1 //===-- llvm-stress.cpp - Generate random LL files to stress-test LLVM ----===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This program is a utility that generates random .ll files to stress-test
11 // different components in LLVM.
13 //===----------------------------------------------------------------------===//
14 #include "llvm/LLVMContext.h"
15 #include "llvm/Module.h"
16 #include "llvm/PassManager.h"
17 #include "llvm/Constants.h"
18 #include "llvm/Instruction.h"
19 #include "llvm/CallGraphSCCPass.h"
20 #include "llvm/Assembly/PrintModulePass.h"
21 #include "llvm/Analysis/Verifier.h"
22 #include "llvm/Support/PassNameParser.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Support/ManagedStatic.h"
25 #include "llvm/Support/PluginLoader.h"
26 #include "llvm/Support/PrettyStackTrace.h"
27 #include "llvm/Support/ToolOutputFile.h"
35 static cl::opt<unsigned> SeedCL("seed",
36 cl::desc("Seed used for randomness"), cl::init(0));
37 static cl::opt<unsigned> SizeCL("size",
38 cl::desc("The estimated size of the generated function (# of instrs)"),
40 static cl::opt<std::string>
41 OutputFilename("o", cl::desc("Override output filename"),
42 cl::value_desc("filename"));
44 static cl::opt<bool> GenHalfFloat("generate-half-float",
45 cl::desc("Generate half-length floating-point values"), cl::init(false));
46 static cl::opt<bool> GenX86FP80("generate-x86-fp80",
47 cl::desc("Generate 80-bit X86 floating-point values"), cl::init(false));
48 static cl::opt<bool> GenFP128("generate-fp128",
49 cl::desc("Generate 128-bit floating-point values"), cl::init(false));
50 static cl::opt<bool> GenPPCFP128("generate-ppc-fp128",
51 cl::desc("Generate 128-bit PPC floating-point values"), cl::init(false));
52 static cl::opt<bool> GenX86MMX("generate-x86-mmx",
53 cl::desc("Generate X86 MMX floating-point values"), cl::init(false));
55 /// A utility class to provide a pseudo-random number generator which is
56 /// the same across all platforms. This is somewhat close to the libc
57 /// implementation. Note: This is not a cryptographically secure pseudorandom
62 Random(unsigned _seed):Seed(_seed) {}
64 /// Return a random integer, up to a
65 /// maximum of 2**19 - 1.
67 uint32_t Val = Seed + 0x000b07a1;
68 Seed = (Val * 0x3c7c0ac1);
69 // Only lowest 19 bits are random-ish.
70 return Seed & 0x7ffff;
73 /// Return a random 32 bit integer.
75 uint32_t Val = Rand();
77 return Val | (Rand() << 16);
80 /// Return a random 64 bit integer.
82 uint64_t Val = Rand32();
83 return Val | (uint64_t(Rand32()) << 32);
86 /// Rand operator for STL algorithms.
87 ptrdiff_t operator()(ptrdiff_t y) {
95 /// Generate an empty function with a default argument list.
96 Function *GenEmptyFunction(Module *M) {
98 std::vector<Type*> ArgsTy;
99 // Define a few arguments
100 LLVMContext &Context = M->getContext();
101 ArgsTy.push_back(PointerType::get(IntegerType::getInt8Ty(Context), 0));
102 ArgsTy.push_back(PointerType::get(IntegerType::getInt32Ty(Context), 0));
103 ArgsTy.push_back(PointerType::get(IntegerType::getInt64Ty(Context), 0));
104 ArgsTy.push_back(IntegerType::getInt32Ty(Context));
105 ArgsTy.push_back(IntegerType::getInt64Ty(Context));
106 ArgsTy.push_back(IntegerType::getInt8Ty(Context));
108 FunctionType *FuncTy = FunctionType::get(Type::getVoidTy(Context), ArgsTy, 0);
109 // Pick a unique name to describe the input parameters
110 std::stringstream ss;
111 ss<<"autogen_SD"<<SeedCL;
112 Function *Func = Function::Create(FuncTy, GlobalValue::ExternalLinkage,
115 Func->setCallingConv(CallingConv::C);
119 /// A base class, implementing utilities needed for
120 /// modifying and adding new random instructions.
122 /// Used to store the randomly generated values.
123 typedef std::vector<Value*> PieceTable;
127 Modifier(BasicBlock *Block, PieceTable *PT, Random *R):
128 BB(Block),PT(PT),Ran(R),Context(BB->getContext()) {}
129 /// Add a new instruction.
130 virtual void Act() = 0;
131 /// Add N new instructions,
132 virtual void ActN(unsigned n) {
133 for (unsigned i=0; i<n; ++i)
138 /// Return a random value from the list of known values.
139 Value *getRandomVal() {
141 return PT->at(Ran->Rand() % PT->size());
144 Constant *getRandomConstant(Type *Tp) {
145 if (Tp->isIntegerTy()) {
147 return ConstantInt::getAllOnesValue(Tp);
148 return ConstantInt::getNullValue(Tp);
149 } else if (Tp->isFloatingPointTy()) {
151 return ConstantFP::getAllOnesValue(Tp);
152 return ConstantFP::getNullValue(Tp);
154 return UndefValue::get(Tp);
157 /// Return a random value with a known type.
158 Value *getRandomValue(Type *Tp) {
159 unsigned index = Ran->Rand();
160 for (unsigned i=0; i<PT->size(); ++i) {
161 Value *V = PT->at((index + i) % PT->size());
162 if (V->getType() == Tp)
166 // If the requested type was not found, generate a constant value.
167 if (Tp->isIntegerTy()) {
169 return ConstantInt::getAllOnesValue(Tp);
170 return ConstantInt::getNullValue(Tp);
171 } else if (Tp->isFloatingPointTy()) {
173 return ConstantFP::getAllOnesValue(Tp);
174 return ConstantFP::getNullValue(Tp);
175 } else if (Tp->isVectorTy()) {
176 VectorType *VTp = cast<VectorType>(Tp);
178 std::vector<Constant*> TempValues;
179 TempValues.reserve(VTp->getNumElements());
180 for (unsigned i = 0; i < VTp->getNumElements(); ++i)
181 TempValues.push_back(getRandomConstant(VTp->getScalarType()));
183 ArrayRef<Constant*> VectorValue(TempValues);
184 return ConstantVector::get(VectorValue);
187 return UndefValue::get(Tp);
190 /// Return a random value of any pointer type.
191 Value *getRandomPointerValue() {
192 unsigned index = Ran->Rand();
193 for (unsigned i=0; i<PT->size(); ++i) {
194 Value *V = PT->at((index + i) % PT->size());
195 if (V->getType()->isPointerTy())
198 return UndefValue::get(pickPointerType());
201 /// Return a random value of any vector type.
202 Value *getRandomVectorValue() {
203 unsigned index = Ran->Rand();
204 for (unsigned i=0; i<PT->size(); ++i) {
205 Value *V = PT->at((index + i) % PT->size());
206 if (V->getType()->isVectorTy())
209 return UndefValue::get(pickVectorType());
212 /// Pick a random type.
214 return (Ran->Rand() & 1 ? pickVectorType() : pickScalarType());
217 /// Pick a random pointer type.
218 Type *pickPointerType() {
219 Type *Ty = pickType();
220 return PointerType::get(Ty, 0);
223 /// Pick a random vector type.
224 Type *pickVectorType(unsigned len = (unsigned)-1) {
225 // Pick a random vector width in the range 2**0 to 2**4.
226 // by adding two randoms we are generating a normal-like distribution
228 unsigned width = 1<<((Ran->Rand() % 3) + (Ran->Rand() % 3));
231 // Vectors of x86mmx are illegal; keep trying till we get something else.
233 Ty = pickScalarType();
234 } while (Ty->isX86_MMXTy());
236 if (len != (unsigned)-1)
238 return VectorType::get(Ty, width);
241 /// Pick a random scalar type.
242 Type *pickScalarType() {
245 switch (Ran->Rand() % 30) {
246 case 0: t = Type::getInt1Ty(Context); break;
247 case 1: t = Type::getInt8Ty(Context); break;
248 case 2: t = Type::getInt16Ty(Context); break;
250 case 5: t = Type::getFloatTy(Context); break;
252 case 8: t = Type::getDoubleTy(Context); break;
254 case 11: t = Type::getInt32Ty(Context); break;
256 case 14: t = Type::getInt64Ty(Context); break;
258 case 17: if (GenHalfFloat) t = Type::getHalfTy(Context); break;
260 case 20: if (GenX86FP80) t = Type::getX86_FP80Ty(Context); break;
262 case 23: if (GenFP128) t = Type::getFP128Ty(Context); break;
264 case 26: if (GenPPCFP128) t = Type::getPPC_FP128Ty(Context); break;
266 case 29: if (GenX86MMX) t = Type::getX86_MMXTy(Context); break;
267 default: llvm_unreachable("Invalid scalar value");
274 /// Basic block to populate
278 /// Random number generator
281 LLVMContext &Context;
284 struct LoadModifier: public Modifier {
285 LoadModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
287 // Try to use predefined pointers. If non exist, use undef pointer value;
288 Value *Ptr = getRandomPointerValue();
289 Value *V = new LoadInst(Ptr, "L", BB->getTerminator());
294 struct StoreModifier: public Modifier {
295 StoreModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
297 // Try to use predefined pointers. If non exist, use undef pointer value;
298 Value *Ptr = getRandomPointerValue();
299 Type *Tp = Ptr->getType();
300 Value *Val = getRandomValue(Tp->getContainedType(0));
301 Type *ValTy = Val->getType();
303 // Do not store vectors of i1s because they are unsupported
305 if (ValTy->isVectorTy() && ValTy->getScalarSizeInBits() == 1)
308 new StoreInst(Val, Ptr, BB->getTerminator());
312 struct BinModifier: public Modifier {
313 BinModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
316 Value *Val0 = getRandomVal();
317 Value *Val1 = getRandomValue(Val0->getType());
319 // Don't handle pointer types.
320 if (Val0->getType()->isPointerTy() ||
321 Val1->getType()->isPointerTy())
324 // Don't handle i1 types.
325 if (Val0->getType()->getScalarSizeInBits() == 1)
329 bool isFloat = Val0->getType()->getScalarType()->isFloatingPointTy();
330 Instruction* Term = BB->getTerminator();
331 unsigned R = Ran->Rand() % (isFloat ? 7 : 13);
332 Instruction::BinaryOps Op;
335 default: llvm_unreachable("Invalid BinOp");
336 case 0:{Op = (isFloat?Instruction::FAdd : Instruction::Add); break; }
337 case 1:{Op = (isFloat?Instruction::FSub : Instruction::Sub); break; }
338 case 2:{Op = (isFloat?Instruction::FMul : Instruction::Mul); break; }
339 case 3:{Op = (isFloat?Instruction::FDiv : Instruction::SDiv); break; }
340 case 4:{Op = (isFloat?Instruction::FDiv : Instruction::UDiv); break; }
341 case 5:{Op = (isFloat?Instruction::FRem : Instruction::SRem); break; }
342 case 6:{Op = (isFloat?Instruction::FRem : Instruction::URem); break; }
343 case 7: {Op = Instruction::Shl; break; }
344 case 8: {Op = Instruction::LShr; break; }
345 case 9: {Op = Instruction::AShr; break; }
346 case 10:{Op = Instruction::And; break; }
347 case 11:{Op = Instruction::Or; break; }
348 case 12:{Op = Instruction::Xor; break; }
351 PT->push_back(BinaryOperator::Create(Op, Val0, Val1, "B", Term));
355 /// Generate constant values.
356 struct ConstModifier: public Modifier {
357 ConstModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
359 Type *Ty = pickType();
361 if (Ty->isVectorTy()) {
362 switch (Ran->Rand() % 2) {
363 case 0: if (Ty->getScalarType()->isIntegerTy())
364 return PT->push_back(ConstantVector::getAllOnesValue(Ty));
365 case 1: if (Ty->getScalarType()->isIntegerTy())
366 return PT->push_back(ConstantVector::getNullValue(Ty));
370 if (Ty->isFloatingPointTy()) {
371 // Generate 128 random bits, the size of the (currently)
372 // largest floating-point types.
373 uint64_t RandomBits[2];
374 for (unsigned i = 0; i < 2; ++i)
375 RandomBits[i] = Ran->Rand64();
377 APInt RandomInt(Ty->getPrimitiveSizeInBits(), makeArrayRef(RandomBits));
379 bool isIEEE = !Ty->isX86_FP80Ty() && !Ty->isPPC_FP128Ty();
380 APFloat RandomFloat(RandomInt, isIEEE);
383 return PT->push_back(ConstantFP::getNullValue(Ty));
384 return PT->push_back(ConstantFP::get(Ty->getContext(), RandomFloat));
387 if (Ty->isIntegerTy()) {
388 switch (Ran->Rand() % 7) {
389 case 0: if (Ty->isIntegerTy())
390 return PT->push_back(ConstantInt::get(Ty,
391 APInt::getAllOnesValue(Ty->getPrimitiveSizeInBits())));
392 case 1: if (Ty->isIntegerTy())
393 return PT->push_back(ConstantInt::get(Ty,
394 APInt::getNullValue(Ty->getPrimitiveSizeInBits())));
395 case 2: case 3: case 4: case 5:
396 case 6: if (Ty->isIntegerTy())
397 PT->push_back(ConstantInt::get(Ty, Ran->Rand()));
404 struct AllocaModifier: public Modifier {
405 AllocaModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R){}
408 Type *Tp = pickType();
409 PT->push_back(new AllocaInst(Tp, "A", BB->getFirstNonPHI()));
413 struct ExtractElementModifier: public Modifier {
414 ExtractElementModifier(BasicBlock *BB, PieceTable *PT, Random *R):
415 Modifier(BB, PT, R) {}
418 Value *Val0 = getRandomVectorValue();
419 Value *V = ExtractElementInst::Create(Val0,
420 ConstantInt::get(Type::getInt32Ty(BB->getContext()),
421 Ran->Rand() % cast<VectorType>(Val0->getType())->getNumElements()),
422 "E", BB->getTerminator());
423 return PT->push_back(V);
427 struct ShuffModifier: public Modifier {
428 ShuffModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
431 Value *Val0 = getRandomVectorValue();
432 Value *Val1 = getRandomValue(Val0->getType());
434 unsigned Width = cast<VectorType>(Val0->getType())->getNumElements();
435 std::vector<Constant*> Idxs;
437 Type *I32 = Type::getInt32Ty(BB->getContext());
438 for (unsigned i=0; i<Width; ++i) {
439 Constant *CI = ConstantInt::get(I32, Ran->Rand() % (Width*2));
440 // Pick some undef values.
441 if (!(Ran->Rand() % 5))
442 CI = UndefValue::get(I32);
446 Constant *Mask = ConstantVector::get(Idxs);
448 Value *V = new ShuffleVectorInst(Val0, Val1, Mask, "Shuff",
449 BB->getTerminator());
454 struct InsertElementModifier: public Modifier {
455 InsertElementModifier(BasicBlock *BB, PieceTable *PT, Random *R):
456 Modifier(BB, PT, R) {}
459 Value *Val0 = getRandomVectorValue();
460 Value *Val1 = getRandomValue(Val0->getType()->getScalarType());
462 Value *V = InsertElementInst::Create(Val0, Val1,
463 ConstantInt::get(Type::getInt32Ty(BB->getContext()),
464 Ran->Rand() % cast<VectorType>(Val0->getType())->getNumElements()),
465 "I", BB->getTerminator());
466 return PT->push_back(V);
471 struct CastModifier: public Modifier {
472 CastModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
475 Value *V = getRandomVal();
476 Type *VTy = V->getType();
477 Type *DestTy = pickScalarType();
479 // Handle vector casts vectors.
480 if (VTy->isVectorTy()) {
481 VectorType *VecTy = cast<VectorType>(VTy);
482 DestTy = pickVectorType(VecTy->getNumElements());
486 if (VTy == DestTy) return;
489 if (VTy->isPointerTy()) {
490 if (!DestTy->isPointerTy())
491 DestTy = PointerType::get(DestTy, 0);
492 return PT->push_back(
493 new BitCastInst(V, DestTy, "PC", BB->getTerminator()));
496 unsigned VSize = VTy->getScalarType()->getPrimitiveSizeInBits();
497 unsigned DestSize = DestTy->getScalarType()->getPrimitiveSizeInBits();
499 // Generate lots of bitcasts.
500 if ((Ran->Rand() & 1) && VSize == DestSize) {
501 return PT->push_back(
502 new BitCastInst(V, DestTy, "BC", BB->getTerminator()));
505 // Both types are integers:
506 if (VTy->getScalarType()->isIntegerTy() &&
507 DestTy->getScalarType()->isIntegerTy()) {
508 if (VSize > DestSize) {
509 return PT->push_back(
510 new TruncInst(V, DestTy, "Tr", BB->getTerminator()));
512 assert(VSize < DestSize && "Different int types with the same size?");
514 return PT->push_back(
515 new ZExtInst(V, DestTy, "ZE", BB->getTerminator()));
516 return PT->push_back(new SExtInst(V, DestTy, "Se", BB->getTerminator()));
521 if (VTy->getScalarType()->isFloatingPointTy() &&
522 DestTy->getScalarType()->isIntegerTy()) {
524 return PT->push_back(
525 new FPToSIInst(V, DestTy, "FC", BB->getTerminator()));
526 return PT->push_back(new FPToUIInst(V, DestTy, "FC", BB->getTerminator()));
530 if (VTy->getScalarType()->isIntegerTy() &&
531 DestTy->getScalarType()->isFloatingPointTy()) {
533 return PT->push_back(
534 new SIToFPInst(V, DestTy, "FC", BB->getTerminator()));
535 return PT->push_back(new UIToFPInst(V, DestTy, "FC", BB->getTerminator()));
540 if (VTy->getScalarType()->isFloatingPointTy() &&
541 DestTy->getScalarType()->isFloatingPointTy()) {
542 if (VSize > DestSize) {
543 return PT->push_back(
544 new FPTruncInst(V, DestTy, "Tr", BB->getTerminator()));
545 } else if (VSize < DestSize) {
546 return PT->push_back(
547 new FPExtInst(V, DestTy, "ZE", BB->getTerminator()));
549 // If VSize == DestSize, then the two types must be fp128 and ppc_fp128,
550 // for which there is no defined conversion. So do nothing.
556 struct SelectModifier: public Modifier {
557 SelectModifier(BasicBlock *BB, PieceTable *PT, Random *R):
558 Modifier(BB, PT, R) {}
561 // Try a bunch of different select configuration until a valid one is found.
562 Value *Val0 = getRandomVal();
563 Value *Val1 = getRandomValue(Val0->getType());
565 Type *CondTy = Type::getInt1Ty(Context);
567 // If the value type is a vector, and we allow vector select, then in 50%
568 // of the cases generate a vector select.
569 if (Val0->getType()->isVectorTy() && (Ran->Rand() % 1)) {
570 unsigned NumElem = cast<VectorType>(Val0->getType())->getNumElements();
571 CondTy = VectorType::get(CondTy, NumElem);
574 Value *Cond = getRandomValue(CondTy);
575 Value *V = SelectInst::Create(Cond, Val0, Val1, "Sl", BB->getTerminator());
576 return PT->push_back(V);
581 struct CmpModifier: public Modifier {
582 CmpModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
585 Value *Val0 = getRandomVal();
586 Value *Val1 = getRandomValue(Val0->getType());
588 if (Val0->getType()->isPointerTy()) return;
589 bool fp = Val0->getType()->getScalarType()->isFloatingPointTy();
594 (CmpInst::LAST_FCMP_PREDICATE - CmpInst::FIRST_FCMP_PREDICATE) +
595 CmpInst::FIRST_FCMP_PREDICATE;
598 (CmpInst::LAST_ICMP_PREDICATE - CmpInst::FIRST_ICMP_PREDICATE) +
599 CmpInst::FIRST_ICMP_PREDICATE;
602 Value *V = CmpInst::Create(fp ? Instruction::FCmp : Instruction::ICmp,
603 op, Val0, Val1, "Cmp", BB->getTerminator());
604 return PT->push_back(V);
608 void FillFunction(Function *F, Random &R) {
609 // Create a legal entry block.
610 BasicBlock *BB = BasicBlock::Create(F->getContext(), "BB", F);
611 ReturnInst::Create(F->getContext(), BB);
613 // Create the value table.
614 Modifier::PieceTable PT;
616 // Consider arguments as legal values.
617 for (Function::arg_iterator it = F->arg_begin(), e = F->arg_end();
621 // List of modifiers which add new random instructions.
622 std::vector<Modifier*> Modifiers;
623 std::auto_ptr<Modifier> LM(new LoadModifier(BB, &PT, &R));
624 std::auto_ptr<Modifier> SM(new StoreModifier(BB, &PT, &R));
625 std::auto_ptr<Modifier> EE(new ExtractElementModifier(BB, &PT, &R));
626 std::auto_ptr<Modifier> SHM(new ShuffModifier(BB, &PT, &R));
627 std::auto_ptr<Modifier> IE(new InsertElementModifier(BB, &PT, &R));
628 std::auto_ptr<Modifier> BM(new BinModifier(BB, &PT, &R));
629 std::auto_ptr<Modifier> CM(new CastModifier(BB, &PT, &R));
630 std::auto_ptr<Modifier> SLM(new SelectModifier(BB, &PT, &R));
631 std::auto_ptr<Modifier> PM(new CmpModifier(BB, &PT, &R));
632 Modifiers.push_back(LM.get());
633 Modifiers.push_back(SM.get());
634 Modifiers.push_back(EE.get());
635 Modifiers.push_back(SHM.get());
636 Modifiers.push_back(IE.get());
637 Modifiers.push_back(BM.get());
638 Modifiers.push_back(CM.get());
639 Modifiers.push_back(SLM.get());
640 Modifiers.push_back(PM.get());
642 // Generate the random instructions
643 AllocaModifier AM(BB, &PT, &R); AM.ActN(5); // Throw in a few allocas
644 ConstModifier COM(BB, &PT, &R); COM.ActN(40); // Throw in a few constants
646 for (unsigned i=0; i< SizeCL / Modifiers.size(); ++i)
647 for (std::vector<Modifier*>::iterator it = Modifiers.begin(),
648 e = Modifiers.end(); it != e; ++it) {
652 SM->ActN(5); // Throw in a few stores.
655 void IntroduceControlFlow(Function *F, Random &R) {
656 std::vector<Instruction*> BoolInst;
657 for (BasicBlock::iterator it = F->begin()->begin(),
658 e = F->begin()->end(); it != e; ++it) {
659 if (it->getType() == IntegerType::getInt1Ty(F->getContext()))
660 BoolInst.push_back(it);
663 std::random_shuffle(BoolInst.begin(), BoolInst.end(), R);
665 for (std::vector<Instruction*>::iterator it = BoolInst.begin(),
666 e = BoolInst.end(); it != e; ++it) {
667 Instruction *Instr = *it;
668 BasicBlock *Curr = Instr->getParent();
669 BasicBlock::iterator Loc= Instr;
670 BasicBlock *Next = Curr->splitBasicBlock(Loc, "CF");
671 Instr->moveBefore(Curr->getTerminator());
672 if (Curr != &F->getEntryBlock()) {
673 BranchInst::Create(Curr, Next, Instr, Curr->getTerminator());
674 Curr->getTerminator()->eraseFromParent();
679 int main(int argc, char **argv) {
680 // Init LLVM, call llvm_shutdown() on exit, parse args, etc.
681 llvm::PrettyStackTraceProgram X(argc, argv);
682 cl::ParseCommandLineOptions(argc, argv, "llvm codegen stress-tester\n");
685 std::auto_ptr<Module> M(new Module("/tmp/autogen.bc", getGlobalContext()));
686 Function *F = GenEmptyFunction(M.get());
688 // Pick an initial seed value
690 // Generate lots of random instructions inside a single basic block.
692 // Break the basic block into many loops.
693 IntroduceControlFlow(F, R);
695 // Figure out what stream we are supposed to write to...
696 OwningPtr<tool_output_file> Out;
697 // Default to standard output.
698 if (OutputFilename.empty())
699 OutputFilename = "-";
701 std::string ErrorInfo;
702 Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo,
703 raw_fd_ostream::F_Binary));
704 if (!ErrorInfo.empty()) {
705 errs() << ErrorInfo << '\n';
710 Passes.add(createVerifierPass());
711 Passes.add(createPrintModulePass(&Out->os()));
712 Passes.run(*M.get());