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/InstrTypes.h"
28#include "llvm/IR/Instruction.h"
29#include "llvm/IR/Instructions.h"
30#include "llvm/IR/LLVMContext.h"
31#include "llvm/IR/Module.h"
32#include "llvm/IR/Type.h"
33#include "llvm/IR/Value.h"
34#include "llvm/IR/Verifier.h"
35#include "llvm/Support/Casting.h"
36#include "llvm/Support/CommandLine.h"
37#include "llvm/Support/ErrorHandling.h"
38#include "llvm/Support/FileSystem.h"
39#include "llvm/Support/InitLLVM.h"
40#include "llvm/Support/ToolOutputFile.h"
41#include "llvm/Support/WithColor.h"
42#include "llvm/Support/raw_ostream.h"
43#include <algorithm>
44#include <cassert>
45#include <cstddef>
46#include <cstdint>
47#include <memory>
48#include <string>
49#include <system_error>
50#include <vector>
51
52namespace llvm {
53
54static cl::OptionCategory StressCategory("Stress Options");
55
56static cl::opt<unsigned> SeedCL("seed", cl::desc("Seed used for randomness"),
57                                cl::init(0), cl::cat(StressCategory));
58
59static cl::opt<unsigned> SizeCL(
60    "size",
61    cl::desc("The estimated size of the generated function (# of instrs)"),
62    cl::init(100), cl::cat(StressCategory));
63
64static cl::opt<std::string> OutputFilename("o",
65                                           cl::desc("Override output filename"),
66                                           cl::value_desc("filename"),
67                                           cl::cat(StressCategory));
68
69static cl::list<StringRef> AdditionalScalarTypes(
70    "types", cl::CommaSeparated,
71    cl::desc("Additional IR scalar types "
72             "(always includes i1, i8, i16, i32, i64, float and double)"));
73
74static cl::opt<bool> EnableScalableVectors(
75    "enable-scalable-vectors",
76    cl::desc("Generate IR involving scalable vector types"),
77    cl::init(false), cl::cat(StressCategory));
78
79
80namespace {
81
82/// A utility class to provide a pseudo-random number generator which is
83/// the same across all platforms. This is somewhat close to the libc
84/// implementation. Note: This is not a cryptographically secure pseudorandom
85/// number generator.
86class Random {
87public:
88  /// C'tor
89  Random(unsigned _seed):Seed(_seed) {}
90
91  /// Return a random integer, up to a
92  /// maximum of 2**19 - 1.
93  uint32_t Rand() {
94    uint32_t Val = Seed + 0x000b07a1;
95    Seed = (Val * 0x3c7c0ac1);
96    // Only lowest 19 bits are random-ish.
97    return Seed & 0x7ffff;
98  }
99
100  /// Return a random 64 bit integer.
101  uint64_t Rand64() {
102    uint64_t Val = Rand() & 0xffff;
103    Val |= uint64_t(Rand() & 0xffff) << 16;
104    Val |= uint64_t(Rand() & 0xffff) << 32;
105    Val |= uint64_t(Rand() & 0xffff) << 48;
106    return Val;
107  }
108
109  /// Rand operator for STL algorithms.
110  ptrdiff_t operator()(ptrdiff_t y) {
111    return  Rand64() % y;
112  }
113
114  /// Make this like a C++11 random device
115  using result_type = uint32_t ;
116
117  static constexpr result_type min() { return 0; }
118  static constexpr result_type max() { return 0x7ffff; }
119
120  uint32_t operator()() {
121    uint32_t Val = Rand();
122    assert(Val <= max() && "Random value out of range");
123    return Val;
124  }
125
126private:
127  unsigned Seed;
128};
129
130/// Generate an empty function with a default argument list.
131Function *GenEmptyFunction(Module *M) {
132  // Define a few arguments
133  LLVMContext &Context = M->getContext();
134  Type* ArgsTy[] = {
135    PointerType::get(Context, 0),
136    PointerType::get(Context, 0),
137    PointerType::get(Context, 0),
138    Type::getInt32Ty(Context),
139    Type::getInt64Ty(Context),
140    Type::getInt8Ty(Context)
141  };
142
143  auto *FuncTy = FunctionType::get(Type::getVoidTy(Context), ArgsTy, false);
144  // Pick a unique name to describe the input parameters
145  Twine Name = "autogen_SD" + Twine{SeedCL};
146  auto *Func = Function::Create(FuncTy, GlobalValue::ExternalLinkage, Name, M);
147  Func->setCallingConv(CallingConv::C);
148  return Func;
149}
150
151/// A base class, implementing utilities needed for
152/// modifying and adding new random instructions.
153struct Modifier {
154  /// Used to store the randomly generated values.
155  using PieceTable = std::vector<Value *>;
156
157public:
158  /// C'tor
159  Modifier(BasicBlock *Block, PieceTable *PT, Random *R)
160      : BB(Block), PT(PT), Ran(R), Context(BB->getContext()) {
161    ScalarTypes.assign({Type::getInt1Ty(Context), Type::getInt8Ty(Context),
162                        Type::getInt16Ty(Context), Type::getInt32Ty(Context),
163                        Type::getInt64Ty(Context), Type::getFloatTy(Context),
164                        Type::getDoubleTy(Context)});
165
166    for (auto &Arg : AdditionalScalarTypes) {
167      Type *Ty = nullptr;
168      if (Arg == "half")
169        Ty = Type::getHalfTy(Context);
170      else if (Arg == "fp128")
171        Ty = Type::getFP128Ty(Context);
172      else if (Arg == "x86_fp80")
173        Ty = Type::getX86_FP80Ty(Context);
174      else if (Arg == "ppc_fp128")
175        Ty = Type::getPPC_FP128Ty(Context);
176      else if (Arg == "x86_mmx")
177        Ty = Type::getX86_MMXTy(Context);
178      else if (Arg.starts_with("i")) {
179        unsigned N = 0;
180        Arg.drop_front().getAsInteger(10, N);
181        if (N > 0)
182          Ty = Type::getIntNTy(Context, N);
183      }
184      if (!Ty) {
185        errs() << "Invalid IR scalar type: '" << Arg << "'!\n";
186        exit(1);
187      }
188
189      ScalarTypes.push_back(Ty);
190    }
191  }
192
193  /// virtual D'tor to silence warnings.
194  virtual ~Modifier() = default;
195
196  /// Add a new instruction.
197  virtual void Act() = 0;
198
199  /// Add N new instructions,
200  virtual void ActN(unsigned n) {
201    for (unsigned i=0; i<n; ++i)
202      Act();
203  }
204
205protected:
206  /// Return a random integer.
207  uint32_t getRandom() {
208    return Ran->Rand();
209  }
210
211  /// Return a random value from the list of known values.
212  Value *getRandomVal() {
213    assert(PT->size());
214    return PT->at(getRandom() % PT->size());
215  }
216
217  Constant *getRandomConstant(Type *Tp) {
218    if (Tp->isIntegerTy()) {
219      if (getRandom() & 1)
220        return ConstantInt::getAllOnesValue(Tp);
221      return ConstantInt::getNullValue(Tp);
222    } else if (Tp->isFloatingPointTy()) {
223      if (getRandom() & 1)
224        return ConstantFP::getAllOnesValue(Tp);
225      return ConstantFP::getZero(Tp);
226    }
227    return UndefValue::get(Tp);
228  }
229
230  /// Return a random value with a known type.
231  Value *getRandomValue(Type *Tp) {
232    unsigned index = getRandom();
233    for (unsigned i=0; i<PT->size(); ++i) {
234      Value *V = PT->at((index + i) % PT->size());
235      if (V->getType() == Tp)
236        return V;
237    }
238
239    // If the requested type was not found, generate a constant value.
240    if (Tp->isIntegerTy()) {
241      if (getRandom() & 1)
242        return ConstantInt::getAllOnesValue(Tp);
243      return ConstantInt::getNullValue(Tp);
244    } else if (Tp->isFloatingPointTy()) {
245      if (getRandom() & 1)
246        return ConstantFP::getAllOnesValue(Tp);
247      return ConstantFP::getZero(Tp);
248    } else if (auto *VTp = dyn_cast<FixedVectorType>(Tp)) {
249      std::vector<Constant*> TempValues;
250      TempValues.reserve(VTp->getNumElements());
251      for (unsigned i = 0; i < VTp->getNumElements(); ++i)
252        TempValues.push_back(getRandomConstant(VTp->getScalarType()));
253
254      ArrayRef<Constant*> VectorValue(TempValues);
255      return ConstantVector::get(VectorValue);
256    }
257
258    return UndefValue::get(Tp);
259  }
260
261  /// Return a random value of any pointer type.
262  Value *getRandomPointerValue() {
263    unsigned index = getRandom();
264    for (unsigned i=0; i<PT->size(); ++i) {
265      Value *V = PT->at((index + i) % PT->size());
266      if (V->getType()->isPointerTy())
267        return V;
268    }
269    return UndefValue::get(pickPointerType());
270  }
271
272  /// Return a random value of any vector type.
273  Value *getRandomVectorValue() {
274    unsigned index = getRandom();
275    for (unsigned i=0; i<PT->size(); ++i) {
276      Value *V = PT->at((index + i) % PT->size());
277      if (V->getType()->isVectorTy())
278        return V;
279    }
280    return UndefValue::get(pickVectorType());
281  }
282
283  /// Pick a random type.
284  Type *pickType() {
285    return (getRandom() & 1) ? pickVectorType() : pickScalarType();
286  }
287
288  /// Pick a random pointer type.
289  Type *pickPointerType() {
290    Type *Ty = pickType();
291    return PointerType::get(Ty, 0);
292  }
293
294  /// Pick a random vector type.
295  Type *pickVectorType(VectorType *VTy = nullptr) {
296
297    // Vectors of x86mmx are illegal; keep trying till we get something else.
298    Type *Ty;
299    do {
300      Ty = pickScalarType();
301    } while (Ty->isX86_MMXTy());
302
303    if (VTy)
304      return VectorType::get(Ty, VTy->getElementCount());
305
306    // Select either fixed length or scalable vectors with 50% probability
307    // (only if scalable vectors are enabled)
308    bool Scalable = EnableScalableVectors && getRandom() & 1;
309
310    // Pick a random vector width in the range 2**0 to 2**4.
311    // by adding two randoms we are generating a normal-like distribution
312    // around 2**3.
313    unsigned width = 1<<((getRandom() % 3) + (getRandom() % 3));
314    return VectorType::get(Ty, width, Scalable);
315  }
316
317  /// Pick a random scalar type.
318  Type *pickScalarType() {
319    return ScalarTypes[getRandom() % ScalarTypes.size()];
320  }
321
322  /// Basic block to populate
323  BasicBlock *BB;
324
325  /// Value table
326  PieceTable *PT;
327
328  /// Random number generator
329  Random *Ran;
330
331  /// Context
332  LLVMContext &Context;
333
334  std::vector<Type *> ScalarTypes;
335};
336
337struct LoadModifier: public Modifier {
338  LoadModifier(BasicBlock *BB, PieceTable *PT, Random *R)
339      : Modifier(BB, PT, R) {}
340
341  void Act() override {
342    // Try to use predefined pointers. If non-exist, use undef pointer value;
343    Value *Ptr = getRandomPointerValue();
344    Type *Ty = pickType();
345    Value *V = new LoadInst(Ty, Ptr, "L", BB->getTerminator());
346    PT->push_back(V);
347  }
348};
349
350struct StoreModifier: public Modifier {
351  StoreModifier(BasicBlock *BB, PieceTable *PT, Random *R)
352      : Modifier(BB, PT, R) {}
353
354  void Act() override {
355    // Try to use predefined pointers. If non-exist, use undef pointer value;
356    Value *Ptr = getRandomPointerValue();
357    Type *ValTy = pickType();
358
359    // Do not store vectors of i1s because they are unsupported
360    // by the codegen.
361    if (ValTy->isVectorTy() && ValTy->getScalarSizeInBits() == 1)
362      return;
363
364    Value *Val = getRandomValue(ValTy);
365    new StoreInst(Val, Ptr, BB->getTerminator());
366  }
367};
368
369struct BinModifier: public Modifier {
370  BinModifier(BasicBlock *BB, PieceTable *PT, Random *R)
371      : Modifier(BB, PT, R) {}
372
373  void Act() override {
374    Value *Val0 = getRandomVal();
375    Value *Val1 = getRandomValue(Val0->getType());
376
377    // Don't handle pointer types.
378    if (Val0->getType()->isPointerTy() ||
379        Val1->getType()->isPointerTy())
380      return;
381
382    // Don't handle i1 types.
383    if (Val0->getType()->getScalarSizeInBits() == 1)
384      return;
385
386    bool isFloat = Val0->getType()->getScalarType()->isFloatingPointTy();
387    Instruction* Term = BB->getTerminator();
388    unsigned R = getRandom() % (isFloat ? 7 : 13);
389    Instruction::BinaryOps Op;
390
391    switch (R) {
392    default: llvm_unreachable("Invalid BinOp");
393    case 0:{Op = (isFloat?Instruction::FAdd : Instruction::Add); break; }
394    case 1:{Op = (isFloat?Instruction::FSub : Instruction::Sub); break; }
395    case 2:{Op = (isFloat?Instruction::FMul : Instruction::Mul); break; }
396    case 3:{Op = (isFloat?Instruction::FDiv : Instruction::SDiv); break; }
397    case 4:{Op = (isFloat?Instruction::FDiv : Instruction::UDiv); break; }
398    case 5:{Op = (isFloat?Instruction::FRem : Instruction::SRem); break; }
399    case 6:{Op = (isFloat?Instruction::FRem : Instruction::URem); break; }
400    case 7: {Op = Instruction::Shl;  break; }
401    case 8: {Op = Instruction::LShr; break; }
402    case 9: {Op = Instruction::AShr; break; }
403    case 10:{Op = Instruction::And;  break; }
404    case 11:{Op = Instruction::Or;   break; }
405    case 12:{Op = Instruction::Xor;  break; }
406    }
407
408    PT->push_back(BinaryOperator::Create(Op, Val0, Val1, "B", Term));
409  }
410};
411
412/// Generate constant values.
413struct ConstModifier: public Modifier {
414  ConstModifier(BasicBlock *BB, PieceTable *PT, Random *R)
415      : Modifier(BB, PT, R) {}
416
417  void Act() override {
418    Type *Ty = pickType();
419
420    if (Ty->isVectorTy()) {
421      switch (getRandom() % 2) {
422      case 0: if (Ty->isIntOrIntVectorTy())
423                return PT->push_back(ConstantVector::getAllOnesValue(Ty));
424              break;
425      case 1: if (Ty->isIntOrIntVectorTy())
426                return PT->push_back(ConstantVector::getNullValue(Ty));
427      }
428    }
429
430    if (Ty->isFloatingPointTy()) {
431      // Generate 128 random bits, the size of the (currently)
432      // largest floating-point types.
433      uint64_t RandomBits[2];
434      for (unsigned i = 0; i < 2; ++i)
435        RandomBits[i] = Ran->Rand64();
436
437      APInt RandomInt(Ty->getPrimitiveSizeInBits(), ArrayRef(RandomBits));
438      APFloat RandomFloat(Ty->getFltSemantics(), RandomInt);
439
440      if (getRandom() & 1)
441        return PT->push_back(ConstantFP::getZero(Ty));
442      return PT->push_back(ConstantFP::get(Ty->getContext(), RandomFloat));
443    }
444
445    if (Ty->isIntegerTy()) {
446      switch (getRandom() % 7) {
447      case 0:
448        return PT->push_back(ConstantInt::get(
449            Ty, APInt::getAllOnes(Ty->getPrimitiveSizeInBits())));
450      case 1:
451        return PT->push_back(
452            ConstantInt::get(Ty, APInt::getZero(Ty->getPrimitiveSizeInBits())));
453      case 2:
454      case 3:
455      case 4:
456      case 5:
457      case 6:
458        PT->push_back(ConstantInt::get(Ty, getRandom()));
459      }
460    }
461  }
462};
463
464struct AllocaModifier: public Modifier {
465  AllocaModifier(BasicBlock *BB, PieceTable *PT, Random *R)
466      : Modifier(BB, PT, R) {}
467
468  void Act() override {
469    Type *Tp = pickType();
470    const DataLayout &DL = BB->getModule()->getDataLayout();
471    PT->push_back(new AllocaInst(Tp, DL.getAllocaAddrSpace(),
472                                 "A", BB->getFirstNonPHI()));
473  }
474};
475
476struct ExtractElementModifier: public Modifier {
477  ExtractElementModifier(BasicBlock *BB, PieceTable *PT, Random *R)
478      : Modifier(BB, PT, R) {}
479
480  void Act() override {
481    Value *Val0 = getRandomVectorValue();
482    Value *V = ExtractElementInst::Create(
483        Val0,
484        getRandomValue(Type::getInt32Ty(BB->getContext())),
485        "E", BB->getTerminator());
486    return PT->push_back(V);
487  }
488};
489
490struct ShuffModifier: public Modifier {
491  ShuffModifier(BasicBlock *BB, PieceTable *PT, Random *R)
492      : Modifier(BB, PT, R) {}
493
494  void Act() override {
495    Value *Val0 = getRandomVectorValue();
496    Value *Val1 = getRandomValue(Val0->getType());
497
498    // Can't express arbitrary shufflevectors for scalable vectors
499    if (isa<ScalableVectorType>(Val0->getType()))
500      return;
501
502    unsigned Width = cast<FixedVectorType>(Val0->getType())->getNumElements();
503    std::vector<Constant*> Idxs;
504
505    Type *I32 = Type::getInt32Ty(BB->getContext());
506    for (unsigned i=0; i<Width; ++i) {
507      Constant *CI = ConstantInt::get(I32, getRandom() % (Width*2));
508      // Pick some undef values.
509      if (!(getRandom() % 5))
510        CI = UndefValue::get(I32);
511      Idxs.push_back(CI);
512    }
513
514    Constant *Mask = ConstantVector::get(Idxs);
515
516    Value *V = new ShuffleVectorInst(Val0, Val1, Mask, "Shuff",
517                                     BB->getTerminator());
518    PT->push_back(V);
519  }
520};
521
522struct InsertElementModifier: public Modifier {
523  InsertElementModifier(BasicBlock *BB, PieceTable *PT, Random *R)
524      : Modifier(BB, PT, R) {}
525
526  void Act() override {
527    Value *Val0 = getRandomVectorValue();
528    Value *Val1 = getRandomValue(Val0->getType()->getScalarType());
529
530    Value *V = InsertElementInst::Create(
531        Val0, Val1,
532        getRandomValue(Type::getInt32Ty(BB->getContext())),
533        "I", BB->getTerminator());
534    return PT->push_back(V);
535  }
536};
537
538struct CastModifier: public Modifier {
539  CastModifier(BasicBlock *BB, PieceTable *PT, Random *R)
540      : Modifier(BB, PT, R) {}
541
542  void Act() override {
543    Value *V = getRandomVal();
544    Type *VTy = V->getType();
545    Type *DestTy = pickScalarType();
546
547    // Handle vector casts vectors.
548    if (VTy->isVectorTy())
549      DestTy = pickVectorType(cast<VectorType>(VTy));
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 (auto *VTy = dyn_cast<VectorType>(Val0->getType()))
630      if (getRandom() & 1)
631        CondTy = VectorType::get(CondTy, VTy->getElementCount());
632
633    Value *Cond = getRandomValue(CondTy);
634    Value *V = SelectInst::Create(Cond, Val0, Val1, "Sl", BB->getTerminator());
635    return PT->push_back(V);
636  }
637};
638
639struct CmpModifier: public Modifier {
640  CmpModifier(BasicBlock *BB, PieceTable *PT, Random *R)
641      : Modifier(BB, PT, R) {}
642
643  void Act() override {
644    Value *Val0 = getRandomVal();
645    Value *Val1 = getRandomValue(Val0->getType());
646
647    if (Val0->getType()->isPointerTy()) return;
648    bool fp = Val0->getType()->getScalarType()->isFloatingPointTy();
649
650    int op;
651    if (fp) {
652      op = getRandom() %
653      (CmpInst::LAST_FCMP_PREDICATE - CmpInst::FIRST_FCMP_PREDICATE) +
654       CmpInst::FIRST_FCMP_PREDICATE;
655    } else {
656      op = getRandom() %
657      (CmpInst::LAST_ICMP_PREDICATE - CmpInst::FIRST_ICMP_PREDICATE) +
658       CmpInst::FIRST_ICMP_PREDICATE;
659    }
660
661    Value *V = CmpInst::Create(fp ? Instruction::FCmp : Instruction::ICmp,
662                               (CmpInst::Predicate)op, Val0, Val1, "Cmp",
663                               BB->getTerminator());
664    return PT->push_back(V);
665  }
666};
667
668} // end anonymous namespace
669
670static void FillFunction(Function *F, Random &R) {
671  // Create a legal entry block.
672  BasicBlock *BB = BasicBlock::Create(F->getContext(), "BB", F);
673  ReturnInst::Create(F->getContext(), BB);
674
675  // Create the value table.
676  Modifier::PieceTable PT;
677
678  // Consider arguments as legal values.
679  for (auto &arg : F->args())
680    PT.push_back(&arg);
681
682  // List of modifiers which add new random instructions.
683  std::vector<std::unique_ptr<Modifier>> Modifiers;
684  Modifiers.emplace_back(new LoadModifier(BB, &PT, &R));
685  Modifiers.emplace_back(new StoreModifier(BB, &PT, &R));
686  auto SM = Modifiers.back().get();
687  Modifiers.emplace_back(new ExtractElementModifier(BB, &PT, &R));
688  Modifiers.emplace_back(new ShuffModifier(BB, &PT, &R));
689  Modifiers.emplace_back(new InsertElementModifier(BB, &PT, &R));
690  Modifiers.emplace_back(new BinModifier(BB, &PT, &R));
691  Modifiers.emplace_back(new CastModifier(BB, &PT, &R));
692  Modifiers.emplace_back(new SelectModifier(BB, &PT, &R));
693  Modifiers.emplace_back(new CmpModifier(BB, &PT, &R));
694
695  // Generate the random instructions
696  AllocaModifier{BB, &PT, &R}.ActN(5); // Throw in a few allocas
697  ConstModifier{BB, &PT, &R}.ActN(40); // Throw in a few constants
698
699  for (unsigned i = 0; i < SizeCL / Modifiers.size(); ++i)
700    for (auto &Mod : Modifiers)
701      Mod->Act();
702
703  SM->ActN(5); // Throw in a few stores.
704}
705
706static void IntroduceControlFlow(Function *F, Random &R) {
707  std::vector<Instruction*> BoolInst;
708  for (auto &Instr : F->front()) {
709    if (Instr.getType() == IntegerType::getInt1Ty(F->getContext()))
710      BoolInst.push_back(&Instr);
711  }
712
713  llvm::shuffle(BoolInst.begin(), BoolInst.end(), R);
714
715  for (auto *Instr : BoolInst) {
716    BasicBlock *Curr = Instr->getParent();
717    BasicBlock::iterator Loc = Instr->getIterator();
718    BasicBlock *Next = Curr->splitBasicBlock(Loc, "CF");
719    Instr->moveBefore(Curr->getTerminator());
720    if (Curr != &F->getEntryBlock()) {
721      BranchInst::Create(Curr, Next, Instr, Curr->getTerminator());
722      Curr->getTerminator()->eraseFromParent();
723    }
724  }
725}
726
727} // end namespace llvm
728
729int main(int argc, char **argv) {
730  using namespace llvm;
731
732  InitLLVM X(argc, argv);
733  cl::HideUnrelatedOptions({&StressCategory, &getColorCategory()});
734  cl::ParseCommandLineOptions(argc, argv, "llvm codegen stress-tester\n");
735
736  LLVMContext Context;
737  auto M = std::make_unique<Module>("/tmp/autogen.bc", Context);
738  Function *F = GenEmptyFunction(M.get());
739
740  // Pick an initial seed value
741  Random R(SeedCL);
742  // Generate lots of random instructions inside a single basic block.
743  FillFunction(F, R);
744  // Break the basic block into many loops.
745  IntroduceControlFlow(F, R);
746
747  // Figure out what stream we are supposed to write to...
748  std::unique_ptr<ToolOutputFile> Out;
749  // Default to standard output.
750  if (OutputFilename.empty())
751    OutputFilename = "-";
752
753  std::error_code EC;
754  Out.reset(new ToolOutputFile(OutputFilename, EC, sys::fs::OF_None));
755  if (EC) {
756    errs() << EC.message() << '\n';
757    return 1;
758  }
759
760  // Check that the generated module is accepted by the verifier.
761  if (verifyModule(*M.get(), &Out->os()))
762    report_fatal_error("Broken module found, compilation aborted!");
763
764  // Output textual IR.
765  M->print(Out->os(), nullptr);
766
767  Out->keep();
768
769  return 0;
770}
771