1//===- llvm-stress.cpp - Generate random LL files to stress-test LLVM -----===//
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 program is a utility that generates random .ll files to stress-test
10// different components in LLVM.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/ADT/APFloat.h"
15#include "llvm/ADT/APInt.h"
16#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/ADT/Twine.h"
20#include "llvm/IR/BasicBlock.h"
21#include "llvm/IR/CallingConv.h"
22#include "llvm/IR/Constants.h"
23#include "llvm/IR/DataLayout.h"
24#include "llvm/IR/DerivedTypes.h"
25#include "llvm/IR/Function.h"
26#include "llvm/IR/GlobalValue.h"
27#include "llvm/IR/IRPrintingPasses.h"
28#include "llvm/IR/InstrTypes.h"
29#include "llvm/IR/Instruction.h"
30#include "llvm/IR/Instructions.h"
31#include "llvm/IR/LLVMContext.h"
32#include "llvm/IR/LegacyPassManager.h"
33#include "llvm/IR/Module.h"
34#include "llvm/IR/Type.h"
35#include "llvm/IR/Value.h"
36#include "llvm/IR/Verifier.h"
37#include "llvm/Support/Casting.h"
38#include "llvm/Support/CommandLine.h"
39#include "llvm/Support/ErrorHandling.h"
40#include "llvm/Support/FileSystem.h"
41#include "llvm/Support/ManagedStatic.h"
42#include "llvm/Support/PrettyStackTrace.h"
43#include "llvm/Support/ToolOutputFile.h"
44#include "llvm/Support/raw_ostream.h"
45#include <algorithm>
46#include <cassert>
47#include <cstddef>
48#include <cstdint>
49#include <memory>
50#include <string>
51#include <system_error>
52#include <vector>
53
54namespace llvm {
55
56static cl::opt<unsigned> SeedCL("seed",
57  cl::desc("Seed used for randomness"), cl::init(0));
58
59static cl::opt<unsigned> SizeCL("size",
60  cl::desc("The estimated size of the generated function (# of instrs)"),
61  cl::init(100));
62
63static cl::opt<std::string>
64OutputFilename("o", cl::desc("Override output filename"),
65               cl::value_desc("filename"));
66
67static LLVMContext Context;
68
69namespace cl {
70
71template <> class parser<Type*> final : public basic_parser<Type*> {
72public:
73  parser(Option &O) : basic_parser(O) {}
74
75  // Parse options as IR types. Return true on error.
76  bool parse(Option &O, StringRef, StringRef Arg, Type *&Value) {
77    if      (Arg == "half")      Value = Type::getHalfTy(Context);
78    else if (Arg == "fp128")     Value = Type::getFP128Ty(Context);
79    else if (Arg == "x86_fp80")  Value = Type::getX86_FP80Ty(Context);
80    else if (Arg == "ppc_fp128") Value = Type::getPPC_FP128Ty(Context);
81    else if (Arg == "x86_mmx")   Value = Type::getX86_MMXTy(Context);
82    else if (Arg.startswith("i")) {
83      unsigned N = 0;
84      Arg.drop_front().getAsInteger(10, N);
85      if (N > 0)
86        Value = Type::getIntNTy(Context, N);
87    }
88
89    if (!Value)
90      return O.error("Invalid IR scalar type: '" + Arg + "'!");
91    return false;
92  }
93
94  StringRef getValueName() const override { return "IR scalar type"; }
95};
96
97} // end namespace cl
98
99static cl::list<Type*> AdditionalScalarTypes("types", cl::CommaSeparated,
100  cl::desc("Additional IR scalar types "
101           "(always includes i1, i8, i16, i32, i64, float and double)"));
102
103namespace {
104
105/// A utility class to provide a pseudo-random number generator which is
106/// the same across all platforms. This is somewhat close to the libc
107/// implementation. Note: This is not a cryptographically secure pseudorandom
108/// number generator.
109class Random {
110public:
111  /// C'tor
112  Random(unsigned _seed):Seed(_seed) {}
113
114  /// Return a random integer, up to a
115  /// maximum of 2**19 - 1.
116  uint32_t Rand() {
117    uint32_t Val = Seed + 0x000b07a1;
118    Seed = (Val * 0x3c7c0ac1);
119    // Only lowest 19 bits are random-ish.
120    return Seed & 0x7ffff;
121  }
122
123  /// Return a random 64 bit integer.
124  uint64_t Rand64() {
125    uint64_t Val = Rand() & 0xffff;
126    Val |= uint64_t(Rand() & 0xffff) << 16;
127    Val |= uint64_t(Rand() & 0xffff) << 32;
128    Val |= uint64_t(Rand() & 0xffff) << 48;
129    return Val;
130  }
131
132  /// Rand operator for STL algorithms.
133  ptrdiff_t operator()(ptrdiff_t y) {
134    return  Rand64() % y;
135  }
136
137  /// Make this like a C++11 random device
138  using result_type = uint32_t ;
139
140  static constexpr result_type min() { return 0; }
141  static constexpr result_type max() { return 0x7ffff; }
142
143  uint32_t operator()() {
144    uint32_t Val = Rand();
145    assert(Val <= max() && "Random value out of range");
146    return Val;
147  }
148
149private:
150  unsigned Seed;
151};
152
153/// Generate an empty function with a default argument list.
154Function *GenEmptyFunction(Module *M) {
155  // Define a few arguments
156  LLVMContext &Context = M->getContext();
157  Type* ArgsTy[] = {
158    Type::getInt8PtrTy(Context),
159    Type::getInt32PtrTy(Context),
160    Type::getInt64PtrTy(Context),
161    Type::getInt32Ty(Context),
162    Type::getInt64Ty(Context),
163    Type::getInt8Ty(Context)
164  };
165
166  auto *FuncTy = FunctionType::get(Type::getVoidTy(Context), ArgsTy, false);
167  // Pick a unique name to describe the input parameters
168  Twine Name = "autogen_SD" + Twine{SeedCL};
169  auto *Func = Function::Create(FuncTy, GlobalValue::ExternalLinkage, Name, M);
170  Func->setCallingConv(CallingConv::C);
171  return Func;
172}
173
174/// A base class, implementing utilities needed for
175/// modifying and adding new random instructions.
176struct Modifier {
177  /// Used to store the randomly generated values.
178  using PieceTable = std::vector<Value *>;
179
180public:
181  /// C'tor
182  Modifier(BasicBlock *Block, PieceTable *PT, Random *R)
183      : BB(Block), PT(PT), Ran(R), Context(BB->getContext()) {}
184
185  /// virtual D'tor to silence warnings.
186  virtual ~Modifier() = default;
187
188  /// Add a new instruction.
189  virtual void Act() = 0;
190
191  /// Add N new instructions,
192  virtual void ActN(unsigned n) {
193    for (unsigned i=0; i<n; ++i)
194      Act();
195  }
196
197protected:
198  /// Return a random integer.
199  uint32_t getRandom() {
200    return Ran->Rand();
201  }
202
203  /// Return a random value from the list of known values.
204  Value *getRandomVal() {
205    assert(PT->size());
206    return PT->at(getRandom() % PT->size());
207  }
208
209  Constant *getRandomConstant(Type *Tp) {
210    if (Tp->isIntegerTy()) {
211      if (getRandom() & 1)
212        return ConstantInt::getAllOnesValue(Tp);
213      return ConstantInt::getNullValue(Tp);
214    } else if (Tp->isFloatingPointTy()) {
215      if (getRandom() & 1)
216        return ConstantFP::getAllOnesValue(Tp);
217      return ConstantFP::getNullValue(Tp);
218    }
219    return UndefValue::get(Tp);
220  }
221
222  /// Return a random value with a known type.
223  Value *getRandomValue(Type *Tp) {
224    unsigned index = getRandom();
225    for (unsigned i=0; i<PT->size(); ++i) {
226      Value *V = PT->at((index + i) % PT->size());
227      if (V->getType() == Tp)
228        return V;
229    }
230
231    // If the requested type was not found, generate a constant value.
232    if (Tp->isIntegerTy()) {
233      if (getRandom() & 1)
234        return ConstantInt::getAllOnesValue(Tp);
235      return ConstantInt::getNullValue(Tp);
236    } else if (Tp->isFloatingPointTy()) {
237      if (getRandom() & 1)
238        return ConstantFP::getAllOnesValue(Tp);
239      return ConstantFP::getNullValue(Tp);
240    } else if (Tp->isVectorTy()) {
241      VectorType *VTp = cast<VectorType>(Tp);
242
243      std::vector<Constant*> TempValues;
244      TempValues.reserve(VTp->getNumElements());
245      for (unsigned i = 0; i < VTp->getNumElements(); ++i)
246        TempValues.push_back(getRandomConstant(VTp->getScalarType()));
247
248      ArrayRef<Constant*> VectorValue(TempValues);
249      return ConstantVector::get(VectorValue);
250    }
251
252    return UndefValue::get(Tp);
253  }
254
255  /// Return a random value of any pointer type.
256  Value *getRandomPointerValue() {
257    unsigned index = getRandom();
258    for (unsigned i=0; i<PT->size(); ++i) {
259      Value *V = PT->at((index + i) % PT->size());
260      if (V->getType()->isPointerTy())
261        return V;
262    }
263    return UndefValue::get(pickPointerType());
264  }
265
266  /// Return a random value of any vector type.
267  Value *getRandomVectorValue() {
268    unsigned index = getRandom();
269    for (unsigned i=0; i<PT->size(); ++i) {
270      Value *V = PT->at((index + i) % PT->size());
271      if (V->getType()->isVectorTy())
272        return V;
273    }
274    return UndefValue::get(pickVectorType());
275  }
276
277  /// Pick a random type.
278  Type *pickType() {
279    return (getRandom() & 1) ? pickVectorType() : pickScalarType();
280  }
281
282  /// Pick a random pointer type.
283  Type *pickPointerType() {
284    Type *Ty = pickType();
285    return PointerType::get(Ty, 0);
286  }
287
288  /// Pick a random vector type.
289  Type *pickVectorType(unsigned len = (unsigned)-1) {
290    // Pick a random vector width in the range 2**0 to 2**4.
291    // by adding two randoms we are generating a normal-like distribution
292    // around 2**3.
293    unsigned width = 1<<((getRandom() % 3) + (getRandom() % 3));
294    Type *Ty;
295
296    // Vectors of x86mmx are illegal; keep trying till we get something else.
297    do {
298      Ty = pickScalarType();
299    } while (Ty->isX86_MMXTy());
300
301    if (len != (unsigned)-1)
302      width = len;
303    return VectorType::get(Ty, width);
304  }
305
306  /// Pick a random scalar type.
307  Type *pickScalarType() {
308    static std::vector<Type*> ScalarTypes;
309    if (ScalarTypes.empty()) {
310      ScalarTypes.assign({
311        Type::getInt1Ty(Context),
312        Type::getInt8Ty(Context),
313        Type::getInt16Ty(Context),
314        Type::getInt32Ty(Context),
315        Type::getInt64Ty(Context),
316        Type::getFloatTy(Context),
317        Type::getDoubleTy(Context)
318      });
319      ScalarTypes.insert(ScalarTypes.end(),
320        AdditionalScalarTypes.begin(), AdditionalScalarTypes.end());
321    }
322
323    return ScalarTypes[getRandom() % ScalarTypes.size()];
324  }
325
326  /// Basic block to populate
327  BasicBlock *BB;
328
329  /// Value table
330  PieceTable *PT;
331
332  /// Random number generator
333  Random *Ran;
334
335  /// Context
336  LLVMContext &Context;
337};
338
339struct LoadModifier: public Modifier {
340  LoadModifier(BasicBlock *BB, PieceTable *PT, Random *R)
341      : Modifier(BB, PT, R) {}
342
343  void Act() override {
344    // Try to use predefined pointers. If non-exist, use undef pointer value;
345    Value *Ptr = getRandomPointerValue();
346    Value *V = new LoadInst(Ptr, "L", BB->getTerminator());
347    PT->push_back(V);
348  }
349};
350
351struct StoreModifier: public Modifier {
352  StoreModifier(BasicBlock *BB, PieceTable *PT, Random *R)
353      : Modifier(BB, PT, R) {}
354
355  void Act() override {
356    // Try to use predefined pointers. If non-exist, use undef pointer value;
357    Value *Ptr = getRandomPointerValue();
358    PointerType *Tp = cast<PointerType>(Ptr->getType());
359    Value *Val = getRandomValue(Tp->getElementType());
360    Type  *ValTy = Val->getType();
361
362    // Do not store vectors of i1s because they are unsupported
363    // by the codegen.
364    if (ValTy->isVectorTy() && ValTy->getScalarSizeInBits() == 1)
365      return;
366
367    new StoreInst(Val, Ptr, BB->getTerminator());
368  }
369};
370
371struct BinModifier: public Modifier {
372  BinModifier(BasicBlock *BB, PieceTable *PT, Random *R)
373      : Modifier(BB, PT, R) {}
374
375  void Act() override {
376    Value *Val0 = getRandomVal();
377    Value *Val1 = getRandomValue(Val0->getType());
378
379    // Don't handle pointer types.
380    if (Val0->getType()->isPointerTy() ||
381        Val1->getType()->isPointerTy())
382      return;
383
384    // Don't handle i1 types.
385    if (Val0->getType()->getScalarSizeInBits() == 1)
386      return;
387
388    bool isFloat = Val0->getType()->getScalarType()->isFloatingPointTy();
389    Instruction* Term = BB->getTerminator();
390    unsigned R = getRandom() % (isFloat ? 7 : 13);
391    Instruction::BinaryOps Op;
392
393    switch (R) {
394    default: llvm_unreachable("Invalid BinOp");
395    case 0:{Op = (isFloat?Instruction::FAdd : Instruction::Add); break; }
396    case 1:{Op = (isFloat?Instruction::FSub : Instruction::Sub); break; }
397    case 2:{Op = (isFloat?Instruction::FMul : Instruction::Mul); break; }
398    case 3:{Op = (isFloat?Instruction::FDiv : Instruction::SDiv); break; }
399    case 4:{Op = (isFloat?Instruction::FDiv : Instruction::UDiv); break; }
400    case 5:{Op = (isFloat?Instruction::FRem : Instruction::SRem); break; }
401    case 6:{Op = (isFloat?Instruction::FRem : Instruction::URem); break; }
402    case 7: {Op = Instruction::Shl;  break; }
403    case 8: {Op = Instruction::LShr; break; }
404    case 9: {Op = Instruction::AShr; break; }
405    case 10:{Op = Instruction::And;  break; }
406    case 11:{Op = Instruction::Or;   break; }
407    case 12:{Op = Instruction::Xor;  break; }
408    }
409
410    PT->push_back(BinaryOperator::Create(Op, Val0, Val1, "B", Term));
411  }
412};
413
414/// Generate constant values.
415struct ConstModifier: public Modifier {
416  ConstModifier(BasicBlock *BB, PieceTable *PT, Random *R)
417      : Modifier(BB, PT, R) {}
418
419  void Act() override {
420    Type *Ty = pickType();
421
422    if (Ty->isVectorTy()) {
423      switch (getRandom() % 2) {
424      case 0: if (Ty->isIntOrIntVectorTy())
425                return PT->push_back(ConstantVector::getAllOnesValue(Ty));
426              break;
427      case 1: if (Ty->isIntOrIntVectorTy())
428                return PT->push_back(ConstantVector::getNullValue(Ty));
429      }
430    }
431
432    if (Ty->isFloatingPointTy()) {
433      // Generate 128 random bits, the size of the (currently)
434      // largest floating-point types.
435      uint64_t RandomBits[2];
436      for (unsigned i = 0; i < 2; ++i)
437        RandomBits[i] = Ran->Rand64();
438
439      APInt RandomInt(Ty->getPrimitiveSizeInBits(), makeArrayRef(RandomBits));
440      APFloat RandomFloat(Ty->getFltSemantics(), RandomInt);
441
442      if (getRandom() & 1)
443        return PT->push_back(ConstantFP::getNullValue(Ty));
444      return PT->push_back(ConstantFP::get(Ty->getContext(), RandomFloat));
445    }
446
447    if (Ty->isIntegerTy()) {
448      switch (getRandom() % 7) {
449      case 0:
450        return PT->push_back(ConstantInt::get(
451            Ty, APInt::getAllOnesValue(Ty->getPrimitiveSizeInBits())));
452      case 1:
453        return PT->push_back(ConstantInt::get(
454            Ty, APInt::getNullValue(Ty->getPrimitiveSizeInBits())));
455      case 2:
456      case 3:
457      case 4:
458      case 5:
459      case 6:
460        PT->push_back(ConstantInt::get(Ty, getRandom()));
461      }
462    }
463  }
464};
465
466struct AllocaModifier: public Modifier {
467  AllocaModifier(BasicBlock *BB, PieceTable *PT, Random *R)
468      : Modifier(BB, PT, R) {}
469
470  void Act() override {
471    Type *Tp = pickType();
472    const DataLayout &DL = BB->getModule()->getDataLayout();
473    PT->push_back(new AllocaInst(Tp, DL.getAllocaAddrSpace(),
474                                 "A", BB->getFirstNonPHI()));
475  }
476};
477
478struct ExtractElementModifier: public Modifier {
479  ExtractElementModifier(BasicBlock *BB, PieceTable *PT, Random *R)
480      : Modifier(BB, PT, R) {}
481
482  void Act() override {
483    Value *Val0 = getRandomVectorValue();
484    Value *V = ExtractElementInst::Create(Val0,
485             ConstantInt::get(Type::getInt32Ty(BB->getContext()),
486             getRandom() % cast<VectorType>(Val0->getType())->getNumElements()),
487             "E", BB->getTerminator());
488    return PT->push_back(V);
489  }
490};
491
492struct ShuffModifier: public Modifier {
493  ShuffModifier(BasicBlock *BB, PieceTable *PT, Random *R)
494      : Modifier(BB, PT, R) {}
495
496  void Act() override {
497    Value *Val0 = getRandomVectorValue();
498    Value *Val1 = getRandomValue(Val0->getType());
499
500    unsigned Width = cast<VectorType>(Val0->getType())->getNumElements();
501    std::vector<Constant*> Idxs;
502
503    Type *I32 = Type::getInt32Ty(BB->getContext());
504    for (unsigned i=0; i<Width; ++i) {
505      Constant *CI = ConstantInt::get(I32, getRandom() % (Width*2));
506      // Pick some undef values.
507      if (!(getRandom() % 5))
508        CI = UndefValue::get(I32);
509      Idxs.push_back(CI);
510    }
511
512    Constant *Mask = ConstantVector::get(Idxs);
513
514    Value *V = new ShuffleVectorInst(Val0, Val1, Mask, "Shuff",
515                                     BB->getTerminator());
516    PT->push_back(V);
517  }
518};
519
520struct InsertElementModifier: public Modifier {
521  InsertElementModifier(BasicBlock *BB, PieceTable *PT, Random *R)
522      : Modifier(BB, PT, R) {}
523
524  void Act() override {
525    Value *Val0 = getRandomVectorValue();
526    Value *Val1 = getRandomValue(Val0->getType()->getScalarType());
527
528    Value *V = InsertElementInst::Create(Val0, Val1,
529              ConstantInt::get(Type::getInt32Ty(BB->getContext()),
530              getRandom() % cast<VectorType>(Val0->getType())->getNumElements()),
531              "I",  BB->getTerminator());
532    return PT->push_back(V);
533  }
534};
535
536struct CastModifier: public Modifier {
537  CastModifier(BasicBlock *BB, PieceTable *PT, Random *R)
538      : Modifier(BB, PT, R) {}
539
540  void Act() override {
541    Value *V = getRandomVal();
542    Type *VTy = V->getType();
543    Type *DestTy = pickScalarType();
544
545    // Handle vector casts vectors.
546    if (VTy->isVectorTy()) {
547      VectorType *VecTy = cast<VectorType>(VTy);
548      DestTy = pickVectorType(VecTy->getNumElements());
549    }
550
551    // no need to cast.
552    if (VTy == DestTy) return;
553
554    // Pointers:
555    if (VTy->isPointerTy()) {
556      if (!DestTy->isPointerTy())
557        DestTy = PointerType::get(DestTy, 0);
558      return PT->push_back(
559        new BitCastInst(V, DestTy, "PC", BB->getTerminator()));
560    }
561
562    unsigned VSize = VTy->getScalarType()->getPrimitiveSizeInBits();
563    unsigned DestSize = DestTy->getScalarType()->getPrimitiveSizeInBits();
564
565    // Generate lots of bitcasts.
566    if ((getRandom() & 1) && VSize == DestSize) {
567      return PT->push_back(
568        new BitCastInst(V, DestTy, "BC", BB->getTerminator()));
569    }
570
571    // Both types are integers:
572    if (VTy->isIntOrIntVectorTy() && DestTy->isIntOrIntVectorTy()) {
573      if (VSize > DestSize) {
574        return PT->push_back(
575          new TruncInst(V, DestTy, "Tr", BB->getTerminator()));
576      } else {
577        assert(VSize < DestSize && "Different int types with the same size?");
578        if (getRandom() & 1)
579          return PT->push_back(
580            new ZExtInst(V, DestTy, "ZE", BB->getTerminator()));
581        return PT->push_back(new SExtInst(V, DestTy, "Se", BB->getTerminator()));
582      }
583    }
584
585    // Fp to int.
586    if (VTy->isFPOrFPVectorTy() && DestTy->isIntOrIntVectorTy()) {
587      if (getRandom() & 1)
588        return PT->push_back(
589          new FPToSIInst(V, DestTy, "FC", BB->getTerminator()));
590      return PT->push_back(new FPToUIInst(V, DestTy, "FC", BB->getTerminator()));
591    }
592
593    // Int to fp.
594    if (VTy->isIntOrIntVectorTy() && DestTy->isFPOrFPVectorTy()) {
595      if (getRandom() & 1)
596        return PT->push_back(
597          new SIToFPInst(V, DestTy, "FC", BB->getTerminator()));
598      return PT->push_back(new UIToFPInst(V, DestTy, "FC", BB->getTerminator()));
599    }
600
601    // Both floats.
602    if (VTy->isFPOrFPVectorTy() && DestTy->isFPOrFPVectorTy()) {
603      if (VSize > DestSize) {
604        return PT->push_back(
605          new FPTruncInst(V, DestTy, "Tr", BB->getTerminator()));
606      } else if (VSize < DestSize) {
607        return PT->push_back(
608          new FPExtInst(V, DestTy, "ZE", BB->getTerminator()));
609      }
610      // If VSize == DestSize, then the two types must be fp128 and ppc_fp128,
611      // for which there is no defined conversion. So do nothing.
612    }
613  }
614};
615
616struct SelectModifier: public Modifier {
617  SelectModifier(BasicBlock *BB, PieceTable *PT, Random *R)
618      : Modifier(BB, PT, R) {}
619
620  void Act() override {
621    // Try a bunch of different select configuration until a valid one is found.
622    Value *Val0 = getRandomVal();
623    Value *Val1 = getRandomValue(Val0->getType());
624
625    Type *CondTy = Type::getInt1Ty(Context);
626
627    // If the value type is a vector, and we allow vector select, then in 50%
628    // of the cases generate a vector select.
629    if (Val0->getType()->isVectorTy() && (getRandom() % 1)) {
630      unsigned NumElem = cast<VectorType>(Val0->getType())->getNumElements();
631      CondTy = VectorType::get(CondTy, NumElem);
632    }
633
634    Value *Cond = getRandomValue(CondTy);
635    Value *V = SelectInst::Create(Cond, Val0, Val1, "Sl", BB->getTerminator());
636    return PT->push_back(V);
637  }
638};
639
640struct CmpModifier: public Modifier {
641  CmpModifier(BasicBlock *BB, PieceTable *PT, Random *R)
642      : Modifier(BB, PT, R) {}
643
644  void Act() override {
645    Value *Val0 = getRandomVal();
646    Value *Val1 = getRandomValue(Val0->getType());
647
648    if (Val0->getType()->isPointerTy()) return;
649    bool fp = Val0->getType()->getScalarType()->isFloatingPointTy();
650
651    int op;
652    if (fp) {
653      op = getRandom() %
654      (CmpInst::LAST_FCMP_PREDICATE - CmpInst::FIRST_FCMP_PREDICATE) +
655       CmpInst::FIRST_FCMP_PREDICATE;
656    } else {
657      op = getRandom() %
658      (CmpInst::LAST_ICMP_PREDICATE - CmpInst::FIRST_ICMP_PREDICATE) +
659       CmpInst::FIRST_ICMP_PREDICATE;
660    }
661
662    Value *V = CmpInst::Create(fp ? Instruction::FCmp : Instruction::ICmp,
663                               (CmpInst::Predicate)op, Val0, Val1, "Cmp",
664                               BB->getTerminator());
665    return PT->push_back(V);
666  }
667};
668
669} // end anonymous namespace
670
671static void FillFunction(Function *F, Random &R) {
672  // Create a legal entry block.
673  BasicBlock *BB = BasicBlock::Create(F->getContext(), "BB", F);
674  ReturnInst::Create(F->getContext(), BB);
675
676  // Create the value table.
677  Modifier::PieceTable PT;
678
679  // Consider arguments as legal values.
680  for (auto &arg : F->args())
681    PT.push_back(&arg);
682
683  // List of modifiers which add new random instructions.
684  std::vector<std::unique_ptr<Modifier>> Modifiers;
685  Modifiers.emplace_back(new LoadModifier(BB, &PT, &R));
686  Modifiers.emplace_back(new StoreModifier(BB, &PT, &R));
687  auto SM = Modifiers.back().get();
688  Modifiers.emplace_back(new ExtractElementModifier(BB, &PT, &R));
689  Modifiers.emplace_back(new ShuffModifier(BB, &PT, &R));
690  Modifiers.emplace_back(new InsertElementModifier(BB, &PT, &R));
691  Modifiers.emplace_back(new BinModifier(BB, &PT, &R));
692  Modifiers.emplace_back(new CastModifier(BB, &PT, &R));
693  Modifiers.emplace_back(new SelectModifier(BB, &PT, &R));
694  Modifiers.emplace_back(new CmpModifier(BB, &PT, &R));
695
696  // Generate the random instructions
697  AllocaModifier{BB, &PT, &R}.ActN(5); // Throw in a few allocas
698  ConstModifier{BB, &PT, &R}.ActN(40); // Throw in a few constants
699
700  for (unsigned i = 0; i < SizeCL / Modifiers.size(); ++i)
701    for (auto &Mod : Modifiers)
702      Mod->Act();
703
704  SM->ActN(5); // Throw in a few stores.
705}
706
707static void IntroduceControlFlow(Function *F, Random &R) {
708  std::vector<Instruction*> BoolInst;
709  for (auto &Instr : F->front()) {
710    if (Instr.getType() == IntegerType::getInt1Ty(F->getContext()))
711      BoolInst.push_back(&Instr);
712  }
713
714  std::shuffle(BoolInst.begin(), BoolInst.end(), R);
715
716  for (auto *Instr : BoolInst) {
717    BasicBlock *Curr = Instr->getParent();
718    BasicBlock::iterator Loc = Instr->getIterator();
719    BasicBlock *Next = Curr->splitBasicBlock(Loc, "CF");
720    Instr->moveBefore(Curr->getTerminator());
721    if (Curr != &F->getEntryBlock()) {
722      BranchInst::Create(Curr, Next, Instr, Curr->getTerminator());
723      Curr->getTerminator()->eraseFromParent();
724    }
725  }
726}
727
728} // end namespace llvm
729
730int main(int argc, char **argv) {
731  using namespace llvm;
732
733  // Init LLVM, call llvm_shutdown() on exit, parse args, etc.
734  PrettyStackTraceProgram X(argc, argv);
735  cl::ParseCommandLineOptions(argc, argv, "llvm codegen stress-tester\n");
736  llvm_shutdown_obj Y;
737
738  auto M = std::make_unique<Module>("/tmp/autogen.bc", Context);
739  Function *F = GenEmptyFunction(M.get());
740
741  // Pick an initial seed value
742  Random R(SeedCL);
743  // Generate lots of random instructions inside a single basic block.
744  FillFunction(F, R);
745  // Break the basic block into many loops.
746  IntroduceControlFlow(F, R);
747
748  // Figure out what stream we are supposed to write to...
749  std::unique_ptr<ToolOutputFile> Out;
750  // Default to standard output.
751  if (OutputFilename.empty())
752    OutputFilename = "-";
753
754  std::error_code EC;
755  Out.reset(new ToolOutputFile(OutputFilename, EC, sys::fs::OF_None));
756  if (EC) {
757    errs() << EC.message() << '\n';
758    return 1;
759  }
760
761  legacy::PassManager Passes;
762  Passes.add(createVerifierPass());
763  Passes.add(createPrintModulePass(Out->os()));
764  Passes.run(*M.get());
765  Out->keep();
766
767  return 0;
768}
769