENT_FCMP(!=, Float);
437     IMPLEMENT_FCMP(!=, Double);
438     IMPLEMENT_VECTOR_FCMP(!=);
439     default:
440       dbgs() << "Unhandled type for FCmp NE instruction: " << *Ty << "\n";
441       llvm_unreachable(nullptr);
442   }
443   // in vector case mask out NaN elements
444   if (Ty->isVectorTy())
445     for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
446       if (DestMask.AggregateVal[_i].IntVal == false)
447         Dest.AggregateVal[_i].IntVal = APInt(1,false);
448 
449   return Dest;
450 }
451 
452 static GenericValue executeFCMP_OLE(GenericValue Src1, GenericValue Src2,
453                                    Type *Ty) {
454   GenericValue Dest;
455   switch (Ty->getTypeID()) {
456     IMPLEMENT_FCMP(<=, Float);
457     IMPLEMENT_FCMP(<=, Double);
458     IMPLEMENT_VECTOR_FCMP(<=);
459   default:
460     dbgs() << "Unhandled type for FCmp LE instruction: " << *Ty << "\n";
461     llvm_unreachable(nullptr);
462   }
463   return Dest;
464 }
465 
466 static GenericValue executeFCMP_OGE(GenericValue Src1, GenericValue Src2,
467                                    Type *Ty) {
468   GenericValue Dest;
469   switch (Ty->getTypeID()) {
470     IMPLEMENT_FCMP(>=, Float);
471     IMPLEMENT_FCMP(>=, Double);
472     IMPLEMENT_VECTOR_FCMP(>=);
473   default:
474     dbgs() << "Unhandled type for FCmp GE instruction: " << *Ty << "\n";
475     llvm_unreachable(nullptr);
476   }
477   return Dest;
478 }
479 
480 static GenericValue executeFCMP_OLT(GenericValue Src1, GenericValue Src2,
481                                    Type *Ty) {
482   GenericValue Dest;
483   switch (Ty->getTypeID()) {
484     IMPLEMENT_FCMP(<, Float);
485     IMPLEMENT_FCMP(<, Double);
486     IMPLEMENT_VECTOR_FCMP(<);
487   default:
488     dbgs() << "Unhandled type for FCmp LT instruction: " << *Ty << "\n";
489     llvm_unreachable(nullptr);
490   }
491   return Dest;
492 }
493 
494 static GenericValue executeFCMP_OGT(GenericValue Src1, GenericValue Src2,
495                                      Type *Ty) {
496   GenericValue Dest;
497   switch (Ty->getTypeID()) {
498     IMPLEMENT_FCMP(>, Float);
499     IMPLEMENT_FCMP(>, Double);
500     IMPLEMENT_VECTOR_FCMP(>);
501   default:
502     dbgs() << "Unhandled type for FCmp GT instruction: " << *Ty << "\n";
503     llvm_unreachable(nullptr);
504   }
505   return Dest;
506 }
507 
508 #define IMPLEMENT_UNORDERED(TY, X,Y)                                     \
509   if (TY->isFloatTy()) {                                                 \
510     if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {          \
511       Dest.IntVal = APInt(1,true);                                       \
512       return Dest;                                                       \
513     }                                                                    \
514   } else if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) { \
515     Dest.IntVal = APInt(1,true);                                         \
516     return Dest;                                                         \
517   }
518 
519 #define IMPLEMENT_VECTOR_UNORDERED(TY, X, Y, FUNC)                             \
520   if (TY->isVectorTy()) {                                                      \
521     GenericValue DestMask = Dest;                                              \
522     Dest = FUNC(Src1, Src2, Ty);                                               \
523     for (size_t _i = 0; _i < Src1.AggregateVal.size(); _i++)                   \
524       if (DestMask.AggregateVal[_i].IntVal == true)                            \
525         Dest.AggregateVal[_i].IntVal = APInt(1, true);                         \
526     return Dest;                                                               \
527   }
528 
529 static GenericValue executeFCMP_UEQ(GenericValue Src1, GenericValue Src2,
530                                    Type *Ty) {
531   GenericValue Dest;
532   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
533   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
534   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OEQ)
535   return executeFCMP_OEQ(Src1, Src2, Ty);
536 
537 }
538 
539 static GenericValue executeFCMP_UNE(GenericValue Src1, GenericValue Src2,
540                                    Type *Ty) {
541   GenericValue Dest;
542   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
543   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
544   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_ONE)
545   return executeFCMP_ONE(Src1, Src2, Ty);
546 }
547 
548 static GenericValue executeFCMP_ULE(GenericValue Src1, GenericValue Src2,
549                                    Type *Ty) {
550   GenericValue Dest;
551   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
552   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
553   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLE)
554   return executeFCMP_OLE(Src1, Src2, Ty);
555 }
556 
557 static GenericValue executeFCMP_UGE(GenericValue Src1, GenericValue Src2,
558                                    Type *Ty) {
559   GenericValue Dest;
560   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
561   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
562   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGE)
563   return executeFCMP_OGE(Src1, Src2, Ty);
564 }
565 
566 static GenericValue executeFCMP_ULT(GenericValue Src1, GenericValue Src2,
567                                    Type *Ty) {
568   GenericValue Dest;
569   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
570   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
571   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLT)
572   return executeFCMP_OLT(Src1, Src2, Ty);
573 }
574 
575 static GenericValue executeFCMP_UGT(GenericValue Src1, GenericValue Src2,
576                                      Type *Ty) {
577   GenericValue Dest;
578   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
579   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
580   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGT)
581   return executeFCMP_OGT(Src1, Src2, Ty);
582 }
583 
584 static GenericValue executeFCMP_ORD(GenericValue Src1, GenericValue Src2,
585                                      Type *Ty) {
586   GenericValue Dest;
587   if(Ty->isVectorTy()) {
588     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
589     Dest.AggregateVal.resize( Src1.AggregateVal.size() );
590     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
591       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
592         Dest.AggregateVal[_i].IntVal = APInt(1,
593         ( (Src1.AggregateVal[_i].FloatVal ==
594         Src1.AggregateVal[_i].FloatVal) &&
595         (Src2.AggregateVal[_i].FloatVal ==
596         Src2.AggregateVal[_i].FloatVal)));
597     } else {
598       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
599         Dest.AggregateVal[_i].IntVal = APInt(1,
600         ( (Src1.AggregateVal[_i].DoubleVal ==
601         Src1.AggregateVal[_i].DoubleVal) &&
602         (Src2.AggregateVal[_i].DoubleVal ==
603         Src2.AggregateVal[_i].DoubleVal)));
604     }
605   } else if (Ty->isFloatTy())
606     Dest.IntVal = APInt(1,(Src1.FloatVal == Src1.FloatVal &&
607                            Src2.FloatVal == Src2.FloatVal));
608   else {
609     Dest.IntVal = APInt(1,(Src1.DoubleVal == Src1.DoubleVal &&
610                            Src2.DoubleVal == Src2.DoubleVal));
611   }
612   return Dest;
613 }
614 
615 static GenericValue executeFCMP_UNO(GenericValue Src1, GenericValue Src2,
616                                      Type *Ty) {
617   GenericValue Dest;
618   if(Ty->isVectorTy()) {
619     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
620     Dest.AggregateVal.resize( Src1.AggregateVal.size() );
621     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
622       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
623         Dest.AggregateVal[_i].IntVal = APInt(1,
624         ( (Src1.AggregateVal[_i].FloatVal !=
625            Src1.AggregateVal[_i].FloatVal) ||
626           (Src2.AggregateVal[_i].FloatVal !=
627            Src2.AggregateVal[_i].FloatVal)));
628       } else {
629         for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
630           Dest.AggregateVal[_i].IntVal = APInt(1,
631           ( (Src1.AggregateVal[_i].DoubleVal !=
632              Src1.AggregateVal[_i].DoubleVal) ||
633             (Src2.AggregateVal[_i].DoubleVal !=
634              Src2.AggregateVal[_i].DoubleVal)));
635       }
636   } else if (Ty->isFloatTy())
637     Dest.IntVal = APInt(1,(Src1.FloatVal != Src1.FloatVal ||
638                            Src2.FloatVal != Src2.FloatVal));
639   else {
640     Dest.IntVal = APInt(1,(Src1.DoubleVal != Src1.DoubleVal ||
641                            Src2.DoubleVal != Src2.DoubleVal));
642   }
643   return Dest;
644 }
645 
646 static GenericValue executeFCMP_BOOL(GenericValue Src1, GenericValue Src2,
647                                      Type *Ty, const bool val) {
648   GenericValue Dest;
649     if(Ty->isVectorTy()) {
650       assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
651       Dest.AggregateVal.resize( Src1.AggregateVal.size() );
652       for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
653         Dest.AggregateVal[_i].IntVal = APInt(1,val);
654     } else {
655       Dest.IntVal = APInt(1, val);
656     }
657 
658     return Dest;
659 }
660 
661 void Interpreter::visitFCmpInst(FCmpInst &I) {
662   ExecutionContext &SF = ECStack.back();
663   Type *Ty    = I.getOperand(0)->getType();
664   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
665   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
666   GenericValue R;   // Result
667 
668   switch (I.getPredicate()) {
669   default:
670     dbgs() << "Don't know how to handle this FCmp predicate!\n-->" << I;
671     llvm_unreachable(nullptr);
672   break;
673   case FCmpInst::FCMP_FALSE: R = executeFCMP_BOOL(Src1, Src2, Ty, false);
674   break;
675   case FCmpInst::FCMP_TRUE:  R = executeFCMP_BOOL(Src1, Src2, Ty, true);
676   break;
677   case FCmpInst::FCMP_ORD:   R = executeFCMP_ORD(Src1, Src2, Ty); break;
678   case FCmpInst::FCMP_UNO:   R = executeFCMP_UNO(Src1, Src2, Ty); break;
679   case FCmpInst::FCMP_UEQ:   R = executeFCMP_UEQ(Src1, Src2, Ty); break;
680   case FCmpInst::FCMP_OEQ:   R = executeFCMP_OEQ(Src1, Src2, Ty); break;
681   case FCmpInst::FCMP_UNE:   R = executeFCMP_UNE(Src1, Src2, Ty); break;
682   case FCmpInst::FCMP_ONE:   R = executeFCMP_ONE(Src1, Src2, Ty); break;
683   case FCmpInst::FCMP_ULT:   R = executeFCMP_ULT(Src1, Src2, Ty); break;
684   case FCmpInst::FCMP_OLT:   R = executeFCMP_OLT(Src1, Src2, Ty); break;
685   case FCmpInst::FCMP_UGT:   R = executeFCMP_UGT(Src1, Src2, Ty); break;
686   case FCmpInst::FCMP_OGT:   R = executeFCMP_OGT(Src1, Src2, Ty); break;
687   case FCmpInst::FCMP_ULE:   R = executeFCMP_ULE(Src1, Src2, Ty); break;
688   case FCmpInst::FCMP_OLE:   R = executeFCMP_OLE(Src1, Src2, Ty); break;
689   case FCmpInst::FCMP_UGE:   R = executeFCMP_UGE(Src1, Src2, Ty); break;
690   case FCmpInst::FCMP_OGE:   R = executeFCMP_OGE(Src1, Src2, Ty); break;
691   }
692 
693   SetValue(&I, R, SF);
694 }
695 
696 static GenericValue executeCmpInst(unsigned predicate, GenericValue Src1,
697                                    GenericValue Src2, Type *Ty) {
698   GenericValue Result;
699   switch (predicate) {
700   case ICmpInst::ICMP_EQ:    return executeICMP_EQ(Src1, Src2, Ty);
701   case ICmpInst::ICMP_NE:    return executeICMP_NE(Src1, Src2, Ty);
702   case ICmpInst::ICMP_UGT:   return executeICMP_UGT(Src1, Src2, Ty);
703   case ICmpInst::ICMP_SGT:   return executeICMP_SGT(Src1, Src2, Ty);
704   case ICmpInst::ICMP_ULT:   return executeICMP_ULT(Src1, Src2, Ty);
705   case ICmpInst::ICMP_SLT:   return executeICMP_SLT(Src1, Src2, Ty);
706   case ICmpInst::ICMP_UGE:   return executeICMP_UGE(Src1, Src2, Ty);
707   case ICmpInst::ICMP_SGE:   return executeICMP_SGE(Src1, Src2, Ty);
708   case ICmpInst::ICMP_ULE:   return executeICMP_ULE(Src1, Src2, Ty);
709   case ICmpInst::ICMP_SLE:   return executeICMP_SLE(Src1, Src2, Ty);
710   case FCmpInst::FCMP_ORD:   return executeFCMP_ORD(Src1, Src2, Ty);
711   case FCmpInst::FCMP_UNO:   return executeFCMP_UNO(Src1, Src2, Ty);
712   case FCmpInst::FCMP_OEQ:   return executeFCMP_OEQ(Src1, Src2, Ty);
713   case FCmpInst::FCMP_UEQ:   return executeFCMP_UEQ(Src1, Src2, Ty);
714   case FCmpInst::FCMP_ONE:   return executeFCMP_ONE(Src1, Src2, Ty);
715   case FCmpInst::FCMP_UNE:   return executeFCMP_UNE(Src1, Src2, Ty);
716   case FCmpInst::FCMP_OLT:   return executeFCMP_OLT(Src1, Src2, Ty);
717   case FCmpInst::FCMP_ULT:   return executeFCMP_ULT(Src1, Src2, Ty);
718   case FCmpInst::FCMP_OGT:   return executeFCMP_OGT(Src1, Src2, Ty);
719   case FCmpInst::FCMP_UGT:   return executeFCMP_UGT(Src1, Src2, Ty);
720   case FCmpInst::FCMP_OLE:   return executeFCMP_OLE(Src1, Src2, Ty);
721   case FCmpInst::FCMP_ULE:   return executeFCMP_ULE(Src1, Src2, Ty);
722   case FCmpInst::FCMP_OGE:   return executeFCMP_OGE(Src1, Src2, Ty);
723   case FCmpInst::FCMP_UGE:   return executeFCMP_UGE(Src1, Src2, Ty);
724   case FCmpInst::FCMP_FALSE: return executeFCMP_BOOL(Src1, Src2, Ty, false);
725   case FCmpInst::FCMP_TRUE:  return executeFCMP_BOOL(Src1, Src2, Ty, true);
726   default:
727     dbgs() << "Unhandled Cmp predicate\n";
728     llvm_unreachable(nullptr);
729   }
730 }
731 
732 void Interpreter::visitBinaryOperator(BinaryOperator &I) {
733   ExecutionContext &SF = ECStack.back();
734   Type *Ty    = I.getOperand(0)->getType();
735   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
736   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
737   GenericValue R;   // Result
738 
739   // First process vector operation
740   if (Ty->isVectorTy()) {
741     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
742     R.AggregateVal.resize(Src1.AggregateVal.size());
743 
744     // Macros to execute binary operation 'OP' over integer vectors
745 #define INTEGER_VECTOR_OPERATION(OP)                               \
746     for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
747       R.AggregateVal[i].IntVal =                                   \
748       Src1.AggregateVal[i].IntVal OP Src2.AggregateVal[i].IntVal;
749 
750     // Additional macros to execute binary operations udiv/sdiv/urem/srem since
751     // they have different notation.
752 #define INTEGER_VECTOR_FUNCTION(OP)                                \
753     for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
754       R.AggregateVal[i].IntVal =                                   \
755       Src1.AggregateVal[i].IntVal.OP(Src2.AggregateVal[i].IntVal);
756 
757     // Macros to execute binary operation 'OP' over floating point type TY
758     // (float or double) vectors
759 #define FLOAT_VECTOR_FUNCTION(OP, TY)                               \
760       for (unsigned i = 0; i < R.AggregateVal.size(); ++i)          \
761         R.AggregateVal[i].TY =                                      \
762         Src1.AggregateVal[i].TY OP Src2.AggregateVal[i].TY;
763 
764     // Macros to choose appropriate TY: float or double and run operation
765     // execution
766 #define FLOAT_VECTOR_OP(OP) {                                         \
767   if (cast<VectorType>(Ty)->getElementType()->isFloatTy())            \
768     FLOAT_VECTOR_FUNCTION(OP, FloatVal)                               \
769   else {                                                              \
770     if (cast<VectorType>(Ty)->getElementType()->isDoubleTy())         \
771       FLOAT_VECTOR_FUNCTION(OP, DoubleVal)                            \
772     else {                                                            \
773       dbgs() << "Unhandled type for OP instruction: " << *Ty << "\n"; \
774       llvm_unreachable(0);                                            \
775     }                                                                 \
776   }                                                                   \
777 }
778 
779     switch(I.getOpcode()){
780     default:
781       dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
782       llvm_unreachable(nullptr);
783       break;
784     case Instruction::Add:   INTEGER_VECTOR_OPERATION(+) break;
785     case Instruction::Sub:   INTEGER_VECTOR_OPERATION(-) break;
786     case Instruction::Mul:   INTEGER_VECTOR_OPERATION(*) break;
787     case Instruction::UDiv:  INTEGER_VECTOR_FUNCTION(udiv) break;
788     case Instruction::SDiv:  INTEGER_VECTOR_FUNCTION(sdiv) break;
789     case Instruction::URem:  INTEGER_VECTOR_FUNCTION(urem) break;
790     case Instruction::SRem:  INTEGER_VECTOR_FUNCTION(srem) break;
791     case Instruction::And:   INTEGER_VECTOR_OPERATION(&) break;
792     case Instruction::Or:    INTEGER_VECTOR_OPERATION(|) break;
793     case Instruction::Xor:   INTEGER_VECTOR_OPERATION(^) break;
794     case Instruction::FAdd:  FLOAT_VECTOR_OP(+) break;
795     case Instruction::FSub:  FLOAT_VECTOR_OP(-) break;
796     case Instruction::FMul:  FLOAT_VECTOR_OP(*) break;
797     case Instruction::FDiv:  FLOAT_VECTOR_OP(/) break;
798     case Instruction::FRem:
799       if (cast<VectorType>(Ty)->getElementType()->isFloatTy())
800         for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
801           R.AggregateVal[i].FloatVal =
802           fmod(Src1.AggregateVal[i].FloatVal, Src2.AggregateVal[i].FloatVal);
803       else {
804         if (cast<VectorType>(Ty)->getElementType()->isDoubleTy())
805           for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
806             R.AggregateVal[i].DoubleVal =
807             fmod(Src1.AggregateVal[i].DoubleVal, Src2.AggregateVal[i].DoubleVal);
808         else {
809           dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
810           llvm_unreachable(nullptr);
811         }
812       }
813       break;
814     }
815   } else {
816     switch (I.getOpcode()) {
817     default:
818       dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
819       llvm_unreachable(nullptr);
820       break;
821     case Instruction::Add:   R.IntVal = Src1.IntVal + Src2.IntVal; break;
822     case Instruction::Sub:   R.IntVal = Src1.IntVal - Src2.IntVal; break;
823     case Instruction::Mul:   R.IntVal = Src1.IntVal * Src2.IntVal; break;
824     case Instruction::FAdd:  executeFAddInst(R, Src1, Src2, Ty); break;
825     case Instruction::FSub:  executeFSubInst(R, Src1, Src2, Ty); break;
826     case Instruction::FMul:  executeFMulInst(R, Src1, Src2, Ty); break;
827     case Instruction::FDiv:  executeFDivInst(R, Src1, Src2, Ty); break;
828     case Instruction::FRem:  executeFRemInst(R, Src1, Src2, Ty); break;
829     case Instruction::UDiv:  R.IntVal = Src1.IntVal.udiv(Src2.IntVal); break;
830     case Instruction::SDiv:  R.IntVal = Src1.IntVal.sdiv(Src2.IntVal); break;
831     case Instruction::URem:  R.IntVal = Src1.IntVal.urem(Src2.IntVal); break;
832     case Instruction::SRem:  R.IntVal = Src1.IntVal.srem(Src2.IntVal); break;
833     case Instruction::And:   R.IntVal = Src1.IntVal & Src2.IntVal; break;
834     case Instruction::Or:    R.IntVal = Src1.IntVal | Src2.IntVal; break;
835     case Instruction::Xor:   R.IntVal = Src1.IntVal ^ Src2.IntVal; break;
836     }
837   }
838   SetValue(&I, R, SF);
839 }
840 
841 static GenericValue executeSelectInst(GenericValue Src1, GenericValue Src2,
842                                       GenericValue Src3, Type *Ty) {
843     GenericValue Dest;
844     if(Ty->isVectorTy()) {
845       assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
846       assert(Src2.AggregateVal.size() == Src3.AggregateVal.size());
847       Dest.AggregateVal.resize( Src1.AggregateVal.size() );
848       for (size_t i = 0; i < Src1.AggregateVal.size(); ++i)
849         Dest.AggregateVal[i] = (Src1.AggregateVal[i].IntVal == 0) ?
850           Src3.AggregateVal[i] : Src2.AggregateVal[i];
851     } else {
852       Dest = (Src1.IntVal == 0) ? Src3 : Src2;
853     }
854     return Dest;
855 }
856 
857 void Interpreter::visitSelectInst(SelectInst &I) {
858   ExecutionContext &SF = ECStack.back();
859   Type * Ty = I.getOperand(0)->getType();
860   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
861   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
862   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
863   GenericValue R = executeSelectInst(Src1, Src2, Src3, Ty);
864   SetValue(&I, R, SF);
865 }
866 
867 //===----------------------------------------------------------------------===//
868 //                     Terminator Instruction Implementations
869 //===----------------------------------------------------------------------===//
870 
871 void Interpreter::exitCalled(GenericValue GV) {
872   // runAtExitHandlers() assumes there are no stack frames, but
873   // if exit() was called, then it had a stack frame. Blow away
874   // the stack before interpreting atexit handlers.
875   ECStack.clear();
876   runAtExitHandlers();
877   exit(GV.IntVal.zextOrTrunc(32).getZExtValue());
878 }
879 
880 /// Pop the last stack frame off of ECStack and then copy the result
881 /// back into the result variable if we are not returning void. The
882 /// result variable may be the ExitValue, or the Value of the calling
883 /// CallInst if there was a previous stack frame. This method may
884 /// invalidate any ECStack iterators you have. This method also takes
885 /// care of switching to the normal destination BB, if we are returning
886 /// from an invoke.
887 ///
888 void Interpreter::popStackAndReturnValueToCaller(Type *RetTy,
889                                                  GenericValue Result) {
890   // Pop the current stack frame.
891   ECStack.pop_back();
892 
893   if (ECStack.empty()) {  // Finished main.  Put result into exit code...
894     if (RetTy && !RetTy->isVoidTy()) {          // Nonvoid return type?
895       ExitValue = Result;   // Capture the exit value of the program
896     } else {
897       memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
898     }
899   } else {
900     // If we have a previous stack frame, and we have a previous call,
901     // fill in the return value...
902     ExecutionContext &CallingSF = ECStack.back();
903     if (Instruction *I = CallingSF.Caller.getInstruction()) {
904       // Save result...
905       if (!CallingSF.Caller.getType()->isVoidTy())
906         SetValue(I, Result, CallingSF);
907       if (InvokeInst *II = dyn_cast<InvokeInst> (I))
908         SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
909       CallingSF.Caller = CallSite();          // We returned from the call...
910     }
911   }
912 }
913 
914 void Interpreter::visitReturnInst(ReturnInst &I) {
915   ExecutionContext &SF = ECStack.back();
916   Type *RetTy = Type::getVoidTy(I.getContext());
917   GenericValue Result;
918 
919   // Save away the return value... (if we are not 'ret void')
920   if (I.getNumOperands()) {
921     RetTy  = I.getReturnValue()->getType();
922     Result = getOperandValue(I.getReturnValue(), SF);
923   }
924 
925   popStackAndReturnValueToCaller(RetTy, Result);
926 }
927 
928 void Interpreter::visitUnreachableInst(UnreachableInst &I) {
929   report_fatal_error("Program executed an 'unreachable' instruction!");
930 }
931 
932 void Interpreter::visitBranchInst(BranchInst &I) {
933   ExecutionContext &SF = ECStack.back();
934   BasicBlock *Dest;
935 
936   Dest = I.getSuccessor(0);          // Uncond branches have a fixed dest...
937   if (!I.isUnconditional()) {
938     Value *Cond = I.getCondition();
939     if (getOperandValue(Cond, SF).IntVal == 0) // If false cond...
940       Dest = I.getSuccessor(1);
941   }
942   SwitchToNewBasicBlock(Dest, SF);
943 }
944 
945 void Interpreter::visitSwitchInst(SwitchInst &I) {
946   ExecutionContext &SF = ECStack.back();
947   Value* Cond = I.getCondition();
948   Type *ElTy = Cond->getType();
949   GenericValue CondVal = getOperandValue(Cond, SF);
950 
951   // Check to see if any of the cases match...
952   BasicBlock *Dest = nullptr;
953   for (auto Case : I.cases()) {
954     GenericValue CaseVal = getOperandValue(Case.getCaseValue(), SF);
955     if (executeICMP_EQ(CondVal, CaseVal, ElTy).IntVal != 0) {
956       Dest = cast<BasicBlock>(Case.getCaseSuccessor());
957       break;
958     }
959   }
960   if (!Dest) Dest = I.getDefaultDest();   // No cases matched: use default
961   SwitchToNewBasicBlock(Dest, SF);
962 }
963 
964 void Interpreter::visitIndirectBrInst(IndirectBrInst &I) {
965   ExecutionContext &SF = ECStack.back();
966   void *Dest = GVTOP(getOperandValue(I.getAddress(), SF));
967   SwitchToNewBasicBlock((BasicBlock*)Dest, SF);
968 }
969 
970 
971 // SwitchToNewBasicBlock - This method is used to jump to a new basic block.
972 // This function handles the actual updating of block and instruction iterators
973 // as well as execution of all of the PHI nodes in the destination block.
974 //
975 // This method does this because all of the PHI nodes must be executed
976 // atomically, reading their inputs before any of the results are updated.  Not
977 // doing this can cause problems if the PHI nodes depend on other PHI nodes for
978 // their inputs.  If the input PHI node is updated before it is read, incorrect
979 // results can happen.  Thus we use a two phase approach.
980 //
981 void Interpreter::SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF){
982   BasicBlock *PrevBB = SF.CurBB;      // Remember where we came from...
983   SF.CurBB   = Dest;                  // Update CurBB to branch destination
984   SF.CurInst = SF.CurBB->begin();     // Update new instruction ptr...
985 
986   if (!isa<PHINode>(SF.CurInst)) return;  // Nothing fancy to do
987 
988   // Loop over all of the PHI nodes in the current block, reading their inputs.
989   std::vector<GenericValue> ResultValues;
990 
991   for (; PHINode *PN = dyn_cast<PHINode>(SF.CurInst); ++SF.CurInst) {
992     // Search for the value corresponding to this previous bb...
993     int i = PN->getBasicBlockIndex(PrevBB);
994     assert(i != -1 && "PHINode doesn't contain entry for predecessor??");
995     Value *IncomingValue = PN->getIncomingValue(i);
996 
997     // Save the incoming value for this PHI node...
998     ResultValues.push_back(getOperandValue(IncomingValue, SF));
999   }
1000 
1001   // Now loop over all of the PHI nodes setting their values...
1002   SF.CurInst = SF.CurBB->begin();
1003   for (unsigned i = 0; isa<PHINode>(SF.CurInst); ++SF.CurInst, ++i) {
1004     PHINode *PN = cast<PHINode>(SF.CurInst);
1005     SetValue(PN, ResultValues[i], SF);
1006   }
1007 }
1008 
1009 //===----------------------------------------------------------------------===//
1010 //                     Memory Instruction Implementations
1011 //===----------------------------------------------------------------------===//
1012 
1013 void Interpreter::visitAllocaInst(AllocaInst &I) {
1014   ExecutionContext &SF = ECStack.back();
1015 
1016   Type *Ty = I.getType()->getElementType();  // Type to be allocated
1017 
1018   // Get the number of elements being allocated by the array...
1019   unsigned NumElements =
1020     getOperandValue(I.getOperand(0), SF).IntVal.getZExtValue();
1021 
1022   unsigned TypeSize = (size_t)getDataLayout().getTypeAllocSize(Ty);
1023 
1024   // Avoid malloc-ing zero bytes, use max()...
1025   unsigned MemToAlloc = std::max(1U, NumElements * TypeSize);
1026 
1027   // Allocate enough memory to hold the type...
1028   void *Memory = safe_malloc(MemToAlloc);
1029 
1030   LLVM_DEBUG(dbgs() << "Allocated Type: " << *Ty << " (" << TypeSize
1031                     << " bytes) x " << NumElements << " (Total: " << MemToAlloc
1032                     << ") at " << uintptr_t(Memory) << '\n');
1033 
1034   GenericValue Result = PTOGV(Memory);
1035   assert(Result.PointerVal && "Null pointer returned by malloc!");
1036   SetValue(&I, Result, SF);
1037 
1038   if (I.getOpcode() == Instruction::Alloca)
1039     ECStack.back().Allocas.add(Memory);
1040 }
1041 
1042 // getElementOffset - The workhorse for getelementptr.
1043 //
1044 GenericValue Interpreter::executeGEPOperation(Value *Ptr, gep_type_iterator I,
1045                                               gep_type_iterator E,
1046                                               ExecutionContext &SF) {
1047   assert(Ptr->getType()->isPointerTy() &&
1048          "Cannot getElementOffset of a nonpointer type!");
1049 
1050   uint64_t Total = 0;
1051 
1052   for (; I != E; ++I) {
1053     if (StructType *STy = I.getStructTypeOrNull()) {
1054       const StructLayout *SLO = getDataLayout().getStructLayout(STy);
1055 
1056       const ConstantInt *CPU = cast<ConstantInt>(I.getOperand());
1057       unsigned Index = unsigned(CPU->getZExtValue());
1058 
1059       Total += SLO->getElementOffset(Index);
1060     } else {
1061       // Get the index number for the array... which must be long type...
1062       GenericValue IdxGV = getOperandValue(I.getOperand(), SF);
1063 
1064       int64_t Idx;
1065       unsigned BitWidth =
1066         cast<IntegerType>(I.getOperand()->getType())->getBitWidth();
1067       if (BitWidth == 32)
1068         Idx = (int64_t)(int32_t)IdxGV.IntVal.getZExtValue();
1069       else {
1070         assert(BitWidth == 64 && "Invalid index type for getelementptr");
1071         Idx = (int64_t)IdxGV.IntVal.getZExtValue();
1072       }
1073       Total += getDataLayout().getTypeAllocSize(I.getIndexedType()) * Idx;
1074     }
1075   }
1076 
1077   GenericValue Result;
1078   Result.PointerVal = ((char*)getOperandValue(Ptr, SF).PointerVal) + Total;
1079   LLVM_DEBUG(dbgs() << "GEP Index " << Total << " bytes.\n");
1080   return Result;
1081 }
1082 
1083 void Interpreter::visitGetElementPtrInst(GetElementPtrInst &I) {
1084   ExecutionContext &SF = ECStack.back();
1085   SetValue(&I, executeGEPOperation(I.getPointerOperand(),
1086                                    gep_type_begin(I), gep_type_end(I), SF), SF);
1087 }
1088 
1089 void Interpreter::visitLoadInst(LoadInst &I) {
1090   ExecutionContext &SF = ECStack.back();
1091   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1092   GenericValue *Ptr = (GenericValue*)GVTOP(SRC);
1093   GenericValue Result;
1094   LoadValueFromMemory(Result, Ptr, I.getType());
1095   SetValue(&I, Result, SF);
1096   if (I.isVolatile() && PrintVolatile)
1097     dbgs() << "Volatile load " << I;
1098 }
1099 
1100 void Interpreter::visitStoreInst(StoreInst &I) {
1101   ExecutionContext &SF = ECStack.back();
1102   GenericValue Val = getOperandValue(I.getOperand(0), SF);
1103   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1104   StoreValueToMemory(Val, (GenericValue *)GVTOP(SRC),
1105                      I.getOperand(0)->getType());
1106   if (I.isVolatile() && PrintVolatile)
1107     dbgs() << "Volatile store: " << I;
1108 }
1109 
1110 //===----------------------------------------------------------------------===//
1111 //                 Miscellaneous Instruction Implementations
1112 //===----------------------------------------------------------------------===//
1113 
1114 void Interpreter::visitCallSite(CallSite CS) {
1115   ExecutionContext &SF = ECStack.back();
1116 
1117   // Check to see if this is an intrinsic function call...
1118   Function *F = CS.getCalledFunction();
1119   if (F && F->isDeclaration())
1120     switch (F->getIntrinsicID()) {
1121     case Intrinsic::not_intrinsic:
1122       break;
1123     case Intrinsic::vastart: { // va_start
1124       GenericValue ArgIndex;
1125       ArgIndex.UIntPairVal.first = ECStack.size() - 1;
1126       ArgIndex.UIntPairVal.second = 0;
1127       SetValue(CS.getInstruction(), ArgIndex, SF);
1128       return;
1129     }
1130     case Intrinsic::vaend:    // va_end is a noop for the interpreter
1131       return;
1132     case Intrinsic::vacopy:   // va_copy: dest = src
1133       SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
1134       return;
1135     default:
1136       // If it is an unknown intrinsic function, use the intrinsic lowering
1137       // class to transform it into hopefully tasty LLVM code.
1138       //
1139       BasicBlock::iterator me(CS.getInstruction());
1140       BasicBlock *Parent = CS.getInstruction()->getParent();
1141       bool atBegin(Parent->begin() == me);
1142       if (!atBegin)
1143         --me;
1144       IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
1145 
1146       // Restore the CurInst pointer to the first instruction newly inserted, if
1147       // any.
1148       if (atBegin) {
1149         SF.CurInst = Parent->begin();
1150       } else {
1151         SF.CurInst = me;
1152         ++SF.CurInst;
1153       }
1154       return;
1155     }
1156 
1157 
1158   SF.Caller = CS;
1159   std::vector<GenericValue> ArgVals;
1160   const unsigned NumArgs = SF.Caller.arg_size();
1161   ArgVals.reserve(NumArgs);
1162   uint16_t pNum = 1;
1163   for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
1164          e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
1165     Value *V = *i;
1166     ArgVals.push_back(getOperandValue(V, SF));
1167   }
1168 
1169   // To handle indirect calls, we must get the pointer value from the argument
1170   // and treat it as a function pointer.
1171   GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
1172   callFunction((Function*)GVTOP(SRC), ArgVals);
1173 }
1174 
1175 // auxiliary function for shift operations
1176 static unsigned getShiftAmount(uint64_t orgShiftAmount,
1177                                llvm::APInt valueToShift) {
1178   unsigned valueWidth = valueToShift.getBitWidth();
1179   if (orgShiftAmount < (uint64_t)valueWidth)
1180     return orgShiftAmount;
1181   // according to the llvm documentation, if orgShiftAmount > valueWidth,
1182   // the result is undfeined. but we do shift by this rule:
1183   return (NextPowerOf2(valueWidth-1) - 1) & orgShiftAmount;
1184 }
1185 
1186 
1187 void Interpreter::visitShl(BinaryOperator &I) {
1188   ExecutionContext &SF = ECStack.back();
1189   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1190   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1191   GenericValue Dest;
1192   Type *Ty = I.getType();
1193 
1194   if (Ty->isVectorTy()) {
1195     uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1196     assert(src1Size == Src2.AggregateVal.size());
1197     for (unsigned i = 0; i < src1Size; i++) {
1198       GenericValue Result;
1199       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1200       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1201       Result.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1202       Dest.AggregateVal.push_back(Result);
1203     }
1204   } else {
1205     // scalar
1206     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1207     llvm::APInt valueToShift = Src1.IntVal;
1208     Dest.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1209   }
1210 
1211   SetValue(&I, Dest, SF);
1212 }
1213 
1214 void Interpreter::visitLShr(BinaryOperator &I) {
1215   ExecutionContext &SF = ECStack.back();
1216   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1217   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1218   GenericValue Dest;
1219   Type *Ty = I.getType();
1220 
1221   if (Ty->isVectorTy()) {
1222     uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1223     assert(src1Size == Src2.AggregateVal.size());
1224     for (unsigned i = 0; i < src1Size; i++) {
1225       GenericValue Result;
1226       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1227       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1228       Result.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1229       Dest.AggregateVal.push_back(Result);
1230     }
1231   } else {
1232     // scalar
1233     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1234     llvm::APInt valueToShift = Src1.IntVal;
1235     Dest.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1236   }
1237 
1238   SetValue(&I, Dest, SF);
1239 }
1240 
1241 void Interpreter::visitAShr(BinaryOperator &I) {
1242   ExecutionContext &SF = ECStack.back();
1243   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1244   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1245   GenericValue Dest;
1246   Type *Ty = I.getType();
1247 
1248   if (Ty->isVectorTy()) {
1249     size_t src1Size = Src1.AggregateVal.size();
1250     assert(src1Size == Src2.AggregateVal.size());
1251     for (unsigned i = 0; i < src1Size; i++) {
1252       GenericValue Result;
1253       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1254       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1255       Result.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1256       Dest.AggregateVal.push_back(Result);
1257     }
1258   } else {
1259     // scalar
1260     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1261     llvm::APInt valueToShift = Src1.IntVal;
1262     Dest.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1263   }
1264 
1265   SetValue(&I, Dest, SF);
1266 }
1267 
1268 GenericValue Interpreter::executeTruncInst(Value *SrcVal, Type *DstTy,
1269                                            ExecutionContext &SF) {
1270   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1271   Type *SrcTy = SrcVal->getType();
1272   if (SrcTy->isVectorTy()) {
1273     Type *DstVecTy = DstTy->getScalarType();
1274     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1275     unsigned NumElts = Src.AggregateVal.size();
1276     // the sizes of src and dst vectors must be equal
1277     Dest.AggregateVal.resize(NumElts);
1278     for (unsigned i = 0; i < NumElts; i++)
1279       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.trunc(DBitWidth);
1280   } else {
1281     IntegerType *DITy = cast<IntegerType>(DstTy);
1282     unsigned DBitWidth = DITy->getBitWidth();
1283     Dest.IntVal = Src.IntVal.trunc(DBitWidth);
1284   }
1285   return Dest;
1286 }
1287 
1288 GenericValue Interpreter::executeSExtInst(Value *SrcVal, Type *DstTy,
1289                                           ExecutionContext &SF) {
1290   Type *SrcTy = SrcVal->getType();
1291   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1292   if (SrcTy->isVectorTy()) {
1293     Type *DstVecTy = DstTy->getScalarType();
1294     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1295     unsigned size = Src.AggregateVal.size();
1296     // the sizes of src and dst vectors must be equal.
1297     Dest.AggregateVal.resize(size);
1298     for (unsigned i = 0; i < size; i++)
1299       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.sext(DBitWidth);
1300   } else {
1301     auto *DITy = cast<IntegerType>(DstTy);
1302     unsigned DBitWidth = DITy->getBitWidth();
1303     Dest.IntVal = Src.IntVal.sext(DBitWidth);
1304   }
1305   return Dest;
1306 }
1307 
1308 GenericValue Interpreter::executeZExtInst(Value *SrcVal, Type *DstTy,
1309                                           ExecutionContext &SF) {
1310   Type *SrcTy = SrcVal->getType();
1311   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1312   if (SrcTy->isVectorTy()) {
1313     Type *DstVecTy = DstTy->getScalarType();
1314     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1315 
1316     unsigned size = Src.AggregateVal.size();
1317     // the sizes of src and dst vectors must be equal.
1318     Dest.AggregateVal.resize(size);
1319     for (unsigned i = 0; i < size; i++)
1320       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.zext(DBitWidth);
1321   } else {
1322     auto *DITy = cast<IntegerType>(DstTy);
1323     unsigned DBitWidth = DITy->getBitWidth();
1324     Dest.IntVal = Src.IntVal.zext(DBitWidth);
1325   }
1326   return Dest;
1327 }
1328 
1329 GenericValue Interpreter::executeFPTruncInst(Value *SrcVal, Type *DstTy,
1330                                              ExecutionContext &SF) {
1331   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1332 
1333   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1334     assert(SrcVal->getType()->getScalarType()->isDoubleTy() &&
1335            DstTy->getScalarType()->isFloatTy() &&
1336            "Invalid FPTrunc instruction");
1337 
1338     unsigned size = Src.AggregateVal.size();
1339     // the sizes of src and dst vectors must be equal.
1340     Dest.AggregateVal.resize(size);
1341     for (unsigned i = 0; i < size; i++)
1342       Dest.AggregateVal[i].FloatVal = (float)Src.AggregateVal[i].DoubleVal;
1343   } else {
1344     assert(SrcVal->getType()->isDoubleTy() && DstTy->isFloatTy() &&
1345            "Invalid FPTrunc instruction");
1346     Dest.FloatVal = (float)Src.DoubleVal;
1347   }
1348 
1349   return Dest;
1350 }
1351 
1352 GenericValue Interpreter::executeFPExtInst(Value *SrcVal, Type *DstTy,
1353                                            ExecutionContext &SF) {
1354   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1355 
1356   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1357     assert(SrcVal->getType()->getScalarType()->isFloatTy() &&
1358            DstTy->getScalarType()->isDoubleTy() && "Invalid FPExt instruction");
1359 
1360     unsigned size = Src.AggregateVal.size();
1361     // the sizes of src and dst vectors must be equal.
1362     Dest.AggregateVal.resize(size);
1363     for (unsigned i = 0; i < size; i++)
1364       Dest.AggregateVal[i].DoubleVal = (double)Src.AggregateVal[i].FloatVal;
1365   } else {
1366     assert(SrcVal->getType()->isFloatTy() && DstTy->isDoubleTy() &&
1367            "Invalid FPExt instruction");
1368     Dest.DoubleVal = (double)Src.FloatVal;
1369   }
1370 
1371   return Dest;
1372 }
1373 
1374 GenericValue Interpreter::executeFPToUIInst(Value *SrcVal, Type *DstTy,
1375                                             ExecutionContext &SF) {
1376   Type *SrcTy = SrcVal->getType();
1377   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1378 
1379   if (SrcTy->getTypeID() == Type::VectorTyID) {
1380     Type *DstVecTy = DstTy->getScalarType();
1381     Type *SrcVecTy = SrcTy->getScalarType();
1382     uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1383     unsigned size = Src.AggregateVal.size();
1384     // the sizes of src and dst vectors must be equal.
1385     Dest.AggregateVal.resize(size);
1386 
1387     if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1388       assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1389       for (unsigned i = 0; i < size; i++)
1390         Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1391             Src.AggregateVal[i].FloatVal, DBitWidth);
1392     } else {
1393       for (unsigned i = 0; i < size; i++)
1394         Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1395             Src.AggregateVal[i].DoubleVal, DBitWidth);
1396     }
1397   } else {
1398     // scalar
1399     uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1400     assert(SrcTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1401 
1402     if (SrcTy->getTypeID() == Type::FloatTyID)
1403       Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1404     else {
1405       Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1406     }
1407   }
1408 
1409   return Dest;
1410 }
1411 
1412 GenericValue Interpreter::executeFPToSIInst(Value *SrcVal, Type *DstTy,
1413                                             ExecutionContext &SF) {
1414   Type *SrcTy = SrcVal->getType();
1415   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1416 
1417   if (SrcTy->getTypeID() == Type::VectorTyID) {
1418     Type *DstVecTy = DstTy->getScalarType();
1419     Type *SrcVecTy = SrcTy->getScalarType();
1420     uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1421     unsigned size = Src.AggregateVal.size();
1422     // the sizes of src and dst vectors must be equal
1423     Dest.AggregateVal.resize(size);
1424 
1425     if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1426       assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1427       for (unsigned i = 0; i < size; i++)
1428         Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1429             Src.AggregateVal[i].FloatVal, DBitWidth);
1430     } else {
1431       for (unsigned i = 0; i < size; i++)
1432         Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1433             Src.AggregateVal[i].DoubleVal, DBitWidth);
1434     }
1435   } else {
1436     // scalar
1437     unsigned DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1438     assert(SrcTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1439 
1440     if (SrcTy->getTypeID() == Type::FloatTyID)
1441       Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1442     else {
1443       Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1444     }
1445   }
1446   return Dest;
1447 }
1448 
1449 GenericValue Interpreter::executeUIToFPInst(Value *SrcVal, Type *DstTy,
1450                                             ExecutionContext &SF) {
1451   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1452 
1453   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1454     Type *DstVecTy = DstTy->getScalarType();
1455     unsigned size = Src.AggregateVal.size();
1456     // the sizes of src and dst vectors must be equal
1457     Dest.AggregateVal.resize(size);
1458 
1459     if (DstVecTy->getTypeID() == Type::FloatTyID) {
1460       assert(DstVecTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1461       for (unsigned i = 0; i < size; i++)
1462         Dest.AggregateVal[i].FloatVal =
1463             APIntOps::RoundAPIntToFloat(Src.AggregateVal[i].IntVal);
1464     } else {
1465       for (unsigned i = 0; i < size; i++)
1466         Dest.AggregateVal[i].DoubleVal =
1467             APIntOps::RoundAPIntToDouble(Src.AggregateVal[i].IntVal);
1468     }
1469   } else {
1470     // scalar
1471     assert(DstTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1472     if (DstTy->getTypeID() == Type::FloatTyID)
1473       Dest.FloatVal = APIntOps::RoundAPIntToFloat(Src.IntVal);
1474     else {
1475       Dest.DoubleVal = APIntOps::RoundAPIntToDouble(Src.IntVal);
1476     }
1477   }
1478   return Dest;
1479 }
1480 
1481 GenericValue Interpreter::executeSIToFPInst(Value *SrcVal, Type *DstTy,
1482                                             ExecutionContext &SF) {
1483   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1484 
1485   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1486     Type *DstVecTy = DstTy->getScalarType();
1487     unsigned size = Src.AggregateVal.size();
1488     // the sizes of src and dst vectors must be equal
1489     Dest.AggregateVal.resize(size);
1490 
1491     if (DstVecTy->getTypeID() == Type::FloatTyID) {
1492       assert(DstVecTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1493       for (unsigned i = 0; i < size; i++)
1494         Dest.AggregateVal[i].FloatVal =
1495             APIntOps::RoundSignedAPIntToFloat(Src.AggregateVal[i].IntVal);
1496     } else {
1497       for (unsigned i = 0; i < size; i++)
1498         Dest.AggregateVal[i].DoubleVal =
1499             APIntOps::RoundSignedAPIntToDouble(Src.AggregateVal[i].IntVal);
1500     }
1501   } else {
1502     // scalar
1503     assert(DstTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1504 
1505     if (DstTy->getTypeID() == Type::FloatTyID)
1506       Dest.FloatVal = APIntOps::RoundSignedAPIntToFloat(Src.IntVal);
1507     else {
1508       Dest.DoubleVal = APIntOps::RoundSignedAPIntToDouble(Src.IntVal);
1509     }
1510   }
1511 
1512   return Dest;
1513 }
1514 
1515 GenericValue Interpreter::executePtrToIntInst(Value *SrcVal, Type *DstTy,
1516                                               ExecutionContext &SF) {
1517   uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1518   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1519   assert(SrcVal->getType()->isPointerTy() && "Invalid PtrToInt instruction");
1520 
1521   Dest.IntVal = APInt(DBitWidth, (intptr_t) Src.PointerVal);
1522   return Dest;
1523 }
1524 
1525 GenericValue Interpreter::executeIntToPtrInst(Value *SrcVal, Type *DstTy,
1526                                               ExecutionContext &SF) {
1527   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1528   assert(DstTy->isPointerTy() && "Invalid PtrToInt instruction");
1529 
1530   uint32_t PtrSize = getDataLayout().getPointerSizeInBits();
1531   if (PtrSize != Src.IntVal.getBitWidth())
1532     Src.IntVal = Src.IntVal.zextOrTrunc(PtrSize);
1533 
1534   Dest.PointerVal = PointerTy(intptr_t(Src.IntVal.getZExtValue()));
1535   return Dest;
1536 }
1537 
1538 GenericValue Interpreter::executeBitCastInst(Value *SrcVal, Type *DstTy,
1539                                              ExecutionContext &SF) {
1540 
1541   // This instruction supports bitwise conversion of vectors to integers and
1542   // to vectors of other types (as long as they have the same size)
1543   Type *SrcTy = SrcVal->getType();
1544   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1545 
1546   if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1547       (DstTy->getTypeID() == Type::VectorTyID)) {
1548     // vector src bitcast to vector dst or vector src bitcast to scalar dst or
1549     // scalar src bitcast to vector dst
1550     bool isLittleEndian = getDataLayout().isLittleEndian();
1551     GenericValue TempDst, TempSrc, SrcVec;
1552     Type *SrcElemTy;
1553     Type *DstElemTy;
1554     unsigned SrcBitSize;
1555     unsigned DstBitSize;
1556     unsigned SrcNum;
1557     unsigned DstNum;
1558 
1559     if (SrcTy->getTypeID() == Type::VectorTyID) {
1560       SrcElemTy = SrcTy->getScalarType();
1561       SrcBitSize = SrcTy->getScalarSizeInBits();
1562       SrcNum = Src.AggregateVal.size();
1563       SrcVec = Src;
1564     } else {
1565       // if src is scalar value, make it vector <1 x type>
1566       SrcElemTy = SrcTy;
1567       SrcBitSize = SrcTy->getPrimitiveSizeInBits();
1568       SrcNum = 1;
1569       SrcVec.AggregateVal.push_back(Src);
1570     }
1571 
1572     if (DstTy->getTypeID() == Type::VectorTyID) {
1573       DstElemTy = DstTy->getScalarType();
1574       DstBitSize = DstTy->getScalarSizeInBits();
1575       DstNum = (SrcNum * SrcBitSize) / DstBitSize;
1576     } else {
1577       DstElemTy = DstTy;
1578       DstBitSize = DstTy->getPrimitiveSizeInBits();
1579       DstNum = 1;
1580     }
1581 
1582     if (SrcNum * SrcBitSize != DstNum * DstBitSize)
1583       llvm_unreachable("Invalid BitCast");
1584 
1585     // If src is floating point, cast to integer first.
1586     TempSrc.AggregateVal.resize(SrcNum);
1587     if (SrcElemTy->isFloatTy()) {
1588       for (unsigned i = 0; i < SrcNum; i++)
1589         TempSrc.AggregateVal[i].IntVal =
1590             APInt::floatToBits(SrcVec.AggregateVal[i].FloatVal);
1591 
1592     } else if (SrcElemTy->isDoubleTy()) {
1593       for (unsigned i = 0; i < SrcNum; i++)
1594         TempSrc.AggregateVal[i].IntVal =
1595             APInt::doubleToBits(SrcVec.AggregateVal[i].DoubleVal);
1596     } else if (SrcElemTy->isIntegerTy()) {
1597       for (unsigned i = 0; i < SrcNum; i++)
1598         TempSrc.AggregateVal[i].IntVal = SrcVec.AggregateVal[i].IntVal;
1599     } else {
1600       // Pointers are not allowed as the element type of vector.
1601       llvm_unreachable("Invalid Bitcast");
1602     }
1603 
1604     // now TempSrc is integer type vector
1605     if (DstNum < SrcNum) {
1606       // Example: bitcast <4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>
1607       unsigned Ratio = SrcNum / DstNum;
1608       unsigned SrcElt = 0;
1609       for (unsigned i = 0; i < DstNum; i++) {
1610         GenericValue Elt;
1611         Elt.IntVal = 0;
1612         Elt.IntVal = Elt.IntVal.zext(DstBitSize);
1613         unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize * (Ratio - 1);
1614         for (unsigned j = 0; j < Ratio; j++) {
1615           APInt Tmp;
1616           Tmp = Tmp.zext(SrcBitSize);
1617           Tmp = TempSrc.AggregateVal[SrcElt++].IntVal;
1618           Tmp = Tmp.zext(DstBitSize);
1619           Tmp <<= ShiftAmt;
1620           ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
1621           Elt.IntVal |= Tmp;
1622         }
1623         TempDst.AggregateVal.push_back(Elt);
1624       }
1625     } else {
1626       // Example: bitcast <2 x i64> <i64 0, i64 1> to <4 x i32>
1627       unsigned Ratio = DstNum / SrcNum;
1628       for (unsigned i = 0; i < SrcNum; i++) {
1629         unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize * (Ratio - 1);
1630         for (unsigned j = 0; j < Ratio; j++) {
1631           GenericValue Elt;
1632           Elt.IntVal = Elt.IntVal.zext(SrcBitSize);
1633           Elt.IntVal = TempSrc.AggregateVal[i].IntVal;
1634           Elt.IntVal.lshrInPlace(ShiftAmt);
1635           // it could be DstBitSize == SrcBitSize, so check it
1636           if (DstBitSize < SrcBitSize)
1637             Elt.IntVal = Elt.IntVal.trunc(DstBitSize);
1638           ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
1639           TempDst.AggregateVal.push_back(Elt);
1640         }
1641       }
1642     }
1643 
1644     // convert result from integer to specified type
1645     if (DstTy->getTypeID() == Type::VectorTyID) {
1646       if (DstElemTy->isDoubleTy()) {
1647         Dest.AggregateVal.resize(DstNum);
1648         for (unsigned i = 0; i < DstNum; i++)
1649           Dest.AggregateVal[i].DoubleVal =
1650               TempDst.AggregateVal[i].IntVal.bitsToDouble();
1651       } else if (DstElemTy->isFloatTy()) {
1652         Dest.AggregateVal.resize(DstNum);
1653         for (unsigned i = 0; i < DstNum; i++)
1654           Dest.AggregateVal[i].FloatVal =
1655               TempDst.AggregateVal[i].IntVal.bitsToFloat();
1656       } else {
1657         Dest = TempDst;
1658       }
1659     } else {
1660       if (DstElemTy->isDoubleTy())
1661         Dest.DoubleVal = TempDst.AggregateVal[0].IntVal.bitsToDouble();
1662       else if (DstElemTy->isFloatTy()) {
1663         Dest.FloatVal = TempDst.AggregateVal[0].IntVal.bitsToFloat();
1664       } else {
1665         Dest.IntVal = TempDst.AggregateVal[0].IntVal;
1666       }
1667     }
1668   } else { //  if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1669            //     (DstTy->getTypeID() == Type::VectorTyID))
1670 
1671     // scalar src bitcast to scalar dst
1672     if (DstTy->isPointerTy()) {
1673       assert(SrcTy->isPointerTy() && "Invalid BitCast");
1674       Dest.PointerVal = Src.PointerVal;
1675     } else if (DstTy->isIntegerTy()) {
1676       if (SrcTy->isFloatTy())
1677         Dest.IntVal = APInt::floatToBits(Src.FloatVal);
1678       else if (SrcTy->isDoubleTy()) {
1679         Dest.IntVal = APInt::doubleToBits(Src.DoubleVal);
1680       } else if (SrcTy->isIntegerTy()) {
1681         Dest.IntVal = Src.IntVal;
1682       } else {
1683         llvm_unreachable("Invalid BitCast");
1684       }
1685     } else if (DstTy->isFloatTy()) {
1686       if (SrcTy->isIntegerTy())
1687         Dest.FloatVal = Src.IntVal.bitsToFloat();
1688       else {
1689         Dest.FloatVal = Src.FloatVal;
1690       }
1691     } else if (DstTy->isDoubleTy()) {
1692       if (SrcTy->isIntegerTy())
1693         Dest.DoubleVal = Src.IntVal.bitsToDouble();
1694       else {
1695         Dest.DoubleVal = Src.DoubleVal;
1696       }
1697     } else {
1698       llvm_unreachable("Invalid Bitcast");
1699     }
1700   }
1701 
1702   return Dest;
1703 }
1704 
1705 void Interpreter::visitTruncInst(TruncInst &I) {
1706   ExecutionContext &SF = ECStack.back();
1707   SetValue(&I, executeTruncInst(I.getOperand(0), I.getType(), SF), SF);
1708 }
1709 
1710 void Interpreter::visitSExtInst(SExtInst &I) {
1711   ExecutionContext &SF = ECStack.back();
1712   SetValue(&I, executeSExtInst(I.getOperand(0), I.getType(), SF), SF);
1713 }
1714 
1715 void Interpreter::visitZExtInst(ZExtInst &I) {
1716   ExecutionContext &SF = ECStack.back();
1717   SetValue(&I, executeZExtInst(I.getOperand(0), I.getType(), SF), SF);
1718 }
1719 
1720 void Interpreter::visitFPTruncInst(FPTruncInst &I) {
1721   ExecutionContext &SF = ECStack.back();
1722   SetValue(&I, executeFPTruncInst(I.getOperand(0), I.getType(), SF), SF);
1723 }
1724 
1725 void Interpreter::visitFPExtInst(FPExtInst &I) {
1726   ExecutionContext &SF = ECStack.back();
1727   SetValue(&I, executeFPExtInst(I.getOperand(0), I.getType(), SF), SF);
1728 }
1729 
1730 void Interpreter::visitUIToFPInst(UIToFPInst &I) {
1731   ExecutionContext &SF = ECStack.back();
1732   SetValue(&I, executeUIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1733 }
1734 
1735 void Interpreter::visitSIToFPInst(SIToFPInst &I) {
1736   ExecutionContext &SF = ECStack.back();
1737   SetValue(&I, executeSIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1738 }
1739 
1740 void Interpreter::visitFPToUIInst(FPToUIInst &I) {
1741   ExecutionContext &SF = ECStack.back();
1742   SetValue(&I, executeFPToUIInst(I.getOperand(0), I.getType(), SF), SF);
1743 }
1744 
1745 void Interpreter::visitFPToSIInst(FPToSIInst &I) {
1746   ExecutionContext &SF = ECStack.back();
1747   SetValue(&I, executeFPToSIInst(I.getOperand(0), I.getType(), SF), SF);
1748 }
1749 
1750 void Interpreter::visitPtrToIntInst(PtrToIntInst &I) {
1751   ExecutionContext &SF = ECStack.back();
1752   SetValue(&I, executePtrToIntInst(I.getOperand(0), I.getType(), SF), SF);
1753 }
1754 
1755 void Interpreter::visitIntToPtrInst(IntToPtrInst &I) {
1756   ExecutionContext &SF = ECStack.back();
1757   SetValue(&I, executeIntToPtrInst(I.getOperand(0), I.getType(), SF), SF);
1758 }
1759 
1760 void Interpreter::visitBitCastInst(BitCastInst &I) {
1761   ExecutionContext &SF = ECStack.back();
1762   SetValue(&I, executeBitCastInst(I.getOperand(0), I.getType(), SF), SF);
1763 }
1764 
1765 #define IMPLEMENT_VAARG(TY) \
1766    case Type::TY##TyID: Dest.TY##Val = Src.TY##Val; break
1767 
1768 void Interpreter::visitVAArgInst(VAArgInst &I) {
1769   ExecutionContext &SF = ECStack.back();
1770 
1771   // Get the incoming valist parameter.  LLI treats the valist as a
1772   // (ec-stack-depth var-arg-index) pair.
1773   GenericValue VAList = getOperandValue(I.getOperand(0), SF);
1774   GenericValue Dest;
1775   GenericValue Src = ECStack[VAList.UIntPairVal.first]
1776                       .VarArgs[VAList.UIntPairVal.second];
1777   Type *Ty = I.getType();
1778   switch (Ty->getTypeID()) {
1779   case Type::IntegerTyID:
1780     Dest.IntVal = Src.IntVal;
1781     break;
1782   IMPLEMENT_VAARG(Pointer);
1783   IMPLEMENT_VAARG(Float);
1784   IMPLEMENT_VAARG(Double);
1785   default:
1786     dbgs() << "Unhandled dest type for vaarg instruction: " << *Ty << "\n";
1787     llvm_unreachable(nullptr);
1788   }
1789 
1790   // Set the Value of this Instruction.
1791   SetValue(&I, Dest, SF);
1792 
1793   // Move the pointer to the next vararg.
1794   ++VAList.UIntPairVal.second;
1795 }
1796 
1797 void Interpreter::visitExtractElementInst(ExtractElementInst &I) {
1798   ExecutionContext &SF = ECStack.back();
1799   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1800   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1801   GenericValue Dest;
1802 
1803   Type *Ty = I.getType();
1804   const unsigned indx = unsigned(Src2.IntVal.getZExtValue());
1805 
1806   if(Src1.AggregateVal.size() > indx) {
1807     switch (Ty->getTypeID()) {
1808     default:
1809       dbgs() << "Unhandled destination type for extractelement instruction: "
1810       << *Ty << "\n";
1811       llvm_unreachable(nullptr);
1812       break;
1813     case Type::IntegerTyID:
1814       Dest.IntVal = Src1.AggregateVal[indx].IntVal;
1815       break;
1816     case Type::FloatTyID:
1817       Dest.FloatVal = Src1.AggregateVal[indx].FloatVal;
1818       break;
1819     case Type::DoubleTyID:
1820       Dest.DoubleVal = Src1.AggregateVal[indx].DoubleVal;
1821       break;
1822     }
1823   } else {
1824     dbgs() << "Invalid index in extractelement instruction\n";
1825   }
1826 
1827   SetValue(&I, Dest, SF);
1828 }
1829 
1830 void Interpreter::visitInsertElementInst(InsertElementInst &I) {
1831   ExecutionContext &SF = ECStack.back();
1832   VectorType *Ty = cast<VectorType>(I.getType());
1833 
1834   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1835   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1836   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1837   GenericValue Dest;
1838 
1839   Type *TyContained = Ty->getElementType();
1840 
1841   const unsigned indx = unsigned(Src3.IntVal.getZExtValue());
1842   Dest.AggregateVal = Src1.AggregateVal;
1843 
1844   if(Src1.AggregateVal.size() <= indx)
1845       llvm_unreachable("Invalid index in insertelement instruction");
1846   switch (TyContained->getTypeID()) {
1847     default:
1848       llvm_unreachable("Unhandled dest type for insertelement instruction");
1849     case Type::IntegerTyID:
1850       Dest.AggregateVal[indx].IntVal = Src2.IntVal;
1851       break;
1852     case Type::FloatTyID:
1853       Dest.AggregateVal[indx].FloatVal = Src2.FloatVal;
1854       break;
1855     case Type::DoubleTyID:
1856       Dest.AggregateVal[indx].DoubleVal = Src2.DoubleVal;
1857       break;
1858   }
1859   SetValue(&I, Dest, SF);
1860 }
1861 
1862 void Interpreter::visitShuffleVectorInst(ShuffleVectorInst &I){
1863   ExecutionContext &SF = ECStack.back();
1864 
1865   VectorType *Ty = cast<VectorType>(I.getType());
1866 
1867   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1868   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1869   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1870   GenericValue Dest;
1871 
1872   // There is no need to check types of src1 and src2, because the compiled
1873   // bytecode can't contain different types for src1 and src2 for a
1874   // shufflevector instruction.
1875 
1876   Type *TyContained = Ty->getElementType();
1877   unsigned src1Size = (unsigned)Src1.AggregateVal.size();
1878   unsigned src2Size = (unsigned)Src2.AggregateVal.size();
1879   unsigned src3Size = (unsigned)Src3.AggregateVal.size();
1880 
1881   Dest.AggregateVal.resize(src3Size);
1882 
1883   switch (TyContained->getTypeID()) {
1884     default:
1885       llvm_unreachable("Unhandled dest type for insertelement instruction");
1886       break;
1887     case Type::IntegerTyID:
1888       for( unsigned i=0; i<src3Size; i++) {
1889         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1890         if(j < src1Size)
1891           Dest.AggregateVal[i].IntVal = Src1.AggregateVal[j].IntVal;
1892         else if(j < src1Size + src2Size)
1893           Dest.AggregateVal[i].IntVal = Src2.AggregateVal[j-src1Size].IntVal;
1894         else
1895           // The selector may not be greater than sum of lengths of first and
1896           // second operands and llasm should not allow situation like
1897           // %tmp = shufflevector <2 x i32> <i32 3, i32 4>, <2 x i32> undef,
1898           //                      <2 x i32> < i32 0, i32 5 >,
1899           // where i32 5 is invalid, but let it be additional check here:
1900           llvm_unreachable("Invalid mask in shufflevector instruction");
1901       }
1902       break;
1903     case Type::FloatTyID:
1904       for( unsigned i=0; i<src3Size; i++) {
1905         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1906         if(j < src1Size)
1907           Dest.AggregateVal[i].FloatVal = Src1.AggregateVal[j].FloatVal;
1908         else if(j < src1Size + src2Size)
1909           Dest.AggregateVal[i].FloatVal = Src2.AggregateVal[j-src1Size].FloatVal;
1910         else
1911           llvm_unreachable("Invalid mask in shufflevector instruction");
1912         }
1913       break;
1914     case Type::DoubleTyID:
1915       for( unsigned i=0; i<src3Size; i++) {
1916         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1917         if(j < src1Size)
1918           Dest.AggregateVal[i].DoubleVal = Src1.AggregateVal[j].DoubleVal;
1919         else if(j < src1Size + src2Size)
1920           Dest.AggregateVal[i].DoubleVal =
1921             Src2.AggregateVal[j-src1Size].DoubleVal;
1922         else
1923           llvm_unreachable("Invalid mask in shufflevector instruction");
1924       }
1925       break;
1926   }
1927   SetValue(&I, Dest, SF);
1928 }
1929 
1930 void Interpreter::visitExtractValueInst(ExtractValueInst &I) {
1931   ExecutionContext &SF = ECStack.back();
1932   Value *Agg = I.getAggregateOperand();
1933   GenericValue Dest;
1934   GenericValue Src = getOperandValue(Agg, SF);
1935 
1936   ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1937   unsigned Num = I.getNumIndices();
1938   GenericValue *pSrc = &Src;
1939 
1940   for (unsigned i = 0 ; i < Num; ++i) {
1941     pSrc = &pSrc->AggregateVal[*IdxBegin];
1942     ++IdxBegin;
1943   }
1944 
1945   Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1946   switch (IndexedType->getTypeID()) {
1947     default:
1948       llvm_unreachable("Unhandled dest type for extractelement instruction");
1949     break;
1950     case Type::IntegerTyID:
1951       Dest.IntVal = pSrc->IntVal;
1952     break;
1953     case Type::FloatTyID:
1954       Dest.FloatVal = pSrc->FloatVal;
1955     break;
1956     case Type::DoubleTyID:
1957       Dest.DoubleVal = pSrc->DoubleVal;
1958     break;
1959     case Type::ArrayTyID:
1960     case Type::StructTyID:
1961     case Type::VectorTyID:
1962       Dest.AggregateVal = pSrc->AggregateVal;
1963     break;
1964     case Type::PointerTyID:
1965       Dest.PointerVal = pSrc->PointerVal;
1966     break;
1967   }
1968 
1969   SetValue(&I, Dest, SF);
1970 }
1971 
1972 void Interpreter::visitInsertValueInst(InsertValueInst &I) {
1973 
1974   ExecutionContext &SF = ECStack.back();
1975   Value *Agg = I.getAggregateOperand();
1976 
1977   GenericValue Src1 = getOperandValue(Agg, SF);
1978   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1979   GenericValue Dest = Src1; // Dest is a slightly changed Src1
1980 
1981   ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1982   unsigned Num = I.getNumIndices();
1983 
1984   GenericValue *pDest = &Dest;
1985   for (unsigned i = 0 ; i < Num; ++i) {
1986     pDest = &pDest->AggregateVal[*IdxBegin];
1987     ++IdxBegin;
1988   }
1989   // pDest points to the target value in the Dest now
1990 
1991   Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1992 
1993   switch (IndexedType->getTypeID()) {
1994     default:
1995       llvm_unreachable("Unhandled dest type for insertelement instruction");
1996     break;
1997     case Type::IntegerTyID:
1998       pDest->IntVal = Src2.IntVal;
1999     break;
2000     case Type::FloatTyID:
2001       pDest->FloatVal = Src2.FloatVal;
2002     break;
2003     case Type::DoubleTyID:
2004       pDest->DoubleVal = Src2.DoubleVal;
2005     break;
2006     case Type::ArrayTyID:
2007     case Type::StructTyID:
2008     case Type::VectorTyID:
2009       pDest->AggregateVal = Src2.AggregateVal;
2010     break;
2011     case Type::PointerTyID:
2012       pDest->PointerVal = Src2.PointerVal;
2013     break;
2014   }
2015 
2016   SetValue(&I, Dest, SF);
2017 }
2018 
2019 GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
2020                                                 ExecutionContext &SF) {
2021   switch (CE->getOpcode()) {
2022   case Instruction::Trunc:
2023       return executeTruncInst(CE->getOperand(0), CE->getType(), SF);
2024   case Instruction::ZExt:
2025       return executeZExtInst(CE->getOperand(0), CE->getType(), SF);
2026   case Instruction::SExt:
2027       return executeSExtInst(CE->getOperand(0), CE->getType(), SF);
2028   case Instruction::FPTrunc:
2029       return executeFPTruncInst(CE->getOperand(0), CE->getType(), SF);
2030   case Instruction::FPExt:
2031       return executeFPExtInst(CE->getOperand(0), CE->getType(), SF);
2032   case Instruction::UIToFP:
2033       return executeUIToFPInst(CE->getOperand(0), CE->getType(), SF);
2034   case Instruction::SIToFP:
2035       return executeSIToFPInst(CE->getOperand(0), CE->getType(), SF);
2036   case Instruction::FPToUI:
2037       return executeFPToUIInst(CE->getOperand(0), CE->getType(), SF);
2038   case Instruction::FPToSI:
2039       return executeFPToSIInst(CE->getOperand(0), CE->getType(), SF);
2040   case Instruction::PtrToInt:
2041       return executePtrToIntInst(CE->getOperand(0), CE->getType(), SF);
2042   case Instruction::IntToPtr:
2043       return executeIntToPtrInst(CE->getOperand(0), CE->getType(), SF);
2044   case Instruction::BitCast:
2045       return executeBitCastInst(CE->getOperand(0), CE->getType(), SF);
2046   case Instruction::GetElementPtr:
2047     return executeGEPOperation(CE->getOperand(0), gep_type_begin(CE),
2048                                gep_type_end(CE), SF);
2049   case Instruction::FCmp:
2050   case Instruction::ICmp:
2051     return executeCmpInst(CE->getPredicate(),
2052                           getOperandValue(CE->getOperand(0), SF),
2053                           getOperandValue(CE->getOperand(1), SF),
2054                           CE->getOperand(0)->getType());
2055   case Instruction::Select:
2056     return executeSelectInst(getOperandValue(CE->getOperand(0), SF),
2057                              getOperandValue(CE->getOperand(1), SF),
2058                              getOperandValue(CE->getOperand(2), SF),
2059                              CE->getOperand(0)->getType());
2060   default :
2061     break;
2062   }
2063 
2064   // The cases below here require a GenericValue parameter for the result
2065   // so we initialize one, compute it and then return it.
2066   GenericValue Op0 = getOperandValue(CE->getOperand(0), SF);
2067   GenericValue Op1 = getOperandValue(CE->getOperand(1), SF);
2068   GenericValue Dest;
2069   Type * Ty = CE->getOperand(0)->getType();
2070   switch (CE->getOpcode()) {
2071   case Instruction::Add:  Dest.IntVal = Op0.IntVal + Op1.IntVal; break;
2072   case Instruction::Sub:  Dest.IntVal = Op0.IntVal - Op1.IntVal; break;
2073   case Instruction::Mul:  Dest.IntVal = Op0.IntVal * Op1.IntVal; break;
2074   case Instruction::FAdd: executeFAddInst(Dest, Op0, Op1, Ty); break;
2075   case Instruction::FSub: executeFSubInst(Dest, Op0, Op1, Ty); break;
2076   case Instruction::FMul: executeFMulInst(Dest, Op0, Op1, Ty); break;
2077   case Instruction::FDiv: executeFDivInst(Dest, Op0, Op1, Ty); break;
2078   case Instruction::FRem: executeFRemInst(Dest, Op0, Op1, Ty); break;
2079   case Instruction::SDiv: Dest.IntVal = Op0.IntVal.sdiv(Op1.IntVal); break;
2080   case Instruction::UDiv: Dest.IntVal = Op0.IntVal.udiv(Op1.IntVal); break;
2081   case Instruction::URem: Dest.IntVal = Op0.IntVal.urem(Op1.IntVal); break;
2082   case Instruction::SRem: Dest.IntVal = Op0.IntVal.srem(Op1.IntVal); break;
2083   case Instruction::And:  Dest.IntVal = Op0.IntVal & Op1.IntVal; break;
2084   case Instruction::Or:   Dest.IntVal = Op0.IntVal | Op1.IntVal; break;
2085   case Instruction::Xor:  Dest.IntVal = Op0.IntVal ^ Op1.IntVal; break;
2086   case Instruction::Shl:
2087     Dest.IntVal = Op0.IntVal.shl(Op1.IntVal.getZExtValue());
2088     break;
2089   case Instruction::LShr:
2090     Dest.IntVal = Op0.IntVal.lshr(Op1.IntVal.getZExtValue());
2091     break;
2092   case Instruction::AShr:
2093     Dest.IntVal = Op0.IntVal.ashr(Op1.IntVal.getZExtValue());
2094     break;
2095   default:
2096     dbgs() << "Unhandled ConstantExpr: " << *CE << "\n";
2097     llvm_unreachable("Unhandled ConstantExpr");
2098   }
2099   return Dest;
2100 }
2101 
2102 GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
2103   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
2104     return getConstantExprValue(CE, SF);
2105   } else if (Constant *CPV = dyn_cast<Constant>(V)) {
2106     return getConstantValue(CPV);
2107   } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
2108     return PTOGV(getPointerToGlobal(GV));
2109   } else {
2110     return SF.Values[V];
2111   }
2112 }
2113 
2114 //===----------------------------------------------------------------------===//
2115 //                        Dispatch and Execution Code
2116 //===----------------------------------------------------------------------===//
2117 
2118 //===----------------------------------------------------------------------===//
2119 // callFunction - Execute the specified function...
2120 //
2121 void Interpreter::callFunction(Function *F, ArrayRef<GenericValue> ArgVals) {
2122   assert((ECStack.empty() || !ECStack.back().Caller.getInstruction() ||
2123           ECStack.back().Caller.arg_size() == ArgVals.size()) &&
2124          "Incorrect number of arguments passed into function call!");
2125   // Make a new stack frame... and fill it in.
2126   ECStack.emplace_back();
2127   ExecutionContext &StackFrame = ECStack.back();
2128   StackFrame.CurFunction = F;
2129 
2130   // Special handling for external functions.
2131   if (F->isDeclaration()) {
2132     GenericValue Result = callExternalFunction (F, ArgVals);
2133     // Simulate a 'ret' instruction of the appropriate type.
2134     popStackAndReturnValueToCaller (F->getReturnType (), Result);
2135     return;
2136   }
2137 
2138   // Get pointers to first LLVM BB & Instruction in function.
2139   StackFrame.CurBB     = &F->front();
2140   StackFrame.CurInst   = StackFrame.CurBB->begin();
2141 
2142   // Run through the function arguments and initialize their values...
2143   assert((ArgVals.size() == F->arg_size() ||
2144          (ArgVals.size() > F->arg_size() && F->getFunctionType()->isVarArg()))&&
2145          "Invalid number of values passed to function invocation!");
2146 
2147   // Handle non-varargs arguments...
2148   unsigned i = 0;
2149   for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
2150        AI != E; ++AI, ++i)
2151     SetValue(&*AI, ArgVals[i], StackFrame);
2152 
2153   // Handle varargs arguments...
2154   StackFrame.VarArgs.assign(ArgVals.begin()+i, ArgVals.end());
2155 }
2156 
2157 
2158 void Interpreter::run() {
2159   while (!ECStack.empty()) {
2160     // Interpret a single instruction & increment the "PC".
2161     ExecutionContext &SF = ECStack.back();  // Current stack frame
2162     Instruction &I = *SF.CurInst++;         // Increment before execute
2163 
2164     // Track the number of dynamic instructions executed.
2165     ++NumDynamicInsts;
2166 
2167     LLVM_DEBUG(dbgs() << "About to interpret: " << I << "\n");
2168     visit(I);   // Dispatch to one of the visit* methods...
2169   }
2170 }
2171