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(Val: 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(Val: 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(Val: 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(C&: Context, AddressSpace: 0),
136 PointerType::get(C&: Context, AddressSpace: 0),
137 PointerType::get(C&: Context, AddressSpace: 0),
138 Type::getInt32Ty(C&: Context),
139 Type::getInt64Ty(C&: Context),
140 Type::getInt8Ty(C&: Context)
141 };
142
143 auto *FuncTy = FunctionType::get(Result: Type::getVoidTy(C&: Context), Params: ArgsTy, isVarArg: false);
144 // Pick a unique name to describe the input parameters
145 Twine Name = "autogen_SD" + Twine{SeedCL};
146 auto *Func = Function::Create(Ty: FuncTy, Linkage: GlobalValue::ExternalLinkage, N: 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(l: {Type::getInt1Ty(C&: Context), Type::getInt8Ty(C&: Context),
162 Type::getInt16Ty(C&: Context), Type::getInt32Ty(C&: Context),
163 Type::getInt64Ty(C&: Context), Type::getFloatTy(C&: Context),
164 Type::getDoubleTy(C&: Context)});
165
166 for (auto &Arg : AdditionalScalarTypes) {
167 Type *Ty = nullptr;
168 if (Arg == "half")
169 Ty = Type::getHalfTy(C&: Context);
170 else if (Arg == "fp128")
171 Ty = Type::getFP128Ty(C&: Context);
172 else if (Arg == "x86_fp80")
173 Ty = Type::getX86_FP80Ty(C&: Context);
174 else if (Arg == "ppc_fp128")
175 Ty = Type::getPPC_FP128Ty(C&: Context);
176 else if (Arg == "x86_mmx")
177 Ty = Type::getX86_MMXTy(C&: Context);
178 else if (Arg.starts_with(Prefix: "i")) {
179 unsigned N = 0;
180 Arg.drop_front().getAsInteger(Radix: 10, Result&: N);
181 if (N > 0)
182 Ty = Type::getIntNTy(C&: Context, N);
183 }
184 if (!Ty) {
185 errs() << "Invalid IR scalar type: '" << Arg << "'!\n";
186 exit(status: 1);
187 }
188
189 ScalarTypes.push_back(x: 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(n: getRandom() % PT->size());
215 }
216
217 Constant *getRandomConstant(Type *Tp) {
218 if (Tp->isIntegerTy()) {
219 if (getRandom() & 1)
220 return ConstantInt::getAllOnesValue(Ty: Tp);
221 return ConstantInt::getNullValue(Ty: Tp);
222 } else if (Tp->isFloatingPointTy()) {
223 if (getRandom() & 1)
224 return ConstantFP::getAllOnesValue(Ty: Tp);
225 return ConstantFP::getZero(Ty: Tp);
226 }
227 return UndefValue::get(T: 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(n: (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(Ty: Tp);
243 return ConstantInt::getNullValue(Ty: Tp);
244 } else if (Tp->isFloatingPointTy()) {
245 if (getRandom() & 1)
246 return ConstantFP::getAllOnesValue(Ty: Tp);
247 return ConstantFP::getZero(Ty: Tp);
248 } else if (auto *VTp = dyn_cast<FixedVectorType>(Val: Tp)) {
249 std::vector<Constant*> TempValues;
250 TempValues.reserve(n: VTp->getNumElements());
251 for (unsigned i = 0; i < VTp->getNumElements(); ++i)
252 TempValues.push_back(x: getRandomConstant(Tp: VTp->getScalarType()));
253
254 ArrayRef<Constant*> VectorValue(TempValues);
255 return ConstantVector::get(V: VectorValue);
256 }
257
258 return UndefValue::get(T: 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(n: (index + i) % PT->size());
266 if (V->getType()->isPointerTy())
267 return V;
268 }
269 return UndefValue::get(T: 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(n: (index + i) % PT->size());
277 if (V->getType()->isVectorTy())
278 return V;
279 }
280 return UndefValue::get(T: 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(ElementType: Ty, AddressSpace: 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(ElementType: Ty, EC: 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(ElementType: Ty, NumElements: 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(x: 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(Tp: 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(Tp: 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(x: BinaryOperator::Create(Op, S1: Val0, S2: Val1, Name: "B", InsertBefore: 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(x: ConstantVector::getAllOnesValue(Ty));
424 break;
425 case 1: if (Ty->isIntOrIntVectorTy())
426 return PT->push_back(x: 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(x: ConstantFP::getZero(Ty));
442 return PT->push_back(x: ConstantFP::get(Context&: Ty->getContext(), V: RandomFloat));
443 }
444
445 if (Ty->isIntegerTy()) {
446 switch (getRandom() % 7) {
447 case 0:
448 return PT->push_back(x: ConstantInt::get(
449 Ty, V: APInt::getAllOnes(numBits: Ty->getPrimitiveSizeInBits())));
450 case 1:
451 return PT->push_back(
452 x: ConstantInt::get(Ty, V: APInt::getZero(numBits: Ty->getPrimitiveSizeInBits())));
453 case 2:
454 case 3:
455 case 4:
456 case 5:
457 case 6:
458 PT->push_back(x: ConstantInt::get(Ty, V: 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(x: 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 Vec: Val0,
484 Idx: getRandomValue(Tp: Type::getInt32Ty(C&: BB->getContext())),
485 NameStr: "E", InsertBefore: BB->getTerminator());
486 return PT->push_back(x: 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(Tp: Val0->getType());
497
498 // Can't express arbitrary shufflevectors for scalable vectors
499 if (isa<ScalableVectorType>(Val: Val0->getType()))
500 return;
501
502 unsigned Width = cast<FixedVectorType>(Val: Val0->getType())->getNumElements();
503 std::vector<Constant*> Idxs;
504
505 Type *I32 = Type::getInt32Ty(C&: BB->getContext());
506 for (unsigned i=0; i<Width; ++i) {
507 Constant *CI = ConstantInt::get(Ty: I32, V: getRandom() % (Width*2));
508 // Pick some undef values.
509 if (!(getRandom() % 5))
510 CI = UndefValue::get(T: I32);
511 Idxs.push_back(x: CI);
512 }
513
514 Constant *Mask = ConstantVector::get(V: Idxs);
515
516 Value *V = new ShuffleVectorInst(Val0, Val1, Mask, "Shuff",
517 BB->getTerminator());
518 PT->push_back(x: 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(Tp: Val0->getType()->getScalarType());
529
530 Value *V = InsertElementInst::Create(
531 Vec: Val0, NewElt: Val1,
532 Idx: getRandomValue(Tp: Type::getInt32Ty(C&: BB->getContext())),
533 NameStr: "I", InsertBefore: BB->getTerminator());
534 return PT->push_back(x: 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(VTy: cast<VectorType>(Val: 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(ElementType: DestTy, AddressSpace: 0);
558 return PT->push_back(
559 x: 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 x: 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 x: 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 x: new ZExtInst(V, DestTy, "ZE", BB->getTerminator()));
581 return PT->push_back(x: 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 x: new FPToSIInst(V, DestTy, "FC", BB->getTerminator()));
590 return PT->push_back(x: 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 x: new SIToFPInst(V, DestTy, "FC", BB->getTerminator()));
598 return PT->push_back(x: 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 x: new FPTruncInst(V, DestTy, "Tr", BB->getTerminator()));
606 } else if (VSize < DestSize) {
607 return PT->push_back(
608 x: 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(Tp: Val0->getType());
624
625 Type *CondTy = Type::getInt1Ty(C&: 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>(Val: Val0->getType()))
630 if (getRandom() & 1)
631 CondTy = VectorType::get(ElementType: CondTy, EC: VTy->getElementCount());
632
633 Value *Cond = getRandomValue(Tp: CondTy);
634 Value *V = SelectInst::Create(C: Cond, S1: Val0, S2: Val1, NameStr: "Sl", InsertBefore: BB->getTerminator());
635 return PT->push_back(x: 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(Tp: 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(Op: fp ? Instruction::FCmp : Instruction::ICmp,
662 Pred: (CmpInst::Predicate)op, S1: Val0, S2: Val1, Name: "Cmp",
663 InsertBefore: BB->getTerminator());
664 return PT->push_back(x: 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(Context&: F->getContext(), Name: "BB", Parent: F);
673 ReturnInst::Create(C&: F->getContext(), InsertAtEnd: 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(x: &arg);
681
682 // List of modifiers which add new random instructions.
683 std::vector<std::unique_ptr<Modifier>> Modifiers;
684 Modifiers.emplace_back(args: new LoadModifier(BB, &PT, &R));
685 Modifiers.emplace_back(args: new StoreModifier(BB, &PT, &R));
686 auto SM = Modifiers.back().get();
687 Modifiers.emplace_back(args: new ExtractElementModifier(BB, &PT, &R));
688 Modifiers.emplace_back(args: new ShuffModifier(BB, &PT, &R));
689 Modifiers.emplace_back(args: new InsertElementModifier(BB, &PT, &R));
690 Modifiers.emplace_back(args: new BinModifier(BB, &PT, &R));
691 Modifiers.emplace_back(args: new CastModifier(BB, &PT, &R));
692 Modifiers.emplace_back(args: new SelectModifier(BB, &PT, &R));
693 Modifiers.emplace_back(args: new CmpModifier(BB, &PT, &R));
694
695 // Generate the random instructions
696 AllocaModifier{BB, &PT, &R}.ActN(n: 5); // Throw in a few allocas
697 ConstModifier{BB, &PT, &R}.ActN(n: 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(n: 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(C&: F->getContext()))
710 BoolInst.push_back(x: &Instr);
711 }
712
713 llvm::shuffle(first: BoolInst.begin(), last: BoolInst.end(), g&: R);
714
715 for (auto *Instr : BoolInst) {
716 BasicBlock *Curr = Instr->getParent();
717 BasicBlock::iterator Loc = Instr->getIterator();
718 BasicBlock *Next = Curr->splitBasicBlock(I: Loc, BBName: "CF");
719 Instr->moveBefore(MovePos: Curr->getTerminator());
720 if (Curr != &F->getEntryBlock()) {
721 BranchInst::Create(IfTrue: Curr, IfFalse: Next, Cond: Instr, InsertBefore: 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(Categories: {&StressCategory, &getColorCategory()});
734 cl::ParseCommandLineOptions(argc, argv, Overview: "llvm codegen stress-tester\n");
735
736 LLVMContext Context;
737 auto M = std::make_unique<Module>(args: "/tmp/autogen.bc", args&: Context);
738 Function *F = GenEmptyFunction(M: 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(p: 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: *M.get(), OS: &Out->os()))
762 report_fatal_error(reason: "Broken module found, compilation aborted!");
763
764 // Output textual IR.
765 M->print(OS&: Out->os(), AAW: nullptr);
766
767 Out->keep();
768
769 return 0;
770}
771

source code of llvm/tools/llvm-stress/llvm-stress.cpp