xref: /llvm-project/llvm/lib/ExecutionEngine/Interpreter/Execution.cpp (revision 730ecf8fd5f5025021a2799a0f8b80431cbc04b1)
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 //                    Binary Instruction Implementations
47 //===----------------------------------------------------------------------===//
48 
49 #define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
50    case Type::TY##TyID: \
51      Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; \
52      break
53 
54 static void executeFAddInst(GenericValue &Dest, GenericValue Src1,
55                             GenericValue Src2, Type *Ty) {
56   switch (Ty->getTypeID()) {
57     IMPLEMENT_BINARY_OPERATOR(+, Float);
58     IMPLEMENT_BINARY_OPERATOR(+, Double);
59   default:
60     dbgs() << "Unhandled type for FAdd instruction: " << *Ty << "\n";
61     llvm_unreachable(nullptr);
62   }
63 }
64 
65 static void executeFSubInst(GenericValue &Dest, GenericValue Src1,
66                             GenericValue Src2, Type *Ty) {
67   switch (Ty->getTypeID()) {
68     IMPLEMENT_BINARY_OPERATOR(-, Float);
69     IMPLEMENT_BINARY_OPERATOR(-, Double);
70   default:
71     dbgs() << "Unhandled type for FSub instruction: " << *Ty << "\n";
72     llvm_unreachable(nullptr);
73   }
74 }
75 
76 static void executeFMulInst(GenericValue &Dest, GenericValue Src1,
77                             GenericValue Src2, Type *Ty) {
78   switch (Ty->getTypeID()) {
79     IMPLEMENT_BINARY_OPERATOR(*, Float);
80     IMPLEMENT_BINARY_OPERATOR(*, Double);
81   default:
82     dbgs() << "Unhandled type for FMul instruction: " << *Ty << "\n";
83     llvm_unreachable(nullptr);
84   }
85 }
86 
87 static void executeFDivInst(GenericValue &Dest, GenericValue Src1,
88                             GenericValue Src2, Type *Ty) {
89   switch (Ty->getTypeID()) {
90     IMPLEMENT_BINARY_OPERATOR(/, Float);
91     IMPLEMENT_BINARY_OPERATOR(/, Double);
92   default:
93     dbgs() << "Unhandled type for FDiv instruction: " << *Ty << "\n";
94     llvm_unreachable(nullptr);
95   }
96 }
97 
98 static void executeFRemInst(GenericValue &Dest, GenericValue Src1,
99                             GenericValue Src2, Type *Ty) {
100   switch (Ty->getTypeID()) {
101   case Type::FloatTyID:
102     Dest.FloatVal = fmod(Src1.FloatVal, Src2.FloatVal);
103     break;
104   case Type::DoubleTyID:
105     Dest.DoubleVal = fmod(Src1.DoubleVal, Src2.DoubleVal);
106     break;
107   default:
108     dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
109     llvm_unreachable(nullptr);
110   }
111 }
112 
113 #define IMPLEMENT_INTEGER_ICMP(OP, TY) \
114    case Type::IntegerTyID:  \
115       Dest.IntVal = APInt(1,Src1.IntVal.OP(Src2.IntVal)); \
116       break;
117 
118 #define IMPLEMENT_VECTOR_INTEGER_ICMP(OP, TY)                        \
119   case Type::VectorTyID: {                                           \
120     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());    \
121     Dest.AggregateVal.resize( Src1.AggregateVal.size() );            \
122     for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)             \
123       Dest.AggregateVal[_i].IntVal = APInt(1,                        \
124       Src1.AggregateVal[_i].IntVal.OP(Src2.AggregateVal[_i].IntVal));\
125   } break;
126 
127 // Handle pointers specially because they must be compared with only as much
128 // width as the host has.  We _do not_ want to be comparing 64 bit values when
129 // running on a 32-bit target, otherwise the upper 32 bits might mess up
130 // comparisons if they contain garbage.
131 #define IMPLEMENT_POINTER_ICMP(OP) \
132    case Type::PointerTyID: \
133       Dest.IntVal = APInt(1,(void*)(intptr_t)Src1.PointerVal OP \
134                             (void*)(intptr_t)Src2.PointerVal); \
135       break;
136 
137 static GenericValue executeICMP_EQ(GenericValue Src1, GenericValue Src2,
138                                    Type *Ty) {
139   GenericValue Dest;
140   switch (Ty->getTypeID()) {
141     IMPLEMENT_INTEGER_ICMP(eq,Ty);
142     IMPLEMENT_VECTOR_INTEGER_ICMP(eq,Ty);
143     IMPLEMENT_POINTER_ICMP(==);
144   default:
145     dbgs() << "Unhandled type for ICMP_EQ predicate: " << *Ty << "\n";
146     llvm_unreachable(nullptr);
147   }
148   return Dest;
149 }
150 
151 static GenericValue executeICMP_NE(GenericValue Src1, GenericValue Src2,
152                                    Type *Ty) {
153   GenericValue Dest;
154   switch (Ty->getTypeID()) {
155     IMPLEMENT_INTEGER_ICMP(ne,Ty);
156     IMPLEMENT_VECTOR_INTEGER_ICMP(ne,Ty);
157     IMPLEMENT_POINTER_ICMP(!=);
158   default:
159     dbgs() << "Unhandled type for ICMP_NE predicate: " << *Ty << "\n";
160     llvm_unreachable(nullptr);
161   }
162   return Dest;
163 }
164 
165 static GenericValue executeICMP_ULT(GenericValue Src1, GenericValue Src2,
166                                     Type *Ty) {
167   GenericValue Dest;
168   switch (Ty->getTypeID()) {
169     IMPLEMENT_INTEGER_ICMP(ult,Ty);
170     IMPLEMENT_VECTOR_INTEGER_ICMP(ult,Ty);
171     IMPLEMENT_POINTER_ICMP(<);
172   default:
173     dbgs() << "Unhandled type for ICMP_ULT predicate: " << *Ty << "\n";
174     llvm_unreachable(nullptr);
175   }
176   return Dest;
177 }
178 
179 static GenericValue executeICMP_SLT(GenericValue Src1, GenericValue Src2,
180                                     Type *Ty) {
181   GenericValue Dest;
182   switch (Ty->getTypeID()) {
183     IMPLEMENT_INTEGER_ICMP(slt,Ty);
184     IMPLEMENT_VECTOR_INTEGER_ICMP(slt,Ty);
185     IMPLEMENT_POINTER_ICMP(<);
186   default:
187     dbgs() << "Unhandled type for ICMP_SLT predicate: " << *Ty << "\n";
188     llvm_unreachable(nullptr);
189   }
190   return Dest;
191 }
192 
193 static GenericValue executeICMP_UGT(GenericValue Src1, GenericValue Src2,
194                                     Type *Ty) {
195   GenericValue Dest;
196   switch (Ty->getTypeID()) {
197     IMPLEMENT_INTEGER_ICMP(ugt,Ty);
198     IMPLEMENT_VECTOR_INTEGER_ICMP(ugt,Ty);
199     IMPLEMENT_POINTER_ICMP(>);
200   default:
201     dbgs() << "Unhandled type for ICMP_UGT predicate: " << *Ty << "\n";
202     llvm_unreachable(nullptr);
203   }
204   return Dest;
205 }
206 
207 static GenericValue executeICMP_SGT(GenericValue Src1, GenericValue Src2,
208                                     Type *Ty) {
209   GenericValue Dest;
210   switch (Ty->getTypeID()) {
211     IMPLEMENT_INTEGER_ICMP(sgt,Ty);
212     IMPLEMENT_VECTOR_INTEGER_ICMP(sgt,Ty);
213     IMPLEMENT_POINTER_ICMP(>);
214   default:
215     dbgs() << "Unhandled type for ICMP_SGT predicate: " << *Ty << "\n";
216     llvm_unreachable(nullptr);
217   }
218   return Dest;
219 }
220 
221 static GenericValue executeICMP_ULE(GenericValue Src1, GenericValue Src2,
222                                     Type *Ty) {
223   GenericValue Dest;
224   switch (Ty->getTypeID()) {
225     IMPLEMENT_INTEGER_ICMP(ule,Ty);
226     IMPLEMENT_VECTOR_INTEGER_ICMP(ule,Ty);
227     IMPLEMENT_POINTER_ICMP(<=);
228   default:
229     dbgs() << "Unhandled type for ICMP_ULE predicate: " << *Ty << "\n";
230     llvm_unreachable(nullptr);
231   }
232   return Dest;
233 }
234 
235 static GenericValue executeICMP_SLE(GenericValue Src1, GenericValue Src2,
236                                     Type *Ty) {
237   GenericValue Dest;
238   switch (Ty->getTypeID()) {
239     IMPLEMENT_INTEGER_ICMP(sle,Ty);
240     IMPLEMENT_VECTOR_INTEGER_ICMP(sle,Ty);
241     IMPLEMENT_POINTER_ICMP(<=);
242   default:
243     dbgs() << "Unhandled type for ICMP_SLE predicate: " << *Ty << "\n";
244     llvm_unreachable(nullptr);
245   }
246   return Dest;
247 }
248 
249 static GenericValue executeICMP_UGE(GenericValue Src1, GenericValue Src2,
250                                     Type *Ty) {
251   GenericValue Dest;
252   switch (Ty->getTypeID()) {
253     IMPLEMENT_INTEGER_ICMP(uge,Ty);
254     IMPLEMENT_VECTOR_INTEGER_ICMP(uge,Ty);
255     IMPLEMENT_POINTER_ICMP(>=);
256   default:
257     dbgs() << "Unhandled type for ICMP_UGE predicate: " << *Ty << "\n";
258     llvm_unreachable(nullptr);
259   }
260   return Dest;
261 }
262 
263 static GenericValue executeICMP_SGE(GenericValue Src1, GenericValue Src2,
264                                     Type *Ty) {
265   GenericValue Dest;
266   switch (Ty->getTypeID()) {
267     IMPLEMENT_INTEGER_ICMP(sge,Ty);
268     IMPLEMENT_VECTOR_INTEGER_ICMP(sge,Ty);
269     IMPLEMENT_POINTER_ICMP(>=);
270   default:
271     dbgs() << "Unhandled type for ICMP_SGE predicate: " << *Ty << "\n";
272     llvm_unreachable(nullptr);
273   }
274   return Dest;
275 }
276 
277 void Interpreter::visitICmpInst(ICmpInst &I) {
278   ExecutionContext &SF = ECStack.back();
279   Type *Ty    = I.getOperand(0)->getType();
280   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
281   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
282   GenericValue R;   // Result
283 
284   switch (I.getPredicate()) {
285   case ICmpInst::ICMP_EQ:  R = executeICMP_EQ(Src1,  Src2, Ty); break;
286   case ICmpInst::ICMP_NE:  R = executeICMP_NE(Src1,  Src2, Ty); break;
287   case ICmpInst::ICMP_ULT: R = executeICMP_ULT(Src1, Src2, Ty); break;
288   case ICmpInst::ICMP_SLT: R = executeICMP_SLT(Src1, Src2, Ty); break;
289   case ICmpInst::ICMP_UGT: R = executeICMP_UGT(Src1, Src2, Ty); break;
290   case ICmpInst::ICMP_SGT: R = executeICMP_SGT(Src1, Src2, Ty); break;
291   case ICmpInst::ICMP_ULE: R = executeICMP_ULE(Src1, Src2, Ty); break;
292   case ICmpInst::ICMP_SLE: R = executeICMP_SLE(Src1, Src2, Ty); break;
293   case ICmpInst::ICMP_UGE: R = executeICMP_UGE(Src1, Src2, Ty); break;
294   case ICmpInst::ICMP_SGE: R = executeICMP_SGE(Src1, Src2, Ty); break;
295   default:
296     dbgs() << "Don't know how to handle this ICmp predicate!\n-->" << I;
297     llvm_unreachable(nullptr);
298   }
299 
300   SetValue(&I, R, SF);
301 }
302 
303 #define IMPLEMENT_FCMP(OP, TY) \
304    case Type::TY##TyID: \
305      Dest.IntVal = APInt(1,Src1.TY##Val OP Src2.TY##Val); \
306      break
307 
308 #define IMPLEMENT_VECTOR_FCMP_T(OP, TY)                             \
309   assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());     \
310   Dest.AggregateVal.resize( Src1.AggregateVal.size() );             \
311   for( uint32_t _i=0;_i<Src1.AggregateVal.size();_i++)              \
312     Dest.AggregateVal[_i].IntVal = APInt(1,                         \
313     Src1.AggregateVal[_i].TY##Val OP Src2.AggregateVal[_i].TY##Val);\
314   break;
315 
316 #define IMPLEMENT_VECTOR_FCMP(OP)                                   \
317   case Type::VectorTyID:                                            \
318     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {      \
319       IMPLEMENT_VECTOR_FCMP_T(OP, Float);                           \
320     } else {                                                        \
321         IMPLEMENT_VECTOR_FCMP_T(OP, Double);                        \
322     }
323 
324 static GenericValue executeFCMP_OEQ(GenericValue Src1, GenericValue Src2,
325                                    Type *Ty) {
326   GenericValue Dest;
327   switch (Ty->getTypeID()) {
328     IMPLEMENT_FCMP(==, Float);
329     IMPLEMENT_FCMP(==, Double);
330     IMPLEMENT_VECTOR_FCMP(==);
331   default:
332     dbgs() << "Unhandled type for FCmp EQ instruction: " << *Ty << "\n";
333     llvm_unreachable(nullptr);
334   }
335   return Dest;
336 }
337 
338 #define IMPLEMENT_SCALAR_NANS(TY, X,Y)                                      \
339   if (TY->isFloatTy()) {                                                    \
340     if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {             \
341       Dest.IntVal = APInt(1,false);                                         \
342       return Dest;                                                          \
343     }                                                                       \
344   } else {                                                                  \
345     if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) {         \
346       Dest.IntVal = APInt(1,false);                                         \
347       return Dest;                                                          \
348     }                                                                       \
349   }
350 
351 #define MASK_VECTOR_NANS_T(X,Y, TZ, FLAG)                                   \
352   assert(X.AggregateVal.size() == Y.AggregateVal.size());                   \
353   Dest.AggregateVal.resize( X.AggregateVal.size() );                        \
354   for( uint32_t _i=0;_i<X.AggregateVal.size();_i++) {                       \
355     if (X.AggregateVal[_i].TZ##Val != X.AggregateVal[_i].TZ##Val ||         \
356         Y.AggregateVal[_i].TZ##Val != Y.AggregateVal[_i].TZ##Val)           \
357       Dest.AggregateVal[_i].IntVal = APInt(1,FLAG);                         \
358     else  {                                                                 \
359       Dest.AggregateVal[_i].IntVal = APInt(1,!FLAG);                        \
360     }                                                                       \
361   }
362 
363 #define MASK_VECTOR_NANS(TY, X,Y, FLAG)                                     \
364   if (TY->isVectorTy()) {                                                   \
365     if (cast<VectorType>(TY)->getElementType()->isFloatTy()) {              \
366       MASK_VECTOR_NANS_T(X, Y, Float, FLAG)                                 \
367     } else {                                                                \
368       MASK_VECTOR_NANS_T(X, Y, Double, FLAG)                                \
369     }                                                                       \
370   }                                                                         \
371 
372 
373 
374 static GenericValue executeFCMP_ONE(GenericValue Src1, GenericValue Src2,
375                                     Type *Ty)
376 {
377   GenericValue Dest;
378   // if input is scalar value and Src1 or Src2 is NaN return false
379   IMPLEMENT_SCALAR_NANS(Ty, Src1, Src2)
380   // if vector input detect NaNs and fill mask
381   MASK_VECTOR_NANS(Ty, Src1, Src2, false)
382   GenericValue DestMask = Dest;
383   switch (Ty->getTypeID()) {
384     IMPLEMENT_FCMP(!=, Float);
385     IMPLEMENT_FCMP(!=, Double);
386     IMPLEMENT_VECTOR_FCMP(!=);
387     default:
388       dbgs() << "Unhandled type for FCmp NE instruction: " << *Ty << "\n";
389       llvm_unreachable(nullptr);
390   }
391   // in vector case mask out NaN elements
392   if (Ty->isVectorTy())
393     for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
394       if (DestMask.AggregateVal[_i].IntVal == false)
395         Dest.AggregateVal[_i].IntVal = APInt(1,false);
396 
397   return Dest;
398 }
399 
400 static GenericValue executeFCMP_OLE(GenericValue Src1, GenericValue Src2,
401                                    Type *Ty) {
402   GenericValue Dest;
403   switch (Ty->getTypeID()) {
404     IMPLEMENT_FCMP(<=, Float);
405     IMPLEMENT_FCMP(<=, Double);
406     IMPLEMENT_VECTOR_FCMP(<=);
407   default:
408     dbgs() << "Unhandled type for FCmp LE instruction: " << *Ty << "\n";
409     llvm_unreachable(nullptr);
410   }
411   return Dest;
412 }
413 
414 static GenericValue executeFCMP_OGE(GenericValue Src1, GenericValue Src2,
415                                    Type *Ty) {
416   GenericValue Dest;
417   switch (Ty->getTypeID()) {
418     IMPLEMENT_FCMP(>=, Float);
419     IMPLEMENT_FCMP(>=, Double);
420     IMPLEMENT_VECTOR_FCMP(>=);
421   default:
422     dbgs() << "Unhandled type for FCmp GE instruction: " << *Ty << "\n";
423     llvm_unreachable(nullptr);
424   }
425   return Dest;
426 }
427 
428 static GenericValue executeFCMP_OLT(GenericValue Src1, GenericValue Src2,
429                                    Type *Ty) {
430   GenericValue Dest;
431   switch (Ty->getTypeID()) {
432     IMPLEMENT_FCMP(<, Float);
433     IMPLEMENT_FCMP(<, Double);
434     IMPLEMENT_VECTOR_FCMP(<);
435   default:
436     dbgs() << "Unhandled type for FCmp LT instruction: " << *Ty << "\n";
437     llvm_unreachable(nullptr);
438   }
439   return Dest;
440 }
441 
442 static GenericValue executeFCMP_OGT(GenericValue Src1, GenericValue Src2,
443                                      Type *Ty) {
444   GenericValue Dest;
445   switch (Ty->getTypeID()) {
446     IMPLEMENT_FCMP(>, Float);
447     IMPLEMENT_FCMP(>, Double);
448     IMPLEMENT_VECTOR_FCMP(>);
449   default:
450     dbgs() << "Unhandled type for FCmp GT instruction: " << *Ty << "\n";
451     llvm_unreachable(nullptr);
452   }
453   return Dest;
454 }
455 
456 #define IMPLEMENT_UNORDERED(TY, X,Y)                                     \
457   if (TY->isFloatTy()) {                                                 \
458     if (X.FloatVal != X.FloatVal || Y.FloatVal != Y.FloatVal) {          \
459       Dest.IntVal = APInt(1,true);                                       \
460       return Dest;                                                       \
461     }                                                                    \
462   } else if (X.DoubleVal != X.DoubleVal || Y.DoubleVal != Y.DoubleVal) { \
463     Dest.IntVal = APInt(1,true);                                         \
464     return Dest;                                                         \
465   }
466 
467 #define IMPLEMENT_VECTOR_UNORDERED(TY, X, Y, FUNC)                             \
468   if (TY->isVectorTy()) {                                                      \
469     GenericValue DestMask = Dest;                                              \
470     Dest = FUNC(Src1, Src2, Ty);                                               \
471     for (size_t _i = 0; _i < Src1.AggregateVal.size(); _i++)                   \
472       if (DestMask.AggregateVal[_i].IntVal == true)                            \
473         Dest.AggregateVal[_i].IntVal = APInt(1, true);                         \
474     return Dest;                                                               \
475   }
476 
477 static GenericValue executeFCMP_UEQ(GenericValue Src1, GenericValue Src2,
478                                    Type *Ty) {
479   GenericValue Dest;
480   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
481   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
482   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OEQ)
483   return executeFCMP_OEQ(Src1, Src2, Ty);
484 
485 }
486 
487 static GenericValue executeFCMP_UNE(GenericValue Src1, GenericValue Src2,
488                                    Type *Ty) {
489   GenericValue Dest;
490   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
491   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
492   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_ONE)
493   return executeFCMP_ONE(Src1, Src2, Ty);
494 }
495 
496 static GenericValue executeFCMP_ULE(GenericValue Src1, GenericValue Src2,
497                                    Type *Ty) {
498   GenericValue Dest;
499   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
500   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
501   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLE)
502   return executeFCMP_OLE(Src1, Src2, Ty);
503 }
504 
505 static GenericValue executeFCMP_UGE(GenericValue Src1, GenericValue Src2,
506                                    Type *Ty) {
507   GenericValue Dest;
508   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
509   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
510   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGE)
511   return executeFCMP_OGE(Src1, Src2, Ty);
512 }
513 
514 static GenericValue executeFCMP_ULT(GenericValue Src1, GenericValue Src2,
515                                    Type *Ty) {
516   GenericValue Dest;
517   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
518   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
519   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OLT)
520   return executeFCMP_OLT(Src1, Src2, Ty);
521 }
522 
523 static GenericValue executeFCMP_UGT(GenericValue Src1, GenericValue Src2,
524                                      Type *Ty) {
525   GenericValue Dest;
526   IMPLEMENT_UNORDERED(Ty, Src1, Src2)
527   MASK_VECTOR_NANS(Ty, Src1, Src2, true)
528   IMPLEMENT_VECTOR_UNORDERED(Ty, Src1, Src2, executeFCMP_OGT)
529   return executeFCMP_OGT(Src1, Src2, Ty);
530 }
531 
532 static GenericValue executeFCMP_ORD(GenericValue Src1, GenericValue Src2,
533                                      Type *Ty) {
534   GenericValue Dest;
535   if(Ty->isVectorTy()) {
536     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
537     Dest.AggregateVal.resize( Src1.AggregateVal.size() );
538     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
539       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
540         Dest.AggregateVal[_i].IntVal = APInt(1,
541         ( (Src1.AggregateVal[_i].FloatVal ==
542         Src1.AggregateVal[_i].FloatVal) &&
543         (Src2.AggregateVal[_i].FloatVal ==
544         Src2.AggregateVal[_i].FloatVal)));
545     } else {
546       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
547         Dest.AggregateVal[_i].IntVal = APInt(1,
548         ( (Src1.AggregateVal[_i].DoubleVal ==
549         Src1.AggregateVal[_i].DoubleVal) &&
550         (Src2.AggregateVal[_i].DoubleVal ==
551         Src2.AggregateVal[_i].DoubleVal)));
552     }
553   } else if (Ty->isFloatTy())
554     Dest.IntVal = APInt(1,(Src1.FloatVal == Src1.FloatVal &&
555                            Src2.FloatVal == Src2.FloatVal));
556   else {
557     Dest.IntVal = APInt(1,(Src1.DoubleVal == Src1.DoubleVal &&
558                            Src2.DoubleVal == Src2.DoubleVal));
559   }
560   return Dest;
561 }
562 
563 static GenericValue executeFCMP_UNO(GenericValue Src1, GenericValue Src2,
564                                      Type *Ty) {
565   GenericValue Dest;
566   if(Ty->isVectorTy()) {
567     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
568     Dest.AggregateVal.resize( Src1.AggregateVal.size() );
569     if (cast<VectorType>(Ty)->getElementType()->isFloatTy()) {
570       for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
571         Dest.AggregateVal[_i].IntVal = APInt(1,
572         ( (Src1.AggregateVal[_i].FloatVal !=
573            Src1.AggregateVal[_i].FloatVal) ||
574           (Src2.AggregateVal[_i].FloatVal !=
575            Src2.AggregateVal[_i].FloatVal)));
576       } else {
577         for( size_t _i=0;_i<Src1.AggregateVal.size();_i++)
578           Dest.AggregateVal[_i].IntVal = APInt(1,
579           ( (Src1.AggregateVal[_i].DoubleVal !=
580              Src1.AggregateVal[_i].DoubleVal) ||
581             (Src2.AggregateVal[_i].DoubleVal !=
582              Src2.AggregateVal[_i].DoubleVal)));
583       }
584   } else if (Ty->isFloatTy())
585     Dest.IntVal = APInt(1,(Src1.FloatVal != Src1.FloatVal ||
586                            Src2.FloatVal != Src2.FloatVal));
587   else {
588     Dest.IntVal = APInt(1,(Src1.DoubleVal != Src1.DoubleVal ||
589                            Src2.DoubleVal != Src2.DoubleVal));
590   }
591   return Dest;
592 }
593 
594 static GenericValue executeFCMP_BOOL(GenericValue Src1, GenericValue Src2,
595                                      Type *Ty, const bool val) {
596   GenericValue Dest;
597     if(Ty->isVectorTy()) {
598       assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
599       Dest.AggregateVal.resize( Src1.AggregateVal.size() );
600       for( size_t _i=0; _i<Src1.AggregateVal.size(); _i++)
601         Dest.AggregateVal[_i].IntVal = APInt(1,val);
602     } else {
603       Dest.IntVal = APInt(1, val);
604     }
605 
606     return Dest;
607 }
608 
609 void Interpreter::visitFCmpInst(FCmpInst &I) {
610   ExecutionContext &SF = ECStack.back();
611   Type *Ty    = I.getOperand(0)->getType();
612   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
613   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
614   GenericValue R;   // Result
615 
616   switch (I.getPredicate()) {
617   default:
618     dbgs() << "Don't know how to handle this FCmp predicate!\n-->" << I;
619     llvm_unreachable(nullptr);
620   break;
621   case FCmpInst::FCMP_FALSE: R = executeFCMP_BOOL(Src1, Src2, Ty, false);
622   break;
623   case FCmpInst::FCMP_TRUE:  R = executeFCMP_BOOL(Src1, Src2, Ty, true);
624   break;
625   case FCmpInst::FCMP_ORD:   R = executeFCMP_ORD(Src1, Src2, Ty); break;
626   case FCmpInst::FCMP_UNO:   R = executeFCMP_UNO(Src1, Src2, Ty); break;
627   case FCmpInst::FCMP_UEQ:   R = executeFCMP_UEQ(Src1, Src2, Ty); break;
628   case FCmpInst::FCMP_OEQ:   R = executeFCMP_OEQ(Src1, Src2, Ty); break;
629   case FCmpInst::FCMP_UNE:   R = executeFCMP_UNE(Src1, Src2, Ty); break;
630   case FCmpInst::FCMP_ONE:   R = executeFCMP_ONE(Src1, Src2, Ty); break;
631   case FCmpInst::FCMP_ULT:   R = executeFCMP_ULT(Src1, Src2, Ty); break;
632   case FCmpInst::FCMP_OLT:   R = executeFCMP_OLT(Src1, Src2, Ty); break;
633   case FCmpInst::FCMP_UGT:   R = executeFCMP_UGT(Src1, Src2, Ty); break;
634   case FCmpInst::FCMP_OGT:   R = executeFCMP_OGT(Src1, Src2, Ty); break;
635   case FCmpInst::FCMP_ULE:   R = executeFCMP_ULE(Src1, Src2, Ty); break;
636   case FCmpInst::FCMP_OLE:   R = executeFCMP_OLE(Src1, Src2, Ty); break;
637   case FCmpInst::FCMP_UGE:   R = executeFCMP_UGE(Src1, Src2, Ty); break;
638   case FCmpInst::FCMP_OGE:   R = executeFCMP_OGE(Src1, Src2, Ty); break;
639   }
640 
641   SetValue(&I, R, SF);
642 }
643 
644 static GenericValue executeCmpInst(unsigned predicate, GenericValue Src1,
645                                    GenericValue Src2, Type *Ty) {
646   GenericValue Result;
647   switch (predicate) {
648   case ICmpInst::ICMP_EQ:    return executeICMP_EQ(Src1, Src2, Ty);
649   case ICmpInst::ICMP_NE:    return executeICMP_NE(Src1, Src2, Ty);
650   case ICmpInst::ICMP_UGT:   return executeICMP_UGT(Src1, Src2, Ty);
651   case ICmpInst::ICMP_SGT:   return executeICMP_SGT(Src1, Src2, Ty);
652   case ICmpInst::ICMP_ULT:   return executeICMP_ULT(Src1, Src2, Ty);
653   case ICmpInst::ICMP_SLT:   return executeICMP_SLT(Src1, Src2, Ty);
654   case ICmpInst::ICMP_UGE:   return executeICMP_UGE(Src1, Src2, Ty);
655   case ICmpInst::ICMP_SGE:   return executeICMP_SGE(Src1, Src2, Ty);
656   case ICmpInst::ICMP_ULE:   return executeICMP_ULE(Src1, Src2, Ty);
657   case ICmpInst::ICMP_SLE:   return executeICMP_SLE(Src1, Src2, Ty);
658   case FCmpInst::FCMP_ORD:   return executeFCMP_ORD(Src1, Src2, Ty);
659   case FCmpInst::FCMP_UNO:   return executeFCMP_UNO(Src1, Src2, Ty);
660   case FCmpInst::FCMP_OEQ:   return executeFCMP_OEQ(Src1, Src2, Ty);
661   case FCmpInst::FCMP_UEQ:   return executeFCMP_UEQ(Src1, Src2, Ty);
662   case FCmpInst::FCMP_ONE:   return executeFCMP_ONE(Src1, Src2, Ty);
663   case FCmpInst::FCMP_UNE:   return executeFCMP_UNE(Src1, Src2, Ty);
664   case FCmpInst::FCMP_OLT:   return executeFCMP_OLT(Src1, Src2, Ty);
665   case FCmpInst::FCMP_ULT:   return executeFCMP_ULT(Src1, Src2, Ty);
666   case FCmpInst::FCMP_OGT:   return executeFCMP_OGT(Src1, Src2, Ty);
667   case FCmpInst::FCMP_UGT:   return executeFCMP_UGT(Src1, Src2, Ty);
668   case FCmpInst::FCMP_OLE:   return executeFCMP_OLE(Src1, Src2, Ty);
669   case FCmpInst::FCMP_ULE:   return executeFCMP_ULE(Src1, Src2, Ty);
670   case FCmpInst::FCMP_OGE:   return executeFCMP_OGE(Src1, Src2, Ty);
671   case FCmpInst::FCMP_UGE:   return executeFCMP_UGE(Src1, Src2, Ty);
672   case FCmpInst::FCMP_FALSE: return executeFCMP_BOOL(Src1, Src2, Ty, false);
673   case FCmpInst::FCMP_TRUE:  return executeFCMP_BOOL(Src1, Src2, Ty, true);
674   default:
675     dbgs() << "Unhandled Cmp predicate\n";
676     llvm_unreachable(nullptr);
677   }
678 }
679 
680 void Interpreter::visitBinaryOperator(BinaryOperator &I) {
681   ExecutionContext &SF = ECStack.back();
682   Type *Ty    = I.getOperand(0)->getType();
683   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
684   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
685   GenericValue R;   // Result
686 
687   // First process vector operation
688   if (Ty->isVectorTy()) {
689     assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
690     R.AggregateVal.resize(Src1.AggregateVal.size());
691 
692     // Macros to execute binary operation 'OP' over integer vectors
693 #define INTEGER_VECTOR_OPERATION(OP)                               \
694     for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
695       R.AggregateVal[i].IntVal =                                   \
696       Src1.AggregateVal[i].IntVal OP Src2.AggregateVal[i].IntVal;
697 
698     // Additional macros to execute binary operations udiv/sdiv/urem/srem since
699     // they have different notation.
700 #define INTEGER_VECTOR_FUNCTION(OP)                                \
701     for (unsigned i = 0; i < R.AggregateVal.size(); ++i)           \
702       R.AggregateVal[i].IntVal =                                   \
703       Src1.AggregateVal[i].IntVal.OP(Src2.AggregateVal[i].IntVal);
704 
705     // Macros to execute binary operation 'OP' over floating point type TY
706     // (float or double) vectors
707 #define FLOAT_VECTOR_FUNCTION(OP, TY)                               \
708       for (unsigned i = 0; i < R.AggregateVal.size(); ++i)          \
709         R.AggregateVal[i].TY =                                      \
710         Src1.AggregateVal[i].TY OP Src2.AggregateVal[i].TY;
711 
712     // Macros to choose appropriate TY: float or double and run operation
713     // execution
714 #define FLOAT_VECTOR_OP(OP) {                                         \
715   if (cast<VectorType>(Ty)->getElementType()->isFloatTy())            \
716     FLOAT_VECTOR_FUNCTION(OP, FloatVal)                               \
717   else {                                                              \
718     if (cast<VectorType>(Ty)->getElementType()->isDoubleTy())         \
719       FLOAT_VECTOR_FUNCTION(OP, DoubleVal)                            \
720     else {                                                            \
721       dbgs() << "Unhandled type for OP instruction: " << *Ty << "\n"; \
722       llvm_unreachable(0);                                            \
723     }                                                                 \
724   }                                                                   \
725 }
726 
727     switch(I.getOpcode()){
728     default:
729       dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
730       llvm_unreachable(nullptr);
731       break;
732     case Instruction::Add:   INTEGER_VECTOR_OPERATION(+) break;
733     case Instruction::Sub:   INTEGER_VECTOR_OPERATION(-) break;
734     case Instruction::Mul:   INTEGER_VECTOR_OPERATION(*) break;
735     case Instruction::UDiv:  INTEGER_VECTOR_FUNCTION(udiv) break;
736     case Instruction::SDiv:  INTEGER_VECTOR_FUNCTION(sdiv) break;
737     case Instruction::URem:  INTEGER_VECTOR_FUNCTION(urem) break;
738     case Instruction::SRem:  INTEGER_VECTOR_FUNCTION(srem) break;
739     case Instruction::And:   INTEGER_VECTOR_OPERATION(&) break;
740     case Instruction::Or:    INTEGER_VECTOR_OPERATION(|) break;
741     case Instruction::Xor:   INTEGER_VECTOR_OPERATION(^) break;
742     case Instruction::FAdd:  FLOAT_VECTOR_OP(+) break;
743     case Instruction::FSub:  FLOAT_VECTOR_OP(-) break;
744     case Instruction::FMul:  FLOAT_VECTOR_OP(*) break;
745     case Instruction::FDiv:  FLOAT_VECTOR_OP(/) break;
746     case Instruction::FRem:
747       if (cast<VectorType>(Ty)->getElementType()->isFloatTy())
748         for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
749           R.AggregateVal[i].FloatVal =
750           fmod(Src1.AggregateVal[i].FloatVal, Src2.AggregateVal[i].FloatVal);
751       else {
752         if (cast<VectorType>(Ty)->getElementType()->isDoubleTy())
753           for (unsigned i = 0; i < R.AggregateVal.size(); ++i)
754             R.AggregateVal[i].DoubleVal =
755             fmod(Src1.AggregateVal[i].DoubleVal, Src2.AggregateVal[i].DoubleVal);
756         else {
757           dbgs() << "Unhandled type for Rem instruction: " << *Ty << "\n";
758           llvm_unreachable(nullptr);
759         }
760       }
761       break;
762     }
763   } else {
764     switch (I.getOpcode()) {
765     default:
766       dbgs() << "Don't know how to handle this binary operator!\n-->" << I;
767       llvm_unreachable(nullptr);
768       break;
769     case Instruction::Add:   R.IntVal = Src1.IntVal + Src2.IntVal; break;
770     case Instruction::Sub:   R.IntVal = Src1.IntVal - Src2.IntVal; break;
771     case Instruction::Mul:   R.IntVal = Src1.IntVal * Src2.IntVal; break;
772     case Instruction::FAdd:  executeFAddInst(R, Src1, Src2, Ty); break;
773     case Instruction::FSub:  executeFSubInst(R, Src1, Src2, Ty); break;
774     case Instruction::FMul:  executeFMulInst(R, Src1, Src2, Ty); break;
775     case Instruction::FDiv:  executeFDivInst(R, Src1, Src2, Ty); break;
776     case Instruction::FRem:  executeFRemInst(R, Src1, Src2, Ty); break;
777     case Instruction::UDiv:  R.IntVal = Src1.IntVal.udiv(Src2.IntVal); break;
778     case Instruction::SDiv:  R.IntVal = Src1.IntVal.sdiv(Src2.IntVal); break;
779     case Instruction::URem:  R.IntVal = Src1.IntVal.urem(Src2.IntVal); break;
780     case Instruction::SRem:  R.IntVal = Src1.IntVal.srem(Src2.IntVal); break;
781     case Instruction::And:   R.IntVal = Src1.IntVal & Src2.IntVal; break;
782     case Instruction::Or:    R.IntVal = Src1.IntVal | Src2.IntVal; break;
783     case Instruction::Xor:   R.IntVal = Src1.IntVal ^ Src2.IntVal; break;
784     }
785   }
786   SetValue(&I, R, SF);
787 }
788 
789 static GenericValue executeSelectInst(GenericValue Src1, GenericValue Src2,
790                                       GenericValue Src3, Type *Ty) {
791     GenericValue Dest;
792     if(Ty->isVectorTy()) {
793       assert(Src1.AggregateVal.size() == Src2.AggregateVal.size());
794       assert(Src2.AggregateVal.size() == Src3.AggregateVal.size());
795       Dest.AggregateVal.resize( Src1.AggregateVal.size() );
796       for (size_t i = 0; i < Src1.AggregateVal.size(); ++i)
797         Dest.AggregateVal[i] = (Src1.AggregateVal[i].IntVal == 0) ?
798           Src3.AggregateVal[i] : Src2.AggregateVal[i];
799     } else {
800       Dest = (Src1.IntVal == 0) ? Src3 : Src2;
801     }
802     return Dest;
803 }
804 
805 void Interpreter::visitSelectInst(SelectInst &I) {
806   ExecutionContext &SF = ECStack.back();
807   Type * Ty = I.getOperand(0)->getType();
808   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
809   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
810   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
811   GenericValue R = executeSelectInst(Src1, Src2, Src3, Ty);
812   SetValue(&I, R, SF);
813 }
814 
815 //===----------------------------------------------------------------------===//
816 //                     Terminator Instruction Implementations
817 //===----------------------------------------------------------------------===//
818 
819 void Interpreter::exitCalled(GenericValue GV) {
820   // runAtExitHandlers() assumes there are no stack frames, but
821   // if exit() was called, then it had a stack frame. Blow away
822   // the stack before interpreting atexit handlers.
823   ECStack.clear();
824   runAtExitHandlers();
825   exit(GV.IntVal.zextOrTrunc(32).getZExtValue());
826 }
827 
828 /// Pop the last stack frame off of ECStack and then copy the result
829 /// back into the result variable if we are not returning void. The
830 /// result variable may be the ExitValue, or the Value of the calling
831 /// CallInst if there was a previous stack frame. This method may
832 /// invalidate any ECStack iterators you have. This method also takes
833 /// care of switching to the normal destination BB, if we are returning
834 /// from an invoke.
835 ///
836 void Interpreter::popStackAndReturnValueToCaller(Type *RetTy,
837                                                  GenericValue Result) {
838   // Pop the current stack frame.
839   ECStack.pop_back();
840 
841   if (ECStack.empty()) {  // Finished main.  Put result into exit code...
842     if (RetTy && !RetTy->isVoidTy()) {          // Nonvoid return type?
843       ExitValue = Result;   // Capture the exit value of the program
844     } else {
845       memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
846     }
847   } else {
848     // If we have a previous stack frame, and we have a previous call,
849     // fill in the return value...
850     ExecutionContext &CallingSF = ECStack.back();
851     if (Instruction *I = CallingSF.Caller.getInstruction()) {
852       // Save result...
853       if (!CallingSF.Caller.getType()->isVoidTy())
854         SetValue(I, Result, CallingSF);
855       if (InvokeInst *II = dyn_cast<InvokeInst> (I))
856         SwitchToNewBasicBlock (II->getNormalDest (), CallingSF);
857       CallingSF.Caller = CallSite();          // We returned from the call...
858     }
859   }
860 }
861 
862 void Interpreter::visitReturnInst(ReturnInst &I) {
863   ExecutionContext &SF = ECStack.back();
864   Type *RetTy = Type::getVoidTy(I.getContext());
865   GenericValue Result;
866 
867   // Save away the return value... (if we are not 'ret void')
868   if (I.getNumOperands()) {
869     RetTy  = I.getReturnValue()->getType();
870     Result = getOperandValue(I.getReturnValue(), SF);
871   }
872 
873   popStackAndReturnValueToCaller(RetTy, Result);
874 }
875 
876 void Interpreter::visitUnreachableInst(UnreachableInst &I) {
877   report_fatal_error("Program executed an 'unreachable' instruction!");
878 }
879 
880 void Interpreter::visitBranchInst(BranchInst &I) {
881   ExecutionContext &SF = ECStack.back();
882   BasicBlock *Dest;
883 
884   Dest = I.getSuccessor(0);          // Uncond branches have a fixed dest...
885   if (!I.isUnconditional()) {
886     Value *Cond = I.getCondition();
887     if (getOperandValue(Cond, SF).IntVal == 0) // If false cond...
888       Dest = I.getSuccessor(1);
889   }
890   SwitchToNewBasicBlock(Dest, SF);
891 }
892 
893 void Interpreter::visitSwitchInst(SwitchInst &I) {
894   ExecutionContext &SF = ECStack.back();
895   Value* Cond = I.getCondition();
896   Type *ElTy = Cond->getType();
897   GenericValue CondVal = getOperandValue(Cond, SF);
898 
899   // Check to see if any of the cases match...
900   BasicBlock *Dest = nullptr;
901   for (auto Case : I.cases()) {
902     GenericValue CaseVal = getOperandValue(Case.getCaseValue(), SF);
903     if (executeICMP_EQ(CondVal, CaseVal, ElTy).IntVal != 0) {
904       Dest = cast<BasicBlock>(Case.getCaseSuccessor());
905       break;
906     }
907   }
908   if (!Dest) Dest = I.getDefaultDest();   // No cases matched: use default
909   SwitchToNewBasicBlock(Dest, SF);
910 }
911 
912 void Interpreter::visitIndirectBrInst(IndirectBrInst &I) {
913   ExecutionContext &SF = ECStack.back();
914   void *Dest = GVTOP(getOperandValue(I.getAddress(), SF));
915   SwitchToNewBasicBlock((BasicBlock*)Dest, SF);
916 }
917 
918 
919 // SwitchToNewBasicBlock - This method is used to jump to a new basic block.
920 // This function handles the actual updating of block and instruction iterators
921 // as well as execution of all of the PHI nodes in the destination block.
922 //
923 // This method does this because all of the PHI nodes must be executed
924 // atomically, reading their inputs before any of the results are updated.  Not
925 // doing this can cause problems if the PHI nodes depend on other PHI nodes for
926 // their inputs.  If the input PHI node is updated before it is read, incorrect
927 // results can happen.  Thus we use a two phase approach.
928 //
929 void Interpreter::SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF){
930   BasicBlock *PrevBB = SF.CurBB;      // Remember where we came from...
931   SF.CurBB   = Dest;                  // Update CurBB to branch destination
932   SF.CurInst = SF.CurBB->begin();     // Update new instruction ptr...
933 
934   if (!isa<PHINode>(SF.CurInst)) return;  // Nothing fancy to do
935 
936   // Loop over all of the PHI nodes in the current block, reading their inputs.
937   std::vector<GenericValue> ResultValues;
938 
939   for (; PHINode *PN = dyn_cast<PHINode>(SF.CurInst); ++SF.CurInst) {
940     // Search for the value corresponding to this previous bb...
941     int i = PN->getBasicBlockIndex(PrevBB);
942     assert(i != -1 && "PHINode doesn't contain entry for predecessor??");
943     Value *IncomingValue = PN->getIncomingValue(i);
944 
945     // Save the incoming value for this PHI node...
946     ResultValues.push_back(getOperandValue(IncomingValue, SF));
947   }
948 
949   // Now loop over all of the PHI nodes setting their values...
950   SF.CurInst = SF.CurBB->begin();
951   for (unsigned i = 0; isa<PHINode>(SF.CurInst); ++SF.CurInst, ++i) {
952     PHINode *PN = cast<PHINode>(SF.CurInst);
953     SetValue(PN, ResultValues[i], SF);
954   }
955 }
956 
957 //===----------------------------------------------------------------------===//
958 //                     Memory Instruction Implementations
959 //===----------------------------------------------------------------------===//
960 
961 void Interpreter::visitAllocaInst(AllocaInst &I) {
962   ExecutionContext &SF = ECStack.back();
963 
964   Type *Ty = I.getType()->getElementType();  // Type to be allocated
965 
966   // Get the number of elements being allocated by the array...
967   unsigned NumElements =
968     getOperandValue(I.getOperand(0), SF).IntVal.getZExtValue();
969 
970   unsigned TypeSize = (size_t)getDataLayout().getTypeAllocSize(Ty);
971 
972   // Avoid malloc-ing zero bytes, use max()...
973   unsigned MemToAlloc = std::max(1U, NumElements * TypeSize);
974 
975   // Allocate enough memory to hold the type...
976   void *Memory = safe_malloc(MemToAlloc);
977 
978   LLVM_DEBUG(dbgs() << "Allocated Type: " << *Ty << " (" << TypeSize
979                     << " bytes) x " << NumElements << " (Total: " << MemToAlloc
980                     << ") at " << uintptr_t(Memory) << '\n');
981 
982   GenericValue Result = PTOGV(Memory);
983   assert(Result.PointerVal && "Null pointer returned by malloc!");
984   SetValue(&I, Result, SF);
985 
986   if (I.getOpcode() == Instruction::Alloca)
987     ECStack.back().Allocas.add(Memory);
988 }
989 
990 // getElementOffset - The workhorse for getelementptr.
991 //
992 GenericValue Interpreter::executeGEPOperation(Value *Ptr, gep_type_iterator I,
993                                               gep_type_iterator E,
994                                               ExecutionContext &SF) {
995   assert(Ptr->getType()->isPointerTy() &&
996          "Cannot getElementOffset of a nonpointer type!");
997 
998   uint64_t Total = 0;
999 
1000   for (; I != E; ++I) {
1001     if (StructType *STy = I.getStructTypeOrNull()) {
1002       const StructLayout *SLO = getDataLayout().getStructLayout(STy);
1003 
1004       const ConstantInt *CPU = cast<ConstantInt>(I.getOperand());
1005       unsigned Index = unsigned(CPU->getZExtValue());
1006 
1007       Total += SLO->getElementOffset(Index);
1008     } else {
1009       // Get the index number for the array... which must be long type...
1010       GenericValue IdxGV = getOperandValue(I.getOperand(), SF);
1011 
1012       int64_t Idx;
1013       unsigned BitWidth =
1014         cast<IntegerType>(I.getOperand()->getType())->getBitWidth();
1015       if (BitWidth == 32)
1016         Idx = (int64_t)(int32_t)IdxGV.IntVal.getZExtValue();
1017       else {
1018         assert(BitWidth == 64 && "Invalid index type for getelementptr");
1019         Idx = (int64_t)IdxGV.IntVal.getZExtValue();
1020       }
1021       Total += getDataLayout().getTypeAllocSize(I.getIndexedType()) * Idx;
1022     }
1023   }
1024 
1025   GenericValue Result;
1026   Result.PointerVal = ((char*)getOperandValue(Ptr, SF).PointerVal) + Total;
1027   LLVM_DEBUG(dbgs() << "GEP Index " << Total << " bytes.\n");
1028   return Result;
1029 }
1030 
1031 void Interpreter::visitGetElementPtrInst(GetElementPtrInst &I) {
1032   ExecutionContext &SF = ECStack.back();
1033   SetValue(&I, executeGEPOperation(I.getPointerOperand(),
1034                                    gep_type_begin(I), gep_type_end(I), SF), SF);
1035 }
1036 
1037 void Interpreter::visitLoadInst(LoadInst &I) {
1038   ExecutionContext &SF = ECStack.back();
1039   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1040   GenericValue *Ptr = (GenericValue*)GVTOP(SRC);
1041   GenericValue Result;
1042   LoadValueFromMemory(Result, Ptr, I.getType());
1043   SetValue(&I, Result, SF);
1044   if (I.isVolatile() && PrintVolatile)
1045     dbgs() << "Volatile load " << I;
1046 }
1047 
1048 void Interpreter::visitStoreInst(StoreInst &I) {
1049   ExecutionContext &SF = ECStack.back();
1050   GenericValue Val = getOperandValue(I.getOperand(0), SF);
1051   GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
1052   StoreValueToMemory(Val, (GenericValue *)GVTOP(SRC),
1053                      I.getOperand(0)->getType());
1054   if (I.isVolatile() && PrintVolatile)
1055     dbgs() << "Volatile store: " << I;
1056 }
1057 
1058 //===----------------------------------------------------------------------===//
1059 //                 Miscellaneous Instruction Implementations
1060 //===----------------------------------------------------------------------===//
1061 
1062 void Interpreter::visitCallSite(CallSite CS) {
1063   ExecutionContext &SF = ECStack.back();
1064 
1065   // Check to see if this is an intrinsic function call...
1066   Function *F = CS.getCalledFunction();
1067   if (F && F->isDeclaration())
1068     switch (F->getIntrinsicID()) {
1069     case Intrinsic::not_intrinsic:
1070       break;
1071     case Intrinsic::vastart: { // va_start
1072       GenericValue ArgIndex;
1073       ArgIndex.UIntPairVal.first = ECStack.size() - 1;
1074       ArgIndex.UIntPairVal.second = 0;
1075       SetValue(CS.getInstruction(), ArgIndex, SF);
1076       return;
1077     }
1078     case Intrinsic::vaend:    // va_end is a noop for the interpreter
1079       return;
1080     case Intrinsic::vacopy:   // va_copy: dest = src
1081       SetValue(CS.getInstruction(), getOperandValue(*CS.arg_begin(), SF), SF);
1082       return;
1083     default:
1084       // If it is an unknown intrinsic function, use the intrinsic lowering
1085       // class to transform it into hopefully tasty LLVM code.
1086       //
1087       BasicBlock::iterator me(CS.getInstruction());
1088       BasicBlock *Parent = CS.getInstruction()->getParent();
1089       bool atBegin(Parent->begin() == me);
1090       if (!atBegin)
1091         --me;
1092       IL->LowerIntrinsicCall(cast<CallInst>(CS.getInstruction()));
1093 
1094       // Restore the CurInst pointer to the first instruction newly inserted, if
1095       // any.
1096       if (atBegin) {
1097         SF.CurInst = Parent->begin();
1098       } else {
1099         SF.CurInst = me;
1100         ++SF.CurInst;
1101       }
1102       return;
1103     }
1104 
1105 
1106   SF.Caller = CS;
1107   std::vector<GenericValue> ArgVals;
1108   const unsigned NumArgs = SF.Caller.arg_size();
1109   ArgVals.reserve(NumArgs);
1110   uint16_t pNum = 1;
1111   for (CallSite::arg_iterator i = SF.Caller.arg_begin(),
1112          e = SF.Caller.arg_end(); i != e; ++i, ++pNum) {
1113     Value *V = *i;
1114     ArgVals.push_back(getOperandValue(V, SF));
1115   }
1116 
1117   // To handle indirect calls, we must get the pointer value from the argument
1118   // and treat it as a function pointer.
1119   GenericValue SRC = getOperandValue(SF.Caller.getCalledValue(), SF);
1120   callFunction((Function*)GVTOP(SRC), ArgVals);
1121 }
1122 
1123 // auxiliary function for shift operations
1124 static unsigned getShiftAmount(uint64_t orgShiftAmount,
1125                                llvm::APInt valueToShift) {
1126   unsigned valueWidth = valueToShift.getBitWidth();
1127   if (orgShiftAmount < (uint64_t)valueWidth)
1128     return orgShiftAmount;
1129   // according to the llvm documentation, if orgShiftAmount > valueWidth,
1130   // the result is undfeined. but we do shift by this rule:
1131   return (NextPowerOf2(valueWidth-1) - 1) & orgShiftAmount;
1132 }
1133 
1134 
1135 void Interpreter::visitShl(BinaryOperator &I) {
1136   ExecutionContext &SF = ECStack.back();
1137   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1138   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1139   GenericValue Dest;
1140   Type *Ty = I.getType();
1141 
1142   if (Ty->isVectorTy()) {
1143     uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1144     assert(src1Size == Src2.AggregateVal.size());
1145     for (unsigned i = 0; i < src1Size; i++) {
1146       GenericValue Result;
1147       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1148       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1149       Result.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1150       Dest.AggregateVal.push_back(Result);
1151     }
1152   } else {
1153     // scalar
1154     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1155     llvm::APInt valueToShift = Src1.IntVal;
1156     Dest.IntVal = valueToShift.shl(getShiftAmount(shiftAmount, valueToShift));
1157   }
1158 
1159   SetValue(&I, Dest, SF);
1160 }
1161 
1162 void Interpreter::visitLShr(BinaryOperator &I) {
1163   ExecutionContext &SF = ECStack.back();
1164   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1165   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1166   GenericValue Dest;
1167   Type *Ty = I.getType();
1168 
1169   if (Ty->isVectorTy()) {
1170     uint32_t src1Size = uint32_t(Src1.AggregateVal.size());
1171     assert(src1Size == Src2.AggregateVal.size());
1172     for (unsigned i = 0; i < src1Size; i++) {
1173       GenericValue Result;
1174       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1175       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1176       Result.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1177       Dest.AggregateVal.push_back(Result);
1178     }
1179   } else {
1180     // scalar
1181     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1182     llvm::APInt valueToShift = Src1.IntVal;
1183     Dest.IntVal = valueToShift.lshr(getShiftAmount(shiftAmount, valueToShift));
1184   }
1185 
1186   SetValue(&I, Dest, SF);
1187 }
1188 
1189 void Interpreter::visitAShr(BinaryOperator &I) {
1190   ExecutionContext &SF = ECStack.back();
1191   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1192   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1193   GenericValue Dest;
1194   Type *Ty = I.getType();
1195 
1196   if (Ty->isVectorTy()) {
1197     size_t src1Size = Src1.AggregateVal.size();
1198     assert(src1Size == Src2.AggregateVal.size());
1199     for (unsigned i = 0; i < src1Size; i++) {
1200       GenericValue Result;
1201       uint64_t shiftAmount = Src2.AggregateVal[i].IntVal.getZExtValue();
1202       llvm::APInt valueToShift = Src1.AggregateVal[i].IntVal;
1203       Result.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1204       Dest.AggregateVal.push_back(Result);
1205     }
1206   } else {
1207     // scalar
1208     uint64_t shiftAmount = Src2.IntVal.getZExtValue();
1209     llvm::APInt valueToShift = Src1.IntVal;
1210     Dest.IntVal = valueToShift.ashr(getShiftAmount(shiftAmount, valueToShift));
1211   }
1212 
1213   SetValue(&I, Dest, SF);
1214 }
1215 
1216 GenericValue Interpreter::executeTruncInst(Value *SrcVal, Type *DstTy,
1217                                            ExecutionContext &SF) {
1218   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1219   Type *SrcTy = SrcVal->getType();
1220   if (SrcTy->isVectorTy()) {
1221     Type *DstVecTy = DstTy->getScalarType();
1222     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1223     unsigned NumElts = Src.AggregateVal.size();
1224     // the sizes of src and dst vectors must be equal
1225     Dest.AggregateVal.resize(NumElts);
1226     for (unsigned i = 0; i < NumElts; i++)
1227       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.trunc(DBitWidth);
1228   } else {
1229     IntegerType *DITy = cast<IntegerType>(DstTy);
1230     unsigned DBitWidth = DITy->getBitWidth();
1231     Dest.IntVal = Src.IntVal.trunc(DBitWidth);
1232   }
1233   return Dest;
1234 }
1235 
1236 GenericValue Interpreter::executeSExtInst(Value *SrcVal, Type *DstTy,
1237                                           ExecutionContext &SF) {
1238   Type *SrcTy = SrcVal->getType();
1239   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1240   if (SrcTy->isVectorTy()) {
1241     Type *DstVecTy = DstTy->getScalarType();
1242     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1243     unsigned size = Src.AggregateVal.size();
1244     // the sizes of src and dst vectors must be equal.
1245     Dest.AggregateVal.resize(size);
1246     for (unsigned i = 0; i < size; i++)
1247       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.sext(DBitWidth);
1248   } else {
1249     auto *DITy = cast<IntegerType>(DstTy);
1250     unsigned DBitWidth = DITy->getBitWidth();
1251     Dest.IntVal = Src.IntVal.sext(DBitWidth);
1252   }
1253   return Dest;
1254 }
1255 
1256 GenericValue Interpreter::executeZExtInst(Value *SrcVal, Type *DstTy,
1257                                           ExecutionContext &SF) {
1258   Type *SrcTy = SrcVal->getType();
1259   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1260   if (SrcTy->isVectorTy()) {
1261     Type *DstVecTy = DstTy->getScalarType();
1262     unsigned DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1263 
1264     unsigned size = Src.AggregateVal.size();
1265     // the sizes of src and dst vectors must be equal.
1266     Dest.AggregateVal.resize(size);
1267     for (unsigned i = 0; i < size; i++)
1268       Dest.AggregateVal[i].IntVal = Src.AggregateVal[i].IntVal.zext(DBitWidth);
1269   } else {
1270     auto *DITy = cast<IntegerType>(DstTy);
1271     unsigned DBitWidth = DITy->getBitWidth();
1272     Dest.IntVal = Src.IntVal.zext(DBitWidth);
1273   }
1274   return Dest;
1275 }
1276 
1277 GenericValue Interpreter::executeFPTruncInst(Value *SrcVal, Type *DstTy,
1278                                              ExecutionContext &SF) {
1279   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1280 
1281   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1282     assert(SrcVal->getType()->getScalarType()->isDoubleTy() &&
1283            DstTy->getScalarType()->isFloatTy() &&
1284            "Invalid FPTrunc instruction");
1285 
1286     unsigned size = Src.AggregateVal.size();
1287     // the sizes of src and dst vectors must be equal.
1288     Dest.AggregateVal.resize(size);
1289     for (unsigned i = 0; i < size; i++)
1290       Dest.AggregateVal[i].FloatVal = (float)Src.AggregateVal[i].DoubleVal;
1291   } else {
1292     assert(SrcVal->getType()->isDoubleTy() && DstTy->isFloatTy() &&
1293            "Invalid FPTrunc instruction");
1294     Dest.FloatVal = (float)Src.DoubleVal;
1295   }
1296 
1297   return Dest;
1298 }
1299 
1300 GenericValue Interpreter::executeFPExtInst(Value *SrcVal, Type *DstTy,
1301                                            ExecutionContext &SF) {
1302   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1303 
1304   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1305     assert(SrcVal->getType()->getScalarType()->isFloatTy() &&
1306            DstTy->getScalarType()->isDoubleTy() && "Invalid FPExt instruction");
1307 
1308     unsigned size = Src.AggregateVal.size();
1309     // the sizes of src and dst vectors must be equal.
1310     Dest.AggregateVal.resize(size);
1311     for (unsigned i = 0; i < size; i++)
1312       Dest.AggregateVal[i].DoubleVal = (double)Src.AggregateVal[i].FloatVal;
1313   } else {
1314     assert(SrcVal->getType()->isFloatTy() && DstTy->isDoubleTy() &&
1315            "Invalid FPExt instruction");
1316     Dest.DoubleVal = (double)Src.FloatVal;
1317   }
1318 
1319   return Dest;
1320 }
1321 
1322 GenericValue Interpreter::executeFPToUIInst(Value *SrcVal, Type *DstTy,
1323                                             ExecutionContext &SF) {
1324   Type *SrcTy = SrcVal->getType();
1325   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1326 
1327   if (SrcTy->getTypeID() == Type::VectorTyID) {
1328     Type *DstVecTy = DstTy->getScalarType();
1329     Type *SrcVecTy = SrcTy->getScalarType();
1330     uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1331     unsigned size = Src.AggregateVal.size();
1332     // the sizes of src and dst vectors must be equal.
1333     Dest.AggregateVal.resize(size);
1334 
1335     if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1336       assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1337       for (unsigned i = 0; i < size; i++)
1338         Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1339             Src.AggregateVal[i].FloatVal, DBitWidth);
1340     } else {
1341       for (unsigned i = 0; i < size; i++)
1342         Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1343             Src.AggregateVal[i].DoubleVal, DBitWidth);
1344     }
1345   } else {
1346     // scalar
1347     uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1348     assert(SrcTy->isFloatingPointTy() && "Invalid FPToUI instruction");
1349 
1350     if (SrcTy->getTypeID() == Type::FloatTyID)
1351       Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1352     else {
1353       Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1354     }
1355   }
1356 
1357   return Dest;
1358 }
1359 
1360 GenericValue Interpreter::executeFPToSIInst(Value *SrcVal, Type *DstTy,
1361                                             ExecutionContext &SF) {
1362   Type *SrcTy = SrcVal->getType();
1363   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1364 
1365   if (SrcTy->getTypeID() == Type::VectorTyID) {
1366     Type *DstVecTy = DstTy->getScalarType();
1367     Type *SrcVecTy = SrcTy->getScalarType();
1368     uint32_t DBitWidth = cast<IntegerType>(DstVecTy)->getBitWidth();
1369     unsigned size = Src.AggregateVal.size();
1370     // the sizes of src and dst vectors must be equal
1371     Dest.AggregateVal.resize(size);
1372 
1373     if (SrcVecTy->getTypeID() == Type::FloatTyID) {
1374       assert(SrcVecTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1375       for (unsigned i = 0; i < size; i++)
1376         Dest.AggregateVal[i].IntVal = APIntOps::RoundFloatToAPInt(
1377             Src.AggregateVal[i].FloatVal, DBitWidth);
1378     } else {
1379       for (unsigned i = 0; i < size; i++)
1380         Dest.AggregateVal[i].IntVal = APIntOps::RoundDoubleToAPInt(
1381             Src.AggregateVal[i].DoubleVal, DBitWidth);
1382     }
1383   } else {
1384     // scalar
1385     unsigned DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1386     assert(SrcTy->isFloatingPointTy() && "Invalid FPToSI instruction");
1387 
1388     if (SrcTy->getTypeID() == Type::FloatTyID)
1389       Dest.IntVal = APIntOps::RoundFloatToAPInt(Src.FloatVal, DBitWidth);
1390     else {
1391       Dest.IntVal = APIntOps::RoundDoubleToAPInt(Src.DoubleVal, DBitWidth);
1392     }
1393   }
1394   return Dest;
1395 }
1396 
1397 GenericValue Interpreter::executeUIToFPInst(Value *SrcVal, Type *DstTy,
1398                                             ExecutionContext &SF) {
1399   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1400 
1401   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1402     Type *DstVecTy = DstTy->getScalarType();
1403     unsigned size = Src.AggregateVal.size();
1404     // the sizes of src and dst vectors must be equal
1405     Dest.AggregateVal.resize(size);
1406 
1407     if (DstVecTy->getTypeID() == Type::FloatTyID) {
1408       assert(DstVecTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1409       for (unsigned i = 0; i < size; i++)
1410         Dest.AggregateVal[i].FloatVal =
1411             APIntOps::RoundAPIntToFloat(Src.AggregateVal[i].IntVal);
1412     } else {
1413       for (unsigned i = 0; i < size; i++)
1414         Dest.AggregateVal[i].DoubleVal =
1415             APIntOps::RoundAPIntToDouble(Src.AggregateVal[i].IntVal);
1416     }
1417   } else {
1418     // scalar
1419     assert(DstTy->isFloatingPointTy() && "Invalid UIToFP instruction");
1420     if (DstTy->getTypeID() == Type::FloatTyID)
1421       Dest.FloatVal = APIntOps::RoundAPIntToFloat(Src.IntVal);
1422     else {
1423       Dest.DoubleVal = APIntOps::RoundAPIntToDouble(Src.IntVal);
1424     }
1425   }
1426   return Dest;
1427 }
1428 
1429 GenericValue Interpreter::executeSIToFPInst(Value *SrcVal, Type *DstTy,
1430                                             ExecutionContext &SF) {
1431   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1432 
1433   if (SrcVal->getType()->getTypeID() == Type::VectorTyID) {
1434     Type *DstVecTy = DstTy->getScalarType();
1435     unsigned size = Src.AggregateVal.size();
1436     // the sizes of src and dst vectors must be equal
1437     Dest.AggregateVal.resize(size);
1438 
1439     if (DstVecTy->getTypeID() == Type::FloatTyID) {
1440       assert(DstVecTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1441       for (unsigned i = 0; i < size; i++)
1442         Dest.AggregateVal[i].FloatVal =
1443             APIntOps::RoundSignedAPIntToFloat(Src.AggregateVal[i].IntVal);
1444     } else {
1445       for (unsigned i = 0; i < size; i++)
1446         Dest.AggregateVal[i].DoubleVal =
1447             APIntOps::RoundSignedAPIntToDouble(Src.AggregateVal[i].IntVal);
1448     }
1449   } else {
1450     // scalar
1451     assert(DstTy->isFloatingPointTy() && "Invalid SIToFP instruction");
1452 
1453     if (DstTy->getTypeID() == Type::FloatTyID)
1454       Dest.FloatVal = APIntOps::RoundSignedAPIntToFloat(Src.IntVal);
1455     else {
1456       Dest.DoubleVal = APIntOps::RoundSignedAPIntToDouble(Src.IntVal);
1457     }
1458   }
1459 
1460   return Dest;
1461 }
1462 
1463 GenericValue Interpreter::executePtrToIntInst(Value *SrcVal, Type *DstTy,
1464                                               ExecutionContext &SF) {
1465   uint32_t DBitWidth = cast<IntegerType>(DstTy)->getBitWidth();
1466   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1467   assert(SrcVal->getType()->isPointerTy() && "Invalid PtrToInt instruction");
1468 
1469   Dest.IntVal = APInt(DBitWidth, (intptr_t) Src.PointerVal);
1470   return Dest;
1471 }
1472 
1473 GenericValue Interpreter::executeIntToPtrInst(Value *SrcVal, Type *DstTy,
1474                                               ExecutionContext &SF) {
1475   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1476   assert(DstTy->isPointerTy() && "Invalid PtrToInt instruction");
1477 
1478   uint32_t PtrSize = getDataLayout().getPointerSizeInBits();
1479   if (PtrSize != Src.IntVal.getBitWidth())
1480     Src.IntVal = Src.IntVal.zextOrTrunc(PtrSize);
1481 
1482   Dest.PointerVal = PointerTy(intptr_t(Src.IntVal.getZExtValue()));
1483   return Dest;
1484 }
1485 
1486 GenericValue Interpreter::executeBitCastInst(Value *SrcVal, Type *DstTy,
1487                                              ExecutionContext &SF) {
1488 
1489   // This instruction supports bitwise conversion of vectors to integers and
1490   // to vectors of other types (as long as they have the same size)
1491   Type *SrcTy = SrcVal->getType();
1492   GenericValue Dest, Src = getOperandValue(SrcVal, SF);
1493 
1494   if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1495       (DstTy->getTypeID() == Type::VectorTyID)) {
1496     // vector src bitcast to vector dst or vector src bitcast to scalar dst or
1497     // scalar src bitcast to vector dst
1498     bool isLittleEndian = getDataLayout().isLittleEndian();
1499     GenericValue TempDst, TempSrc, SrcVec;
1500     Type *SrcElemTy;
1501     Type *DstElemTy;
1502     unsigned SrcBitSize;
1503     unsigned DstBitSize;
1504     unsigned SrcNum;
1505     unsigned DstNum;
1506 
1507     if (SrcTy->getTypeID() == Type::VectorTyID) {
1508       SrcElemTy = SrcTy->getScalarType();
1509       SrcBitSize = SrcTy->getScalarSizeInBits();
1510       SrcNum = Src.AggregateVal.size();
1511       SrcVec = Src;
1512     } else {
1513       // if src is scalar value, make it vector <1 x type>
1514       SrcElemTy = SrcTy;
1515       SrcBitSize = SrcTy->getPrimitiveSizeInBits();
1516       SrcNum = 1;
1517       SrcVec.AggregateVal.push_back(Src);
1518     }
1519 
1520     if (DstTy->getTypeID() == Type::VectorTyID) {
1521       DstElemTy = DstTy->getScalarType();
1522       DstBitSize = DstTy->getScalarSizeInBits();
1523       DstNum = (SrcNum * SrcBitSize) / DstBitSize;
1524     } else {
1525       DstElemTy = DstTy;
1526       DstBitSize = DstTy->getPrimitiveSizeInBits();
1527       DstNum = 1;
1528     }
1529 
1530     if (SrcNum * SrcBitSize != DstNum * DstBitSize)
1531       llvm_unreachable("Invalid BitCast");
1532 
1533     // If src is floating point, cast to integer first.
1534     TempSrc.AggregateVal.resize(SrcNum);
1535     if (SrcElemTy->isFloatTy()) {
1536       for (unsigned i = 0; i < SrcNum; i++)
1537         TempSrc.AggregateVal[i].IntVal =
1538             APInt::floatToBits(SrcVec.AggregateVal[i].FloatVal);
1539 
1540     } else if (SrcElemTy->isDoubleTy()) {
1541       for (unsigned i = 0; i < SrcNum; i++)
1542         TempSrc.AggregateVal[i].IntVal =
1543             APInt::doubleToBits(SrcVec.AggregateVal[i].DoubleVal);
1544     } else if (SrcElemTy->isIntegerTy()) {
1545       for (unsigned i = 0; i < SrcNum; i++)
1546         TempSrc.AggregateVal[i].IntVal = SrcVec.AggregateVal[i].IntVal;
1547     } else {
1548       // Pointers are not allowed as the element type of vector.
1549       llvm_unreachable("Invalid Bitcast");
1550     }
1551 
1552     // now TempSrc is integer type vector
1553     if (DstNum < SrcNum) {
1554       // Example: bitcast <4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>
1555       unsigned Ratio = SrcNum / DstNum;
1556       unsigned SrcElt = 0;
1557       for (unsigned i = 0; i < DstNum; i++) {
1558         GenericValue Elt;
1559         Elt.IntVal = 0;
1560         Elt.IntVal = Elt.IntVal.zext(DstBitSize);
1561         unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize * (Ratio - 1);
1562         for (unsigned j = 0; j < Ratio; j++) {
1563           APInt Tmp;
1564           Tmp = Tmp.zext(SrcBitSize);
1565           Tmp = TempSrc.AggregateVal[SrcElt++].IntVal;
1566           Tmp = Tmp.zext(DstBitSize);
1567           Tmp <<= ShiftAmt;
1568           ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
1569           Elt.IntVal |= Tmp;
1570         }
1571         TempDst.AggregateVal.push_back(Elt);
1572       }
1573     } else {
1574       // Example: bitcast <2 x i64> <i64 0, i64 1> to <4 x i32>
1575       unsigned Ratio = DstNum / SrcNum;
1576       for (unsigned i = 0; i < SrcNum; i++) {
1577         unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize * (Ratio - 1);
1578         for (unsigned j = 0; j < Ratio; j++) {
1579           GenericValue Elt;
1580           Elt.IntVal = Elt.IntVal.zext(SrcBitSize);
1581           Elt.IntVal = TempSrc.AggregateVal[i].IntVal;
1582           Elt.IntVal.lshrInPlace(ShiftAmt);
1583           // it could be DstBitSize == SrcBitSize, so check it
1584           if (DstBitSize < SrcBitSize)
1585             Elt.IntVal = Elt.IntVal.trunc(DstBitSize);
1586           ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
1587           TempDst.AggregateVal.push_back(Elt);
1588         }
1589       }
1590     }
1591 
1592     // convert result from integer to specified type
1593     if (DstTy->getTypeID() == Type::VectorTyID) {
1594       if (DstElemTy->isDoubleTy()) {
1595         Dest.AggregateVal.resize(DstNum);
1596         for (unsigned i = 0; i < DstNum; i++)
1597           Dest.AggregateVal[i].DoubleVal =
1598               TempDst.AggregateVal[i].IntVal.bitsToDouble();
1599       } else if (DstElemTy->isFloatTy()) {
1600         Dest.AggregateVal.resize(DstNum);
1601         for (unsigned i = 0; i < DstNum; i++)
1602           Dest.AggregateVal[i].FloatVal =
1603               TempDst.AggregateVal[i].IntVal.bitsToFloat();
1604       } else {
1605         Dest = TempDst;
1606       }
1607     } else {
1608       if (DstElemTy->isDoubleTy())
1609         Dest.DoubleVal = TempDst.AggregateVal[0].IntVal.bitsToDouble();
1610       else if (DstElemTy->isFloatTy()) {
1611         Dest.FloatVal = TempDst.AggregateVal[0].IntVal.bitsToFloat();
1612       } else {
1613         Dest.IntVal = TempDst.AggregateVal[0].IntVal;
1614       }
1615     }
1616   } else { //  if ((SrcTy->getTypeID() == Type::VectorTyID) ||
1617            //     (DstTy->getTypeID() == Type::VectorTyID))
1618 
1619     // scalar src bitcast to scalar dst
1620     if (DstTy->isPointerTy()) {
1621       assert(SrcTy->isPointerTy() && "Invalid BitCast");
1622       Dest.PointerVal = Src.PointerVal;
1623     } else if (DstTy->isIntegerTy()) {
1624       if (SrcTy->isFloatTy())
1625         Dest.IntVal = APInt::floatToBits(Src.FloatVal);
1626       else if (SrcTy->isDoubleTy()) {
1627         Dest.IntVal = APInt::doubleToBits(Src.DoubleVal);
1628       } else if (SrcTy->isIntegerTy()) {
1629         Dest.IntVal = Src.IntVal;
1630       } else {
1631         llvm_unreachable("Invalid BitCast");
1632       }
1633     } else if (DstTy->isFloatTy()) {
1634       if (SrcTy->isIntegerTy())
1635         Dest.FloatVal = Src.IntVal.bitsToFloat();
1636       else {
1637         Dest.FloatVal = Src.FloatVal;
1638       }
1639     } else if (DstTy->isDoubleTy()) {
1640       if (SrcTy->isIntegerTy())
1641         Dest.DoubleVal = Src.IntVal.bitsToDouble();
1642       else {
1643         Dest.DoubleVal = Src.DoubleVal;
1644       }
1645     } else {
1646       llvm_unreachable("Invalid Bitcast");
1647     }
1648   }
1649 
1650   return Dest;
1651 }
1652 
1653 void Interpreter::visitTruncInst(TruncInst &I) {
1654   ExecutionContext &SF = ECStack.back();
1655   SetValue(&I, executeTruncInst(I.getOperand(0), I.getType(), SF), SF);
1656 }
1657 
1658 void Interpreter::visitSExtInst(SExtInst &I) {
1659   ExecutionContext &SF = ECStack.back();
1660   SetValue(&I, executeSExtInst(I.getOperand(0), I.getType(), SF), SF);
1661 }
1662 
1663 void Interpreter::visitZExtInst(ZExtInst &I) {
1664   ExecutionContext &SF = ECStack.back();
1665   SetValue(&I, executeZExtInst(I.getOperand(0), I.getType(), SF), SF);
1666 }
1667 
1668 void Interpreter::visitFPTruncInst(FPTruncInst &I) {
1669   ExecutionContext &SF = ECStack.back();
1670   SetValue(&I, executeFPTruncInst(I.getOperand(0), I.getType(), SF), SF);
1671 }
1672 
1673 void Interpreter::visitFPExtInst(FPExtInst &I) {
1674   ExecutionContext &SF = ECStack.back();
1675   SetValue(&I, executeFPExtInst(I.getOperand(0), I.getType(), SF), SF);
1676 }
1677 
1678 void Interpreter::visitUIToFPInst(UIToFPInst &I) {
1679   ExecutionContext &SF = ECStack.back();
1680   SetValue(&I, executeUIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1681 }
1682 
1683 void Interpreter::visitSIToFPInst(SIToFPInst &I) {
1684   ExecutionContext &SF = ECStack.back();
1685   SetValue(&I, executeSIToFPInst(I.getOperand(0), I.getType(), SF), SF);
1686 }
1687 
1688 void Interpreter::visitFPToUIInst(FPToUIInst &I) {
1689   ExecutionContext &SF = ECStack.back();
1690   SetValue(&I, executeFPToUIInst(I.getOperand(0), I.getType(), SF), SF);
1691 }
1692 
1693 void Interpreter::visitFPToSIInst(FPToSIInst &I) {
1694   ExecutionContext &SF = ECStack.back();
1695   SetValue(&I, executeFPToSIInst(I.getOperand(0), I.getType(), SF), SF);
1696 }
1697 
1698 void Interpreter::visitPtrToIntInst(PtrToIntInst &I) {
1699   ExecutionContext &SF = ECStack.back();
1700   SetValue(&I, executePtrToIntInst(I.getOperand(0), I.getType(), SF), SF);
1701 }
1702 
1703 void Interpreter::visitIntToPtrInst(IntToPtrInst &I) {
1704   ExecutionContext &SF = ECStack.back();
1705   SetValue(&I, executeIntToPtrInst(I.getOperand(0), I.getType(), SF), SF);
1706 }
1707 
1708 void Interpreter::visitBitCastInst(BitCastInst &I) {
1709   ExecutionContext &SF = ECStack.back();
1710   SetValue(&I, executeBitCastInst(I.getOperand(0), I.getType(), SF), SF);
1711 }
1712 
1713 #define IMPLEMENT_VAARG(TY) \
1714    case Type::TY##TyID: Dest.TY##Val = Src.TY##Val; break
1715 
1716 void Interpreter::visitVAArgInst(VAArgInst &I) {
1717   ExecutionContext &SF = ECStack.back();
1718 
1719   // Get the incoming valist parameter.  LLI treats the valist as a
1720   // (ec-stack-depth var-arg-index) pair.
1721   GenericValue VAList = getOperandValue(I.getOperand(0), SF);
1722   GenericValue Dest;
1723   GenericValue Src = ECStack[VAList.UIntPairVal.first]
1724                       .VarArgs[VAList.UIntPairVal.second];
1725   Type *Ty = I.getType();
1726   switch (Ty->getTypeID()) {
1727   case Type::IntegerTyID:
1728     Dest.IntVal = Src.IntVal;
1729     break;
1730   IMPLEMENT_VAARG(Pointer);
1731   IMPLEMENT_VAARG(Float);
1732   IMPLEMENT_VAARG(Double);
1733   default:
1734     dbgs() << "Unhandled dest type for vaarg instruction: " << *Ty << "\n";
1735     llvm_unreachable(nullptr);
1736   }
1737 
1738   // Set the Value of this Instruction.
1739   SetValue(&I, Dest, SF);
1740 
1741   // Move the pointer to the next vararg.
1742   ++VAList.UIntPairVal.second;
1743 }
1744 
1745 void Interpreter::visitExtractElementInst(ExtractElementInst &I) {
1746   ExecutionContext &SF = ECStack.back();
1747   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1748   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1749   GenericValue Dest;
1750 
1751   Type *Ty = I.getType();
1752   const unsigned indx = unsigned(Src2.IntVal.getZExtValue());
1753 
1754   if(Src1.AggregateVal.size() > indx) {
1755     switch (Ty->getTypeID()) {
1756     default:
1757       dbgs() << "Unhandled destination type for extractelement instruction: "
1758       << *Ty << "\n";
1759       llvm_unreachable(nullptr);
1760       break;
1761     case Type::IntegerTyID:
1762       Dest.IntVal = Src1.AggregateVal[indx].IntVal;
1763       break;
1764     case Type::FloatTyID:
1765       Dest.FloatVal = Src1.AggregateVal[indx].FloatVal;
1766       break;
1767     case Type::DoubleTyID:
1768       Dest.DoubleVal = Src1.AggregateVal[indx].DoubleVal;
1769       break;
1770     }
1771   } else {
1772     dbgs() << "Invalid index in extractelement instruction\n";
1773   }
1774 
1775   SetValue(&I, Dest, SF);
1776 }
1777 
1778 void Interpreter::visitInsertElementInst(InsertElementInst &I) {
1779   ExecutionContext &SF = ECStack.back();
1780   VectorType *Ty = cast<VectorType>(I.getType());
1781 
1782   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1783   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1784   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1785   GenericValue Dest;
1786 
1787   Type *TyContained = Ty->getElementType();
1788 
1789   const unsigned indx = unsigned(Src3.IntVal.getZExtValue());
1790   Dest.AggregateVal = Src1.AggregateVal;
1791 
1792   if(Src1.AggregateVal.size() <= indx)
1793       llvm_unreachable("Invalid index in insertelement instruction");
1794   switch (TyContained->getTypeID()) {
1795     default:
1796       llvm_unreachable("Unhandled dest type for insertelement instruction");
1797     case Type::IntegerTyID:
1798       Dest.AggregateVal[indx].IntVal = Src2.IntVal;
1799       break;
1800     case Type::FloatTyID:
1801       Dest.AggregateVal[indx].FloatVal = Src2.FloatVal;
1802       break;
1803     case Type::DoubleTyID:
1804       Dest.AggregateVal[indx].DoubleVal = Src2.DoubleVal;
1805       break;
1806   }
1807   SetValue(&I, Dest, SF);
1808 }
1809 
1810 void Interpreter::visitShuffleVectorInst(ShuffleVectorInst &I){
1811   ExecutionContext &SF = ECStack.back();
1812 
1813   VectorType *Ty = cast<VectorType>(I.getType());
1814 
1815   GenericValue Src1 = getOperandValue(I.getOperand(0), SF);
1816   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1817   GenericValue Src3 = getOperandValue(I.getOperand(2), SF);
1818   GenericValue Dest;
1819 
1820   // There is no need to check types of src1 and src2, because the compiled
1821   // bytecode can't contain different types for src1 and src2 for a
1822   // shufflevector instruction.
1823 
1824   Type *TyContained = Ty->getElementType();
1825   unsigned src1Size = (unsigned)Src1.AggregateVal.size();
1826   unsigned src2Size = (unsigned)Src2.AggregateVal.size();
1827   unsigned src3Size = (unsigned)Src3.AggregateVal.size();
1828 
1829   Dest.AggregateVal.resize(src3Size);
1830 
1831   switch (TyContained->getTypeID()) {
1832     default:
1833       llvm_unreachable("Unhandled dest type for insertelement instruction");
1834       break;
1835     case Type::IntegerTyID:
1836       for( unsigned i=0; i<src3Size; i++) {
1837         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1838         if(j < src1Size)
1839           Dest.AggregateVal[i].IntVal = Src1.AggregateVal[j].IntVal;
1840         else if(j < src1Size + src2Size)
1841           Dest.AggregateVal[i].IntVal = Src2.AggregateVal[j-src1Size].IntVal;
1842         else
1843           // The selector may not be greater than sum of lengths of first and
1844           // second operands and llasm should not allow situation like
1845           // %tmp = shufflevector <2 x i32> <i32 3, i32 4>, <2 x i32> undef,
1846           //                      <2 x i32> < i32 0, i32 5 >,
1847           // where i32 5 is invalid, but let it be additional check here:
1848           llvm_unreachable("Invalid mask in shufflevector instruction");
1849       }
1850       break;
1851     case Type::FloatTyID:
1852       for( unsigned i=0; i<src3Size; i++) {
1853         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1854         if(j < src1Size)
1855           Dest.AggregateVal[i].FloatVal = Src1.AggregateVal[j].FloatVal;
1856         else if(j < src1Size + src2Size)
1857           Dest.AggregateVal[i].FloatVal = Src2.AggregateVal[j-src1Size].FloatVal;
1858         else
1859           llvm_unreachable("Invalid mask in shufflevector instruction");
1860         }
1861       break;
1862     case Type::DoubleTyID:
1863       for( unsigned i=0; i<src3Size; i++) {
1864         unsigned j = Src3.AggregateVal[i].IntVal.getZExtValue();
1865         if(j < src1Size)
1866           Dest.AggregateVal[i].DoubleVal = Src1.AggregateVal[j].DoubleVal;
1867         else if(j < src1Size + src2Size)
1868           Dest.AggregateVal[i].DoubleVal =
1869             Src2.AggregateVal[j-src1Size].DoubleVal;
1870         else
1871           llvm_unreachable("Invalid mask in shufflevector instruction");
1872       }
1873       break;
1874   }
1875   SetValue(&I, Dest, SF);
1876 }
1877 
1878 void Interpreter::visitExtractValueInst(ExtractValueInst &I) {
1879   ExecutionContext &SF = ECStack.back();
1880   Value *Agg = I.getAggregateOperand();
1881   GenericValue Dest;
1882   GenericValue Src = getOperandValue(Agg, SF);
1883 
1884   ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1885   unsigned Num = I.getNumIndices();
1886   GenericValue *pSrc = &Src;
1887 
1888   for (unsigned i = 0 ; i < Num; ++i) {
1889     pSrc = &pSrc->AggregateVal[*IdxBegin];
1890     ++IdxBegin;
1891   }
1892 
1893   Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1894   switch (IndexedType->getTypeID()) {
1895     default:
1896       llvm_unreachable("Unhandled dest type for extractelement instruction");
1897     break;
1898     case Type::IntegerTyID:
1899       Dest.IntVal = pSrc->IntVal;
1900     break;
1901     case Type::FloatTyID:
1902       Dest.FloatVal = pSrc->FloatVal;
1903     break;
1904     case Type::DoubleTyID:
1905       Dest.DoubleVal = pSrc->DoubleVal;
1906     break;
1907     case Type::ArrayTyID:
1908     case Type::StructTyID:
1909     case Type::VectorTyID:
1910       Dest.AggregateVal = pSrc->AggregateVal;
1911     break;
1912     case Type::PointerTyID:
1913       Dest.PointerVal = pSrc->PointerVal;
1914     break;
1915   }
1916 
1917   SetValue(&I, Dest, SF);
1918 }
1919 
1920 void Interpreter::visitInsertValueInst(InsertValueInst &I) {
1921 
1922   ExecutionContext &SF = ECStack.back();
1923   Value *Agg = I.getAggregateOperand();
1924 
1925   GenericValue Src1 = getOperandValue(Agg, SF);
1926   GenericValue Src2 = getOperandValue(I.getOperand(1), SF);
1927   GenericValue Dest = Src1; // Dest is a slightly changed Src1
1928 
1929   ExtractValueInst::idx_iterator IdxBegin = I.idx_begin();
1930   unsigned Num = I.getNumIndices();
1931 
1932   GenericValue *pDest = &Dest;
1933   for (unsigned i = 0 ; i < Num; ++i) {
1934     pDest = &pDest->AggregateVal[*IdxBegin];
1935     ++IdxBegin;
1936   }
1937   // pDest points to the target value in the Dest now
1938 
1939   Type *IndexedType = ExtractValueInst::getIndexedType(Agg->getType(), I.getIndices());
1940 
1941   switch (IndexedType->getTypeID()) {
1942     default:
1943       llvm_unreachable("Unhandled dest type for insertelement instruction");
1944     break;
1945     case Type::IntegerTyID:
1946       pDest->IntVal = Src2.IntVal;
1947     break;
1948     case Type::FloatTyID:
1949       pDest->FloatVal = Src2.FloatVal;
1950     break;
1951     case Type::DoubleTyID:
1952       pDest->DoubleVal = Src2.DoubleVal;
1953     break;
1954     case Type::ArrayTyID:
1955     case Type::StructTyID:
1956     case Type::VectorTyID:
1957       pDest->AggregateVal = Src2.AggregateVal;
1958     break;
1959     case Type::PointerTyID:
1960       pDest->PointerVal = Src2.PointerVal;
1961     break;
1962   }
1963 
1964   SetValue(&I, Dest, SF);
1965 }
1966 
1967 GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
1968                                                 ExecutionContext &SF) {
1969   switch (CE->getOpcode()) {
1970   case Instruction::Trunc:
1971       return executeTruncInst(CE->getOperand(0), CE->getType(), SF);
1972   case Instruction::ZExt:
1973       return executeZExtInst(CE->getOperand(0), CE->getType(), SF);
1974   case Instruction::SExt:
1975       return executeSExtInst(CE->getOperand(0), CE->getType(), SF);
1976   case Instruction::FPTrunc:
1977       return executeFPTruncInst(CE->getOperand(0), CE->getType(), SF);
1978   case Instruction::FPExt:
1979       return executeFPExtInst(CE->getOperand(0), CE->getType(), SF);
1980   case Instruction::UIToFP:
1981       return executeUIToFPInst(CE->getOperand(0), CE->getType(), SF);
1982   case Instruction::SIToFP:
1983       return executeSIToFPInst(CE->getOperand(0), CE->getType(), SF);
1984   case Instruction::FPToUI:
1985       return executeFPToUIInst(CE->getOperand(0), CE->getType(), SF);
1986   case Instruction::FPToSI:
1987       return executeFPToSIInst(CE->getOperand(0), CE->getType(), SF);
1988   case Instruction::PtrToInt:
1989       return executePtrToIntInst(CE->getOperand(0), CE->getType(), SF);
1990   case Instruction::IntToPtr:
1991       return executeIntToPtrInst(CE->getOperand(0), CE->getType(), SF);
1992   case Instruction::BitCast:
1993       return executeBitCastInst(CE->getOperand(0), CE->getType(), SF);
1994   case Instruction::GetElementPtr:
1995     return executeGEPOperation(CE->getOperand(0), gep_type_begin(CE),
1996                                gep_type_end(CE), SF);
1997   case Instruction::FCmp:
1998   case Instruction::ICmp:
1999     return executeCmpInst(CE->getPredicate(),
2000                           getOperandValue(CE->getOperand(0), SF),
2001                           getOperandValue(CE->getOperand(1), SF),
2002                           CE->getOperand(0)->getType());
2003   case Instruction::Select:
2004     return executeSelectInst(getOperandValue(CE->getOperand(0), SF),
2005                              getOperandValue(CE->getOperand(1), SF),
2006                              getOperandValue(CE->getOperand(2), SF),
2007                              CE->getOperand(0)->getType());
2008   default :
2009     break;
2010   }
2011 
2012   // The cases below here require a GenericValue parameter for the result
2013   // so we initialize one, compute it and then return it.
2014   GenericValue Op0 = getOperandValue(CE->getOperand(0), SF);
2015   GenericValue Op1 = getOperandValue(CE->getOperand(1), SF);
2016   GenericValue Dest;
2017   Type * Ty = CE->getOperand(0)->getType();
2018   switch (CE->getOpcode()) {
2019   case Instruction::Add:  Dest.IntVal = Op0.IntVal + Op1.IntVal; break;
2020   case Instruction::Sub:  Dest.IntVal = Op0.IntVal - Op1.IntVal; break;
2021   case Instruction::Mul:  Dest.IntVal = Op0.IntVal * Op1.IntVal; break;
2022   case Instruction::FAdd: executeFAddInst(Dest, Op0, Op1, Ty); break;
2023   case Instruction::FSub: executeFSubInst(Dest, Op0, Op1, Ty); break;
2024   case Instruction::FMul: executeFMulInst(Dest, Op0, Op1, Ty); break;
2025   case Instruction::FDiv: executeFDivInst(Dest, Op0, Op1, Ty); break;
2026   case Instruction::FRem: executeFRemInst(Dest, Op0, Op1, Ty); break;
2027   case Instruction::SDiv: Dest.IntVal = Op0.IntVal.sdiv(Op1.IntVal); break;
2028   case Instruction::UDiv: Dest.IntVal = Op0.IntVal.udiv(Op1.IntVal); break;
2029   case Instruction::URem: Dest.IntVal = Op0.IntVal.urem(Op1.IntVal); break;
2030   case Instruction::SRem: Dest.IntVal = Op0.IntVal.srem(Op1.IntVal); break;
2031   case Instruction::And:  Dest.IntVal = Op0.IntVal & Op1.IntVal; break;
2032   case Instruction::Or:   Dest.IntVal = Op0.IntVal | Op1.IntVal; break;
2033   case Instruction::Xor:  Dest.IntVal = Op0.IntVal ^ Op1.IntVal; break;
2034   case Instruction::Shl:
2035     Dest.IntVal = Op0.IntVal.shl(Op1.IntVal.getZExtValue());
2036     break;
2037   case Instruction::LShr:
2038     Dest.IntVal = Op0.IntVal.lshr(Op1.IntVal.getZExtValue());
2039     break;
2040   case Instruction::AShr:
2041     Dest.IntVal = Op0.IntVal.ashr(Op1.IntVal.getZExtValue());
2042     break;
2043   default:
2044     dbgs() << "Unhandled ConstantExpr: " << *CE << "\n";
2045     llvm_unreachable("Unhandled ConstantExpr");
2046   }
2047   return Dest;
2048 }
2049 
2050 GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
2051   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
2052     return getConstantExprValue(CE, SF);
2053   } else if (Constant *CPV = dyn_cast<Constant>(V)) {
2054     return getConstantValue(CPV);
2055   } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
2056     return PTOGV(getPointerToGlobal(GV));
2057   } else {
2058     return SF.Values[V];
2059   }
2060 }
2061 
2062 //===----------------------------------------------------------------------===//
2063 //                        Dispatch and Execution Code
2064 //===----------------------------------------------------------------------===//
2065 
2066 //===----------------------------------------------------------------------===//
2067 // callFunction - Execute the specified function...
2068 //
2069 void Interpreter::callFunction(Function *F, ArrayRef<GenericValue> ArgVals) {
2070   assert((ECStack.empty() || !ECStack.back().Caller.getInstruction() ||
2071           ECStack.back().Caller.arg_size() == ArgVals.size()) &&
2072          "Incorrect number of arguments passed into function call!");
2073   // Make a new stack frame... and fill it in.
2074   ECStack.emplace_back();
2075   ExecutionContext &StackFrame = ECStack.back();
2076   StackFrame.CurFunction = F;
2077 
2078   // Special handling for external functions.
2079   if (F->isDeclaration()) {
2080     GenericValue Result = callExternalFunction (F, ArgVals);
2081     // Simulate a 'ret' instruction of the appropriate type.
2082     popStackAndReturnValueToCaller (F->getReturnType (), Result);
2083     return;
2084   }
2085 
2086   // Get pointers to first LLVM BB & Instruction in function.
2087   StackFrame.CurBB     = &F->front();
2088   StackFrame.CurInst   = StackFrame.CurBB->begin();
2089 
2090   // Run through the function arguments and initialize their values...
2091   assert((ArgVals.size() == F->arg_size() ||
2092          (ArgVals.size() > F->arg_size() && F->getFunctionType()->isVarArg()))&&
2093          "Invalid number of values passed to function invocation!");
2094 
2095   // Handle non-varargs arguments...
2096   unsigned i = 0;
2097   for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
2098        AI != E; ++AI, ++i)
2099     SetValue(&*AI, ArgVals[i], StackFrame);
2100 
2101   // Handle varargs arguments...
2102   StackFrame.VarArgs.assign(ArgVals.begin()+i, ArgVals.end());
2103 }
2104 
2105 
2106 void Interpreter::run() {
2107   while (!ECStack.empty()) {
2108     // Interpret a single instruction & increment the "PC".
2109     ExecutionContext &SF = ECStack.back();  // Current stack frame
2110     Instruction &I = *SF.CurInst++;         // Increment before execute
2111 
2112     // Track the number of dynamic instructions executed.
2113     ++NumDynamicInsts;
2114 
2115     LLVM_DEBUG(dbgs() << "About to interpret: " << I << "\n");
2116     visit(I);   // Dispatch to one of the visit* methods...
2117   }
2118 }
2119